BUILDING CONSTRUCTION VOLUME ONE
METRIC EDITION
11
By the same Author
I I
BUILDING CONSTRUCTION Volumes One, Two and Three BRICKWORK CARPENTRY JOINERY
By
Ii I
II
J. K. McKay
BUILDING CONSTRUCTION Volume Four
w. B. McKay M.Sc.Tech., M.I.Struct.E. Former registered architect and
BUILDING CONSTRUCTION
chartered structural engineer and Head
of the Department of Building and Structural Engineering in the
VOLUME ONE
Manchester University Institute
FIFTH EDITION (METRIC)
of Science and Technology.
By j. K. McKay, BA, B.Sc.Tech .. A.R.I.B.A .. C.Eng., M.I.Struct.E., F.F.B. With drawings by the authors
o
Orient Longman
ORIENT LONGMAN LIMITED RegiIfered Office 3-6-272 llimayatnagar. Hyderabad 500 029 Other Offices
II I I
Kamani Marg, Ballard Estate, Bombay 400 038 17 Chittaranjan Avenue. Calcutta 700 072 160 Anna Sahli. Madras 600 002 1124 Asaf Ali Road. New Delhi lld-002 8011 Mahutma Gandhi Road, l3angalorc 56() 001 365 Shahid Nagar, Bhuhancshwar 751007 411316 'Gour Mohan' _ Ambady Lane, Chiltom Road. COl;hin 682 Oil S.c. Goswami Road, Panbazar, Guwahati 781 001 3-6-272 Himayatnagar, Hyderabad 500 029 28/31. 15 Ashok Marg. Lucknow 226 001 City Centre Ashok, Govind Mitra Road, Patna 800 004
Fourth Edition
© Longman
Group Limited 1970
OLBN 0 00212 002 X First published in India 1985 Reprinted 1988, 1990, 1991, 1993 (twice), 1995
Published in India by arrangement with Longman Group Ltd., London For sale in India, Nepal, Bhutan. The Maldive Islands. Bangladesh an,i Sri Lank
II
Published by Orient Longman Limited, R. Kaman; Marg. Ballard Estate. Bombay 400 038. Printed in Indil! t>y Town Printery. Bombay 400 062.
,
PREFACE TO THE FIFTH EDITION
IN this edition the various units have bt'en converted to metric terms. Since the first appearance of this volume in '938, the materials of construction for simple two~storey structures have hardly changed although techniques have been modified. As the earlier editions were pub~ lished obsolete methods wefe given a secondary place and this has been continued once more . . Th ~y cannot he omitted entirely whilst thirt}' per cent of building expenditure is still devoted to repair and alteration work. The chapter contents have been extended and amended. Several of the drawings have been revised or replaced to illustrate up-to-clate applications. Eleven new Figures arc included as follows: 10, on founda~ tions; 381\, tfussed rafter roofs; 39, showing a built-up timber roof trU!iS and interlocking tiles; 55, a storm lipped timber window and cavity walling; 62, metal windows; 65, stairs; 68, pCirtable power tools; 70 and 7', giving larger details of slating; 78, domestic water services and 8" a vocabulary of structural steel components; the associated text has been added and sections on plastering are included.
). K.
MCKAY .
II
PREFACE TO THE FIRST EDITION
DUR1KG the past few years syllabuses in Building Construction have been extensively revised, and to-day those operating in Technical Schools and Colleges approved for National Certificate purposes show general agreement as to what parts of the subject should be treated in the earlier stages. This also applies to Building Construction as taught in Schools of Architecture, although its treatment and presentation may not be the same. Accordingly, one of the aims of the author has !:oeen to include in this first volume only such matter as is now generally accepted as being suitable for the first stage of the subject. Each cbap:rer is headed with the appropriate sectio:l of the syllabus in detail, and this is covered by the text and drawings. Most of the drawings have been prepared to large size to enable associated details to be grouped conveniendy for reference. In Schools of Architecture. where Building Constructiull is closely related to DeSign, the illustrations may prove helpful to the first-year st~dent in preparing his constructional sheets, particularly during the early months of the session, when adequate design subjects are not available and his ability to design is limited.
II
Attention is drawn to the suggested" Homework Programme." It is recognised that only a relatively small proportion of the details shown in the book can be drawn to scale by the student during a session , and a selection has therefore been made of those which may be regarded as typical; as far as time win permit, additional alternati\·e details should be skt,tched by students in their notebooks.
II!
Teachers of apprentice-students attending Trade Courses, such as Brickwork and Masonry, Car?entry and Joinery, etc., will find that the subject matter in the chapters concerned more than covers the first~year syllabuses. Whilst the Homework Programme docs not apply to such courses, where the subjects need to be developed more gradually and treated in greater detail, it is hoped that the arrangement of Fig. 58, referred to in the programmt·, "ill serve as a useful guide to these students in preparing well-balanced sets of homework sheets.
III
In preparing certain sections of this book the author has had assistance from several sources, and he is especially indebted to Mr D. H. England and Mr W. I. Tarn who gave him many valuable and practical suggestions in connection with the chapter cn Plumbing. Thanks arc also extended to his colleague Mr E. Spencer for reading the proofs of the chapters on Carpentry and Joinery. and for much useful criticism bearing upon these sections.
w. B. McK. August 1938
CONTENTS PAGE
CHAPTER
I.
BRICK \\'ALU., FOUl'DATlONS
\Iaterials-Bonding-Stopped Ends--Junctions ~nd Quoins- Piets-Jambs-Cavity Walls--Foundations-Damp I'roor Courses-Site Concrete--Offsets ~nd Cotbcls- I-intds-:\rches-Windo,," Sills-Thrcsho!ds-CopingsPlll1(hs -~Tools , Construction, Joint ing and Po i nting--'- Plast~ red \\'alls.
II.
3S
i\'lASO:->RY \r,\LL~
Classification of Stoncs-Quarryinll- Preparation- Dcfects- Wai!ing-Hubbie \\"ork- .-\shlar-.l,rchcs- Window Si lls-Phnt hs- ( .om ices-String Courses- Cop; ngs-:'>.1asonr\· Joints-:\-lortar Join ting- Li fting ..-\!-'PI ianees.
.
I II.
TnlllER, FLOORS '"
"n
ROOb
Structure , {irowth, F"lljn~, Oil',,,on ing, Prcs<: n-ation, Conversion, Defccts and Classification of Timbcr- FloorsI' la~ r (' r<'J ( 'ei lings Single, 1)""1,1,, . Truss<·J Rafter and Framed Roofs- Tren"h Timh('ring Centering
'
IV. DOOR3,
\VIXDOWS,
STAms
I. cd w:d Braced and D"ttcn"d. Fn, m cu I.c-dgc-d Brace<.:! and Battened, Panelled and Flush !)oors-Timber Casement, (,,,",,d Fram~ , Pi,-oted and Yorkshir" \\'i ndows, lI.letal \Vinuows-Hardware--.·\rchitraves, Skirtings, Picture Rails and .-\ngle Br"Js-Slairs "ails, Scre"'s and Fa~teners-Too l s. V. ROOF COVERINGS
131
Formation, Quarrying. ('onycrs;nn, Preparation and ChHacteristics of Slatcs-Centre -nail~d Slating Details- ""ils-Ridges- llips- Valle\'s-Tools- Plain and Interlocking Tilinjl.
VI.
~nd
Ilead-nailed
PLUMBI:'lG
l\lanllfactUl'(, and Characteristics of Lcau-Le'ld Rolls, Drips, Fbshiogs and Soakers-Det~ils of Leadwork at Gutt~rs. FLits . Chimn~,- St~cks, Ridg<-s. H ips and Valleys-Lead and Copper Pipe Joints-Eav<:s Glltlers- Downpipes-n"" ,ntie '\\';tlcr Sen'ices- Tools. VII. 'IrLD STEEL SECTlO]\'S. BOLTS AND RIVETS
HO:\IE\VORK PROGRc\:\\l\'lE I~DEX
vii
1
LIST
OF
ILLUSTRATIONS NO.
NO.
OF FiC.
PAGE
Bricks 3. English Bond: Square Stopped Ends.
.... Flemish Bond: Square S{OppW.
5
6 8
E,,"'~
s. Riaht Angled Junctions
9
6. Right Angled Quoins
"
'.
,. Piers 8. Rebated Jambs 9. Foundation {or 10. Foundations.
" One-and-a-h~!f
Brick Wall
'5
,6
Offsets,
12.
" "
" "
III
!
42. 43. 44. 45. 46. 47. 48. 49.
Lcdged and Battened Door and Frame Ledged, Bra(:ed and Battened Door and Furnin ..e Framed, Ledged, Brac::ed and Ballened Door Flush Doors (Laminated and Framed) Various Types of Doors and Panel Mouldings Mitred and Scribed Joinl$ Single Panelled Door Door Casings and Methods of Fixing So. Two Panelled Door 51. Detail, of Twin Tenon Joint 52. Four Panelled Door 53. Setting Out and lIand Preparation of Doors H. Casements and Solid Framed Windows 55, 56, 57. Casement Window Details 106, loS, s8, 59. Details of Window with Cased Fr~me and Sliding Sashes 11O, 60. Window wilh Pivoled Sash 6 •. Window with Horizontal S]idinR Sash 62. Metal Windows 63, 6 4 . Ar(:hitu\,C!l, Skirtings, Picture Rails and Angle Beads '"21, 65. Stairs 66. Nails, Screws and Fasteners 67. Joiners' Tools 68. Portable Power Tools 69. Tool. Ind Preparation of Slates 70. Slating Details 7'. Slating Details 72. Plain Tiling Detaib 73. Lead Details of Parapel Gutters 74. Lead Flat Details 75. [.eadwork at Chimney', etc. 76. Protection of Corni(:es " . Rain-Vl'ater Pipes ,8. Domestic Waler Services. ., 70· Plumber's Tools Sted F!:it, Square, Rouod and Tee BU$, Angles, Channels, Beams, So. Bolt. and Rivets TypIcal Steel Sectioos
Cor~ls, ButtTe.. eappings '9 Lintels . '0 13- Isometric Sketch of Portion of Brick Arcade I .... Key DetAil, showina Application of Arehe., etc. 15. Brick Archet (Flat Gauged, Segmental, Semicircular, etc.) '5 16. Window Sills and Threshold. 17. Copings, Plinths and Joints '9 ,6 18. Section throush Face of Limestone Quarry 19. Preparafion of SlOne, Surface Finishes and Masons' Tools J7 ao, :no 23_ Rubble Work 41, 43, +4 al. Key Detail of Stone Gable 24. Ashlar . .6 ,8 as- Slone Arches, Window Sills ~nd Plinths l6. Cornice. 50 27. Copinge and Joints 5' l8. Lifting Appliance. 53 19. Structure and Seasoning of Timbtlr 56 30. Conversion of Timber 57 31. Defcct, in Timber 57 3l. Plan, Se(:tioos and Details of Single (Ground) Floor of Domcstic Dwelling 6. 33. Methods of Laying Floor Boards, F.'c. 6, 34. Plan, Section and Dctails of Single (FIrst) Floor of Domestic:: Ow,,1\ing . 66 3S. Sketch showing various Roof Members 68 36. Plans, Sec::tions Ind Details of Single Roofs 37, 38. Plans, Sections and Details of Double Roof 75, 76 77 38". TrUSSl·d Raftcr Hoof~ 39. BUIlt-up Roof Tru.s and Int!."r1ocklng Tiles ,8 40. Timbering to Trench" 79 Not~: UNLESS INDICATED OTHERWISE ALL DIMEt-;SIONS ON THE FIGURES ARE GIVEN IN MILLIMETRES
II.
"
,..
I III 11 ,
PAG8
41. Centering
I. Comparative Strength of Bonded and Unhonded Wall. ~.
Of FIG.
8, 8,
"8, ," "
94
"
97 99
'00
'0' ,oJ
'0,
''''' "4 ,,6
'"
,,8
'"
"J "4
'" '"
'",,6 ,,8 '39 '45
'47 '49 '5'
'53 '56 '57
'59
,60
CHAPTER ONE
BRie K
W A L LS.
FOUNDATIONS
Syllabl/s-Brid description of Ihe manufactun: of bricks; char.lcteristic.s. Lime mQrtKT. ~ent mortar and com::~tt. 51'!'!:s ~nd shapes of bricks; terml; heading, stretchmR. English and FiHnish bonds'; I, II and 2-br;tk walls with twpped ends; i 10 I, ! 10 I and I 10 Ii-brick junctions; righI-angled quoins 10 I, I! and l_brick walls; piers; rebated jamb~ wilh 56 mm and 112 mm recesses to I and I ,·brick walls; 275 mm cavity walls. Foundations for t. I, 11 and a-brick walls; surface concrete; horizontal dam p-proof courses. Linlels; axed and ~auged flat, segmental and semicircular nrches; rough relieving arches; terms, Copings; windo~' sills; steps; cor~ls and o\-ersailing courses. Jointing and pointing. Plaster;n!!: 10 "ails.
MATERIALS l
Bridts.-Bricks are made chiefly from clay and shale. Clay, a plastic earth, is constituted largely of sand and alumina and may contain various quantities of chalk, iron, manganese dioxide, etc. Shale is a laminated deposit of day rock which is capable of being reduced to a plastic condition when broken up and ground to a fine state of division. Bricks are approximately 215 mm by 102·5 mm by 65 mm (see p. 3). Manufacture of Bricks.-The processes of manufacture vary considerably aa::ording to the variety of day used, machinery available, etc., and the following is a brief general description. Bricks are moulded either by machinery or by hand . Machine·madeBricb.-Most bricks are made by machinery. The various processes are: (I) preparation of the earth, (2) moulding, (3) drymg and (4) burning. (I) Pupararion.-The clay or shale is excavated, and after large 5ton~ or other extraneous maner have been removed, it is conveyed to a pug mill ar.d findy ground by heavy rotating wheels which force it through small perforations in the bottom of the mill. (a) Moulding.-There are two kinds of machine-made bricks, i.t., ",i,.e·cuts and pressed. Wire-c;:"t Bricks are moulded as follow,:-The fine clay from the pug milliS forced through a mouthpiece (approximately alS mm by loa·s mm) ofa machine in a continuous band and conveyed by rollers to a frame which containl several fine vertical wires about 65 mm apart. A portion of this continuous band, equal in length to that of the frame, is pU5hed forward through the frame by means of a metal plate and the wires divide it into ten or more alS mm by 10a'S mm by 65 mm slabs of clay. Pte$Sed Briclts.-Gf the many different types of machines for moulding brick. by pressure the limplest is worked by hand and the larger by steam power. The fonner consilts of a metal box the size of a brick, containing a elay slab which has been wire_cut a. explained above; a descending meta l plate exerts pressure upon the elay to consolidate it; it is then removed. The larger type of machine oon5i8'* of a rotating table containing t .... e1ve or mote boxes or dies each being the aiae of a brick; IS the table revolves each die in turn is brought under a hopper containing the prepared clay or .hale; a plunger operating in the hopper descends and forces the elay into the die after which the raw brick (or . Iab of clay) is pUlhed out the tahle rotates. I Flemish bond is sometimet deferred until the second year of the Course. t Sand-lime bricks (consilting of a mixture of lime and und) and concrete brick. are alao manufactured (see Chap. I, Vol. II).
a.
,
(3) Drying and (4) Burni",.-Both of these operations arc carried out in a modern kIln, one type of which contains several chambers, each accommodating 40,000 or more bricks. The wire-cut or prelsed. raw bricks are carefully stacked with a space between each and in alternate layers ut ,.ight angles to each other. Heat, produced from gas or coal dUM, is Rradual1y applied until a maximum temperature is obtained (which ia maintained fo,. approltimatciy two days), when the brICks are then allowed to cool. The loading, drying, burning, cooling and emptying of the kiln may occupy two "ceo, and at it is a continuous process, a chamber of finished bricks is emptied daily. HAND-MAD£ BRlcKs.-Whilst most bricks are machine-made and used for general purposes (on account of their relati"e cheapness) there II also demand for hand-made bricks for supenor facing work. The preparation, dryinR and burning proccsaes arc similsr to those already descnbed, but the moulding is done by hand. The mould is of wood or metal and resembles the sides of a rectangular box equal in size to the required bricks.' It i. either wetted or sanded to prevent the clay from adhering to it. A ponion of the prepared cl~y sufficient to fill the mould is now taken, roughly shaped, and duhed by the moulder into the mould. The clay is pressed with the fingers to fill the mould completely and the slab is levelled off by a wood fillet or I piece of ... ire drawn across the top; the slab i. then removed and finally taken to the kiln, dried and burnt.
ChaTacttristics.- Good bricks should be thoroughly burnt; this makes them hard and durable (the quality of lasting for a long period without ptrishing) and enables them to withstand pressure. A hard ringing sound emitted when two bricks are struck together indicates that they have been burnt satisfactorily. Generally the bricks should be true to size and shape, with st{aight edges and even surfaces, SO as to facilitate laying them in position.: They should be free from cracks, chips and large particles of lime. Unless desired, uniformity of colour is not now specified.' Inferior bricks are generally underburnt and as a consequence are easily broken and are very porous; these are neither hard nor durable and are incapable 1 Clay shrinks during the drying and burning processes by approximately one _tenth and allowance for this il made by using a mould which is larger than the finished brick. t Bricks havin, rough surfaces (tenned texture) and sliChtly irregular edges arc .elected purposely for cenain first-c1na work. Thul the external wall, of country houses are frequently faced with such bricks. I Bricks of a variety of colours in tonu of -red, purple, grey, brown, etc., are now available, and, provided the colours have been carefully selected, brickwork when faced with bricka of mixed sh.adca hu a very "tisfactory appearance.
BRICK WALLS
2
of withstanding: heavy IO
This has
Ih~
properly of ""nina
und~r wal~r.
incorporate~
after ahout twenty minutes' applicatioll of the rotating and grinding rollers. The mortar should be used fresh and just sufficicnt should be mixed for each Jay's usc.
Cement Mortar.- This is a mixture of 1 cement: 3 sand. The sand is placed on a platform, the correct amoun! of cement is added to it, both are thoroughly mixed dry before water is addt:d and the mass gradually worked up into a plmn1c condition. As cement mortar scts comparativcly quickly, it should only be mixed in small amounts and not be ust:d after it has started to set. Cement mortar is used in the construction of piers (sec pp. 12 and 13), walling below d~rnl' course level (sec p. 17), chimney stacks, etc., a~ brickwork built in ct:ll1ent mortar is much stronger than that built in lime mortar. A mix of I .6 can lliso be used for general walling; hut as this is harsh, then an additive, which forms ~ir buhbles to impro\'e the'plasticity, can be included in the mixing II ,ncr in the proportion of about 3°'u. ('('m(,l1/ Grout is cement which has been reduced to a thick liquid COIlsi!>tency by the addi tion of sufficient water. Cement -Lime Mortar (also known as compo).- This is thc most usual gellcral purpose morlar comprising 1 cement: 2 lime: 9 sand, or 1 : I : 6 if thert: is a danger of frost as this is yuicker setting. The addition of limc im~ proves workability making it easier to place. Concrete consist~ of a fine aggregate (or body), a coarse aggregate and a matrix (binding material). The fine aggregate is usually sand, common coarse aggregatt:s are broken brick or stone (or gran:l) and the matrix is usually cement. The proportions vary, but a common mix is composed of I part cement, 2 parts sand and .j. parts broken brick or stone; the maximum size of the latter depends upon the use to which the concrete is to be put and may be 38 mm (that passed through a 38 mm square mesh sieve) for foundations and 20 mm for reinforced concrete work. The aggregates must be carefully graded from a minimum to a maximum, so that when the materials aremixed the space between the particles is reduced to a minimum and a dense concrete ensured. The mixing is done either by hand or by machinery. If mixed by hand, th..: materials in correct proportion are placed on a boarded platform and mixed t ..... ice (or thrice) dry and then twice (or thrice) wet. The amount of water added after the materials have been tllrned over dry (by using shovels) must be carefully regulated, as an exuss of water considerably reduCts the strength of the concrete. The mixing should always be done on a platform otherwise dirt would be shovelled into the mixture and ils strength thereby reduced. ILa concrete-mixing machine is used, the materials in proper proportion are charged through a hopper into the mixer, the correct amount of water is then added; the ffii;>;cr is rotated at a specified speed for a definite period, usually a minute, after which the concrete is discharged from the machine. The concrete should be carefully deposited where required on the building so as to ensure Ihat the density of the material shall be uniform throughout.
,
r
BONDING BONDING, SOLID BRICK WALLS The craft of the bricklayer is concerned with emhedding bricks in mortar and suitably arranging them so that the mass, called brickwork, conforms with ce~tain requirements such as strength and appearance. Strength depends a good deal Il\)()n the bond. The Building Regulations require external walls to be adequatt.: to prevent undue heat loss from the huilding; some typical examples of thermally insulated waJ!s for dwellings arc given 011 p. 34. . BOlld is the interlacement of bricks produced when they lap (project bt:yond) those immediately above and below them. An unbonded wall, with its continuous t;fftiwl joints, has little strength and stability and such joints must he avoided. Fig. I illustrates the comparati\'e strength of a bonded \\.111 A and weakness of an unbonded wall B which are shown supporting a load. The portion of the load tral1~mi!ted to the wail A is distributed over a rclatil'elylarge area, as indicated within the broken lines c and 0, whereas that transmitted to the wall H is practically concentrated on the portion betwel'll the continuou~ vertical joints E and F, with the result that this portion \\'ould tend to drop as shown; in addition, the two vertical sections G and II would lend to separate because of the ahsence of bond. Various bonds are descnbed on PI'· 4 and 7. Size of Bricks.-Uniformity in the siz~ of bricks is essential if the maintenance of the correct bond is to be facilitated during the construction of a wall; time is wasted if a consignment contains bricks of varying sizes as the bricklaver is required to make a selection as the work proceeds. . The length of a brick should be twice its width plus the thickness of one vertical joint in order that a proper bond may be maintained (See A, Fig. 2). Brick~ in common use \'ary in size from 210 to 230 mm long by 100 to 110 mm wide by 38 to 75 mm thick, The following sizes are a\ailable: (I) Clay bricks are mostly 215 by 102'5 by 65 mml; using a 10 mm joint this gives a nominal s:ze or format of 225 by 112'5 by 75 mm; this is adopted in must oflhe Figures in this book. (2) Concrete bricks may be as (I) or 190 by 90 by 65 mm; with a 10 mm joint Ihis makes a format of zoo ry 100 by 75 mm. Terms.~ The following defines those which ha\'e a general application to brickwork :Arris.-An cdgc of a brick (sec A, Fig. z). Bed.- The lower 215 mm by 102'5 mm surface of a brick when placed in position (sec A, Fig. 2). }/eader.-The end or 102'5 mm by 65 rnm surface of a brick (sec A, Fig. 2). Strl'tcher .-The side (usually referred to as the" edge ") or 215 mm by 65 mm surface of a brick (see A, Fig. 2). Fact.-A surface of a brick such as the header focl'(loz'5 mm by 65 mm) and Jtre/chtT face (215 mm by 65 mm) (see A, Fig. 2); is also applied to.1.l1 exposed surface of a wall. Frog or Kick.-A shallow sinking or indent (either rectanguillr, triangulaTor 1 Bricks 50 and 75 mm thick may b", obtained.
215 UN60NDED
S~ETCH SHOWING COMPAI<.ATIVE SH,ENGTH Of A SONDED WAll" WEAKNESS OF AN UNSONDED WALL F[ct' R ~
1
trapezoidal in section) formed on either one or both 215 mm by 102'5 mm faces of a brick (sec 0 and 111, Fig . 2); a wire-cut hrick has no frogs, a pressed brick has two frogs as a rule and a hllnd-madc hrick usually has only one frog; a frog affords a good key for the mortar (sec 1'01, Fig. 2) and therefore walls which arc required to show thin bed joints should be constructed of bricks with frogs; bricks having only one frog should be laid with the frog uppermost so as to ensure it being completely filled with monar. Bed Joint.l.- :\Iorlar joints, parallel to the beds of the bricks, and therefore horizontal in general walling; thickne~s varies from 3 to 12 mm the most usual lhickness is 10 mm shown at LJ, Fig. 2. CQurse.-A compkle la),':J of bricks plu~ it" mortar bedding joint; a hlading couru consists of headers and a s/rf/ching course comprises stretchers (see u, Fig. 2); a brick-on-tdgt courst consists of brICks placed on their 215 mm by 65 mm faces (see J and K, Fig. 17) and a brick-un-tnd or .lolditr course is composed of bricks laid on their 102'5 mm by 65 mm faces (see Nand 0, Fig. 17)' Brick Gaugt.· The height of a number of brick courses, e.g., four courses to 300 mm if 65 mm brickS
4
BRICK WALLS
ContinuQus Vnticoi Joints or Straight Joinlf.- Vertical joints which come immediately over each other in two or more consecutive courses (see R, Fig. I); although these aTC sometimes unavoidable (see Flemish bond, Fig. 4) they should not appear on the face of brickwork' (see English Bond, p. 7). Quoin.-A corner or external angle of a wall (see u, Fig. 2 and G, Fig. 6). Stopped or Cloud End.- A square termination to a wall (see Fig. 3) as distinct from a wall which is returned as shown in Fig. 6. PtTpends.-Imaginary vertical lines which include vertical joints (see broken lines at lJ, Fig. 2); these should be plumb or true. Lap.-The horizontal distance which one brick projects beyond a vertical joint in the course immediately above or below it; it varies from 46'25 to 10::;'5 mm, ·j.t., 46 to 102 mm; or, allowing for the joint thickness, 56 to 112 mm (see u, Fig. 2). Racking Bach.- The stepped arrangement formed during the construction or a wall when one portion is built to a greater height than that adjoining (see u, Fig. 2). No part of a wall during its construction should rise more than 900 mm above another if unequal settlement is to be avoided. Toothing.-Each alternate course at the end of a wall projects in order to provide adequate bond if the wall is continued horizontally at a later date (see u, Fig. 2). When a new Willi has to be conn«<:ted to ~nexistinlf wall and "'here such provision has not bolen made. II is necetlsary to form a sinkinlj: or indrnl in each ;lltt:rnate course of the existing Willi 50 that th!: new \\ork may be prop!:rly tied inlo II; the depth of th!: indents should be such as to allow the new work to be bonded into the old for at I!:ast .,6 mm and the width should be "'lual to the thickn!:$S of the n!:w wall. Sometimes the indents are fonn!:d thr!:e Or fuur courses high with a s,milar dislanCe betw~n each.
Bat.-A portion of an ordinary brick with the cut made across the width of the brick; four different sizes are shown at E, F, C and H, Fig. 2. Applications are illustrated in the following: Half Bat (£) at F, Fig. 4; Thut.quarter Bat (F) at K, Fig. 3; BnMlled Bats (0) at N, Fig. 8, and (H) at E, Fig. 8. Closer.-A portion of an ordinary brick with the cut made longitudinally and usually having one uncut stretcher face; seven forms are shown at J, K, I., N, 0, P and v, Fig. z. The Quem Closn (1) is usually placed next to the first brick in a header course (see j, Fig. 3); sometimes the abbreviated queen closer v is used (see K, Fig. 3); the queen closer K is obtained by cutting an ordinary brick into two half bats nnd then splitting one into half; K is more often used than J as it is easier to cut, although (as shown at L, Fig. 3) it generally produces a 56 mm wide continuous vertical joint. The King Cluser (L), formed by removing a corner and leaving half·header and half-stretcher faces, is shown bonded at D, Fig. 8. The Btf}tll~d Closn (N) has one stretcher face bevelled (splayed or slanted) and is shown at E, Fig. 8. Mjtr~d CkJurl (0 and p) are only used in exceptional cases as when the ends are required to be mitred (joined at an angle), i.e., quoins of certain bay windows. TIle remaining bricks Q, R, sand T shown in Fig. z are usually moulded
specially to the required shape and are called specials or purpose-mades, although for common work or where the hrickwork is to be covered with plaster, ordinary bricks may he cut by a trowel or chisel to form all but the last of these. Bullnofe (Q).-Thesc are used for copings (see D, Fig. 17) or in such positions where rounded corners are preferred to sharp arrises (see Q, Fig. 7); a brick with only one rounded edge is known as a Singlt Bullnose and one with both edges rounded is termed a DO!Jblt Bullnose; the radius of the quadrant curve varies from 28 to 56 mm. Splay (R and s).- These are often used to form plinths (see P, Fig. 17); the amount of splay varies. Dogltg or Anglt (T).- These bric~s arc used to ensure a satisfactory bond at quoins which depart from a right angle and are to be preferred to the mitred closers 0 and 1'; the angle and lengths of faces forming the dogleg vary. The abo,"e purpok-mRde bricks He ontya few of mRny wh'ch can now be obtllined. Most of th!: larger brick.manufacturing firm$ make" standard spe<:ials " which ar!: kepI in stock. Wherever p()ssiblc. a ,election should be mad!: from these. Q$ purpascmade! which differ from tl>f:' standard arc most costly on account of the moulds which ha\·t to be made specially and ddi\'~ry mo}' be delayed.
Types of Bond.- There are many varieties of bond, and in a First Year Course it is usual to confine the instruction t,=, Heading, Stretching, English and Flemish bonds. It is sometimes considered advisable to postpone the study of Flemish bond until the following year. In cavity· wall construction (see p. 13) it is most usual to have stretching bond, but as this is somewhat monotonous, English garden wall bond can be used. This comprises a row of half·bricks to every three rows of stretchers (see A., Fig. 18, Vol. II). The thickness of a wall is either expressed in millimetres or in terms of the length of the brick, thus: 102'5 mm or i·brick, 215 mm or t·brick, 327'5 mm (often specified 328 mm) or I !.brick, 440 mm or 2·brick, etc. 1 A bond is usually identified by the appearance of the external face of the wall, and it is this face appearance which is referred to in the following description of bonds. Thus the expression .. alternate courses of headers" refers to the arrangement of the bricks on the face, even if the headers in each course are backed by stretchers. Kote that th!: join" in most of Ihe details are indicated by single linn, the thiekness not being: shown. Stud!:nlS ar!: not Tf:'COmmend!:d to ~how the joint.i .br double lines for unless thev ar!: "!:T'I' accuratdv drawn, accumulatIVe urors are Ilkelv to OCXUf rcs~lting in the hOOd beinjl StlO" n ttlcOrrectly. I.)rawing is furth~r facililat!:d ,f. ~s shown ttl the examplu, the d,menslons 01 a bnck :lfe 1I$5umf:'d to b!: :us mm by I U ' ~ mm by 7S mm.
Heading Hond.-Each course of a wall consists of headers only. It is used chiefly in the construction of footings (see Fig. 10) and walls which are sharply curved, where the long faces of stretchers would unduly break the line of the cun·e. , Large mod!:m buildin,. ar!: usually of s teel-framed or reinforc.ed concrete copstruction which provide for the support of heavy loads by the use of e.llher Iteelwork or reinforced cancret!:. and therefore wall, which !:xc!:!:d l bricks in thickness are T:\rely requirm.
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\ BONDING Stretching Bond.-Each course consists of stretchers with exception of a half hat which mUS1: be placed at the stopped end of a wall at each alternate course so that the work will break joint. Note that at H, Fig. 3, the break joint i$ formed by the first or quoin stretcher appearing as a header on the return facc,l This bond is suitable for 102'5 mm thick walls, such as are required for cavity walls, chimney stacks, sleeper walls and division walls. English Bond.- T his consists of alternate courses of headers and stretchers (sec Fig. 3). Observe: (I) in each heading course a quem closer is placed llext to the quoin header2 and the remaining bricks are headers, ( 2) every alternate header in a course comes centra!1y over the joint between two stretchers in the course below, gi\'ing a lap of 56 mm, and (3) there are no continuous vertical joints, excepting at certain stopped cnds and particularly where queen closers of the form K (Fig. 2) and not] are used . It is this comparative lack of straight joints which gives to English bond its characteristic strength . Square Stopped Ends. - Fig. 3 shows details of stopped ends to a I-brick wall (J), a I!-brick wall (K), a 2-brick wall (L), a 2!-brick wall (M) and a 3-brick wall (N) . A key plan of a portion of a building is shown at A, and the treatment of the stopped end of the doorway opening at c (which is called a square jamb ~see p . 13) would be in accordance with one or other of these details, depending upon the thickness of the wall. The external walls of a house ifbuilt of solid brickwork arc usually 328 mOl thick, and the division walls He either 10Z· 5 or ZI5 mm thick; othCT types of buildings may han, th icker walls, but, as already explained, walls exceeding Z hricks in thicknes, He now rarely requlred. IllS nmc general practice to "'" cat."ity ex/en",/ .mll•.
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Speci:tl attention should be taken in the construction of stopped ends of walls as these arc often required to take concentrated loads from lintels, etc. (see Fig. 12). The following should be noted :~ I. At least every alternate transverse joint is continuous from face to facc; a I!-brick wall cons:sts of units comprising a strctcher backed with two hcaders, or vice versa (see broken lines at K, Fig. 3); a stretcher course of a 2- brick wall is formed of units having a stretcher on each face with two headers in the middle (see L, Fig. 3).
7
4. The middle portion of each of the thicker waUs consists entirely of headers (see L, M and N, Fig. 3).1 Flemish Bond.~ This comprises alternate headers and stretchers in each course. There are two kinds of Flemish bond, i.e., (I) Double Flemish and (:!) Single Flemish. (I) Double Flemish BOlld (see D, E, F and G, Fig. 4) shows the characteristic appearance of Flemish on both external and internal faces . As shown at D, each header comes centra!ly over a stretcher and, unlike English bond, no header comes over a vertical face joint. It is not so strong as E nglish bond because of the largc number of short continuous vertical joints (indicated by thick lines) which occur in the longitudinal joints. Some consider that double Flemish bond has a more pleasing apiJearance and is more economical than English bond . A differen~e of opinion exists abou t the supniority Or otherwise of the appearance of Flemish bond, some favour the pattern of units of cross formation which appears on the face- see D. Fig. 4 Where a flush face is required on both sides of a I- hrick wall this is more readih obtained in Flemish rather than English bond. This is because the stretcher face of bricks may vary in len gth due to the unequal shrinkage during the i-urning process; thus the combined length of two headers plus one joint m:l}' excecd the length of a stretcher. Although this defect will not occur in well·made bricks, if it does then a I-brick English·bondcd wall could have One face flush with the other f~ce showing each heading course set back slightly from the stretching course. This irrcgularity is less pronounced in Flemish bond with Its alternate headers and stretchers in each courst for the set·back at each short header is mOre evenl\" distributed ; the resu lting appearance is considered to improve the surface texture or character of the work.
2. Walls of an even number of half bricks in thickness present the same appearance on both faccs, i.e., a course consisting of !\.tretchers un the front elevation will show stretchers on the back elevation (see], I. and '-', Fig. 3). 3. Walls of an odd number of half bricks in thickness will show each course consisting of headers on oile face and stretchers on the other (see K and M, Fig. 3).
Square Stopped Ends.~On reference to the elevation 0 and the plans E, F and G, Fig. 4, it will be seen that in every alternative course a queen closer is placed next to the quoin header so as to provide a lap of approximately 56 mm. This agrees with the rule for English bond. Attention is drawn !O the units of which every coursc in each wall is comprised and which are indicated within the broken diagonal lines. The notes on Fig. +should be carefully studied . (2) Single Flemish Bond consists of a facing of Flemish bond with a backing of English bond in each course (see Hand], Fig.. 4). It is adopted where expensive facing bricks are required to give the characteristic appeararH.:e of Flemish bond and where comparatively cheaper bricks are used as a backing. This bond cannot be applied to walls which are less than Ii-brick thick . It is relatively weak, as can be seen on reference to II and J , which show 225 mm long continuous vertical joints appearing in the longitudinal joints. Note that half bat!; are used which arc known as snap headers or false headers. An alternative arrangement of bricks in the 2-brick wall at J is shown at K (where the snapheader anJ full-header backing are substituted by two three-quarter bats);
1 Low division walls which are not required to support loads may be built with the bricks placed on edge and in stretching bond; the thickness is thus reduced to 65 mm. , A heading cOUrSe should never commence with a queen doser, for, in this positiun it wou ld be liable to displacement.
\ A scale of 1:10 is generally used "hen detailinl'( brick bonding; students are recommended to commence with the he"ding course followed by the stretching course immediately belo" it; a tracing of the latter COUrse trunsposed over the heading courSe will emphasize the fact that there are no continuous vertical joints (see L, Fig. 3).
Students al eMminations frcquentlr make the mistake of .he ,,"ing non_contin uous transverse joints.
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this results in a reduction in the length of the continuous vertical joints with a corresponding increase in strength, but an increase in cost due to the lahour and wastage of bricks involved in the cutting of the three-quarter bats. This alternative bond may also be substituted for the corresponding course of the
Ii-brick wall (H). The comparative weakness of single Flemish bond is illustrated at
L,
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Fig. 4, all
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adequately. bonded wall of the same thickness built in single Flemish bond; the continuous vertical joint shown by a thick line in the section through the latter waH is 225 mm wide, as shown in the plan at J, Fig. 4. JUNCTIONS AND QUOINS
The key plan at A, Fig. 3, sho,",ll several connections between walls. One type of connection is termed a junction (D, E, U, \V and x) and another form is known as a quoin (F and Y). Junctions.- These are classified into right-angled junctions and squint junctions. l There are two forms of right-angled junctions, i.e., (a) tee-junctioqs and (b) cross-junctions or intersections. (a) l'ce-junctions.-A tee-junction is a connedion between two walls which on plan is in the form of the letter T (see n, u, wand x in the key plan). Plans of tee-junctions between walls built in English bond are sllOwn at A, Band c, Fig. 5. At A one of the wurses of the 102'5 mm internal division wall enters the stretching course oftht-215 mm external wall, giving a ! 12 mm lap, and the alternate course of the division wall butts against the heading course of the main wall. ::"-Iote the following in connection with details Hand c: (1) the heading course of the internal \\'al1 is bonded into the stretching course of the main wal1, the first header or tie brick (shown shaded) giving a 56 mm lap and being adjacent to a queen closer; (2) the stretching course of the cross waU butts against the heading course of the external wall. The tic bricks are also shown in the section at K, Fig. 5. Plans of junctions between external walls built in double Flemish bond and English bonded division walls arc shown at F and G, Fig. 5. As in the above examples, the key header has a lap of 56 mm. (b) Cross-junclions or Intersections. - A cross-junction is an intersection between two continuous walls (see E in the key plan at A, Fig. 3). Details are given at nand E, Fig. 5; the walls arc shown in English bond, it being assumed that they are to be plastered. i\ote: (I) one of the courses is continuous and the course at right angles butts against it; (2) these continuous courses alternate; and (3) a key header forms a 56 mm lap at each side of the non-continuous course. Thc aboye ~r~ only ~ few examples of s('vcrHI m~tl)ods of bonding l!t junctions. The arrangement of the bricks depends largc!y upon: the relative position of the w~lIs . \ ' ariations of these exampks "ill be ne£ess~ry \,hen d comilluoos trnllSVl'rse 1 Squint junctions are detailed in Chap. i., Vol: I I.
joint in the JT\"din wall docs not eoine;G" with a face of the entering course of the adjacent wall. The essenti,1I requirem~nts arc the avoidance of continuous vertical joints with the employment of the mini,,-,um number of cut bricks.
Quoins or External Angles.-There are two forms of quoi'ns, i.e., rightangled or square quoins and squint quoins. I As is implied, a right-angled quoin is formed by two walls which meet at 90°. Example~ of right-angled quoin:; arc shown al ~- dllll Y, Fig. J. Square QIIOillS in English BOlld.-Plans of alternate cOllfses of right-angled quoins formed by walls built in English bond arc shown detailed at A, Band c, Fig. 6. The following should he noted :--. l. At the same level, the heading course on one face of the angle is returned by a stretching eOllTSC; tlHls at ,\ the heaqing course I' is returned by a stretching course similar to 1'1. 2. There arc no continuous vertical joints. 3. When the wall is an N'CII numher of half-bricks in thickness the brick figured 3 is a header projecting 56 mm (oee ,\ and c, Fig. 6). 4. When the wall is ~ln odd ;lumber of half-bricks thick, the brick figured 3 is a siretcher projecting 56 mm (sec B. Fig. 6). 5· At the 56 mm projection (or quarter hond) of number 3 brick the trans\t~rse joint is continuous (sec ,\1 at B, Fig. 6). 6. r n the 1 and 2-brick quoins the heading course of one w~l1 is continuous to the front of the return face and that in the 1 ~-brick quoin is continuous to the back of the stretching LICe; the return stretching course in each case butts against the heading course. When dn", i"g thl'SC dc·t;oih (u~u.llly to a scale ! '0) th., studcnt should SCI nut th~ outline or 1)'" quuin and. UHnmc'!!Ung ""th tIle' headin" "ourse. fill in the thrce bricks !!uml)<'rt,d !,~. and, fo]lo','l'll by thl' Tl'rn"inl!!" bnl'ks; ,f numoer J briek " pL1<'~u in corrcct po~'t'()'; "c"ordill c In <·ill",c ( 3) or (4) "h""<:
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::iquar(' Quoills ill DUI/blt' Flemish BUlI
, S'lomt qUOlllS arc usu~J1y dcah with in til<' ,ecolld n'ar of the Course 1h.,refore de1m ].,d m Chap. I, Vol. II.
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BRICK WALLS
Piers (also known as pillars or columns) of brickwork are adopted either to support concentrated loads such as are transmitted by arches, floor beams and roofs, or to strengthen walls. Such piers may be isolated (or detached) or they may be attached to walls. Detached Pjers.- Such may be either square, rectangular, circular or polygonal on plan. A plan of a portion of a building in which piers are employed is shown at A, Fig. 7, and a detached pier is shown at c. Such a building may be an arcade or loggia, or it may be considered as a portion of a factory, although modern buildings of the latter type usually have pillars of mild steel or reinforced concrete._ Maximum strength is obtained if pillars are constructed with sound dense bricks built in English bond and in cement mortar. English Bonded Detached Piers (see plans J, K and L and the corresponding elevations D, E and F, Fig. 7).- It is only necessary to show one course of each pier, as in every case the arrangement of the bricks in each course is the same.
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Thus the 215 mm pier has eve ry alternate course constructed as shown at J with similar intennediate courses at right angles isee elevation D); the 328 mm pin has alternate courses as shown at K with similar adjacent COUTS"s, havinjl; the stretcher face of two three-quarter bats at the front over the three headers (see E); eaeh course in the 440 mm pie r is as shown at L, but every alternate course is turned to the side (see elevation F).
The only continuous vertical joints are those shown by thick lines at K. A stone pad or template as shown in each elevation is usually provided at the top of a pier to ensure a firm bed for a beam or roof truss and to distribute the load effectively. Detached pillars to which gates are hung are often finished with a coping as illustrated in Fig. 17. Doub/e Fkmuh Bonded Detached Pias (~e G, H, M and N, Fig. 7).-In the It-brick pier (which is the smallest that ca!l be constructed in this bond) continuous vertical joints are produced, as indicated by thick black lines at N; owing to the small size of this pier the true face appearance of Flemish hand is not presented in the elevation at H (as the headers are not centrally over the stretchers), but the pier is nevertheless considered to he in Flemish bond as in each course there is a header adjacent to a stretcher. The short continuous vertical joints shown in the plan M of the 2-hrick pier can be avoided if bevelled closers (see broken lines) are used as an alternative. Piers may be formed with rounded arrises by using bullnose bricks; thus double bullnose bricks (see Q , Fig. 2) may be used in the construction of pier J and single bullnose bricks for the remaining piers. Attached Piers or Pilasters.- Such arc shown at H in the key plan at A, Fig. 7, and some alternative details are gi\-en at 0 to S inclusive . The stability of walls is increased by the use of these piers at int~als, and like those of the detached type they may be used as supports for concentrated loads. Examples in English bond are shown at 0, P and Q. Rounded arrises may be obtained by using bullnose bricks (see Q). The width of a pier is usually a
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CAVITY WALLS multiple of 112 mm and the projection may be either 112 mm (as at 0 and 1'), 225 mm (as at Q) or upwards. The piers and adjacent walling shown at II. and,; UTC in double Flemish hond; the 112 mm projection may be increased as rC(.juiTed. A gate pier of the attached type is shown at A, Fig. 17. Buttresses are piers which are provided to resist thrusts from roof trusses or to strengthen boundary walls, etc. Examples of buttress eappings arc illustrated in Fig. II. The brick and concrete foundations for piers
EXCl'ptlOJ{ at Q ,md M, the jmnts "f Ih.· hnck,,,,,k "oo\'e and bclm, the \\H')do" opening <1r~ ;ndic"ted by broken l111e,. Cnns,de'ratlnn shnukl be' ,l!i\'cn to tht' .11.e of th.· bricks to be u .• ed ,,,,d the lk~i"'d th,t:kn,·ss nf jOints" hen dccidiog upon lhe ~i~cs of door and" indo" OpClll11l:', Th,' widd, of ~n op~l1;ng ~hould be a multiple ,,( , brick for EnJ{I,sh bund '11Id fur d"uhle FI"mish bond (h" "idth should be " multipl"
ll'S III or"krw f~c,h,a'" d ..... uJ{htm~n~h,p. Th" h"i)!hl 'If np,'n;n,1..'" 111U~t c"nf"ml ",th thl' hrick cour~eS ,f an "l1satisfact')~· ~ppcaTlln,,~ ;~ to he a'-oid~d (sec p_ :w)
JAM B S
Jambs are the \'crtical sides of openings which aTC formed in walls to rcccl\"C doors, windows, fireplaces, etc. There arc three forms of jambs, r.t'., (a) square or plain, (b) rebated or recessed and (c) rebaled and splayed. 1 (a) Square Jambs.-Examples of s4uare jambs are shown in Figs. 42, H, 4Q, '50, 5z, 54, 56 and 57 in connection with door and window openings. Thc stopped end details in Figs. 3 and 4 show the construction of the brickwork. ..\ frequ~'m c~us" of d.Ullpnl·ss III huddings IS due to door und "indo" fr"'""~ being fiX<'d in op"nings "Ilh 'qu.,,',· j.unbs on ,"eeount of the' pointing h,·com,,}).! defect;\,c ,"od allO'\1ng "ind ,,"d r"in I.. ,·nteL
(b) Rebated Jambs (see Fig. R). The"" details are shown in both English and double Flemish bond. The plam and ~ketch c show that a rebated jamb consists of (I) an outer revral or face, (z) a rece~s and (3) an inner rcveal.~ Window and external door openings are best provided with rebated jambs for the reasons stated below, and applications of these are illustrated in Figs. 43, iX, 55 and 60. As is implied, the outer reveal is that portion of the jamh "hich is seen from the outside; it may be 102 mm (see D, M, C, etc., Fig. 8), or it may be 215 mm wide (see Q and R). The rccess \'aries in depth from 56 mlll or les~ suitable for external doors (see Fig. 48) and casement windows (sec Fig. ::;:;) w 10Z mm-suitable for windows of the boxcd frame type illustrated in Fig: 51'( A 56 mm recess is shown-at I) and that at K is lIZ mm deep. The object of the recess will be appreciated on reference to P, Fig. 8, \,hich indicates by broken lines the relative position of a window frame; the protC<.:lilJll afforded by the outer "nib" of brickwork assists effectively in pren~ntil1i! thl' access of rain into a building betwccn the frame and adjoining brickwork; tiK' bedding and pointing of the frame (see p. 84) affords additional protection. Rebated jambs having 102 mm outer reveals and 56 mm recesses in I, I~ and 2~brick walls built in English bond are detailed at D, E and F, Fig. 8; thcse aTe plans of the alternate courses T and u shown at A. The corresponding courses in double Flemish bond are shown a Ie, Hand J. Jambs with liZ mm recesses are shown in English bond at K, Land M, and in double Flemish bond at N, 0 and p, Examples of rebated jambs in both English and Flemish bonds having • Reb.ted and aplayed jambs are detailed in Chap. I, Vol. II, I Sometimes frames are lUed in r~Tle rebated jamb. (~ D, Fig. 57).
'3
ZI5 mm outcr reveals and 56 mm recesses are detailed at Q, and with liZ mm recesses at R. These details may he associated with the window z shown at A, Fig. 3, and which is shown in the alternati\'c cle\'ations A and B, Fig. S; the former indicates 65 mto thick bricks built in English hond and R shows 50 mm thick hricks huilt in Flemish hondo
A careful l\tuuy of the uetaili> shows that either king, qUe"n or bevelled doscrs or half, three-quarter or he\'elled bati> are employed in order to prC\ent continuous \'ertical joints and to ohtain the correct face appcar;H\ce; notc that any half bats and header qucen doscrs arc placed on the inner fac" at least 10Z mm from thc sides of the opening~ in order to prerent their displacement and to pro\'idc a strong suppOrt for the t'nds of th" lintels (dct~iled in Fig. IZ).
BRICK CAVITY WALLS'
Thc hollow or ca\ity wall is now thc mOl\t usual one for domel\tic huildings. The simplest form is 275 mm thick having two loz'5 mm thick It';l\e~ nfbrickwork l\cparated hy a 70 mm ca\'ity hut connected at inteT\·al~ hv wall tie~, In comparison with a ZI5 mm thick wall which use" the ~ame amou;\1 of bricks as a 275 mm cavity ""all, the latter atfords better protection tv rain penctration to the in~ide of the huilding and gre:lII:r resi~tant.:c 10 heat los~cs from the room. In ordcr to exclude dampncl\s, the minimum thickn~ss of II ~olid wall is 3z8 mm,2 hence the 275 mm cavity wall is more' economical. The pre\'ention of dampness, impro\'ed insulation and economy of the cavity wan arc substantial advantages. It is not usual to ventilate the cayity as this seriously atf~cts the insulation 1 Some te~cher~ prd"r 10 le3,-e lh,s unlrl the ~fi:ond rur of the COUTSe. Th,' ~ubj"ct Introducrd herc and i~ consu.len:d In I:re~tcr det,,,1 in Chap. I, Vol. II. &" also p, ",. I Thnc h,l\'~ been. of cour,e. muny thousands of housu erected In the p~st ,.ith external w"lls only 2'5 mm thIck. WIll 1st much depends on the pennewbihlY of lhc bricks 3nd the ~"undneiS of the mortar. ~uch walls on exposed .;It'~ 31.' 'n,'uiubh' damp mtern_ 311y, In sheltered place. in towns the :us mm Will. in many cues, has bUn salisf~ctory; prob"bly in an equal number of cgUS dump patches h."e de\'eloped. 1~
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FOUNDATIONS of the wall, slight ventilation is provided at the drainage gaps left in certain vertical joints as described below. The ties used to strengthen and aid the stability of the wall are of several kinds, the simplest being made of galvanized wire shaped as a figure of eight. They are put in the bed joints to span the cavity. 450 mm apart vertically, 900 mm apart horizontally and staggered (Fig. 13. Vol. II). At the jambs of openings the vcrtical spacing of the ties is reduced to 300 mm. It is important to keep the cavity free of mortar droppings which would collect on the ties and make a bridge for dampness to the inner leaf. T he bottom of the cavity can be cleaned out if temporary gaps arc left at the hase of the wall . Where the cavity is bridged as at lintels, sills and at the jambs of openings, a d.p.c. must be provided. These are shown in Fig. 55· The lintel detail at B shows the felt or lead d .p.c. tucked into the inner leaf and extending downwards to the outside; it is desirable to leave a few of the vertical joints open in the first outer course on the lintel so that water can drain from the cavity. (Similar gaps should also be provided at the base of the wall below the d.p.c.). The dt'"tail at E shows the d.p.c. nailed to a groove in the timber sill and passing to the outside of the walL The rebated jamb plan detail at D also has a d.p.c. which is taken up the full height of the window. The top of a cavit~ wall is preferably bridged with one or more courses of 5 mm bricks to increase stability and to enable the roof load to be shared 21 between both leaves (see E, Fig. 39 and G, Fig. 71). The base of the wall is normally constructed as at A, Fig. 10; this has one weakness on damp sites where a timber joisted ground floor is used, water may penetrate the two leaves and spread over the site concrete. This action is eliminated if the cavity at the base of the wall is filled with fine concrete to a distance 150 mm below the d.p.c. (see 0, Fig. to).
settlement i~ the usual cause of cracks and similar def«:ts occu".;ng in walls, floors, etc. The size and typ e of foundation depend upon the character of the subsoil and the \.',.ei~ht which is transmitted to il .. The bearinj:( capacity of a soil means thc maxImum load per umt of area (usually In tenns of kilonewtonsJsq. metre) which the ground Will support without tlisplacement. As the nature of the soil varies considerably it follows that the capacit)' of the soil to support loads is also variable.
FOUNDATIONS
t n its widest sense the term foundations may be defined as an expanded base of a wall or pier in addition to the ground or subsoil which supports it. The ground which receives the buitding is known as a natural foundation, and the extended bases which are constructed of concrete or masonry are called artificial foundations. An artificial foundation may consist of: (I) a concrete bed only (see A, B and D, Fig. 10), or (2) one or more courses of stone-work (see section DD at B, Fig. 20) which are wider than the wall or pier they support and which are called footings or (3) a concrete bed together with footings (see c, Fig. 10). Type (I) is the most common, being known as a strip f(JUmktion. The object of a foundation is to distribute the weight to be carried over a sufficient area of bearing surface so as to prevent the subsoil from spreading and to avoid unequal settlement of the structure. Whilst slight settlement or subsidence of a building may, in some cases, be unavoidable, it is essential that any such subsidence shall be unifonn. Unequal
SKETCH SHOWING FOUNDATION FOI!. A ONE ~ " ~AlF el'JCK WML FIGURE 9
This difference in the bearing capacity of soils may be experienced on a single building site, as frequently its character is not exactly the same throughout. Hence it is not always possible to adopt a unifonn sitt of foundation for the whole building, even if the walls and piers may support equal loads.
,6
FOUNDATIONS
The design of foundations to support heavy loads is beyond the scope of this volume and the following are typical details only. The requirements of many local authorities in respect to foundations (cspeciaHy for small buildings which transmit relatively light loads) have been modified considerably within recent years. Briefly, the following arc the requirements of the Building Regulations : ~ The foundation shaH be (I) Constructed to sustain the dead and imposed loads and to transmit these to the ground in such a way that the pressure on it will not cause settlement which would impair the stability of the building Of adjoining .~tT1ll"tures (z) Taken sufficiently deep to guard the building against damage by swelling or shrinking of the subsoil. For domestic buildings where strip foundations are used the concrete shall be composed of 50 kg of cement I to 0 · 1 mS of fine aggregate and 0·2 mS of coarse aggregate and the regulations are satisfied if :(a) There is no wide variation in the type of subsoil beneath the building and there is no weaker type of soil below that on which the foundations rest which would sffect stability. (h) The foundation width is not less than that summarized below and given fully in Tahle II, Vol. IV for different subsoils and loadings, and in any case not less than the width of the wall. (c) The thickness of the concrete is not less than its projection from the base of the wall or footing and in no case less than 150 mm. For a two-stOrey house the wal! load is usually not more than 33 kN/m; the foundation width for different subsoils would then be: Rock, equal to the wal! width; compact gravel and sand or stiff clay, 300 mm; loose sand, 600 mm (as A, Fig. 10); soft clay, 650 mm; very soft clay, 850 mm. Examples of foundations are given in Fig. 10; they should be at a minimum depth, in this country, of 450 mm so as to be unaffected by frost. The one at A shows a typical strip foundation on loose sand where the minimum width is 600 mm for a 275 mm wall; this necessitates a 162·5 mm thick strip to comply with (c) above. 450 mm is about the minimum width of shallow trench that can be excavated by hand, but where machine excavation (see Chap. I, Vol. IV) is used, the 305 mm wide type at B is satisfactory in compact sand or stiff day; the who:e of the trench is filled with concrete. The type at D has to be used on soft clay which is liable to expansion and contraction due to the variation in water content. At a depth of 915 mm this action is normally absent in the U .K. The one at c illustrates the use of a course of brick footings which were often used in earlier days (when cement was not the reliable product it is today) to give a gradual spread of the load. The rule illustrated is a useful one and I From 1 January 1971 .cement is available in So kg. bags.
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DAMP PROOF COURSES consisted of making the concrete foundation twice th~ wall width and of a thickness equal to one and one-third its projection from the footing. The depth of the foundations varies with the character of the subsoil and the relative importance of the work. Clay soils arc liable to expand and contract, and such movement may cause damage to the foundations unless they are placed at a sufficient depth; if such sites are waterlogged it may be d~irable to adopt 900 mm deep foundations. I t is not necessary to 'exceed 450 mm depth in many situations; this is the minimum to prevent damage by frost. All brickwork below the ground level should be built in cement mortar in order to increase its stability, and engineering bricks are preferred. The construction of the floor shown by broken lines at c is described on pp. S8 to 64. Pier Foundations. - An example of a foundation suitable for a detached pier (as illustrated in Fig. 7) is shown at E, j, K, Land M, Fig. 10. Whilst footings may be dispensed with and the foundation designed in accordance with the Building Regulations, it should be noted that brick footings serve a useful purpose in gradually transmitting the concentrated load from the pier to theconcrete. Timbering to foundation trenches is described on pp. 79-80. DAMP PROOF COURSES One of the chief essentials in building is that the structure shall be dry. A damp building is unhealthy to those who occupy it, it causes damage to the contents of the building, and it gradually impairs the parts of the structure affected. There are various causes of dampness in walls, the chief of -Which are: (I) moisture rising up the walls from the adjacent ground, (2) rain passing down from the tops of walls, (3) rain beating against the walls which may absorb the water to such an extent as to show dampness on the internal faces and (4) the absorption of water from defective rain-water pipes. With reference to the fiut cause, the stud~nt of Building Science (a subjeo::t which nonnally fonns part of a grouped course in Building) WIll ha"e probably studied the tlructure of Ii porous material such as a brick; he may have carried out tests to detennine its po~otity (the percentage of its pore spao;e), relative ptrmtablfity (its capadty to permit the passalle of water throul(h It). and the amount of water that it wi\! absorb. H e will appreciate that brickwork below the Jlround level will draw the moisture from the ground and may impan it from one course to another for a COn,idenoble height. The amount of moiuurc ~b""rbed depend. upon the water <:ontent of the soil and the quality of the bricks, mortar and workmanship.
To prevent water absorbed from the soil rising and causing dampness in the wall and any adjacent woodwork and plaster, a continuous layer of an impervious material is provided. This layer is known as a horizontal damp proof course (d.p.c.) The position of such a course varies from ISO to 300 mm above the ground level (see sections in Fig. 10). The level should not be less than ,somm otherwise soil (forming flower beds and the like) may be deposited against the external face of a wall at a greater height than the impervious layer and thus water may be transmitted from it to the wall above the damp proof course.
'7
Some of the materials used to form horizontal damp proof courses are: Asphalt.-The raw material is a chocolate-coloured limestone which is impregnated with bitumen or natural pitch. It is quarried and imported from the West Indies (Lake Trinidad), France (Seyssel), Switzerland (Val de Travers) and Germany. Fine grit in varying proportions is added and completely incorporated with the asphalt Jlt a vey high temperature, after which it is cast into blocks (weighing about 25 kg each). These are received on the site, when they are re-heated and applied in the following manner: Wood battens are fixed horizontally along both faces of the wall with their top edges usually 13 mm above the top of the course of the wall which i$ to receive the asphalt. The heated material is placed on the wall between the battens and finished off by means or hand floats to the top of Lilt: battens. The asphalt is kept slightly back from the external face of the wall so that it may be pointed with cement mortar after the wall has been completed; this covers the dark line of the asphalt and assists in preventing the asphalt from being squeezed out and discolouring the brickwork, especially if it is subjected to intense action of the sun. Asphalt forms an excellent damp proof course, it being impervious and indestructible; in addition it does not fractu re, if, on acCount of unequal settlement, cracks are caused in the brickwork. Fibrous Asphalt Felt.- There are many varieties of this damp proof course, one of which consists of a base of tough hessian (woven jute cloth) or felt which is impregnated with and covered by a layer of hot natural bitumen, and sanded on the surface or covered with talc to prevent the layers from adhering to each other. It is obtained in rolls, 22 m long and in various widths from 102'S 10m to 9IS m:n. In laying it in position, a thin layer of mortar is spread on the brickwork and the damp proof course is bedded on it. It should be lapped 75 mm where joints occur and lapped full width at all crossings and angles. It should be pointed in cement mortar. This type of damp proof course is extensively used, it being easily handled and, provided it is adequately impregnated with bitumen and obtained from a reputable manufacturer, it forms a thoroughly reliable damp-resisting material. Some of the cheaper varieties are practically worthless; they are comparatively thin and both the bases and the bitumen are of inferior quality; such should be avoided. It)s not suitable for certain classes of stone walling. i. t' .• I .~k ... District Masonry (described on p. 45), as the weight of the ragged undresscd stones cuts it and produces defects through which moisture may pas~ to cause dampness. Slate.r.-Such a damp proof course consists of two layers of sound slates embedded in cement mortar composed of I : 3 cement and sand. A layer of mortar is spread over the brickwork, upon which the first layer of slates is bedded with bUIt joints; more mortar is spread over these slates and the second layer of slates is laid in position so as to form a half lap bond with the first course of slatcs (when the slates are said to" break joint "); the next course of brickwork is then bedded in cement mortar on the top layer of slates. The slates must extend the
18
BRICK WALLS
full thickness of the wall, be at least 215 mm long, and be neatly pointed in cement
SURFACE OR SITE CONCRETE
mortar. It is a very efficient damp proof course and has been used on important buildinga.l It is used in connection with Lake District walling and simil~r construction as it is not damaged by the sharp edges of the rough stones. This damp proof course i. liable to be broken if unequal settlement occurs, causing water to be absorbed through the craw. . Lead.-This is a costly but very effective damp proof course. It consIsts of a layer of sheet lead (see Chapter VI) which weighs from 3 to 8 lb. per sq. ft.' embedded in lime mortar ,I It is either lapped as described for fibrous asphalt felt or the joints may be welted (see p. 144). The mortar does not adhere to it readily unless the lead is well scored (scratched). . . Another variety of this class of damp proof course consists of a contmuous core of light lead (weighing only 1'22 kg/ml) covered both side1l with bitun:ainous felt which is surfaced with talc to prevent sticking of the folds. It is made In two or three grades of varying widths and in rolls which ~re in 8 m I~n~h~. It is an excellent damp proof course, eapedally for damp Sites, and whilst It IS more expensive than the above, it is more durable. CopPt'T.-This is another excellent damp proof course. The copper should be at least 0'022 mm thick, lapped or jointed as described for lead, and embedded in lime or cement mortar. Blue Staffordshire Brnks.-These provide effective damp proof course~, They are built in two to four courses in cement mortar; the colour of the bncks may render them unacceptable for general application. P(astic.-This is a relatively new type of d.p.c. material. It is made of black polythene, 0'5 or I mm thick in the usual walling widths and roll lengths of 30 m.
The area of a building below wood floors must be covered with an impervious material1 in order to exclude dampness. The material used may be concrete or asphalt. The Building Regulations require a 100 mm layer of concrete consisting of So kg of cement to not more than 0'1 m~ of fine aggregate (sand) and 0'2 m3 of coarse aggregate (broken brick, stone, etc.), laid on a bedof broken bricks, clinker, etc. The concrete should be well surfaced with the back of the shovel (known as " spade finished "); its top surface must not be below the level of the ground outside the wall of the building. Surface concrete Is shown in Fig. 10. Besides excluding dampness, surface concrete prevents the growth of vegetable matter and the admission of ground air. Dwarf 102'5 mm walls, known as sleeper and fmJ~r walls (see Fig. 32), are sometimes constructed on the surface concrete (see c, Fig 10, and R, Fig. 32) or they may have the usual concrete fO\lndations (see Q, Fig. 32). The site concrete adjoining the walls may be finished as shown at c, Fig. 10 (this is the best method if a separate sleeper wall as shown is to be supported), or at ... and a, Fig. 10. Offsets.-These are narrow horizontal surfaces which have been formed by reducing the thickness of walls. c, Fig. 10 shows 56'25 mm offsets. Wider offsets than these may be required to support Boor joists, roof timbers, and the like. Walls of tall buildings are formed with offsets; thus a 15 m high wall may be +40 mm thick at the base, 215 mm thick at the top, with an intermediate thickness of 328 mm, and the 112 nun wide ledges or shelves so fonned are termed offsets. A broken vertical section through a portion of such a wall is shown at A, Fig. II. The 112 mm offsets support horizontal wood members called wall plates which receive the ends of the floor joists (see p. 60). The plan at B, Fig. II, shows an alternative and cheaper method of sup· porting wall plates than at A. In the latter the increased thickness of the wall at the base to form the offset is continuous for the full length of the wall, whereas at B the wall plate rests upon small piers which are usually not more than 790 mm apart. Two methods of forming ~hese piers ~re shown at c and o~ the former being the stronger as it is bonded mto the mam wall and the latter IS not. The foundation for pier 0 is strengthened if the site concrete is formed to occupy the space at w. Corbels.-These are similar to offsets except that the ledges are formed by oversailing or projecting courses (sec Fig. 11). They are constructed to support floor beams, lintels, etc. As a load carried by a corbel tends to overturn the wall, certain precautions arc taken to ensure a stable structure; !hese are: (1) the maximum projection of the corbel must not exceed the thickness of the wall, (2) each corbel course must not project more than 56'25 mm, (3) heade~s
The second cause of dampness stated on p. 17 (i.e., rain passing down from the tops of walls) may be prevented by the provision of a. horizontal damp p~f course either immediately. below the top course of bnckwork or some httle distance below it. Thus, in the case of boundary walls, the damp proof course may be placed immediately under the coping (see Figs. 17 and 27), and parapet walls may be protected by continuing the cover Bashing (see p. 143) the .rull thickness of the wall. Similarly, a horizontal d.p.c. should be placed In a chimney stack at its junction with a roof. Vertical damp proof courses which are necessarf to exclude dampness in basement, etc., walls are described in Chap. I, Vol. II. I Horizontal slate damp proof courses are used in both the Anglican and Roman Catholic cathedrals 11 Liverpool. In addition, lead and blue Staffordshire briCks are uted in. connection with the latter building. .... . I 1.~., 13'5 to 35 ka/m'. Despite the change to metnc uOlu,!ead 1$ $~111 ma.de In these Imperial weiahts but t pecified as "NO.3 lead, No... lead etc., accordlna to .ts I",penal weight (aee p. 1"2). . . I Certain mortars hpecu,l1y cement mortan, act upon lead II.lld ultImately dCltroy ,t; l uch thould therefor~ not be ute
I Vegetable loil or turf covering a aite should be rem~ ... ed as II. pr.e liminary building operation' the excavated soil may be Ipnad over that panlon of the Ilt~ set apan for the prden, e~ .••nd the turf may be ltacked (rotted turf!a a valuable. ",a-':lure). The depth of soil removed variel from I So to 230 mm and the Ille concrete IS laid on the exposed surface. The omiuion of the concrete has been a frequent cause of dry rot (see p. 57)·
.'
LINTELS
19
must be used as they are more adequately tailed into the wall than stretchers, and (4) only sound bricks and workmanship should be employed. The corbels shown at L, M and N aTe continuous and that at 0 (with the sketch at p) is an example of an isolated or non-continuous corbel. The latter is used to support concentrated loads (as transmitted from large floor beams) and the stone pad is provided to distribute the load more effectively. Oversailing Courses.- These aTe frequently employed as decorative features, as for example in the construction of comius (a crowning member of a wall), string courstS (provided between the base and top of a wall), taves (top of a wall adjacent to a roof) and chimnty stacks (the upper portion of brickwork which end05es chimnp.y flues-see Figs. 38 and 75). Simple examples of brick oversailing courses are shown at E, Fig. 17, D, Fig. 38, and j, Fig. 70. Stone cornices etc., are detailed in Figs. 24 and 26. Buttress Cappings.- Buttresses have been referred to on p. 13. These arc usually completed with simple cappings (see Fig. Il). The section at Q shows the capping to consist of two courses of splay bricks of the type illustrated al Rand s, Fig. 2; a sketch of this capping is shown at R. The sketch at T shows another weathered capping formed of ordinary bricks which are tilted or tumbled into the wall; the section at s shows the cutting of the bricks which is involved. As mentioned on p. 13, the \'enical sides of doorways and window openings are known as jambs. Thc top or head of such an opening consists of a lintel or an arch, or both, amI the bottom of a window opening is called a sill whilst the bottom of a door opening is usually provided with one or more steps or threshold.
OFFSETS
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SE.CTION E.F
LINTELS A lintel is a member of wood, brick or concrete which is fixed horizontally and used to support the structure abovc the opcning. Most lintels now are of reinforced concrete. Jll S 2111 \
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In the class In Duikhn~ $cil'"nc(' the student w,1I study the behaV Iour of lintels or beams wh en lo"dcd. b'pcr,ments w,1l show that If a wood beam .s loaded as indicated at T , Fig. 12. it w ill chan!:" (u shape AS the load increast~. Thc b",lm wil! bend, and ,f it is ult,mately broken it 'loll be s«n that the fibres of the upper portion ~rc cru~hed and those of the lowl'r portIOn a r" torn apart; the bending actoon tends to contract or compress tht upper fibres and to sueteh the lower fibres. H ~nee the statem cnt that th' " upper part is suhJ~cted to ;0 stress called (omp.ruio" and the lower portion 10 ~ stress klln ..... n as le'lsio" "; the fibre_ along the centre of Ih e bc"m are n .. ithe r in cornpre!isoon 110r tension ~nd this horizontal plane IS ear"d the nflliral (.... is. I n addItion, the load tends to produc" ~lIh .... r "e rhcal, horizontal Or d"l.gonal crach which ind,e;lIC fa!lur~ In she",. Lintels must of course be sufficiently slron g to re$lst fa,lu r.. b~' comprl'ss,o n , lC!lS,nn. sheH and defll'Cl,un.
{Food Linfeh.- Thesc are usually of red\\ood (sec p. 59). The size depends upon the thickness of the \\ all, the "pan (di",tanee between opposite jambs) and tlic weight to be ~upported . The deptll i~ :lpp roximatcly onc-twelfth of the span with a minimttm of 75 mm; the width may equal the full thick.ness of the .-
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wall-as is necessary for internal door openings (see s, Fig. 52)---or the width of the inner reveal as shown at B, Fig. 12. A further example of a wood lintel is illustrated in Fig. 44. Bu ilt-up lintels may be used for larger spans; the section at Il, Fig. 12, shows such a lintel which comprises three 175 mm by 7S mm pieces bolted together with 13 mm diameter bolts near the ends and at every 380 rom of its length; a part elevation is shown at c and indicates the bolts which are provided with the necessary nuts and washers (see j , Fig. 80). An alternative to this built -up lintel is shown a~ H; this consists of two 175 mm by 50 mm pieces (which bridge the opening and have a 150 mm bearing or wall-hold at each end) and 50 min thick packing or distance pieces at the ends and at 380 mm centres; holes are bored through the continuous pieces and packing pieces through wh ich bolts an: passed to secure them and ensure that the pieces will act as one unit. the elelation or lintel )I is similar to that at c except that the pack in? pieces would be indicated by broken lines at each bolt, as shown at J. The ends of the lintels have a J 75 mm wall-hold and are bedded on mortar so as to ensure a level and firm bearing. \rood lintels afford a ready means of securing the heads of door and window frames (see p. 98). Brick l.intels. As is implied, a brick lintel is a horizontal member consi~ting of bricks which are generally laid on end and occasionally cn edge. It is a relatively weak form of construction and is quite unsuited t~ support hea,y loads. They ~hould therefor<.: he used to ~pall small openings only (unless they arc to receive .ldditional support as expldlOed later) dnd the Sp;lI\ ;;.hould not exceed 900 mm. A section and part elevation of a brick lintel arc sh()\1 n at .~ and B, Fig. 12. Cement mortar should be used, and pressed bricks hal'ing d frog on each b~d are better than ",i re-cuts. The term joggled brick lintel is sOlnetires applied to .his type when bricks baying flOgs are used, the Joggle or notch being formeo by the widened joint at each frog: the joggle assists in re~i!jting the sliding or shearing action to which the lintel is subjected. The hnt,,1 is con$true t,'d un n te"'porar)' wood ~upport known ~s a tunlln:.! I'''·e .... (sec p. Ikl); lTon~r IS $pread O'er Ihc low .... r, hack .and front cdl<:es of c.«-h hr1<:k beforc be1ll~ plJced 10 posmon; wh"n all of the bricks han~ ben, laId . .l:ro ... t (sn' p. 2) IS poured Ihrough the hules 'Ih,ch haH prc";oush hn'nfonned;1t Ihc top umll ~~ch fwg 's c",""pl.·tdy filled wllh Ihc l"IU'u 1ll0rtM; \1. Fa:. 12, show1" ~"Cl!on throu/!h ~ bnc~-on."nd 1101 ..1 \Ilth the frOI<: and Ih" h(ll" ~I the top "I<.hcdled hy bTes of the adjoining brickwork (set" t:); onc trod of c3eh brick
is carefully removed (usually with a hammer and bolster--see 35. Fig. 19) and the bricks are placed in position with the cut ends uppermost ; the grouting operation is facilitated as the frogs are exposed at the top. An alternative method of forming the ends of a brick lintel, which has a somewhat stronger ap:>earance, is shown at F in the elevation It, Fig. 12.
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Urick lintels arc sOlTlctilTll'S ktWI\J1;1S" soldier :ITches" presumably becau~e of the upright aprear;\!K'~ of the hrick~. This i~:t mhllmlleT. for sl1ch does not comply \lith the re(luiH:menh of a trHe ;tTl-h a" Jdillt:d bdow. lne:dentally great carc "hould be taken to ensure that each brick is placed ahsolutely vertical J~ the appearance is spoilt if one or two of them show a depJrtore from the n:rtical, howc\er slight. EX,Hllpll"s of stH;h alt "arch" are shown at -', Fig. +4, and H, Fig. 54. .'>'uppurrs fur BriCR Llille/s. :\ddltional suppurt must be provided if a brick
,-,
ARCHES lintel is required for a greater span than qoo mm. Alternative methods of sueh reinforcement arc sholll1 in section at K, L, M and N, Fig. 12. At K a 7S mm by 10 mm stcel flat bar (set: Fig. 80), having alSo mm bearing at each end, is used. For spans exceeding 1800 mm it is n.'{:ommencled that one of thl' following should be used: (a) a steel angle (see Fig. 80) hal'illg 150 mm bearing;; as shown at L aTHl in detail \\", Fig. 5+, or (b) purpose~made hricks supported bY:I rcinfnrtl.:d concrete lintel as indicated at !'l or (c) a n:infon.:ed brick lintel which is ilhlstrated at '"'-I. The latter consists of a 20 mm diameter steel rod which i~ threaded through the bricks before they have been grouted; each end of the rod is bedded 150 mm into the wall; the bric:"s used for this purflOSC are holed during the moulding process before being bunt, the centre of cach hole being appro:-oilllatcly ]8 mm from the underside of the lintel. The exposed surfaces of the aho\'e tlat bar and angle may be n'ndered inconspicuous by painting them to conform .... it;.. the colours of thc bricks; alternatively they may be completely covered by the door and II1I1dow frame~; the soffit or underside of the concrete lintel at :-.; betwcen the briek lintel and the door frame may be covered by bedding t 2 Illlll thick tiles to the concrete as shown. It is a common practice for small spans to bed brick lintels directly upon the heads of the door and window frames; such frames should be set back for not more than 25 mm from the external face of the wall (see c, Fig. +4). . Slone Lintels or Helld$. · These are rectangular bloch of stone of varying thickness and depth; tht; latter should be at least 215 mm. It should course with the adjacent brickwork as shown at 0, Fig. 12. Additional examples are shown in Figs. 22, 24, 58 and 61Concrete Lintels.-A suitable mix of concrete consists of t part Portland cerr:ent. 2 parts sand and 4 parts gravel or broken brick or stone of 20 mm gauge. The lintel may be cast in situ (in position) or precast (formed and allowed to set before being fixed); the former is cast in a wood mould (with]2 to 38 mm thick bottom and sides) which is removed when the concrete has set. The precast method is more often employed as the lintels can be formed in the wood moulds well in advance to allow them being sufficiently matured for fixing when required and the construction of the walling above them may be continued immediately after fixing. As concrete is comparatively weak in tension, the use of plain concrete lintels should be limited to spans not exceeding 900 mm and not used to carry point loads, otherwise failures may occur which arc usualJy due to shear and which may produce fractures such as that indicated by the brokell line U at Q, Fig. 12. If this span is to be exceeded, the lintel must be strengthened by using mild steel bars or some other form of steel reinforcement. A simple type of TtI'nfOTced concrdt lintel is shown at p and Q; the number and siz.e of the reinforcement depend upon the span, width and load to be supported; the steel is placed in the moulds and at about 25 mm from the bottom; the concrete is poured in, care being taken in packing it round the reinforcement. The ends of the bars are hooked as shown in order to increase the bond or grip between them and the concrete. If precast, the top of the lintel should be marked so that the
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will h,'d it WIth the r("i,,(nrccmcnt lowt·rmost. Olhercx:lmple,; of a reinforced COncrde lintd arlO -:hOIIIl at A and c, Fig. 25, and B, K and 0, Fig. 58. An example of A hoot-shaped lintel is shown at H, Fig. 55.
ARCHES
An arch is a stnKtun: compri~ing a number of rdatil'c1y small units' such as bricks or 1TI;bonry hlocks which arc wcdgo::-~hapeJ, joined together with mortar, and spanning 0111 opening to support the weight above. Because of their \Iedge-like form, the unit>. suppmt eAeh OIlu:r, the load tends to mOlke them l'Ol1ll'lKt and cnahles them to [ran~mlt the pres~ure downll.lTds to their suppOrts. Terms.-Thc technical term~ ipplicd to an arch and adjacent structure ;ire shuwll in the isometric sketch (Fig. I]); thc following i~ a brief description :I '!lus.win.-The wedgc-sl,aped bricks or blocks of stone which comprise an arch; the last \oll~soir to be placed in po-:itioTl is usuaily the central onc and is known as the kty brick or key stuni; It is »ometimes emphasized by making It larger and projectmg It abol'(' and below the outlines of the arch. The key shOll n In the sketch consists of sel"Cral 12 or 20 mm tIleS. Ring, Rim ur RinK Cvun(.-~Tbe (ircuJar course or eour~es comprising the arch. The arch 111 Fig. '3 consists of three half-brick rings, the olle at D, Fig. '5, has two half-brick rings, and those at 10 and [', Fig. IS, and I· anuJ, Fig. +1, have each a olle-hrick ring. Extrado$ or Back.- The external eurre of the arch. Intrados. The inner cune of t.le arch. Soffit.-The inner or under surface of the arch; in sarno:: localities the term5 " soffit" and" intrados " arc accepted as meaning the same. Ahutmenl$.- The portions of the wall which support the arch. Sketooacks.--Thc inclined or splayed surfaces of the abutments prepared to receive the arch and from which the arch springs (see A, Fig. 15). Springing Point.s.- The points at the intersection between the skewbacks and the intrados (see A, Fig. 15). Springing I.ine.- The horizontal line joining the two springing points. Springi'T.s.-The lowest \"oussoirs immediately adjacent to the skewbacks. Crown.- The highest point of the extrados. Haunch.- The lower half of the arch between the crown and a skewback. Span.- The horilontal distance betwecn thc reveals of the supports. Rist.-The vertical distance between the springing line and the highest point of the intndos. Cmtre (or Striking Point) and Radius (see Fig. 1]). Depth or lleight.-The distance between the extrados and intrados. Thicknl'SS.- The horizontal distance between and at right angles to the front and back faces; it is sometimes lefcrred to as the width or brFtldth of the soffit. , Sud and reinforced concrete arches of large ,pan are adopted
In
bridge cOnstruction.
T
BRICK WALLS
22
In some districts the teIll1 " thickness" is considered to have the same meaning as" depth ", to remove any doubt, the arch at A, Fig. IS, would be specified as being a" flat gauged arch, 290 mm deep with 102'S mm wide soffit, to a 1135 mm opening."
Bed Jcnnts.- The joints between the voussoirs which radiate from the centre. Spandril.-The triangular walling enclosed by the extrados, a vertical line from the top of a skewback, and a horizontal line from the crown; when arches adjoin, as in Fig. 13. the spandril is bounded by the two outef curves and the horizontal line between the two crowns. Impost.- The projecting course or courses at the upper part of a pier or other abutment to stress the springing line; sometimes moulded and known as a cap (see Fig. 13. and D. Fig. IS). Plinth.- The projecting brickwork at the base of a wall or pier which gives the appearance oi additional strength; also known as a hase. Arcade.- A series of arches, adjoining each other, supporting a wall and being supported by piers. Classification of Arches.- Arches are classified according to (a) their shape, and (h) the materials and workmanship employed in their construction. (a) Themore familiar forms of arches are either fiat, segmental or semicircular, whilst others which arc not so generally adopted are of the semi-elliptical and pointed types.1 (h) The voussoirs may consist of either (I) rubber bricks, (2) purpose-made bricks. (3) ordinary or standard bricks cut to a wedge shape and known as axed bricks or (4) standard uncut bricks. The following is a brief description of these bricks ;1. Rubber Bricks, Rubbers. Cutters or Malms. - These are soft bricks, obtainable in various sizes, and of a warm red or orange colour. They can be readily sawn and rubbed to the desired shape. They are used in the construction of gauged arches (see below). 2. Purpose-made Bricks.- These are specially hand-moulded to the required shape and are used for good class work in the construction of purpose-made brick arches (see below). Owing to the standardized form and size of many arches, stocks of the more commonly used purpose-made VOUSSOlfS are carried by the larger manufacturers, and delivery is thereby expedited; such bricks are usually machine-pressed. 3. Ordinary B7I·ck~· CUi lu Wed,!;'te Shupte. - These are st
OF A POR.TION OF A 1 The~
are illustrated in Fig.
19,
Vol. II.
BR.ICK AR.CADE. ILLUSTRATING TE.R.M5 FIGURE 13
A R CH E S (a) gauged Rat arch, (h) purpose-made Aat arch and (c) axed brick Aat arch, depending upon the class of bricks and labours used in their construction. (a) Gauged Flat or Camber Arch (sec A and c, Fig. I$ ).- Rubbcrs arc used. T he extrados is horizontal and the intrudos is given a slight curvature or camber by providing a rise of 1·5 to 3 mm per 300 mm of span; thus the arch at ,\ would have a rise of approximately 12 mm. The reason for the camber is to avoid the appearance of sagging which is produced if the intrados is perfectly ho rizontal and which defect would be accent uated if the slightest settlem ent occurred . T he angle of the skewbacks may be 60° (as IIhown at A and c) or th e amou nt of skewback (the horizontal distance between the springing poin t and t he top of the skewback) may equal 38 mm per 300 mm of span per 300 mm depth of arch (as shown at A, Fig. 48, and A, Fig. 54). The adoption of the laller ru le gives a more pleasing appearance (compare A and c, Fig. 15, with A, Figs . 48 and 54); if it had been appl ied to the two arches in F ig. 15, the amount of skewback at A would be 1135 290 . 685 290 J8x _ - x = 139 mm, and at C It would he 3Rx x - =84 as com300
300
300
3 00
\\·h •.'I\ urn'''''g Ihis Heh to seak. Ihc slUd~m ~hould nOle thaI all bed jOints of thc '·OUSSll,rS radiate w\\aru s thccentr" and thJt Ih" 75 mm meJsur~m"nts (or 50 mm if th" Re"erJI "ailing is eOlls[rUCled of SO mm bricks) arc sel off along the t;rlTadoJ.
pared with 167 mm, which is common to both arches when the skewback has a slope of 60°.
I<. E Y
DETAIL
SHOWI NG
THE
23
This type of arch is not very strong and should be limited to spans of from I 220 to I 520 mm unless they are ~trengthened by means of a steel bar or angle, as desc ri bed on p . 2 1. Ohservc t hat in each case the extrados coincides w ith a horizontal joint of the adjacent walli ng and thu~ a split course is a\"oided (sec p.20); the intrados of the arch at A, Fig. 15, also coincides; with a bed joint; this; is not alway~ desirable, as the brick at T is difficult to cut on account of the sharp edge produced; such is :l\oided if the intrados comes midway up the course (see s, Fig. [5). " Cauge " means " m ell~ure" ;md a ch>lracteristic of gauged work is its exactness . T he bricks arc accurately shaped a~ described below and the bed joints are \·ery thin, bcing as fine as 0·8 mm, although a thickness of joint va rying fmm 3 to 6 mm is much Ll\oured. Such accurate work is possible by the use of rubbers and a jointing m>ltcrial known as pUll)" lim, (lime chalk which has been well slaked, worked up to a consistency rl:"~clllhling thick crcam and passed through a fine sic\·c).
A P P L CATION
OF
ARCHES
ETC
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5 E C T ION
FIGU RE 14
• F G'
BRICK WALLS Students make a common miatake in meuuring off along the intradol. When the bricka are 65 mm thick at the extrados, "tiaractory jointinr retulu ir the number of vouuoin in the arch when divided by .. gives a renuinder 0 ',i.t., '3. 17, ::t I, etc. Cunstnlch'01I 0/ Art/I.-In order that the rubbe~ shall be coIT«t1y shaped, • full-si::te drawing of the arch (showing the vouuoirs and joinll) ia prepared and thin pieeea of ::tinc, allied tmtputr, are cut to the Ihlpe of the vouuoin shown on the drawing. The btwi. or inclinations are markcd on each voupoir by tranferring them from the templet which is placed on it. The voussoirs are then sawn to shspe with each saw-cut parallel and near to the marks. They are finally dressed down to the marks by rubbin; each cut surface on a .Iab of hard stone or by using a rasp (lee p. ,~8). A 'So nun long groove
(b) Prnprue.made Bmk Flat ATch (see II, Fig. IS. A, Fig. ~8, and A, Fig. 54.). - Thill arch differs from the guuged Ilrch type in that purpose-made bricb (sec above) are used instead of rubbers; the jointing material and the thickness of the joints are the same as for the general walling; the camber and size of skewback are as described for gauged arches. This type of arch is frequently employed in good-class work.
Segmental Arcb.-Half elevations of two varieties of this arch are shown at F and G, Fig. 15. The geometrical construction for determining the centre for the curved extrados and intrados and from which the bed joints of the voussoin radiate is shown. There are four varieties of this type of arch, i.e. : (a) Gau.ged Segmental Arth (see G, Fig. 15).-lt is constructed of rubbers upon a temporary wood support called a cmtre (see f, Fig .•p). Cross joints may be omitted if desired. (b) Purpose-made Brich Segmmtal Arch (see F, Fig. 15).-This is similar to the above, except that purpose·made bricks and not rubbers are employed and the thickness of the joints is the same as that of the adjoining brickwork. (c) Axed Bn'ch Stgmmtal Arch.-Whilst this arch resembles (b) its appearance is not so good, as it is constructed of ordinary bricks which have been cut to the required wedge shape.
(d) Ruugh Brick Segmental Arch.--': This consi.II of one or more half-brick rings conlltructed of ordinary stock un
WINDOW SILLS A sill provides a suitable finish to the window opening and it affords a protection to the wall below. Sills may be of brick, brick with one or more
(e) Axed Bmk Fillt ATCh.-This is similar to (6) except that iu appearance is not so satisfactory as the voussoirs arc ordinary bricks cut to a wedge shape a8 described on p. u. This type of arch is now used oaly for common work.
• Although the thickness of the join" of the brickwork (including those of the archei) haa been shown in Fig. IS, it il usual for Itudent. when preplrin, homework ,hcetl to .how the jointl by lingle lines only.
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FIGURE 15
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section) and a zo mm projection beyond the jamb (see elevation); they are laid to break joint (see also A, Fig. 41). The tiles must be solidly and uniformly bedded in mortar otherwise they may be easily damaged. An alternative arrangement is shown at B, Fig. 16, where a double course of tiles is 'bedded on a brick-on-edge course. An equally satisfactory and inexpensive finish is provided by a double course of tiles bedded on the top course of the general walling (see D, Fig. 14). The tiles l1l2y be given a much greater slope if desired (see E, Fig. 55), and the brick-on-edge course may project 20 to 25 mm beyond the face of the wall. An internal sill of one course of tiles (F) is shown at A, Fig. 16. Lead-covered brick-on-edge sills are shown in Figs. S6 and 57.
courses of tiles, tiles, stone (natural or reconstructed), concrete, terra-cotta and WGod. The top of a sill should have a slight fall outwards to prevent the lodgment of water; this slope is called the toeathering of a sill. Fig. 16 shows three forms of external sills. That at A shows a section and part elevation of a brick sill upon two courses of tiles. Stahdard bricks are placed on edge and are slightly tilted. The tiles vuy from 13 to 45 nun thick; those shown are 16 mm thick. Ordinary roof tiles-(known as plain tiin, see Fig. 72)-are sometimes used; these are ap. roximately 270 nun by 165 mm by 13 nun. Purpose-made tiles, called qudrry liln, arc thicker than plain tiles and are usually square of 150 to 300 mm length of aide. The tiles are given a 2.0 mm projection beyond the face of the wall (see
"
BRICK WALLS
26
The sill at c, Fig. 16, is of moulded concrete, or reconstructed stone (see Vol. IV). The top surface is weathered and slightly moulded; it has a ~roo\'e to receive a wrought iron weather bar (sec p. 104). The underside is grooved or'throated to throw off the water and prevent it from passing underneath the sill and staining the brickwork helow. The ends of the sill are called stools or seatings and pro\ide lc\'c! beds to receive the jambs. In all cases the sills should course wilh the adjacent walling ill order /0 atloid the umightly splil courses which ha'IJe bun re/erred to 011 p. 20. Sills should be protected during the construction of the building, other,vise falling bricks, etc" may cause damage. This protection is usually in the form of pieces of wood w:,ich rest upon the sills and are tightly fitted between the re\·eals. Stone sills are described on p. 49.
THRESHOLDS The bottom of an external door opening is provided with onc or more steps which form a threshold. Such may consist of bricks, stone or concrete. Fig. 14 shows a threshold cOllSisting of three steps which are formed entirely of bricks Iaid on edge. An alternative to this, to a larger scale, is shown at D, Fig. 16. Ordinary standard bricks may be used, but they must be very hard, othemise the edges ur arri~c~ wiil be reauily tlamagcu. The steps must have a satishctory founda· tion, hence the concrete bed. The height of each step, called the riser, is 130 mm although this varies from I 15 to '75 mm. Th~isers consist of bricks laid on end and the rest of each tread (or horizontal portion) comprises bricks laid on edge. Treads should be at least 280 mm wide so as to afford adequate foot space. The top step is given a slight fall {about 3 mm) to discharge water away from the door. The two lower steps ha\'e returned ends; this gives a much better appeolirance than when all steps are of the same length. The bonding of the bricks is shown on the plan and elevation. The whole of the brickwork should be in cemf.7lt mortar. A single step in bricks on edgo is shown in Fig. 13. The threshold at E, Fig. 16, consists of two steps' having brick.on.edge risers and 60 mm thick. stone trcads. The stone must be extremely hard and finegrained,
in concrete, although thesc do not look so weU as those in stone. A conc·cte step, which is a continuation of the concrete floor, is shown in Fig. H. It is advisable to defer the construction of thresholds until the completion of the b~ilding, otherwise they may be damaged during the building operat.ons unless adequately protected.
COPINGS
Copings arc provided \0 serve as a protectile cm-ering to walls such all boundary walls (yard and garden walls) and parapet walls (those which arc carried up abOle roofs). Their object i~ to exclude water from the walling below. Vl:' ry serIOus dnmagc may hI:' caused to n waH if watcr gains acc.,ss, especially dur;nR culd weather when the waleI' may free~e. Under such cundltiuns the resultinR "xpallsion may mpidly disinteRrate the upper courses of the briekwurk. In addition, the wutcr may penetrate sufficiently to cause dampness to hedrooms, etc.
The most effective coping is that which throws the water clcar of the wall below. The fewer joints in the coping the better, and the jointing and bedding material should be ument mortar. Copings may be of bricks, bricks and tiles or slatcs, stone, terra-colla and concrete, and all must be sound and durable Some of the simpler brick copings arc shown in Fig. 17. They form an effective finish to a brick bt;ilding. A portion of a garden wall is shown at A, Fig. '7, and alternative copings which would be suitable for this and similar walls are shown at B to L inclusive. Brick-on-Edge Coping.- The section at II and part elevation at c shows this type, which consists of ordinary hard and durable bricks laid on edge. It has a simple but satisfactory appearance , is inexpensive and is adopted extensively. Another applicat:on is shown at M, Fig. 36, and in Fig. 74. Sometimes the bricks are placed on end, or as shown in Fig. the coping may consist of two courses with the lower set back about 13 mm and comprising bricks-on·end and the upper course set back a similar amount and consisting of bricks-on-edge. Bulloose Coping.- This ;s shown in section 0 and the elevation IS simila: 10 that at c. The double bullnose bricks are placed on edge. Semicircular Coping (see ~; and F).-The purpose.made semicircular bricks are bedded upon an oversailing stretching course of ordinary bricks. The space between the stretchers (about 60 mm as shown in the section) should be filled solid with pieces of brick and mortar if the dwarf wall is likely to be subjected to side stresses from traffic, etc. The curved surface of the coping and the weathered or jlaunched bed joint cause water to get away quickly, and the projecting course assists water to drip clear of the wall. A similar coping, shown at G and H, consists of a top course of double bullnose bricks placed on edge upon a projecting CQurse of bats (or stretchers similar to E with the intervening space filled as above described).
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BRICK WALLS
Brick-07I-Edge Coping with Tile CrtMing.-One form is shown at J and K. The tile course is known as a creasing and serves to throw the water clear of the wall. The creasing may also consist of two or more tile courses, laid in cement to break joint. A creasing consisting of a double course of slates in cement may be used instead of tiles. Saddh-lxuk C&pin.g (see Land M).-This is effective, it provides a satisfactory finish and may be used in conjunction with either a tile or slate creasing. Brick or terra-cotta saddle-back copings can also be obtained which have throated projections and resemble the stone coping shown at C, Fig. 27. A vertical joint in a coping is a potential weakness, and therefore one of the demerits of brick copings is the comparatively large number of such joints which have to be made. Hence it is advisable to provide a horizontal damp proof course on the top course of the brickwork before the coping is fixed (see p. 17). Whilst a simple brick coping can form an attractive feature of a brick structure and is extensively used, copings of stone are often preferred even for brick erections. Stone copings are illustrated in Fig. 27.
PLINTHS
The projecting feature constructed at the base of a wall is known as a plinth. It gives to a building the appearance of additional stability.
Three forms of simple brick plinths are shown in Fig. 17. Brick-an-End Plinth (see Nand o).-As is implied, this plinth consists of a course of bricks laid on end, projecting about 20 mm and backed with ordinary brickwork. Splayed Plinth (see p and Q).-This comprises two stretching courses of purpose-made splayed or chamfered bricks similar to those shown at R, Fig. 2. If preferred, the top course may consist of headers similar to that at s, Fig. 2. Moulded Plinth.-One of the many moulded types is shown at Rand S, and consists of a simple curve (called a cavettQ mould) and a narrow fiat band known as aJdIet. Stone plinths are detailed in Fig. 25.
TOOLS. CONSTRUCTION. JOINTING AND POINTING
Tools.-The tools in general use by a bricklayer are: trowel, plumb-rule, straight-edge, gauge-rod, line and pins, square, spirit-level, two-foot rule, bolster, dub hammer, brick hammer and chisels. Other tools used for special
purposes inaJude: bevel, scutch, saw, pointing-trowel, frenchman, jointer, pointing-rule and hawk. Trowtl (lee 31, Fig. 19).-COnlilu of a ateel blade and shank into which a wood handle i. fixed; used (or li(ting Ind sp~lding manu on tn I wall, forming joinll ""U .;'.ltt;ng briclu. h i, the chief tool of tho bricklayu. Plumb-,ul~.-A dressed piece of wood, 100 mm by 13 nun by I 400 mm to I 800 mm long, hiving parallel edit'S, holed nur the bottom 10 permit Ili,ht movement of I lead plumb-bob which it luspended by a piece of ... hipcord; Similar to that shown at A, Fig. a8, but with parall~lloni edg~s; us~d for plumbing (obtaining or maintainillf I vertical face) I wall. StMig"t-~dg~.-A piece of wood, about 75 mm by 13 mm by 900 mm long hiving pU1IIIci edges; used for t~ting brickwork (especially It quoins) Ind checking if fac~s of bricks are in alignment. Longer straight-edges are used for I~velling CQncrete, etc. GtnIg~_,od or St"'I)'-rod.-Simililr to the straight_edge but 100 mm by 19 mm by a'7 m long, upon which the CQurses, inchlding the joints, are marked by horizontal lines; courses which conform with the tops and bottoms of window lills, springing points of arches, etc., are also indicated on the gauge; used at quoins in setting out the work and ensuring that the (;OUr$('S are maintained at correct I~\'e l Ind uniform th1ckness. Lin~ and Pi'll (see 33, Fig. 19).-The line (at least 30 m long) is wound round two steel pins: used 10 mlintain the correct alignment of courses. Squar~ (see 26, Fig. '9).-ConsislI of a st~el blade and wood stocle or entirely of "eel; used for setting out nght anglea from the face of a Will (IS required (or openings), testing pcrpends and marking brickt preparatory to cutting. Spirit-It'litl {see 17, Fig. 19).-UseU, in conjunction with the straight-edge, for obtaming horizontal .urfaces. O~-m~tr~ Ru/~ (see I, Fig. 67l..-Used for tlking measurem~nta. BoIJt~, (see 35, Fig. '9).-Made of steel; used (or cutting bricks; the edge of the tool is placed on the brick where requ.ired when a smart blow with the hammer on the end of the steel handle is usually IUfficient to split the brick. CM Ha",mer Or Lump HQlII''''~r.-Similar to thlt shown It a7, Fig. 19, and with the head weighing from I to a kg; used in conjunchon wilh the bolster, chisels, etc:. Brick l1ammer.-Similar to that at K, Fig. 69, but without the claw and with a chiselled end instead of that shown pimi,,# TTO..:el. Similar to that at JI, Fig. 19, but m" .. h ~m.lI"r; used for placing mortar into joints, etc. Frlffltnman.-A discarded table knife the blade of which i. cut to a point which is bent 10 mm at right angl('$ to the blade; used for tuck pointing (see p. 31). Joi"'~r (lee 3:l, Fig. 19).-This hu I steel bllde (50 to 150 mm long), the edge of which is either Rat, groo\'ed, concave or convex rounded; used for jointing and pointing brickwork (s« p. 31 J. PointiJ1i-ruh (see 18, Fig. 19).-A dressed piece of 7S by ~2 rom wood having a bevelled edge with 10 mm thick wood or cork diltlnce pieces fixed on the bevelled sid~; used for jointmg (see p. 31). Han,k or Hand Board.-A 125 mm by 125 mm by 13 mm board having a ao mm diameter stump handle in the centre; used for holding smlll quantities of mortar during pointing operations.
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K.EY DETAIL
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GAR.D£N ENTR.ANCE
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FIGURI! 17
C, :1l-ON-It·"'7
BRICK WALLS
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Construction of a Wall. 1 - The corners or leads arc fir~t built to a height of several courses (sec u, Fig. 2) and the walling between the corners is completed course by cOurse. :\formany the leads should nuL exceed 900 mm in height. Each quo in is set lruly vertic,,) by placing an edge of the plumh_rule against one of the faces, any adjustment of the bricks bein)1 made until the ",,11 is true; the return face is then plumbed. The gauge-md is llsed to ensure that the brick courses arC" correct. Each course is now constructed, aided by the line and pins; Om, of the pins is inseneJ in and near the top of a vertical joint (usually on the return face of the wall) and, after the line has been stretched taU!. the second pin is inserted to bring the line len:l with the top of the course to be built and at ". slight distancc (about 3 mm) from the face. Beforc being laid in position the bricks should have been wettl"d' (particularly in hot wcathcr) to prc'/cnt thcm from absorbing moisture from the mortar. In constructing a ,vall, the bricklayer collccts sufficient mortar On the nnwel and spreads it on the last completed cour.c for scveral bricks ahead (not less than ')00 mm length of bed being recommended). He then prcsses the point of the trowel into the mortar and draws it in zigzag fashion along the centre of the laver to form a level and uniformly thick bed .-\ brick is taken, placed in position, and pressed into the mortar against the last la id brick; ~ s~art tap with the edj.(e of the trowel or the end of the handle may be nccessary to bnng the brtck into Ime. The mortar whIch has been squeezed out beyond the face of the "all is " cut off" by and 'collected on to thc trowel' and returned to the heap of mortar on the bOHd. The cross joint is then formed, a small portion of mortar being taken On the trowel and pressed on the end Or side of thc brick to fonn a vertical joint against "hich the .lext brick is pressed." Plumbing-up" by means of the plumb-rule should be frequently resorted to as new brickwork has a tendency to overhang; the work is corrected and a \'ertical face obtained by tapping the handle of the trowel (or using the brick hummer) against the bricks concerned. Perpends must be !ccepl venical; this is checked as the work proceeds by placing the straight-edge flat on the COurse and slightly projecting beyond the f"ce. The stock of the square is set against the underside of the straight-edge with the blade coinciding with th" last-formed vertical joint ~nd (if the work is satisfactory) with tbat in the Course next but one below. The plumbing of the reveals of openings and the perpends adjoining them should receive special attention. in, the construction of thick walls, mortar is spread on the bed and the outer bricks On both faces are fi,.st laid as described above; th" inner bricks are then pressed and rubbed into position to cause some of the mOnar to rise between the vertical joints, which are finally filled flush with liquid mortar or grout. Hand_mad" bricks, having only ont frog, should be laid with the frogs uppermost to ensUre that. they will be completely filled with mortar. Machine-pressed bricks, having two frogs, should bave the" lower" frogs filled with mortar b"fore b"ing laid in position. Car" mUSt be taken that certain textured or rustic bricks are laid On their proper beds; it is not uneommon to see these laid" upside-down".
I
Jointing and Pointing,- Joints on t!-e face arc usually compressed by one or other of the methods referred to below so as to eliminate pore spaces along which water may pass. The nature of this finish depends upon the type of bricks used and the appearance required. The setting out of buildings is described in Chap. I, Vol. II. • C"rtain smooth-surfaced machin,,-pressed bricks should not be watered, otherwise they are difficult to lay. I The mortar may be left slightly projecting if the surfac" of the wall is to be plastered. • The projecting mortar which has b""n removed is often trowelled on to the end of the brick to fonn the v"rtical joint. When this is the only mortar applied; the joints are inad"quate1y filled lind inferior work results. 1
\Vhen this finish is done in sel:tions as the brickwork proceeds the operation is called jointillg; when it is deferred until afterwards it is known as pointing. The following examples are illustrated at T, Fig. 17. Struck Joint. -This is probably more extensively :lsed than any other. It is a good weather joint as it permits of the ready discharge or water. Its appearance is not entirely satisfactory for every class of work as it exaggerates any inaccuracy of the lower edges of the bricks (owing to the difference in the thickness of the bricks which may exist); its smooth mechanical character detracts from the appearance if adopted for bedding and jointing sand-faced bricks of good texture. It is best used in conjunction with smooth-surfaced machine-pressed hricks of uniform colour. This joint is formed when them~rtar is sufficiently stiff(usually after four stretchers or their equi, alent have been laid) by holding the handle of the trowel below th" bed joint and smoothinj.( the mortar several times in One direction with the blade to an approximate bevel of 60°. The vertical joints are usually fonned by pressing the tip of the trowel down the centre to produce a V-section, or these joints may be flush (sec below). The vertical joints arc first struck, followed by the bed joint.
Overhand Struck Juillt (sec broken line at x) .-It should not be adopted as water collecting on the ledge may pass through the mortar to cause dampness on the inside, or frost action may destroy the upper edges of the bricks, especially if they are not of good quality. Flush or Flat Joint.-As shown, the joint is flush with (in the same plane as) the face of the brickwork. When rubbed, it forms an excellent finish for first class faced work.
,
Mortar i. pressed into the joints during the progress of the work, any dcprhsions arc filled by the addition of mortar, and when this is " semi-stiff" each joint is care. fully rubbed in one direction by a piece of rubber held against the wall. This gives a satisfactory t"xture which agreeably conforms with that of a sand-faced brick. Provided the mortar is of good quality, this joint gives a satisfactory finish to rustic brickwork if it ;5 just left as the mortar is cut off with the trowel, no attempt being made to smooth the surface of the joint. The faidy rough texture of sucb joints gives to rustic brickwork a mOTe satisfactory appearance than smooth struck jomts. The flush joint is also adopted for walls requiring smooth internal faces such as may be required for factories, cellars, coal-houses, garages, etc. Recessed Joinl.-This is very satisfactory for facing work of good textured bricks and good quality mortar. The bricks should be carefully selected of uniform thickness and the bed joints should be at least 10 mm thick. The joint is mad" by applying a jointing tool immediatdy after th" projecting mortar has been cut. This tool may b" similar to the jointer (see 3~, Fig. (9) or the improvised tool shown at v, Fig. '7; the thickness of the rubb"f should <:qual that of the joint. The rubber accommodates itsclf to any irregularities of the brick edges as it is press ed in and worked to and fro until the mortar is removcl. That sbown at v is suitabl" for th" b"d joints, a similar shorter tool being used for the vertical joints. The bricks must be hard and durable, otherwise any water collecting on the ledges may become frozen and cause pieces to flake off.
WALL PLASTERING Keyed Joint.-Such joints give an appearance to the brickwork which is distinctively attractive. It may be fonned with either the convex rounded jointer (s~ above) or the wood jointer shown at W, Fig. '7, which varies in thicknc» with that of the joint. The vertical joints are formed first, followed by the bed joints. The latter are formed by using the jointer in conjunction with the pointing rule (see 18, Fig. 19); the rule is usually held by two men against the wall with the bevelled edge uppermost on the sante level as and parallel to the lower edge of the joint; the jointer, resting upon it, ;s p ......ed into the soft mortar lind passed along seve .... l times in both directions until the required depth is obtained, the surplus mortar falling between the distance pieces of the rulf:. The vertical joints should have a slightly less impression than d·.e bed joints.
Vee-joint (see broken Jines at z).-Its effect is to give the appearance of narrow Joints, especially if the colour of the mortar resembles closely that of the bricks, It is not recommended . The joint is made as described for the keyed joint and with a steel jointer having its lower edge suitably shaped, [7ojecting Joint.-As stated in a footnote on p . 30, the inside faces of walls which are to be plastered (in addition to external surfaces which are to be roughcast) are left with the mortar projecting. This gives a good key for the first coat of plaster, as shown. Another good key is afforded if the joints are raked out to a depth of about 12 mm before the mortar has set. In addition to its fonn, consideration should be given to the colour and texture of the joint. Bricks of various colours and textures are now obtainable, and it is very important that the colour of the mortar should conform with that of the brich. Thus, mortar composed of Hme and yellow sand is very suitable for certain sand_faced bricks. Pointing and Re-Pointing.-It has been stated that pointing is the method of finishing Ihe joints after the whole of the brickwork has been completed. It m~y be applied to a new building just beforecomplehon, or It may be used on existing buildmgs when th~ joints have become defective The first op~ration in pointing is the removal of the mortar for a depth of 12 mm to give an adequate key for the fresh mortar. after which the face is hrushed down with a oa,s broom to remove pieces of mortar and dust and finally well drenched with water. The mat~rial used for refilling the joints may be either lime mortar or cement mortar and the colour should conform with the brickwork (cement can nOw be obtain<'d in a varietv (>f colours for this purpose). . Waterproofed lime and Portland cement mixtures are now extensively used for pointing; the former mixtule may consist of ! part lime to 3 parts sand gauged with a solution of I part waterproof compound to 15 parts water; alternatively a mortar com posed of I part waterproofed c<'ment (contain;,,!: ~ pH C"nt. of the wnt" rproofin" compound) to 3 parts sand can be used. The form of joint to be used for pointing Or re -poimin/{ depends a good deal upon tl:e condition of the brickwork. If the edges of the bricks arc true
Tuck Pointing, as illustrated at T, is occasionally adopted where the jointing materi",l has become defective and the brickwork at the joints has become ragged. Generally it is only used when an alternative flush joint would cause the joints to appear excessively wide; in course of time it becomes defective. Tuck pointing is done in the fo ilowing m~nner: The joints are raked out, brushed and watered as be fo!"e describe d . Co!our"d cement may be used to match th " =IOI.;r
3'
of the existing brickwork and this is trowelled with a flush joint and rubbed as described for flush jointing-a small trowel being used together with a hawk (see p . ~8) to hold the mortar, AS mm or 6 mm wide by 3 mm deep groove is immediately and carefully formed along the centre of each joint. With the aid of the pointingrule and a flat edged jointer (J2, Fig. 19) the groove is filled or" tucked in " (hence the name given to the pointing) with putty lime (lICe p. ~3) to which a small amount of silver sand btu been added. The putty is given a maximum proj~tion of 3 nun and both top and bottom edges are neatly cut off by means of the frenchman (see p. ~8), the bent pointed end of which removes the surplus material as the knife is drawn along the edge of th" rul" . Th" b"d joints ar<: formed lint, in ahout 2'S m I""gths (when two men ar~ working together), followed by the vertical joints.
Bastard Tuck Pointing,- This is an imitation of tuck pointing and is formed entirely of the infilling mortar. The profile of the joint is similar to that of tuck pointing but the band which projects consists of the pointing material. Whilst this does not look so well as th() true tuck pointing, it is more durable, but the projecting mortar is apt to become affected by weather action. Another form of pointed joint which projects is known as a beaded joint. This is indicated by broken lines at Y, Fig. 17. It is formed, in conjunction with the pointing rule, by a jointer having a concave edge. It is liable to be damaged and is not recommended.
PLASTERING TO WALLS INTE'RNAL
PLASTERING
Plastering is a relatively cheap means of providing a durable hygienic surface to walls and ceilings, First-class plastering is done in three layers, i,e, ;-render coat (10 mm) (known also as a pricking coat), floating coat (6 mm), and setting coat (3 mm), to give a total thickness of 19 mm. Now, for much general building work, the render coat is omitted, the floating coat is made thicker and the overalJ thickness is 16 mm; this is sufficient for all but very rough walls. Formerly, lime pluster was the bas'.c material for this purpose, mixed with sand and, more latterly, ceITjent, for cer~ain layers; the constituents are measured by ·,-o!um;:. Thus for walls, a tipi;::a! sp""cification for the first coatI used to be (and still is, in some are<'ls)! cement; I lime putty: 3 sand, incorporating 0'535 kg of c!~:m ox hair ;1(:' 0'1 m 3 of this COM. " -.;;ff; for the second coat, I lime putty ; 2 sand; with ncat lime putty for the final coat. The lime used was the '101I-hydrau[j(2 or fallime prepared in a pit on the site one month before use by 1 An alternative undercoat s t,H chosen in SOme places is black-pan mortar obtained by grindmg down 3sh~s In a pug_mill and addmg lime. • A second typc of lime is magnesian lime som~imcs used for plastering and mortar mixes. . A third is hydraulic iimt' which can set under water (unlike the non-hydraulic type). It was Once used for concrete mixes before the introduclIon of Portland cement; it is stlll uscd for mortars.
BRICK WALLS
32
mixing qvidtUme (CaO). obtained by burning limestone in a kiln, with water to {ann liIIU pt4ty. The latter process is known as sl41tmt or hydratitm and the putty haa the formula Ca(OH)I' Such mixes containing lime and cement shrink on drying out, hence each coat was allowed to shrink before further coats were added. This lengthy procedure delayed completion of the work and lime pinte~ have been replaced almost entirely by calcilDft nIlplulte or gypnnn pJtUt~sl for th~ have the following comparative advantages: set within a few hours, produce a harder finish. expand slightly on setting and. finally, they enable decoration to proceed at an earlier date. Lime is stilJ used in two ~ays because it improves workability, making plastering easier, and in some cases accelerating the set of gypsum plasters (sec below), viz.: (I) to gauge gypsum mixes [see (c) below), and (2) in lime mixes gauged with gypsum plaster [see (b) below]. For these purposes, hydrated lime, obtainable as a powder requiring mixing with water only 24 hours before use is ofter,.a more convenient form of lime putty than that obtained from quicklime on the site. The addition of lime reduces hardness and in final coats decoration b); oil paints cannot proceed until the wall has dried out; this may take from 6 to 12 months. Distempered finishes are unaffected. Calcium Sulphate Plasters.2-These are in two groups subdivided into t'tI'ur classes A, B, C and D, in B.S. Il91. Gypsum (CaSO,.2H 2 0) is the raw material for the first group (classes A and B); it is mined in this country and several parts of the world. When gypsum is heated, water is expelled and a white, grey or pink powder is obtained. This is class A plaster and is known as Plaster of Paris (CaSOdH,O). When mixed with water it sets within a few minutes, so it is unsuitable for general plasterwork but it may be used for patching. An additive (a retarder) must be incorporated with it to delay the set and so produce class B plasters (retarded hemi-hydrate gypsum plasurs) which are softer than the two remaining classes. The second group, classes C and D, are based on chemically produced anhydrous calcium sulphate (CaSO,) obtained as a by-product or by heating the gypsum to a higher temperature than for group one. These classes are slow in hardening and so the additive is an accelerator to make them suitable for plastering. (a) Plalter of Paris-class A.-A neat mix of this or one gauged with lime (i.e. 1 to 1 plaster: I lime) can be used for repair work in small patches. (b) Retarded hemi-hydrate gyp~m plaster-class B,~ is ct:Iadc in three main 1
t
kn~'n as" hardwal1 plaster." An additiOn to this range is Perlite platter (e.g. Murilite) in four grades: (I) liS all
Commonly, but inadvisably, also
undercoat on brickwork. (2) on metal lathing, (J) onltoncrete and plasterboards and (4) as a finishin(/: COat. It docs not need the addition of an,aggregate such as sand for it is lupplied ready for use incorporating expanded per-lift (Q very light mineral of volcanic o rigin ) Bnd I(ypsum plastEr. The pmduct is therefore read), for use on water being added, it i, one-third the weight of, and has better insulating qua}itie.; than, ordlOHry sanded
mixes. , I E.,. Clrrisle, Gothite, Thistle.
-
types :-undercoat, finishing and dual-purpoee; it Ihould be made in small batches. For undercoat work (known also as browning) the normal proportions are 1 plaster: 3 sand for brick walla and 1 : Ii for concrete surfaces. Hair is sometimes added to the mix on backgrounds such as metal lathing to reinforce it especially whilst it is setting. This class is also used to gauge traditional I lime: 3 sand batch mixes where one part of plaster is added to about nine batches of the coarse stuff. Lime hastens the set, Class B finishing coats are used neat on strong backing coats of plaster and sand, and on those of cement and sand. An alternative finishing coat is i to i plaster: 1 lime, but this is a lime mix gauged with plaster and has a softer finish. A special finishing type (without lime) gives the best surface on plasterboards and fibre boards. The dual-purpose grade can be used for both under and finishing coats except for one coat work on plasterboard or fibreboard. (c) Anhydrouf gypsum plaster-class C.l_ This is also made in the same three types as above; due to the slower setting time these can be worked longer. For undercoats a 2 plaster: 1 lime: 5 sand mix is suitable. Finishing coats can be applied neat or have a small amount of lime added to aid plasticity. The dual-purpose type is used for both coats. This class is unsuitable for finishes to plasterboards and fibreboards as it has insufficient adhesion. (d) Keene's or Porion Plaster-doss D.~This is made in the same three types but is generally designed for use as finishing coais. As they provide a hard surface, they are much used for external angles, often on a cement and sand backing (see p. 107). Like (c) above it is not usually suitable for a board finish and lime slwuld not be added to finiyhi"g coats. General.-The mixing water must be clean and free from impurities. The sand should be clean and well graded; rounded particles are preferred to the harsher kinds and a clay and silt content, up to a maximum of 5%, aids workability. Plaster should be stored in a dry place. Cement should not be mixed with gypsum plasters. Strong layers of plaster should not be laid over weaker ones. Class n plaster can be allowed to dry out immediately after application, but classes C and D require up to 48 hours for adequate hydration and so should not' be permittcd to dry out during this period . All classes should be.applied before they start to stiffen and re-tempering after the commencement of the initial set must not be allowed . Tools and the mixing boards (spot boards) must be thoroughly cleaned after each batch has been used because portions of old plaster left on the boards will accelerate the set of the 1 E.g. Sirnpite, Statite, Xdite. • E.g. Keene's, Parian, Supavlte. Olten tenned Keeoe', ummt.
, ,
WALL PLASTERING The intermixing of different classes is inadvisable. Gypsum plaeten cannot be ueed in damp situations and lime or preferably cement plasten are better in such places. Plastering with the latter mixes must be given time to dry out and shrink after each coat; this lengthy waiting time is eliminated with gypsum plasters. Due regard must be paid to the nature of the background and an appropriate mix selei;ted as described above; gypsum mixes are best for concrete walls. For brickwork I cement: ~ lime: 9 sand, and I class B plaster: I t to 3 sand aceording to the porosity of the bricks are suitable (the denser the bricks, the Mronger the (llix) for undercoats. Walls lined with fibreboard, plasterboard, metal lathing and wood wool should be treated as for ceilings-see pp. 6]-68. Brick walls must have their joints raked out 10 nun or keyed bricks can be used. Smooth concrete surfaces must he roughened by (1) hacking, or (2) the application of a thin I cement: 2 sand splatterdash coating, or more easily (3) by applying a retarder to the formwork which prevents the setting of the outer skin of concrete enabling this to be wire brushed and roughened. These provisions are vital in ensuring adequate adhesion be-tween the background and the undercoat; similarly, render and floating coats musl l>c scnu:hed whilst they arc setting to give a good key for later coats. Excessive draughts must be prevented whilst the set is taking place, the drying out should be allowed to proceed naturally, traffic on floors having a plastered ceiling should not he allowed u:1til the set has been completed . The cracking of plaster frequently ocrurs where there is a change of background, as for example, between the walls of a house and the ceiling. This can be prevented by having a cornice or by making a horizontal cut with the trowel at the junction. The plastering of ceilings is described on pp. 67-68.
next mix.
Plastering Technique.-Door and window frames, skirting plugs and similar joinery work- known as fi.~st fixing- having been ccmplet"d, thc surfaces to be plastned are prepared as deSCribed above lind cleaned. W~ lllurfaces are don" first and those that are very porous are dampened if necessary. Assuming that three-coat work is bcing used, the render coat is mixed and applied evenly by a plasterer's trowel; this is made reaSOn_ ably true by a twa.-handed trowel about 1 to 2", long known as a Derby jfMt . If metal or timber angJc beads (see pp. 122-123) are used instead of Keene's cement (see pp. 32 and 107) at the angle., they are fixed before the render coat. Bdore the undercoat has hardened, the surface is well scratched to give a key for the next layer. ScrudJ or 1So mm wide strips of floating coat are then formed vertically at ,·8 to 3 m interval., they are made plumb and in exact alignment. Intermediate screttB are than made about 1 IT\, apart and the ap""e8 between lOre filled ~nd. levelled "~hpf'rlre . The surface is al:uln rou~hcncd, the setting coat applied, and this is polished ....·ith the steel trowel just before it sets; overtrowelling is dcpn:cated at it can cau.e cra'l;lng (fine hair cracks). The technIque IS similar for t ....·o-coat work. Cement andOT lime undercoats must be allowed to dry bcfon: further COOts are added and unlike gypsum mixes, the surfaces must nlSt be spnnkJcd with wOler. Skirtings, architraves and other co'·er moulds should not be fastened~kno"n as Itcllnd fixillg~until the plastering has set. PLASTERll'OO FAILURES.-P(lppjn.f, pillillg and blouillg caused by unsound lime and thnt which has not been slaked properly. The unslaked partides expand to leave small holes in the plaater.
33
Poor adhesion etused by rngh suction of the backing, too ... pid drying out or by moisture being imprisoned in the wall which subtequently emer~ through the plaster in the fonn of blisters. Due also to inadequate key -.nd incorrect choice of plaster. Crqcking due to shrinkage on drying out, it is associated with cement or lime m.ixeIJ. Movement of the background is also respomible, as for e)[llmple the drying out or timber ceiling joists. Caused also by using $8nclt cootaining more than S per cent &ilt and clay. Failure to provide dillContinuity ($CC pre<:eding column) where the background changes i$ another reason. Ceiling Collapse. Wood lath and plaster ceilings are rarely used now, they collaple (as will metal lathed ceilings) if the key i, inadequate or if they are vibrated by traffic before they have set. Ceilings on concrete surfaces must be given a good me<:hanietl key (see preceding column).
EXTERNAL
PLASTERING
OR RENDERING
Rendered walls are an alternative finish to facing bricks, they can be made in different colours and are used in places where clay bricks would be out of harmony with the surrounding landscape or where the only local brick is a con~ crete one of dull appearance. Rendering is used extensively as a waterproof finish to no-fines concrete walls, such walls are made from 300 mm thickness and upwards and consist of 1 part cement: 8 parts of large aggregate (13 mm); sand is not included in the mix and a sound ""ell-insulated wall results because of the air voids. Gypsum plaster mixes arc quite unsuitable for external rendering; much traditional work still exists and Ihis is made of lime mixes protccted by paint. Cement: lime: sand mixes are now adopted and the proportions of these three materials is again dependent on the nature of the background and also upon the dcgree of exposure. A good key must always be provided, the bricks must be well fired and durable and the joints raked out 13 mm; surfaces should be dampened if they are too dry before plastering starls and strong finishing coats must not be applied over weaker undercoats. Of the many types of rendered finishes, the following arc popular : scraped finish, roughcast (wet-dash), pebble dash (dry-dash) and machine finishes. Smooth well-trowelled surfaces should be avoided as they tend to "craze" (see prcceeding column), if cracks develop they are very obvious. The range of cement: lime: sand mixes given below varies in strength in order to suit the degree of exposure; two types of background are considercd: viz., (a) strong, as given by dense bricks and concrete, and (b) moderately wcak as with lightweight concrete, etc. Scraped Finish.-l : I: 6 to I: 2: 9 on (a) and (b) backgrounds for both undercoats and finishing coats, the top 1·5 mm of the latter is scraped oft Just as it begins to harden. This removes the top fatty skin which tends to develop during the application of the wood trowel which should always be used in preference to the steel trowel. Roughcast Finish_-I : 0 : 3 to I !: 6 for (a), with t : I : 6 for (b) as both undercoats and the second coat. Whilst the latter is still soft, a mix of the same proportions but includi:lg 60% of 6 mm gravel in the aggregate is thrown on to the
BRICK WALLS
34
wall to give the wet-dash finish. This is more durable than the next finish described. Pebble~dash Finish.-The mix and procedure is the same as for roughcasting except that the thrown-on coat consists of dry pebbles or crushed gravel only; the pebbles tcnd to drop off in time. Machine-made Finish (Tyrolean).-The undercoat procedure is the same as for the scraped finish. The final coat is thrown on by the blades of a small hand machinc, alternatively it can be sprayed on by a hose delivering the mix by air pressure. THERMAL INSULATION OF WALLS I. The subject of thermal insulation is described fully in Chap. lZ, Vol. 4. The Building Regulations give approved specifications for Ihe thermal insulation of walls; there are four main types: I. Cavity walls with insulation material applied to either side of the inner leaf. For example a two leaf brick \\:all, each leaf at least 100 mm thick enclosing
a So mm minimum width cavity with 10 mm thick expanded polystyrene insulating board stuck to the inner face of the inner leaf. The board is in 1800 and 2400 mm lengths, 600 and 1200 mm widths and 10,25,38 and So mm thicknesses. The joints \0 the board arc covered with scrim cloth (p. 68) and the face of the board plastered. 2. Cavity walls with a brick outer leaf and an inner leaf 108 mm thick made of lightweight concrete blocks of density not exceeding 800 kgJm 3 . Note that the usual block thickness a\'ailable is 100 mm and is made to satisfy the Regulations. This type of construction is the most usual being cheaper than type I above. 3. Cavity walls with the cavity filled with urea formaldehyde foam. Holes are bored in the wall and the foam injected. This method has been u'scd widely but failures have occurred due to water penetration. 4. Solid walls of lightweight concrete block rendered externally and plastered internatiy, the block being 240 mm thick made of concrete of density not exceeding 1000 kgJm 3 . Thermal insulation of roofs is described on p. 141.
, CHAPTER TWO
MASONRY WALLS Syllabus-Classification of stones and brief description of tne quarrying, preparation and characteristics of limestone and sandstones. Surface finishes. Tools. Natural bed. Defects in stone. Classes of walling, including ranuom rubble unrouned, random rubble built to courses, squared rubble uncoursed, squared rubble built to ;;:OU1$e8, regular coursed squared rubble, polygonal, Ilint, Lake District and ashlar. Dressings to door and window openings, including inbands, outbands, linlch, arches, sills, mullions, transomes, and step~. Plinths. Simple string courses, friezes, cornices, parapets and copings. Joints, dowels, cramps ' and plugs. Mortar jointing. Construction of wal!s. Liftin g appliances.
art of construction io stone is called masonry.l BS 53<)0: Code IJf PrJuin' (ur Stone :\la~onry i:; rdevant.
THE
CLASSIFICATION OF STONES Rocks are divided into the following groups: (I) igneous, (2) sedimentary and (3) metamorphic. (I) Igneous rocks have been formed by the agency of heat, the molten material subsequently becoming solidified. The chief building stone in this class is granite. (2) Sedimentary rocks are those that have been formed chiefly through the agency of water. Most of them have been derived from the breaking up of igneous rocks, the particles, conveyed and deposited by streams, accumulated to form thick strata that have been hardened by pressure. The principal building stones in this group are limestones and sandstones. (3) Metamorphic rocks forrn a group which embraces eithcr igneous or sedimentary rocks which have been changed from their original form (metamorphosed) by either pressure, or heat, or both. Slates (sec Chapter V) and marbles come under this class. Limestones and sandstones are those which are used chiefly for general building purposes. Limestones.-A limestone consists of particles of carbonate of lime cemented together by a similar material . Portland stone and Bath stone are in this class. Portland Stone , obtained from the I sle of Portland (Dorset), is one of the best-known limestone~, and stone from one of the beds or seams, known as Whitbed (sec Fig. 18), is one of the best building stones used in this country for high-class work. Whitbed varies in colour from white to light brown, the latter being the best; it is durable, and, on account of its fine grain, is easily I
More advanced masonry is described in Vol •. II and IV.
carved and moulded. The Basebtd~ is not so durable and should only be used for external purposes after careful selection. The Roach bed is not suitable for general building purposes on account of the large number of cavities which are present, but because of its great strength and good weathering properties it is used in the construction of sea walls and similar marine work. Bath Stone, obtainable in the vicinity of Bath, is used for general building purposes. It varies in colour from white to light cream or yellow, it has a fine grain and, because of its relative sGftness, it can be easily worked. Sandstones.- These are composed of consolidated sand and consist chiefly of grains of quartz (silica) united by a cementing material. The quartz grains are practically indestructible, and the quality of the stone therefore depends essentially upon the cementing material which may be silica (forming siliceous sandstones), oxides of iron (forming ferruginous sandstones), calcium carbonate (forming calcareous sandstones), etc. Many excellent building sandstones arc quarried in Derbyshire, Lancashire and Yorkshire. Stancliffe stone (Darley Dale, Derbyshire) is light brown or honey coloured, is very strong and durable, and , although relatively difficult to work on account of its hardness, it, can be moulded to give fine arrises. Woolton (L ancashire) stone is used in the construction of the Liverpool Anglican Cathedral. Some of the Yorkshire stones arc exceedingly hard (especially those from the Bradford and H uddersficld districts) and arc suitable for steps, landings, flags, as well as for general walling wherc fine mouldings are not required. QUARR Y ING
The methods adopted in quarrying stone vat)' and depend upon the type and its depth below the surface. Most stone is obtained from open quarries, but where it is very deep (such as Bath stone) underground mining is used. 1 The basebed is slightly whiter and the texture is ~omewhat fineT than the whitbed; it is easily worked on account of its fine and even grain, and is suitable for internal work as for monuments and for purposes where carving or much fine detail is required.
MASONRY WALLS Fig. l8 thOWI a section through the face of an open limestone (Ponland) quarry. As much as pou,ible of the overburden (which varies from a few f«lto 15 m Ihick) i, removed by mechanical HalVator,1 hand picking and cnnn. The top Ind dtull caps arc loosened by blasting. After the roach bed hi! betn cleared, the stone il removed from each stratum. This
operation is facilitated by the presence of natural vertical jointB and horizontal beds of wells which aepanle the layers of stone. Commencing from one of the right~angled vertiCIII joints, a number of strong metal wedges (see c, Fig. 19) are inserted at intervals alool;l: • llhell bed and gradually hammered in until the atone is split horizontally and the slab bec;:omH detached; if necclSaJ')', it i. divided vertically by wedging (see e, Fig. 19). Each block is now lifted clear of the stratum by means of a crane, roughly squared up by the use of a SKnCH large hammer and loaded into a truck for transit to the worb for final drcssing. Blauing is sometimcs n«
""""..0
'"
PREPARATION
Whereat fonnerly the whole of Ihe IMbours involv.-d in dreuing building Slone. after removal from the quarry \\ere done by hand, by the" banker mason," mOSI of this work is now executed by machinery. There are certain surfau firiishtt which can only be worked by hand; these are described below. Machine Dre5liing.-Themachines used include the frame saw, circular saw, ruhbing bed, and pillning and moulding machines; some of these are shown in Fig. 36, Vol. II. The rough block of Slone from the quarry is fint taken to theframt ww \\hieh oon"erts it into. number of slsb. such as are shown al A, Fig. 19, the thickness of the slahs Yllryinll in '""cowsn.... 'With rH\Uif.-ments. I Eanh ffiO'.'ing machinery is described in Chap. I, Vol, IV.
The frame saw is the best machine for cutting hard stone. The speed of cutting depends upon the number of cuts and the hardnen of the stone. Hard lI3ndlione may be cut at Ihe rate of 150 mm (thickness) per hour and Ponland s:one may be cut at the rale of 300 mm per hour. • The frame saw has a rectangular horizontal frame, suspended by roos, which holds several (sometimes six) plain or corrugated steel blades, each blade being from 7S to I So rom deep, 5 mm thick, and from 2 to 4'5 m long. These blades are parallel to and at adjust_ able di.rances from each other. Ekctric or other power is iupplied to give the frame a $hort backward and tOni ard motion at a rate of from I So to 180 .trokes per minute . During this procets, water is supplicd Immediately over the euts. At the same time an abrasive sgent such IS sharp sand, chilled shot (small llcel balls) or carborundum is applied along the length of the cut 10 assist the cutting action. Sand should be the abrasive used for Ihe sawing of Portland stone as steel shot tends to discolour the stone on account of rust. The (rame is raised after Ihe sawing operation has been completed, the lable is pushed clear of the frame, and Ihe slabs are unload.-d and taken to another machine for the next dressing operation. Assuming that these slabs of stone ne reqUIred for genelal walling, each is now conveyed to the circular taw for the cuttinll of the remaining fates. There are two types of this machine, i.e., the diamond saw and the carborundum sm". The diamond JQfI!.-This consists of a circular st.... 1 blade, one size being 1'5 m in diameter and 6 mm thick. :Some 240 diamonds Ire secured In small U·shape.d sockets round the edge of the hlade. The slab of slant: is clamped on to a moving table which is caused to travel toward» thc billde at a unifonn rate; at the same lime the blade rotates at a speed which , ... ries from 500 10 600 revs. per min. The CUlling rate of the machin e depends upon its po"er and the hardness of the stone. Thus a IS kw machine \\111 cut from 645 to 1000 ern' of Portland stone per minute. Whilst this rale is consider~bly faSler than th~t of the frame ~W, the circular saw .:-an only deal cffectively with stuncs which are leu than I m thick. Only limestones or soft Mlndatones should be cut by mcans of the diamond saw, hard s~ndstones CaUse >In cxcessive we~rjng action on the sockets and blade. The carborurldllm sau'.--This has a So mm "ide continuoU!i rim of carborundum" hich is dovetailed round the periphery of the steel blade. Its cutting rate is half that of th e diamond sa"'. It is preferred to the diamond saw on accoullt of the more accurate "ork which it produces, and it is therefore very suitable for thc jointin;! (forming Ihe ends) of cornices and similar stones which have been moulded. Cuts as fine as 6 mm are obtllinable. Water il supplIed during Ihe cutting opcralion in order to cool the blade of each of thc above two circular sa", Some circular ~ws ha"e two blades. Another lypc consists of a bladc which traver~es the fixed Stone as it rotates, and it is therefore particularly useful for cutting long ston es. The "bow oper~tiom ~rc usuallY:l1I thHt arc neccss~ry for the cutting and dressinR of stones for walling, but It is sometimes requircd to have the surface oi eHch stone which will be expost'd when fi1>ed, rubbed SO as to remo,'e the machine marks. ThIS is aCCOm. plished on a machine eall.-d a robbin;! INd. This consists of B steel circular table, about 3 m In diameter, which rotatc~. The stone is pluccd on the bed, clamped from above, and as the table rotale~, thc abrasi'e action of carboru ndum, sand and water ehminHtes the machine marks. Cornices, string courses, plioths, etc., arc moulded by m ~ant of pion;,,/! ami mOlllding ma£hines. After the moulding op.muions ha"e been complded IS described below, the stone 15 jointed into the required lengths by the carborundum saw as explaioed abo,·c. Inters«tion. of moulding' ore usually "orked by hand, th e m~xjmum length of mouldingll being machined "0 as to reduce the hAnd labour 10 a minimum. A simple type of planing and mauldin,1/:" machinc consisu,.,f a cutting tool of cast steel suspended from a box al an angle of about 4-5 &. Cutting tool. Art of varioul s hapes and sizes and their C1Jtting edges Ire shaped the n:verse of the desired moulds. One end of the stone is first hand-moulded to Ihe required'section. The 1001 traverses Ihe stone backwards Ind forwards until il conform. WIth the section cut al the end. In another type of planer the stone i. fixed to I moving tabl .. below. fixcd tool.
37
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, MASONRY WALLS In both of thf>W ~.~ •• flu tach Irlnt'rlt', th., box I1,Jlnmatically~" onJ,'a o~'t'r to bTln~ thc !vOl In the corr('Ct poslliul\ for Ihc.' return. Anolh",r type of machin~ has four cuthnl( tonl~ and I~ therdnrr P:'ThCul... ]v clfe(:lI\c for I.rgc cornlcr\!. Thtr", i, .1$0 a mouldillR ~ppar.llu~ kn')\\ 10 as Ihf 1>"~U7f"llu D,,"'tIJ! w.d C(l"-"'~ Pltlllf. Th .. cunsi~l~ "r an wir cOmrrCa.5()T "hleh ('l"'r3It'1; 1<>01501 '-"nuus 5hapt"S and SIZt'. cal1 ....1 pneumatic hammt'r!< The tinesl earn nil, n~ I' ("]1 a. 11ll" h"anl'sl dre~'m/!. can bl' ('x!:Cutcu by IM~ tonI •. Ha n d Oreliliing.-In the abst'flcc of madlllwry, th.: follol' mil Dre certain of thc opt'ralion. \lhLeh are performed by han,j;Spill/I"!!, ~IOp'''Il. Wcdll/ll/( Or ('v/)fftl.:.-.\ l"r/oi'~ block ,,( $\0"<; is split mlO smaller urlll~ U sho,," at II, hR. IC). S,ra,!:ht 1111<"5 "f<- marknl on Ill." .. ul Inl;' faces ;llon~ "Illen a narrm, J:rOO\l' IS eh,,..,l1l;'d by mto~II~ of Inl;' punl;'h (u, !-o),l. Il)} <)"·. a ,t,·,·1 har Il placed uIIJcr Ih(' ,I<,ne In Ihe ""llIc pl.. n~ ~. Ih("" ..:roo"· .• " ....·1 '''uc,·. '" II"U, "r ,,,:dll"1 and f('uth('rl ~rc plae.·J in Ihe hok6. anJ Ihc "I;'U~l'l ~rc IIr".!u"lI\" ,,,,.I ullilurrnly h~mmu ...1 in unlll th" MOlle Iplll~. J.~rl!e blocks of han.! """dstone .11,· d",ul'<.l at the 'Iuarry a~ dc.enho.·u hut th,' "ork I~ e);pnliled by u"mll a plleum~lIe dnll10 f"'llI 100 to 'SO mm d,"'p h"ln tu renll,· Ihe "oo.l!el. S'IIJpp,"I!.- Th" I~ udopted for 5pllllmll n'.nl ,Ionts" b,eh an' "I>oul ,~o I\,m Ih,~k 10 ~ph"inJ! II block of .Ione, a ~rOOH' 1$ forml'u on all lour "Uel and m Ih" unlf."" phln~. Thc p,tehm)l 1001 (I. Fi)l. 19) " held "'r!leall~' ~IId hITuck smorlly "S;I " IIloved 1I10nl; .he groou, on eIIch f ..ce. A P""CC of"il5le Slone 'I pl"cl'd unu('r the block ~nd ~ fl''' blo"1 01 a ht."\l'Y bammtr on the blll'r ,"h,en ,s prol«ud h,- a p,«e of"ootl) ",II lx' ~ufl,cl(.·nllo InaI' Ih .. Btone. Ah('m"III"Cly, a eon"ouou~ mck ,. formtod "crou the top 3nd I,,'th s,de_, the block I. turned mer on 10 a Imall stone "nd '1'111 "lIh a sman bIOI, from ~ h";I\")' . harnm('r. HDtn or 11rn1131 stone •• M.t dl\"ld .. d inlO unliS by sa"lnjollmmt:"h,lIel<' ..ftcr 'I hal 00'" quarTled, III" Ihen conta'n mOIsture (qua,..y .IIp) "hien r.. nders II eompara"Hh' 50fl For",;", a TrrJr FlIu.-A tru .. face il ,\orknl 00 tne Slime 3. (.,110", 'InU u .hu"n 31 0, FiJE. '9. 'The marg,n
Qu.tTY DTe5aiq.--5lone quarned 10 mllny dlltr;CU i. ".lIed III 111 rou-JEh lIate. In certa,n qUlTnea lhe IIO!"lt liea in Inin bedl and 'phllin" i•• !llh.t may be neceuary
10 iii th, 1>1",,,-,, IIIr \\.,11"'11 "" "nllUnl III Ih ....r ""lUI.,] ~n"",\h f~cea lind fluln ... s~ of heu. ~u.,h '·"lh·I'."·,·,I.~",,, i. l' ~n a ~ u lj-j'lfrJ ,11\,1 h." 1.....-0 used '-\Iens; .... "· ,n Ihl' eon~Irun"'n "I 100111'<-'"•• ('th~'r a'n '" '" ,,- ""IU'''''' "" II "m"unt ,r' bho'Jr, .uch 35/"""'''l'r,Irnl'.! ,,,,,..I """,:11,-(", lilll~h.,~. II,m,"' .... ·,/rO'fll'd- \1". k"""" ,,_ I""""" ••jmr./. <{,,,,,'y-f,ut.l. qlldrry·pih}"d and rmlrr-i",,·,I. lIs "pp,·.Ir;.".·,· ...,me"h.,t "'''''",1>1..,. th~1 ~ho"" ~I 1_. I'",. "). The f~el' I, roullht<· ~h.,p,·,1 hy 111I"Ul~ 01 Ihe m",h h~ml11.-r 1~7. I·,jo!, I'll UM'U III 'CIl1'-""e Ih,' 1"TJ!Cf r"'M-u !'on",,,. "f ,1"Il" and ,h"p,'" 'i"t", h\,,,J.,. M,· ."ml"lIllWI 5\jU:lrcJ, th .. ht...!~ ;lnd J"'!1\i 1x-"1.!! .Ir<·~", U h~ck IIOn1l' 7~ ur 100"lm h"m tI,,- 1,,'(" ( ....,. PI.I" il1 I·'I!. 22), T'hh l~ 0.1"",. lor u,,"~ th,' "1\1,"" to m;l,l 110,' h"uI1J"n,·~ .",,1 " "k"'l: II,,· pllchm1l tool Jlonll' Ih,·",. 'rhi~ ... ,,,':>Iu Ih<' SlOl1", til h,' tiul'u !\lon' 0:1, ..... [,- I(>~(-th~r tu \:1\'t' r('''100113hl<' um(,m1l Ih,ck }" I,'rlle' hlt..-k. ~rc- ojlll\;1\ TI}!ht ""l:k~ tu til<' ";olur,,II ... J (".,. 1' . .1'.' ,1\111 . ",•• II,·r 1.),,,-,,", .lIld II '5 11;" ,pIli ~urLlC"e "h'eh I'r"\ld~. the t..",., Ih,· ,I".:htl< un,'"',, t"~lu,,' 11<"11.),1 \~r'" dl...-m. TIle.., '"":111 bIOl·k, are <\u,ekh' ~\ju"r ...1 ],,- ,'1'I'h-1Il1: tI,,· """h 10",11111"1 ..tlln/! Ill!' ",h:,". f"l1"""d h)' II.... punch ElahOrate Dressing. -Th,· 1,,11"'''''11 "n' r.ofllt "I Ib,· f",,~IIt·s \lb,eh Jre \\ork(·J b\" h.,nt! ,,\1 ·.!u.,rN _I'" . 5: It.'a_' .... ] pu"e~'·J_ r,,·k.·. 1,,,,I ... t!. furr<»H·d. rock.t:ceJ. ,e"bbl ... t. c,,,,,h.,,\. H'I\",cubt.~1 .,nt! a'l,eul~tnl H'~II'I'OdIoter (~) Ill" lonl1'oj;! a wril" of _Iii 10 ~o mm ",0.1,' h"n.l~ "I' nh',,· ,,' I".~ p,'r:111d 1..,,1 ,,,,"k.,, hId; e,,\'~r th ... "h"le ~urf~ee. '/'h,· ••· ",ark- m.,}" h,." ('lIhn h"r"."",~II>l·'· Z), \.-rI,t,,1 (3) or ~I "'1 nn.lllt" Of.H lofl a~ rnIUlH'd, .Intl '11 '*I~'\1jo1lh"l\l tb,' ht,.I~I"r ,. m ..,,·.1 III Ihe u""elloll flf Ih.· h~nt! UI c~ch ~IT<'C,f.. Ihc numIK-r of hn", rer 2 ~ mm Ih~ num1>.,r ,.'''-'''!! irhm l'i to 10, d,'p"n,llnlf ul'"n th .. h~rdneu uf th .. ,1"111' .100.1 Ihe d"o.:ln of lin~n" .. re\julln!. Thh " ~ common Jrl'S~IO),I f, III t,ooled "ork thc 1m.,. ,IT~ d...,per .mt! .ire comllIU<)U<. FIIl,,,,,,-J ,., FI'II,·d(~.·c Q. 1"Il. I<)}.- The ~url~..,.· is fir" boast.,d ;tIlt! th .. n rubheu (5"" p, .110\; i> to 10 mill ",d~ flul.., (se.· ~el'on ,\) H(" th .. n r~rcfull .. forml't! b\'. 1I:0UII:e (1.l1 ,·"h.. r, "r\lc"ll,' ('of) \.Ir h"ri2<>11I.,II<·, I ~l. I.rn,·s 5h('1\\ "'1: the ~rn!loh of the flutu ~r~ ho;zhtl,' M:""'d ~nd Ih.·,c Serl(' '" ~ ~u1tl~ 10 tlie m,l.on a~ he "orh Ihe ~(lUQ~ along each. This fin,sh .. I(>ml'l"l\~~ appl"..d I" Ihe hlkls or 11;.1 h~nlh 01 cornices, .tri"ll eourSt", uoor ~od \\",do" arehnn'''', ele. Nocic-faud, Rl1SlIra'nl '" 1'lfd,-/"u,1 (SC'<" R. h.l! I'}), \flu tn(" mar~",~1 dr~ft. hne IK-en "orked (1« abo,r), thl' Pllchmlt 1001 i. uscd \0 r~mo"~ een .. ,o of th,' supcrtluous Itone 'n Ihec("nlre "h,eh ,s left r;,,~ ..d or roulln to Imll.lt ......",k-hkl' surf"..,., It'" boltier Ihan hammer-dressed "ork .",0.1 's \Omel;m(", appl"'d I" plonlhs to ),I,,-e a ICmbl~nee of '''enRth and 5OIId,ty. S(tlbbl,d Or Smp"hJ.-ThIS " SImilar to Ibe lattl"t, Ihe sc3hblllll! or !\Cappllllil: h~mn"'l (Ihu\\ n by brokl'n 1111" al 2Q) belnl<: used 10 r.. mo'·e ">I11e of the orr"llul.ntICi. D,tlKlftd or Combrd.· Th'I fimsh IS 1I"" .. n to soft l,me51~n('., such h Uath alone, by tI\l" 'pplicallon of drap (all. Thl'K drill' arc .Ieel pidtCll (lbout 1'S mm thIck) hning Krrated WI",.nd IBded Into" ~oallC," " sccond ...nd " nne," Mccordlllg to Ihe number
J
DEFECTS-MASONRY of teeth per:lS mm. After the surface: of the stone has brt-n brought 10 the requIred Ic'-cl by means of the dummy (the: head of which is mad" of zinc or PC'" let and is shown at z~) and :oafl stone dusel (19), thc ants., drag IS dragged backwards and forwards In d,ffucnl directions acron the surface until thc 1001 mnks have been eliminated; tillS is followed by the IIKOnd drag and finany b, thc fine drag until all 5(:ratchc$ hdV", disappeared. Vnmic"IDttd (see s, Fig. 19).-Thc face is brought 10 .. 1c'-cl ;md smooth fmi.h. Marginal draftl are lunk at least 10 mm below Ihc surface, wh .." slnklngs aTC then \\orkNl 10 a depth equal to that of thc drafts (see Sl'CtLon L'L') so as 10 fonn II ,\lndmll snake-like (t:tTlmnous) rid~ ",hieh is oftcn continuous (as shown m T) and "hlch h~s to be can-LoU by meanl or l{Ouges (I). R~IIClllattd (see v, FiR. 19).-Thil is SImIlar 10 '·ermleulUled. e)(eepllng that the ridge. or veins are 11'$5 wonding ~nd arc lonked up 10 fonn" network of ITregulady lih~ped sinkingll, or r,ticlIl,J; the bottom of th""e hullows IS sometImes SP~Trow-plckcd (see p. )8) wIth a fine pomt (9) as sho"n lit ,'. Neither vennicullltr-d nor retlculated ruslieated dressings lire applIed much tu modun work, probably on account of theIr ("xpe""e, but they arc occasionally adopt_~d for
39
laminae ,·"rtical and parallel 10 Ibe face of the wall, for in Ihi$ polIL!ion the aClion of the "cather m~y c~u,e decav alonl: the ed~es of the Slon", and, in .... xtreme cases the exposec la~'cr m .. y s~parate and flak" off (b) Cornices, strinlt COUr~"8 and similar projcclinlt coUTSCS sh(luld be constructed of stones wh.eh arc" edlte·bedded" or "joint-bedded." i.t., the ,t;ceplion to this rule Dpplie$ to quoin cornice, elC., stones which are returned, DS tnc r~lurn f"cc~ would he fsc,,-bedded and would result in rapid IlH~ of shape; therefore such must be car"fullv selectcd compact stone., fTl'e from ob,-ious laminations, and b.:dded on the natural bed. . (r) .'rcb,," should be constructed ha\'ing the natural bed of Ihe ,·otlssoir& nonnal 10 th" fllce of th" "rch and perpe,'!d,cular to Ihe lioe of thrust (sec 3', Fig. Z4)·
DEFECTS The following arc some of the defects in stone :~ I'tnts.- These :lr~ small fissures or hollows in the stone which may cause it to deteriorate rapidly, especially if e.\posed. Stone with \'ents should not be used for huilding purposes. Shakt$ or snailuttp are minute cracks in the stone containing calcite (a carbonate of lime) and forming hard \·eins which, in course of time, project beyond the general face on account of their gr~ater durability. It is not advisable to use stone containing them on account of the difference in texture which resultS. Sand-holes are cracks which appear in the stone and which are filled with sandy matter. Clay-holes are vents which contain matter of a clayey nature. Both are readily decomposed when subjected to the action of weather, and the stone should be rejected. Afoult is a defect which causes the stone to have a spotted appearance dlle to the presence of small chalky patches. Such stone is unfit for building purposes. An inherent defect which occurs in Portland stone is the preseoce of shells (known as shelly bars), fossils, cavities and Hints. These ar~ often not detected until the large blocks from the quarry are being converted into smaller units, the saw-cuts revealing their presence. The affected portions must be removed and therefore waste results. The presence of clay and oxide of iron is apt to cause disfigurement of the stone, producing brown· coloured bands which interfere with the unirormity in colour of the stone and diminish it!! durability.
MASONRY WAllS ClassmcatioD.-The various classes of walling may be divided into: I. Rubble Work, which consisls of blocks of stone that are either undressed or comparatively roughly dressed and having wide joints, and ~. Ash/ar, consisting of walls constructed of blocks of carefully dressed or wrought stone with narrow joints. RUBBLE WORK I,
Rubble Work includes:
(a) Random Rubble
(b) Squared Rubble
(e) I\IisceilaneoU9
(i) Uncoursed. Built to courses.
( (ii)
(i) Uncoursed. (ii) Built to courses. (iii) Regular cour~d. Polygonal walling. ( (i) (ii) Flint walling. (iii) Lake District masonry.
(
(a) Random Rubble.- The stones aTC those which have been quarry dressed (see p. 38). The principles of bonding referred to on p. 3 apply equally well to this class of work as they do to brickwork. Unlike bricks, the atones an: not of uniform size and shape, and therefore greater care and ingenuity have to be exercised in arranging that they shall adequately distribute the pressure over the maximum area and in the avoidance of long continuf'us vertical joints. The bond should be sound both transversely (across the thickness of the wall) and longitudinally. Jransverse bond is obtained b}' the liberal use of headers (or bonders) and throughs Headers are stones which reach beyond the middle of the wall from each face to overlap in the centre (sometimes called dog's tooth bond). Through stones or throughs extend the full thickness of the wall (see Fig. 20). Satisfactory stability may reasonably be assured if one· quarter of the face consists of headers (approximately two per square metre), in addition to one.eighth of the face area of throughs (one per square metre).
eing as much as 50 mm or more in places. A reduction in the quantity of mortar results if small pieces of stone are driven into the mortar at the face joints; these splinters may also bC' used to wedge up the stones; such joints are said to be glJ[ltted (see A). The larger stones are selected for the quoins and jambs to ~i\'e increastd strength and, incidentally, to improve the appearance. Boundary walls constructed of this class arC' usu:ally gi\'en J. slight batter on both faces. as shown. tn gl\'e addittonal stability (see p. 54). It is common 10 build dwarf walls, such as garden or field boundary walls or fences, of common ruhble tdthou! mortar. ~uch is known as dry rubble walling. The stability of these walls is entirely dependent upon the careful inft'rlocking and honding of the stones. (a) (ii) Random Rubble, Built to Courses (R, Fig. 20).-This wallin~ is simIlar to the above, cxceptinK that the work is rouJi:hly levelled up to form course's varying from 300 to 4.'0 mm thick. These courses usually coincide with tht: varying heights of the quoin and jamb stones. In the construct,on of Ih(" "'-111, the qUOin) ar~ budl Ii .... ' (as for brickwork~see p, 30), the line II stretched level ... ith the top. of thcquom stun.,s, and th~ inlcrv"mnJol' ...alling is broulfht up 10 Ihll level On" of the courses IS sho ... n number~d In the order in ... h,ch thc ltun" would be bC'dd.,d. The stones arc s~, In muTtlrand~, every caurK thc work i. well flushed wilh mOrtar and pr~u.,d Inl" the mt .. mal jOints.
UnlCH the ~Iative impenn"bility of the aton" ia utilfactory il is not adviuble to use through Ilonet for external Wills, II moisture mly be conducted through than and cawe dampnCH on the internal flees. This mly be prevented by either Ca) usIng three·qulrter bonden or (II) using through. extending to wlthm 20 mm of the Internal race and covering the ends with Ilate bedded on aood mortar. The laller method i. only applied if the internal flKes of the Will. are 10 be plastered.
This forms a stronger wall than th~ uncoursed type (long continuous vertil,:al joints being more readily avoided), although the somewhat regular horizontal joints at the courses detract from its appearance. Provided the site and stone are satisfactory, one course of through stones at Il (equal to twice the thickness of the wall) is a sufficient foundation for boundary Wills, otherwise a double cour~ (E and F) would be required ~s shown in the section.
The footings should consist of concrete (see section CC at A, Fig. 20) or, in the case of garden walls, large eat-bedded .tones twice the thickness of the wall in width (u in elevation at A, Fig. 20).
NOII.-Ahhoulfh Ih~ II1Ulll1lled " ..mplu refer 10 boundlry Willi, this fonn of construction ha. been adopted m Ihe erecuon of thousands of houKs Ind flnn.teld. in VlriOUI partl of the country.
RUBBLE WORK in Fig. 22 and details of three varieties are shown. The stones fonning the window may be given a smoother finish than that of the general walling so as to form a contrast. A description of the head, sill, mullions, transome and coping is given on pp. 41)--52. (b) (i) Squared Rubble, Uncoursed (F, Fig. 22).- This is often known as Square-snecked R~bb/e. The stones are available in various sizes and are arranged on face in several irregular palterull. A vely effective appearance results if the walling comprises a series of combined units consisling of four stones, i.e., a large stone called a riser or jumper (generally a bonder or through stone), two thinner stones known as levellers and a small stone called a meek or check.
(b) Squared .lIbble.-The stone used i. generally onc which is found in quarries in thin beda, or in thicker beds of laminated 8tone which can be easily aplit into smaller units. Little labour is neceuary to form comparatively straight bed and side joinu; the stones au usually squared and brought to a hammerdreeaed or straight-cut finish (see p. 38) although they may be given either tooled (see p. 38) or draggtd (see p. 38) surface finishes. Fig. 21 show,! a gable wall (i.e., an end wall which is continued up to and sometimes above the roof line and the upper P9rtion of which conforms with the shape of the roof) of a building which may be constructed in anyone of the three types of squared rubble. A portion of the wall is drawn to a larger scale
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MASONRY WALLS Although uniformity is neithe r essential nor desirable, it is found that an extremely well.bQnded wall of pleasing appearance n:sults if the approximate depths of the snecks, levell ers and risers are in the proportion of I ;
The snecks arc characteristic or-this
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on plan, the side joints of the face stones are only dressed square for about 75 mm from the face which is usually only quarry-dressed (see p. 38). Another form of snecked rubble is shown at F, Fig. 23. (b) (ii) Squared Rubble, Built to Courses.- The stones are similar to those used for snecked rubble, but, like the random rubble built to courses class, the work is levelled up to courses of varying depth. The squared "face stones may be arranged as shown at B, Fig, 20, or each course may consist of quoins, jamb stones, bonders and throughs of the same height, with smaller stones built in between them up to the height of these larger stones, to complete the course. This latter arrangement is sometimes known as Coursed Header W?,k and is shown at G, Fig. 22. (b) (iii) Squared Rubble, Regular Coursed (II, Fig. 22).-This type of walling is built in courses of varying height, but the stones in anyone course are all of the same depth. The stones vary from 50 to 225 mm thick and are from 150 mm to 225 mm wide on bed. The faces may be pitched to give a rusticated appeanlnce, or they may be dressed to a smoother finish, the straight-cut dressing described on p. 38 being particularly efi"ective. This work ;s very popular in certain parts of the country where there is available
a plentiful and convenient supply of hard SlOne of good colour and satisfactory weathering quality. Many buildings in Lancashire and Yorkshire are built of this class of external walling.
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Rcg:ubr cuursed rubble walling which consists of large squarcd blocks that arc usually either hammer-faced or pitch-faced is sometimes called Block-inCourse. It is usually associated with heavy engineering work, such as in the construction of sea walls, retaining walls, etc., and i" not often used in general building work . (c) Misccllaneous.- There are many variations of walling which may he classed under Rubble \Vork. These variations are due to the particular characteristic qualities of the local materials available and the traditional forms of construction peculiar to those localities. The tbree examples mentioned under cla~s (c) Oil p. 40 arc all well known, and hence their incluRion. It should be ohscn'ed that, owing to the comparative cheapness of bricks, these ha\"C, to a certain extent, repldeed the local material and thus none of the' following three examples are :ldopted for new work to the same cxtent as formerly. (c) (i) Polygonal Walling (A and B, Fig. 23).- The stone useel for this class of \\'311, although tough, can be easily split and dressed to any shape. It is hammer-pitched on face to an irregular polygonal shape and is bedded in position to sho\\ the face joints running irregularly in all directions. In one cla.« of this work the stones arc onh' roughly sh"ped, clll& ing (hem to fit togethl"r onk approximate h'. This is fi:ollJ,h-picked and is shown :;t A. A ~econd clnss shows more accurate \\ork as the fac<' cdges of {he stones arc more ean'fulh formed to permil "f the small bloek~ !O fit more inti!l1a{~h' into each other to fnrtll "h"t i~ ,,,,lled ("/"s" - picked work (sec n). \"alls faced wiTh th;~ maleri,'} art· ¥cnerally h~cked with hrickwork. This work is pl'rhar~ better known as Kell/ish Ra:; on "CcoUnt of ~ Iim<'5tonc found in Kent which ha . been u,,·d f~irlv ~x'en,iY~lY for ,hi,
43
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MASONRY WALLS purpote. II i, common in the .outhem oountiCi. adopted to give I .inl.llar appearance.
A soft pndltone hal also been
The external walls, which are generally from 350 to 450 mm thid, may consist of either (I) a facing of flints which have been snapped transversely acrosa .the centre, with a backing of the undre88ed flints as in section GG, or (2) similar but with the broken surfaces of the facing flints squared at the edges as shown at Dar (3) undressed flints throughout. The face arrangement may either be uncoursed, built-to-courses or regular coursed. Uncoursed flint walling especially is deficient in strength on account of the small-5ized material. This is partly made good by the introduction of through stones (two to every square metre), or continuous courses-known as ladfrl courlel--of long thin stones or bricks or tiles at vertical intervals of J to 2 m and stone or brick pieri at about "5 m
(e) (ii) Flint Walling (c and D, Fig. 23).-The stones used in this class are Rints or cobbles. They vary in width and thidness from 75 to 150 mm and in length from 150 to 300 mm, being irregularly shaped nodules of silica. A1though extremely hard, they are brittle and can be readily snapped across. They are sometimes employed for the construction of walls in thOR counties where the flints are readily obtainable from the gravel beds which are often associated "ith chalk or limestone. Buildings ncar the coast have been constructed of walls in which the rounded flints from the beach have been used.
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RUBBLE WORK intervals; alternatively, brick headers may be inserted in dia~ondl lines across the face to give a diaper appearance. An elc\'ation and sectirm of a portion of a wall faced with splil Aints, hackeJ with undressed Hints, and provided with brick lacing courses and piers arc shown at c. The snapped flints are laid in courses. This is knoYl n as pol/l'd (;Icing.
600 mm \\ide liy 900 mOl Ion$!. These blocks are broken and drel;scd hy the ".lllers to the size ami shape re(luired as the work pro(;ec(is. The amount of dressing dOlll' depends upon Ihe de§in:d face appearance of the I\all. There are tl\O type§ of thi!; masonry, i.t .. ruul?h-factd ranJom u:allill,r.:, hUllt 10 CfJunn, dnd bnl-f{/ud Tall/10m R,(/lIi,,_t:. Uuugh-factll U(/I/JO/ll rr ·(llIin.r:, Buill /IJ ('ourst's (E, Fig. 23). The faces of the stones arc roughly dressed and the st/)ncs arc irrcg:ular in sh"pe. The hlocks arc closely fitted together, sp~lI§ heing lIsed to pdCI;. up the larger of them, and at verti(;al illter\'~ls of from 300 til 450 10m th~y ;Ire lel'elled lip to the fcalus/wl. (sec hclow) til form a wntinullus joint \\ hieh is more or less horizonl:.!.l. The through stones form continullus courscs ;It fmlll 600 tn I}OO mm imenals. Ilul-laud UandoHl WIII/ill.t: (I, Fi~. 23). Thi!; Tl'scmhles squ~re snecked ruhhle (Fig. 22), the stones hcing s(lu;lre(1 un face with the hammer. The faces dre n"tllr~lIy smooth and thc stooes arc rcfcrred 10 ;I§ being self-faced. Some of the Sllech arc vcry thin (f.g., tlMt at \1 IS only 20 mm thick). t-nlikc the lasl mentioned, the thrllll~h~ arc st'll-:J.(ercd, 1I1d un ;111 :I\crage t,,-n thrmlghs per S(luare melre of Lice an: allulled.
The r~cing flints ate out'l'ard~ Thts fllnng
placo;d in position "ilh the black or dQrk Itrey sflht ~urf:II';lS may either ~ bu.1I up wilh the body of thc work, or toc Will mar Dc eonslrucled by bedding the face Hints on hOlh •• des In ~ hc.),:h! "f "bout 225 mm, ",hen a thick layer of soft mortar IS spn,.~d In bet"'",," int" "hllh ,m, nodules ~re placed to force the mortar up bcl",,,,,n them Ihts IS knm,'" "s/"nl'in~; ~hern3\1\'cJy. grQuting mar be adopted, liquid m"rt~r h~onlol p"ute..! on" tn~ n"..!uk~
packed m tne heart of the WI.]] to fill up the Int~r~tlccs. Tne spIlt nr pullnl tlml~ shoul..! bt· at least lOOmm long from front to back, un..! Ihc mkrnal fdCln.ll Rlnh ...r"I;nJ p~ headers in order that they may be well uilcd Into thc body of tht: wall. Thill flakes remO\'cd from the flint. may bt: used to g~llet the jnint ~ fur thc' rt:3Sf)nS ... lld on p. ",0 and shown at L.
Knapped flint facing, in conjunction with a brick quoin, is sho\\n at n. Th" larger cobhles are snapped across, and the split surfaces are dressed (knapped) to give faces which are approximately 100 mm square. This is the Il\:st tYlle of flint \Ialling and is sometimes known 35jftJuged or !quared flint. The facinJ! flints are laid very close toll"cther .!IO th~1 lilll ... if am'. m"rt,lt joinl"> ure "islblc Knapped flint work is sometImes 3rran~d 10 form pands OCI" "cn ~tom' or bm:k dressings. when Ih" flmts 3re sometimes unbondcd, i.~., Ihc' ,"emt:a1 j"ints arc conunuous. When the flints arc undressed thro\lghout (as for collage work) the e'l.ternal and internal face flints arc laid as headers and the hearting of headers and stretchers arc tightly packed between. 1'he appearance is impro\'ed if the mortar joints on the outer face are well raked hack with a pointed stick. If the joinB arc brouRht up flush with the face of the work, the appearance which results of only small portions of the flints surrounded by broad joints i§ not good. The colour of the crust of the flint varies from a white 10 greyish blue, but, when snapped, the btoken surface is almost black (flecked \\ith brown or white) and glassy in appearance. Thus polled and knapped facin~ is of a shiny blad. colour, and that of undressed flint work is much lighter. Cotta!!:" In the Norfolk dilarict werc Bometim"s constructed with 318 mm thid external" ails \\ Ith brick foundations, .. nd abo\-c ground 1e",,1 they conSIsted of AlOt work "ith IO~ 10m brick intnnalllOings h&\"1011" C1~~terin!l und reduc('d the amount of plaster reqUIred .
45
appro'l.imlltcl:~
The \\alling is (;on!;lru(;1eJ in a ITlJnncr "hieh il\ unique and nilJl,:h skill is demanded o! thc I"dlers. As !lhown in the set'linns, the \1<111 in etfeet t"!IOSlsts or three portions. i.~., inner and outer faces wilh an intermediate" he the through st"ne~ \\hich an' tilted tIO\lll""rds towards the C:I.tenMI face. Thi~ is knt!\\n as" \\atershot," and Ihe amount of watershot is 50 to 64 mm per Joo mm thickness of .... all. Thu§ if the \\.Ltershot is 50 mOl, Ih(' back tdgc of the hed in a 600 111m thick w.tll will be ahollt 100 IlHTl a~"'e the corresponding front edge. The rcm;linin).! face stoncs ;Ire gi\cn ,I similar watershot. The top ned of stone window and door hC'ld~ and the hottom he..! of window ",ills arc watershot. As mentioned on p. d~, thl,; dampproof course COllsists of two courses of slates in cement mortar. The quoins ,Lre of limestone or ~late. The characteristic colour and ri(h te'l.lun' of thc stone gilt;: a dt:lightful dppt;:ar.mce to this dass of work. Solitl "ails \~ry in thickne."'~ from 525 to i50 mm. Altcrnati\'dy, a 320 mOl thick cur'ily wall h:l.\in~ a .60 mm siJte out~r leaf. 70 mm c~\'ily and 90 mm concrete brick inner leaf can he made. 'l'he "ul,t.! tylX' of \ul1 I~ constructt'll In Ihc f"n,""n~ manner; The ..-,,11 IS oft"n _taMed ,,,th Iht: slun"s "all'rsh"t, U thc natural f...,., of tt..: stont: II nnt sQ\lue bUI cantt-u to th,'Ix...!.1 Thc "all",.,. "orl.: '" pdir', Iht: lOur" """"nt'nc"d man worl.:inl! on the outside and the otht:r IOsidt: to assist in the packlOl{ up of thc' flce !'tonCII with .mall "ieces flf ston" or 5p;lll~ limn fac"s ar(' pnll"lIy bt...!d....! 10 lllurL.. r \\hlch IS SN back from ","ch f;l~e 5ume SO Dr 7S mm. '10<1 the \\ idth uf c-ach 1a~'er of murt
(c) (iii) Lake District Masonry (E and F, Fig. 23).- This is peculiar to buildings in certain parts of Cumberland and Westmorland. The stone, which is a slate, is obtained locally. The colour of the two \'arieties used chiefly for walling is olive (popularly known as "blue ") and green,! both are durable and used for the best work. The stone arrives on the job in irregularly shaped flat-bedded blockJ varying from small pieces to a maximum size of , Thi, Itone i, often the waste from the ,late quarries.
I Th,s is due to the clea""II"" pblOes bf:IOIl ",dined to the beddlOll plane. (see A, Fill" 69).
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ASHLAR stone is bedded. The maximum overlap in the centre is given to the $tonl'5 In bo'h flees of the wall. The hl'arting between the two-faced portions cunslsts of small stones pndud dry. The object of thIS ,5 to ensure that any" at .. r ~netratln~ the outeT face ".11 pass dow n the dry tillm!,: K> the throughs belo", "h,ch on account of thtwatl'rshol, w,1I not p.enl'lrate and cause dampness on the InternAl fileI'. If an}, of the mOrllr joints were conllnuous from fmnt to back, dampness would be causcd by capillary aHr1Iction. This form of construction has been provcd to be most cffecti":: on rc~i~unJl d~mp ne55 In I distrtct wilh a notoriuusly high rainfall, and II 15 for thIS rca~on Ihal il i~ still employed in fht area.'
ASHLAR
2. Ash/or.-This class of masonry consists of blocks of accur~tcly dressed stone with extremely fine bed and end joints. The thickness of these joints i~ often only 3 mm and ~ardy exceeds 5 mm .2 Such accurate work is only possible when the blocks are cut perfectly true to the required shape, and therefore the hf'n~ ~nd jnints at II'~sT ar(' sawn. The backs art: lIs11~lIy s~wn. I'''frr' whf'n Ihl' ashlar is to be backed with rubble, when they may be given a rougher dressing. The surface finish is usually that left by the carborundum saw or it may be rubbed; several of t:le more elaborate dressings described on pp. 38-39 may also be applied. The face arrangement of ashlar may resemble either of the three varieties shown in Fig. 22, the regular coursed bcing common with the courses of varying height, depending upon the size and charactcr of the building. Grtat {arl! must bl! I!xerciud uhtll determining the sizes and praf>
47
districts, the usual backing is rubble (St:e- 0, generally of brickwork (sec Fig. 24).
Fi~.
25), othe-rwise the backing is
It is essenti~1 Ihat the f~cmJ.! ~h.,11 hl' eff"":li\<:l> bonded with th" backin.!!, lind if Ihe laner i~ nf hri,·k"mk ... nne~eSSdrV cuttln~ rtar, a "c,··shaped notch is usually fMIIll:d III carh l"crllcaljomt surface so as 10 form a squ;,rc hole between e3ch pa, r nf 3dja~cnt hlucks III c{)n~trUCllnl{ 3out $" nun wid,·) of th" I~S! fixed ~ton"; the adj~cent stone i~ thell pLll·cd in pOSlllon, the back of the ,ertical joint '5 pomtcd "ith the mnn.,. ,,,,d liquid mort;!r (J.!rllut) " pnun·O onwn the hole /0 form ~ j.lj{j{I~ so as 10 fill completely the space I"ICI" ""11 c
The complete beds of ue ashlM hlocks shall be square with the face. If a bed is "worked hollo\, " (i.t., thc surface is brought below the outer edge of the stone to form an equi\alclII to a frog of a brick) there is a danger of the pressure being concentrated Oil the outer edge, causing the stonc to crack and splinter off or spall (sec p. 53 ,lIld x, Fig. 27). Fig. 24- shows a portion of a huildin~ "hich i!> faced with ashhir backed with brickwork. i\lost of the ashlar CoUTSc$ arc of IInif()rm height and (excepting wherc the work is interrupted hy windo\\s) are ahcrnatcly 2t5 and IC2 mm thick on bed. This permils of a brick b:.!cking cOtl!>isting of alternate sections which are 215 and 328 mm thick respectively. The plan at IIA shows the speci:.!l bonding in alternate cours~s o\\inj;! to the prese-nce of the door and \Iindow openings. The splaying of the back of the out band (sec below) at 0 is often done to avoid continuous vertical joints. The bonding of thc qU\lins (sometimes I:alled rcunlionr or seOlllions) should be noted, where the 215 mn thil:k courses arc c(lntinued to the re turn face. An unsatisfactory appearance, indicating \,eakno::ss, would result if the 102 mm thick courses were to show on the return face. The diagonal lines and the ringed figures shown in the ele\·ation indicate the extent and amount of bed -espectively of each stonc. This conforms w,th the usual practice, the diagonals being especially necessary when cornice-s, etc. , comprise two or more stones in height. The plan at Band tbe sketch D, Fig. 25, show the wall faced with ashlar with a backing of rubble. Door and Window Openings.- As shown in the plan All, Fig. 24, the jambs are bonded by using alternate heade-rs (called inbands) and stretchers (termed
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ARCHES OJltbtmds), the fonner being rebated to receive the door or window frames. Some· times the outer edges of these stones are splayed or chamfered which may be stopped (see broken Jines at R) or may be continued round the head to form intersections called mason's mitres (see Fig. 22). The head of an opening is finished. with either a lintel or an arch, and the bottom is completed with a sill. Lintels or Heads.-These have been described on p. 21. Arches.-Brick arches have been described on pp. 21-2+, and the terms geometrical construction, etc., there detailed are also applicable to stone arches. The temporary supports used in the con's truction of stone arches are shown in Fig. iJ. Flat Arches (see H, Q and P, Fig. 24, and A, B, C and D, Fig. 25).-Alternatives of that at H are shown at Q (partly indicated by broken lines and showing the arch equal to two courses in depth) and P, which shows a stepped txtrados. The alternatives at A and B, Fig. 25, are called joggkd or rebated arches. That at A shows the keystone with small (about 2S mm) projections at the joints which fit into corresponding sinkings worked on the adjacent voussoirs; the object of these rebates or joggles is to prevent sliding taking place and dropping of the voussoirs. An isometric sketch of one of the voussoirs, with a portion of a reinforced concrete lintel behind it, is given at C. An alternative to arch A is shown at Bj this shows secret joggles or rebates as they are not seen on the face; the construction IS more clearly shown in the sketch at D. Semicircular Arches (see N, Fig. 24, and J and K, Fig. 25).-That at N shows a stepped extrados. The best appearance is obtained if an elliptical constructional line is drawn and the top of the vertical portion of each joint made to conform with the ellipse. An alternative arch is shown at J where each voussoir has an elongated horizontal portion (called an ear or crosseue) which courses in with the wall. That at K has a semicircu lar intrados and extrados. This type usually necessitates the cutting of some of the adjacent walling stones to an awkward shape (see w). Segmental Arches, having either curved or stepped extradoses, are also built of stone. The geometrical construction of these is similar to that required for brick arches (see Fig. IS). Window Sills.- Reference should be made to die brick sills described on pp. 2-1-- 26 as the terms are applicable to stone sills (see Figs. 22, 24 and 25). The sill shown in Fig. 22 is weathered, twice rebated and chamfered; that shown in section l. and part elevation M, Fig. 25, would be specified as a " 350 mm by 175 mm sunk weathered l and throated sill, grooved for water bar," and that at 0 and P, Fig. 25, is sunk-weathered, moulded and grooved, the upper portion ofthe mould forming a throat to prevent water trickling do\lo'Tl the face of the masonry below. See p. 104 regarding the bedding of the water barf The level seatings , Nor.. thAI nmk ...eatherina bellins with a vertical .inking.
or stools fonned at tbe end. of the sills to support the jambs may be finished externally as shown in Fig. 25, or they may be weatbered as indicated at c, Fig. 16; seatings, as shown at ji Fig. 22 are also formed for the mullions. The sills are in one length, having a ISO mm wall-hold at each end. They should be solidly bedded only under the jambs-and mullions (Fig. 22)--with the intervening portion of each bed left perfectly clear of mortar until the building has completely settled and the mortar in the walling has set. The joint is then neatly pointed. If this is not dOf'e, and the sill is bedded solidly throughout its len~h Il$ the rett of the work proceeds, the lill may be fractured unless it is very thick and " of very hard stone. This damage is due 10 the unequal stress produced by Ihe prelSure transmitted from the jambl being concentlllted only at the ends and not evenly distributed throughout the entire length of the .ill; this'unequal pressure tencb to cause the portions of the wall irruned"uely below the end. of the ,ill to settle more than the portion under Ihe centre of the sill. To prevent .uch damage, each ,ill i, somelimes conltructed of thT« 510001 al showo in Fig. u, the two vutical joinn (indicated by broken lines at k) being in the same vertical plane as that of the jambt. When this is done the central stone of Ihe sill may be bedded solid. The appearance of the sill shown in Fig. 22 (the face of which is flush with the wall) is sometimes preferred to that of the sills shown in Fig. 25 which project beyond the wall. Thec,lauer type causes water to drip clear of the wall below, whereas when the face of the sill is in line wilh that of Ihe wall, disfiguration of a building results (especially if it is faced with Portland or similar light coloured .tone) by the Slllnlnl: of the Wills immediately below the ,ill.. Thi. is due to the WIler (whieh collec" din from the windows and dust from the w~thered portion. of the ,.iIl.) paning down the walls. Further, unless the bed joint between each lill and the wall is well pointed, water proceed. through the joint to cause dampness on the internal face of the wall. Mullions and Transomes.-The window shown in Fig. 22 is dividl!d into six lights.! The vertical dividing stones are called mullions and the horizontal dividing stone is known as a transome. The mullions are rebated to receive the windoW frames and are chamfered to cOnform with the jambs, etc. They are connected at the bed joints to the head, transome and sill by d()U)eis of either slate or gunmetal, which prevent displacement (see J and p. 53). The transomes are rebated for the window frames, they are weathered and the ends are stooled as for window sills. It is customary to divide a transome into units with a joint over each mullion, as a single stone may fracture if the settlement at the jambs exceeds that at the mullions. Steps.-Two steps are shown at the door opening in Fig. 24. The stone should be a hard wearing sandstone and should be carefully selected. Much of the description on p. 26 is applicable to these steps (see also p. 123 and Fig. 65)· Plinths.-Brick plinths are described on p. 28. An enlarged detail of the upper portion of the plinth at M, Fig. 24, is shown at Q. Fig. 25, and alternative , A window of this type i, often provided with stetl frames lind leaded lights instead of Metal ·window. lire described in eh.pter IV.
wood frames and luhes.
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COPINGS plinth mouldings are shown at R, s, T, u and v, Fig. 25. In each case the top of the projection is slightry weathered to prevent water lodging and passing through any defect in the joint. The names of the mouldings are stated in the
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String Courses.--A Siring course is a horizontal course of masonry (.or br:ckwork) which usually projects and is provided as an architectural feature. A simple example is shown at E, Fig. 24, and this is detailed at D, Fig. 26. A larger string course is il1u~trated at B, Fig. 26; because of the greater projection, it is possible to incorporate a throat with the lower (ovalo) moulding which prevents water trickling down and staining tt:e work below. 1'hc upper portion of the facade (elevation) shown in Fig. 24 consists of a coping, parapet, cornice and frieze. These are described below in the order that they are constructed. Frieze.-This is a stone course which is surmounted by a cornice. That at D, Fig. 26, is a detail of the frieze shown in Fig. 24. If there is not a projecting member immediately below the frieze (such as a string course or architra\'c) emphasis may be given to the frieze by projecting it slightly as shown at e, FiC;.26.
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The upper projecting portion of the cornice is weathered and the vertical joints are saddle(l to prevent water from penetrating them. 2 A saddle joint is shown at A, C, Q and ;0.1, Fig. 26. It is formed by rounding off the stone from the top bed to the weathering at each end; this prevents rain from lodging on top of the joint. The saddle is rendered inconspicuous by bevelling it back· wards from the front edge as shown. The stones arc joggle jointed at the end, to prevent any movement due to uneqwll settlement which would cause irregularity in the horiwlL\a\ lilles ..,r t!'.e cornice. Such joggle joints (down which grouted mortar is poured) are t Sec p. 9.1 conc.:rning the importance of ,,-ell_designed mouldings. , \\"'alhcred s(,rfn<"es of <'omices and similar projcctin,l!; members built of comparatively soft stone should he protected" ith shcct1ead or asph~lt (sec Fig. 76). Saddle joints are not r.:quircd when this is done.
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The proj.:eting portion of a cornice consi$ts of the (j'''mlium and the corona (see 26). The cyrnatium is composed of :wo or more mouldings. that at c con· of a narrow flat band or fillet and a eyma recta moulding which is separated by 1\ second fillct from 3 cyma rcnrsa or o.t!~e moulding. The corona has a compnrativdy broad vertical face w,th a recessed .offit which stops water from travelling along ,t 10 th" f;lCe of the wall. The lower portion of the cornice is spoken of as II bed mould. which at c consists of a fillet, ogee moulding and a bead. l', Fig. ~istin~
S,"CTICN
V
Cornices.-A cornice is a comparatively large projecting moulded course which is fixed r,ear to the top of a wall. Its object is to provide an architectural feature which will serve to discharge water clear of the building and thereby protect the face of the wall. Cornices vary considerably in detail. 1 Two designs are shown in the sections A lOd c, Fig. 26, and A and D, Fig. 76, the two former being alternative details of the cornice shown in Fig. 24.
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MASONRY WAllS ahown by broken lines at A and c and by full lines at M. Metal cramps may a1ao be used (especially for securing quoin cornice stones) to resist any movement which tends to separate the joints (see p. 53). ParapeL-This is the upper portion of a wall which is used as an architectural feature to cover a gutter (as in Fig. 24. when it is sometimes referred to as a bloclting COIlrSt, as it blocks from view the gutter behind it) or to protect the edge or wrgt of a roof (see Fig. 21). It is provided with if. coping, and its weig~t assists in tailing down the cornice below it. The stability of the parapet IS increased if each block of stone in the lower course is connected to the cornice by means of onc of two slate dowels (see Fig. 26 and p. 53)" Copings.-Brick copings are described on p. 26. Sections through stone copings are shown at A to E, Fig. 27. Thefeather edge co~i ng (A) is ~n e~large ment of that at F, Fig. 24; that at B is a detail of the coping shown In Fig. 21. The saddle back coping (c) provides a more effective covering than those at L, Fig. 17, and B, Fig. 20, because of the throated overhanging portions, altho~gh the latter section is more in keeping with the rough character of the wall whlch it protects. The segmental coping D is occasionally used for dwarf walls where the curved surface can be seen to advantage. The tops of some walls are inclined or raked and are protectc~ ~y r~king copings (see Fig. 21). Such copings need not be weathered as the ram IS qUIckly discharged down the slope in the direction of t~~ir length .and th~refor.e the parallel coping E, Fig. 27, is suitable for such poSitIOns. Rak~g. coplOgs, If not supported, would tend to slide. This is.preve~ted by the provlslo~ of adeq~ate supports at the bottom and at intermediate polOt.s (see A and H, ~Ig. 21). ~he intermediate supports are called knee/ers or knee·stones lsee F, Fig. 27), which is an enlargement of B, Fig. 21. A kneeler is a block of stone (which should be well tailed into the wall) with the inclined or raking portion worked to the section of the coping stones and finished square to form butt joints with the adjacent coping stones. The butt joint may be for~ed as indi~ated by the thick broken line at F, but this requires a larger stone hanng the portion shown s~aded removed. The lower support is provided by a spring" orJootlume- see A, Fig. 21 and the enlarged detail at G, Fig. 27. This may be shaped as shown partly by broken lines at G (the thin diagonal lines indicating the extent of the stone) which, like the kneeler, is well tailed into the wall, or it may take the form indicated by the thick full lines at G when two slate dowels (see p. 53) are used to secure it to the stonework below and so provide an adequate resistance to the thrust from the raking coping. The top stone at the intersection of the coping is termed an apex stone or saddle stone, the raking portions being worked solid to the section of the coping to form a vertical mitre (see Fig. 21). When the rake or inclination is less than 40°, the joints between coping stones are sometimes rebated (indicated by full lines at H, Fig. 27) to prevent water penetrating through them into the wall hel~w. The correct ~ebate shows the upperyortion of the upper stone
as shown by broken lines at H. An alternative form of nking coping is shown in the side elevation }. Fig. 27.
MASONRY JO I N T S The following are some of the various joints which are used in masonry: butt, rehated. tongued and grooved, rusticated, saddled, joggled, dowelled and plugged. Some of these have been referred to on the previous pages. Butt or Square Joint.-This is extensively adopted and is formed by placing the square surface of one stone against that of another. Of the many examples of this joint which have been illustrated are the ashlar joints at B, Fig. 25, and those at F and G, Fig. 27. Rebated or Lap~d Joint (see A, B, C an.d D, Fig. 25, and n, Fig. 27).-ln the former figure the check or rebate prevents movement between the arch voussoirs, in the latter example the rebate is adopted to secure a weather.tight joint. Another form, known as a rebated and broken joint, is shown at J, Fig. 27· Tongued and Gr(}()tJed Joint (see K, Fig. 27).-It is now rarely us~d. It consists of a tongue or projection worked along one edge of a stone which fits into a corresponding groove in the adjacent stonc. It is sometimes adopted as an alternative to the rebated joint in Rat arches and between the horizontal slabs forming the landings of stone staircases. 1 It is also known as a joggled joint, which must not be confused with the mortar joggled joint described below. Rusticated Joints (see Fig. 27).-Pliuths, lower storeys of buildings, and quoins are sometimes emphasized by the use of blocks of stone which have their margins or edges sunk below the general face. The term" rusticated" is applied to such masonry. That 3t Land M shows a channelled or rectangular joint and is often adopted (see also B, Fig. 26). Note that the sinking is on the lower stone; if the bed joint was at the bottom of the channel, water would lodge on the bottom and perhaps penetrate into the mortar joint. The vee.joint at Nand 0 is form~d when stones having chamfered edges arc placed in position; see also Q and v, Fig. 19. A more elaborate form of vee-joint is shown at p and Q, Fig. 27, and is known as a vn and channelled joint. Saddle Joint.-These are illustrated at A. C, M and Q, Fig. 26, and have been described on p. 5 I. Joggles, uuwe/s and Crampf.- ln order to prevent movement and displace. ment of certain stones the ordinary mortar joints between them have to be supplemented and strengthened by various means. This additional strength is obtained by the employment of joggles, dowels and cramps. Joggled Joinl.- The mortar joggled joint is adopted for the end joints of ashlar, especially when the blocks have a small bed (see p. 47), and for cornice 1
Ston~ landings llf~ $~ldom used nowaday" reinforced concrete construction being
preferred.
I
JOINTS stones (see p. 51). The grooves down which the grout is poured are roughly formed by means of a hammer and punch (see 6, Fig. 19)' Dowelled Joint.-Stones which are liable to bt:come displaced are prevented from doing so by the introduction of dowels at the joints (see J, Fig. 22 and 0, Fig. 27)' Dowels are either of slate or gunmetal (an alloy of copper and tin) which are from 25 to So mm square in section and two or three times the thickness in length. They are set in cement mortar. A horizontal dowel in an end joint is usually run in with grout (through a vertical hole prepared for the purpose) after it has been inserted and the adjacent stone fixed (see R, Fig. 27)' Cramped Joint.-The joints between stones which are liable to be pulled apart in the direction of their length are reinforced with either metal or slate cramps. Details of a metal cramped joint are shown at T, Fig. 27, which may be considered to be an enlargement of that shown by dotted lines at 5, Fig. 24, and used to connect the coping stones. The cramp is a piece of nan-corrosive metal,! such as gunmetal, which is from 25 to So mm wide, 6 to 13 mm thick and uS to 450 mm long with ends which are turned down from 20 to 40 mm. The cramp must be fitted in tightly, after wl}ich it is grouted and covered with either cement or asphalt. A slate cramped or keyed joint, consisting of a double dovetailed piece of slate set in cement, is shown at 5, Fig. 27. It is not so effective as the metal cramped joint. Plugged Joint (see Y, Fig. 27).-This is an alternative to the cramped joint but is now rarely adopted. It is formed by sinking a hole (dovetailed on plan) below the top surface and a vertical vee-joggle in each end of the adjacent stones. The stones are jointed in the usual way (the hole and joggle being kept free from mortar), after whIch cement grout is poured down to form a cement plug. Formerly, molten lead was poured in to form what was called a lead plug.
53
beds when very fine ashlar joints are required. This may cause the edges to spall off when the stone is fixed owing to the pressure not being distributed over the whole area of the bed but concentrated at the edges. A portion 'of a hollow bed is shown at x, Fig. 27, where the bed surface of the upper stone only is concave. The shaded triangular portion is likely to be splintered off, especially if the joint is not completely filled with mortar. There is little likelihood of the beds being worked hollow when the stone is sawn by machinery.
1+
MORTAR JOINTING The thickness of the mortar joints varies considerably, thus for ashlar the joints may be as fine as 3 mm whereas those in random rubble work may exceed So mm width on face. Certain of the joints used for brickwork illustrated at T, Fig. 17, are also suitable for stonework, e.g., flush joints are used for ashlar and the keyed or vee-joint may be adopted for thicker joints. The mason's joint is also used for wide joints. This may be of the three forms shown at u, v. and w, Fig. 27. The two for{Iler are sometimes used for rubble work, and that at w is frequently adopted for pointing. . These projecting joints should be of cement mortar if the character of the stone will permit it. As mentioned on p. 47, the beds of ashlar blocks should be square with the face. When hand·dressed, there is a tendency for the mason to work /wI/ow , Corrodible metal, auch as wrought iron, mUlt JUVn be used for enmps, bolt. , etc .. which are fued in Itonework. Extensive damaae has been caused to masonry which has been connected by wrouaht iron fasteni~ on ICCOu..lt of them corroding. Durine ill formation, the NIt eltCl'tl prequre upon the stOlle to IUch an extent as to fncrure It.
FIGURE 28 The mortar specified for jointing masonry depends a good deal upon the character of the stone. Mortar joints for •• hlar should be a. inconspicuous IS possible, lind it is often neces.ary to experiment with vllfiou. compositions of mortar until the desired colour (which should confonn with that of the stone) i, obtained. That used for walling built of sandstone is sometimes composed of t part Portland cement and 4 parts sand, and occasionally a lottie lime !5 added. The mortar recommended. for certain limestones, t.g., Portland Itone, comist. of I part Portland cement, ai part. lime putty (well slaked. lime mixed. with water to a consi5te~cy of a pUle) and 3i parts stone dust (powder obtained by the crushinlr of waste PleclC1l of the hm~tone). Neat c~ent ahould nttlu be used. for grouting Ponland stone bloch, as thll may Clu.e .talnlfilr of the f,ce of the work; only liquid mortar of the above composition ahould be used fot this purpose. Rubble walling (especially if of sandstone) . hould be built with cement mortar composed. of 1 pan cement to .. partiland, as the .trfflgth of the work depends very l.rrely upon that of the monu.
MASONRY WALLS
54
Construction of Masonry Walls.-\Iuch of the description on p. 30 referring to the constru!.:tion of brickwork is applicable to stone walls. The batter which is sometinl";s given to walls may be maintained by the use of the plumb-rule which has one edge shaped to the required batter (sec A, Fig. 28). Where a wall is to receive a batter on both faces (as at B, Fig. 20), the batter is preserved by the use of frames built of wood. One form of such" frame is sho\\ n 'It
Fig. 28. The frame ;, shaped to that of of each inclined leg coincides with Cal'll wall face. During the construction of the waJl a frame IS fixed krnporarily at each end. The cone,,! alignment and the b,llter of each face are maintained by 1\\"0 lines, the ends of which are wound round n
I),
cd~c
LIFTING APPLIANCES Blocks of dressed stone which are too large to be lifted by hand are raised by means of a crane or other hoisting apparatus ,md lowered gently into the correct position in the wall. Various appliances, such as Chain Dogs and Lewises, are used for this purpose-see Fig. 28. Chain Dogs.-Oogs in "nrious sizes are made of steel and shnped as shown at c . The~tone to be lifted hasa hok (about 20 mm deep) punched in the centre of each end ,md from 75 10 loomm down. A Meet cham is passed throuJ
stone very securely aod are particulady suikJ for lifting heavy stones and long stones with n"rrOw beds. Cham Leu·is.~ This comprises three ~teel ri,:,gs and Iwo curved steel legs (see E). The. legs vnry In. sIze. The hok w[ueh IS formcd III the ccntre of the top bed of the ~tone IS sfl.r:h11y dO'Tlalled. I f it is exceSSively doveladed there IS a tendency for Ihe lewis 10 be pulled out o\~ing 10 the legs bursting the StOne during the lifting operation. The size of the hole "aries from So to 7S mm deep; the 50 mm deep hole shown is about 20 mm wide. The le\\is IS placed c>!refully mto the hole, one leg al a I1me. If the hole is found to he too brj!nd size of the legs, as shown. The n':o dovetniled legs are in. serted in the hole, the centre leg is d:iven down, the pin is pass~d through holes in the shackle and legs, and the cotter is dnven down 10 m~ke all SeCUre. The hook from the sling is passed through the sh3ckle, when the stone is then ready for hoisting. If the hole m Ihe stone has been cut too large, a piece of z'nc passed between a pair of legs before they are assembled may be sufficient to .enable the lewis to grip the stone securely. The crane operator must exer<;lse reasonable Care during th~ hois(mg operations and the blocks of stone must be hoisted with uniform movement. Any sudden jerk of the crane chain may cause the stone to slip, with disastrous results.
)1
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i
J
CHAPTER THREE
TIMBER, FLOORS AND ROOFS S.rlfabus-Srlef d~criptlon of Ihe Siructur.. , ~rowlh, s ..aiSOnlng, I'rcscn'3uon. SI7."$. com'''r!!ion, d ..feclS, claSSIficaTiOn, charact"TlSlic$ and us"s of softwoods and hardwoods~ . Ground floor.!, siz,," and sP.aclnlo: of JOISts, hoard In!!:, J0lnIS, ~('nlllalion Sin!!le upp ... flOOr!! up 10 3'7 nl span, struning, trimming to fir"places and VOIds C~lhngs. Pitch, span and ""olutl{'" of rod or dutnll/in (durab,l,ty), (e) outer and h~hter coloured concentric flngs of woody tissue called wpm){'Jd, (d) radial n~rrow bands of tissue called me,dullary myJ Or tmnronu upt" (partitions) which conlain cells ~nd rad.ate from the centre and (e) Ihe bark. The Irre~ular concentric rings of tissue, forming the heartwood and sap ..... ood. are called mlllua! rirl/(J or grou;/h nrl./!s as in temperate climates one ring is generally formed annually A diagrammatic view of a portion of an annual ring of a soft"'ood (see p. 58) IS shown 10 cross·section at n, Fig. zQ; thIS is much enlarged, for the number of nnlls may vary from three to forty per zs mOl. A rinl(, consisting of rows of cells of variable size whIch run longitudinally (parallel to the lrunk), is di"id"d into an inner portion called the slmrlg u'()()d and an outer and dark"r ponion,.kno"n as Ihe summu rtood. The cells diminish in s,~e from a maximum forming Ih., sprinlo[ layu 10 a nllnimum at the outer layer; in add,tIOn, the cell walls of the SUmmer "ood ar .. thicker than those of the spring wood. Hence SUmmer "ood is morecompa<:l andd"rker colour.. d than spring wood. The cells communicate" IIh nch other throuj,[h holes in their SIdes, and thc narrow cells In Ihe medullary ra)'s also communicate with the annual ring cells. Certain timbert have annual rinR! which are "ery distInct and the sprin!l: wood and summer "nod Ire eas.ly dIstinguished; oth"r!! have rings which are ind,st,"ct and there;s no contrast between the· tWO_ Th" m"dullary rays ar" well defined in certPin "oods but usually they are only perc"ptlble through the microscnp" (~ p. 56) Growth.-Moisture, salts, etc., are absorbed from the soil by Ihe rOOtS of the Iree, and in Ihe early sprtng these ascend through the cells (see a) 10 Ihc branches to develop the lcaves which conVert the absorbed material, called w.p. into hquid food suitahle for the nee. M~anwhiJc the camb,um-a thin co'·erio!! of cdls between the hatk and the last· formed annual ring (see A)-produces n .. w c .. ll~ which form tht ~pTlnRwood of the next annual rin!!,. In the late summer and ~ar1y autumo the food d ... tends between Ihe spring layer and the bark to form the denser SUmmer wood of the annual ring. Thus trees which proquce tImber used for building purposes grow outwards Immedlatcly un-lcr the b:ITk and are called n:ogtns, as dislinCI from mdogms whIch mamly mcrcase 10 $I?e by )(Towth at their ends. The cells in the medullary rays act as reservoirs for tree fnod In courge of time the layers next tn" pith become stronger and the c"tJ~ cease 10 convey up; this i, the hear/a·ood. The outer part of the tree, or sapu'ood, contaIns much more sap and is softer and lighter in colour than th" more mature heartwood. :;apwood is also known as albur7l11m due to its relatively light colour. Building timbers are divided into softwoods and hardwoods (sec p. 59). Fellin,.-Trees used for building purposes should be felled as soon as possible after reaching maturity. If felled prematurely, the wood is not so durable and contains an
excess of s~pwood; if cut after its prime, it produces limber which is brill Ie and the central ponion especially may show "vidence of decay. The time taken before trees reach th,,;r prim~ may VHy from fifty years ( ~.fI., ash) to a hundred years (t .g., oak). The best time for fdlm!! trees is in the autumn just before the fall of the leaf (when the sap is still thin) or during wioter "fter thc f~11 of the leaf (when the trees con tam little sap), as during these periods the evapor·,·ion of moisture And the rcsullmg shrmkag" arc comparatively small. Seasoning.- TImber cannot be used for either carpenlers' or joiners' work imme. diatcly il has been felled hecause of the large ~ap CO'Hent. Most of this moisture must be remo\Cd. otherwise the timber witl shrink e"ces':\'cly, causing ddects in the work and II tend .. ncy 10 decay. Eliminalion of the moistur~· Increases the strength, durability and T<'silience of th .. !imb"" the "ood is lighter in weight, ~asier 10 work w'ith the saW and other tools. it mamtains its sile and it is not so Ilabl~ to split, t"ist or warp. Th~ process of removing thc moisture is called uasonirlg or maturing. This is accomplished by either (a) natural or (b) artificial means. In recent ~'ears the lallcr methods have been considerahly impro,'cd and e"lenstvely employed; natural processes are not now SO frequently adopl"d owing to th" longer period required (a) Natum! S ..aJoning.-ImmOOiale)y afler fellinlo[ the branches are removed, the trees are CrOSS-eul into fOgI and Ihe bark is smpped. If th~ lOllS are of softwood, they are shaped by machme sawing 10 a square in cron·section (called baullu) and stacked (as shown at c, Fig. 29) under cover to allow Ihe air circulating round thcm to remOve much of the moisture content. Ha rdwood trees are usually sawn by machmery alon'l th"ir length into planks (pieces from 50 to 150 mm thick at leaS! 250 mm WIde) and stacked with cross-lags (ple<;"sofwood about I) mm Ihick) belween, 15 shown at 0, FiJI:. 29. Thin pieces of wood (as shown 3t E) arc nall .. d to the end of each plank to pre vent the timber splitting during th" drying proc"ss. This is known as Dry Natural Stolonirlg, and the time occupied depends upon the size and character of the limber. Thus, w/ttuood boards, 25 mm thick, may take two months to season and So mm thick planks four months; lumJwood of th~ same thickness may take about three times as long to season. Th" time occupied in seasonin!!, is much reduced if the timber is subjected to Waltr iVatllral Stawning. By this method, the logs may be floatcd down a river 10 the sawmill or they may be placed in the river, tNally submerged with the butt (thick) ends facing upstream, Idt for a fortnight to allow the water during iu passage th~ough the pores to eliminate much of the sap, when they arc removed, sawn and stacked as shown at c. (h) Artificial Seasoning.-The time taken for this varies from approximately one to NO "ech. The process is carried out In kilns of which there are several types. One form consists of a long chamber, about
TIMBER
56
during the lellOning i, rigidly controlled; if it is too low, it is at once raised by th'" admission of steam. II is imporllnt 10 nOle that the uho(t Gfthe mOIsture content (" m.e. ") is not removed from the timber when seasoned. A certain amount is allowed to remain. Thus, for interna~ work (as for Hoot boards, doors and panelling), the timber is allowed to remain in the kiln until the moisture content is reduced to [II per cent.; the maximum for goodcia" carpenters' work IS 20 per cent. If timhu is used In II JX)lmion where the humidity
of the atmosphere is
In
excess of that
In
the umber, the latter will absorb
ffiOISllue
from
its lurroundlllgs and sv.eUing will result. Con~·er5ely. If the tlmher is msuffic,,~nlly seasoned (i.t., contams an excess of mOIsture), it wdl, if fixed in a very dry positIon, losea certain amount of moisture and will shrink. Therefore If movement of the timber is to be kept to a minirrmm, the moisture content should apprO~lmate close ly to that of its environment. Th., extent of shrinkage movement in timber may vaT}' from about 6 to '3 mm per ]00 mm of original width if the moisture content is reduced from ao to 10 pu cent. Preservation.-In order to increase the durability of seasoned timbe,. it is sometimes necessary to apply a preservative. Next to painting the most common prc:sen'ati~c process is cUfJsoti"g, which consists of placing the tImber m steel cylinders in "hlCh hot creolOte (an oil dIs t illed from coal tar) IS admitted and forced into the pores of the wood. A less effective method is to apply two or more coats of creosote to the surface of the timber. Treatment by melanic salts (copper based) is also adopted. Convenion.-A log of tImber is converted Into vanous p,eces 10 which the following tenns aTe applied. Basi, fC"lIlhs rise from "8 10 6'3 m m mcrements of 300 mm. Deals are sawn pieces of softwood which are from So to 100 mm thick by aas to under aso mm wide. Bat/tmJ are from 50 to 100 mm thick by las to:zoo mm wide; .Ialing balUnJ are from 13 to 31 mm thick by a5 to 63 mm WIde. Boards are under So mm thick by 100 mm or more in ",dth. Scantlings are from 50 to 100 mm thick by So to 100 mm wide. The tenn is often applied to the dimensions of a piece of timher, thus" the joist is of 100 mm by SO mm scantling."
Quartmngs are square seCllons of from So to 'So mm side. StriPS are under So mm thIck and leu than 100 mm wide . There arc VarIOUs wars of c~mvertlllg a log into planks, deals, t>Jards, ttc., I.t., (a radlalaawln.g, (b). tangenlla l sawing and (e) ,lab sawing--sc:e Fig. 30. .
'ArUI
FIGURE 29
DEFECTS-TIMBER
57
CONVERSION OF TIMBEF>-.
•
IlJFT SAWING
SLAB SAWING
WARPING OF TIMBE:ll
FLOC>P... SOARD SAWING.
FIGURE 30
.hown at M, wh~n the remainmg stctions, consisting of sapwood, are converted into scantlings al required, .. at s. Although rift sawn hoards Ihrink lUI and have better wuring quliities, such board. are often sawn tangentially for economy. Tangentially sawn floor boards should be fixed with the heut side downwards a'nen.-Reddilh or yellowish brown stains In o~k caused by over-maturity or badly ventilated stonge durin6 shIpment; is an early sign of decay. COOTie G~ajn timber hu vcr-y wide annual nnll~ caused by the tree (lrOWlnlt too rap,dly: wood is deficient in strength Ind not durable. Tu;jsud Grain o~ Fib~e (tee l).-F,bres are tWisted 10 such an Ulent thaI a relat"'el), large number are CUI through when the lo/ol ;s convened InIO planh. elc.; such planks or boards willlwlSC or wrap; c:ilused by Wind acllon In branches twisling the tree trunk. Cup S'I(JJces or Ring SllalleJ (s« A).-Cracks Of dcfts de'eloped between 1...·0 adjacenT In:lual rings; mlerfere with con,·en.on of IIm~r, u'$ull.ng II> waste; caus ... d by sap freezing during ucene m 'prln!! Hearl ShaluJ (see B).-Shakes which begin al the hean or pith of the log; a smgle cleft is not serious. A Slar Sha/u consish of several heart shakes somewhat in the form of 8 star; render convers.on of timber difficult lnd uneconomical. They are an "arly sign of decay and are caused by shrin kag" m an over m~rurc tree Up$~ts or Rupturt (sec ~.)-FLbres deformed due to mJury by crushing durtng the growth of the tree. KnolJ are sections of branches present on the urface of wood in the fonn of hnd dark pLeCes. It'$ almoSf ImposSIble to obtain cerlam convert~d ttmbeu entirely" free from knots" (as IS sometimes spec.fied). Those kno .... n u " t.ght knots" are sound (bem.l( s.e<:urely jOined to Ihe surroundmg wood) and arc nOt objectionable unless Inll'" \Vood wilh " lar~ " or " loose" knots should nOf be used I~ they arc uns.ghtly and rud.ly removed; wood COn13m"..!! many knots IS difficult 10 work KnOls are a source of v.eaknets if present m lImber to be used as struts or sl"TI.lar members.
Dou Or Doatintu.-From of incipient decay indicated by patches of greyish Itains speckled. with black which are relatively soft; due to imperfect seaso ning or badly ventilated storage and found in American oak, be«h and birch.
DEFECTS IN TIMBEF>-.
B
C
TWISTED GR.A1N
WANE FIGlJR.E 31
Dry Rot.-D«ay caused by funllUS which feed. upon the wood and reduces il 10 a dT)' and powdery condmon It may appear as masS" resembling cOllon-wool with grey or brown coloured stnnds Whllh br~nch nut In net",ork formahon 10 adjacent timber. BaJly aR"c.., ... d lImber hn I"tle Ot no slrcnRth and read.ly crumbles by pre$$ute of the
TIMBER
58
Timber containing an e=eJl 0/ sap and in badly ventilattd pon'tioru is readily affected (sec pp. 60 and 77). Diseased or 1U$p«tM timber mUll!: be removed at once.' Wei Rot iSI chemical and not a fungoid decay of timber; affected portions are reduced to. greyish brown powder and these only need to be removed md replaced; caused by timber beilll subjected to alternating wet and dry conditions. Shn"nkjng alld S~lIing.-When the amount of moisture in timber is reduced during Ie.toning the wood shrinks, and if it absorhs additional moisture afttr seasoning an increase in \'olume result.. The extent of this movement is referred to on p. S6 and is
fingers.
inRuenccd by the manner of conversion, moiSlu~ content and proportion of heartwood. Circum/trlmtial Shrinkage (see c).-Defe.:t denoted by clcfu which radiate from the circumference of the log towards the centre; clefu decrease ill width from the outside pnd are usually iimit'!d to the sapwood; result of shrinkage which occurs during seasoning. Warp is distortion or twis:ing out of shape which may occur during shrinkage; in one fonn (when is it calledbMll or OOtcing) the plank or board is slightly curved in the direction of its length and in another form (called ,up or ,upping) the limber is curved in cross_ stctlon. IVane is the original splayed or rounded surface of the tree which remains at the edge or. edges of l piece of timber after convcrsion; sometimes known as u'anty t dgts. A baulk WIth two waney edges is shown at F. Wane IS due to convertin" too lar~ a baulk from a II"<:C; nOI con~idered 10 be determinal if used for shoring, "iliny', ......., Ami in positions where the appearance and large amount of sapwood arc unimportant considerations. Chipped or Torn Groin is Q slight defect caused by the planing machine or tool removing a portion below the surface of the wood as it is being dressed.
CLASSIFICATION Timbers used for building purposes are divided into two groups called (a) softwoods :md (b) hardwoods. This division has been established by long usage and is not in accordance with the relative hardness of the woods (as certain softwoods are harder than some hardwoods) but is concerned with the specific species of the trees. Thus softwoods are a group which is confined to COtliftrS which are evergrcen (having [ea\'es throughout the year) t(ees having needle-like leaves ami which bear cones (seeds contained in conical sheaths), whilst hardwoods fonn a class of broad leaf trees which cast their leaves in the autumn. Softwoods are in general characterised by (I) distinct annual rings, (2) indistinct medullary rays, (3) comparatively light colour and (4) the heartwood and sapwood are not readily distinguished. They are classified as Group I or II accordmg to the species (see p. 59) . Hardwoods have (t) less distinct annual rings, which are closer together than in softwoods, (2) distinct medullary rays, (2) richer colour and (4) darker coloured :teart wood which is rcadily distinguished from the sapwood. The thickness of the annual rings varies, thus in redwood (see Table I.) the number of rings vanes from five to thiny per 25 mm. Thi~ -:arintion is due to the differ~nce m the length of the swomer. Where the summer IS short, as in North Russia, there ia comparatively little gn;"'th each year, and therefore the number of rings per 25 mm is large. Generally, the annu~1 rings ofhamwoo
The detection and cure of dry rot arc described in Chap. I, Vol. Ill.
load it supports. Such construction may be permanent in character, as floors •. roofs and partitions, or it may be of a temporary nature, e.g., timbering for trenches or similar excavations, centering for arches and formwork to support reinforced concrete floors, etc., during construction. The following is a description of some of these structUtCSl ; -
FLOORS Wood covered floorsl may be divided into two classes, u., (r) suspended floors consisting of bearing timbers, called joists, in addition to the boards which are used to cover them, and (2) solid Roors which consist of either wood boards or blocks upon a concrete foundation. (I) Boarded and Joisted Floors.- Such are usually classified into; (a) Single Floors. - This class consists of only one set of joists, called common joistr or hridging joists. (b) Double Floors . - In this class, additional and larger joists, called hinders, arc imroJucl:!J to :support tltl:! briJging jui:SlS. (c) Triple or Framed Floors.- Such a floor comprises three sets of joists, i.e., bridging joists which transmit the load to binders, which are in turn framed into and supported at intervals by larger joists called girders. Double and triple floors are required for buildmgs of large uea. Whereas formerly the binders and girders were of wood, this material is now rarely used for this purpose. If wood joists are to be used in conjunction wilh binders, the latter are now usually of mild steel, "hen they are called stul beams or gjrdfrs--or rolled steel jo;sH, abbreviated to " R.S.l.'5 " (see Ii, Fig. 80). Floors of large span are now usually constructed of fire resistln~ materials, such as (i) reinforced concrete beams and slabs, or (Ii) main steel beams to which are fixed secondary steel beams that support floon consisung of either sm~1I steel beams encased 10 concrete, concrete floors .... ith ,,~panded metal Or simtlor reinforcement, or patent fire resisting terra_ cotta Or concrett bloch. Such floors :Ire detailed in Vols. II, III and IV. Single Floors.- The floors of domestic buildings, e.g., houses, are gen..:rally of thi~ type, and the following description is applicable to the construction of a typical ground floor and an upper floor of such a building. Floor Insulation.-The Building Regulations require that suspended floors be insulated to a given value if; (I) the floor is not resistant to the passage of air and (2) If the space beneath the floor is not fully ..:ttdu~J apart frum ventilation by air bricks (see p. 63). It cannot be said that the t. & g . floorboard (see p. 63) is completely air-resistant so it is advisable to insulale the floor to the required value by nailing 12'5 mm thick expanded polystyrene slabs on top of the floor joists before the boarding is fixed. GROUND !"lOOR
Fig:. 32 shows the plan, secti',ns and various details uf a ground floor which is of the single floor class. 5izet ofJoists.- The sizes of jo:~ts depend upon (a) span, (b) distance between each joist, (c) load on the floor and (d) the timber used. 1 Cork, rubher . mosaic, fireda.' ,rry, thermoplastic, and marble tiles arc also uscd to cover floors, sec Chap. I, Vol. Ill.
CLASSIFICATION
59
TABLE 1 WEIGHT N~.
SoURCB
(kg per m')
CHARACTERISTICS
U,..
RwWOOD ~orthern Pine, Scotch ir, Red Deal,
Russia, Norway, Sweden, Finland
5)0
Reddish brown heartwood, yellowish brown IJ;\pwood; well defined annual rings. medullary rays invisible; worka easily; very durnble when painted; atrong.
Doors, windows, floors, .roofs,
GROUP
Yellow Deal) 00
"00 ~ E-<
"'0 00
00.
WHrfBwooo (White Deal,
While Pine, European Spruce)
C"N"'OI"NSPR1JCE~Quebee
430
While 10 whitish yellow; well defined annual rings; slightly difficult to work owing to hard knots; not durable for external work White; well defined annual rip-g5; straight gra;n('d, easy to work; liable to wrap; not durable . Pink to light reddish brown; well defined Dnnual rings (spring WOQd lind summer wood approximately of equal width); fairly easy to .....ork; fairly durable for external ..... ork; should be rift sawn for flooring Light red; well defined annual rings with I~rge proportion of swnmer wood (duk) which gives good figure; contain, much resin, hard to work; very durable and strong Reddish brown: distinct annual rings; straight grained, easy to work; very durable under all conditions; brittle
Eastern Canada
Spruce, White pruce) DOUCLAS FIR (British Columbian Pine, Oregon Pine)
45 0
British Columbia (Western Canada), Oregon State (U.S.A.)
530
PITCH PiNE
Texas (U.S.A.)
WESTERN RED CEDAR
Canada
"0'
IA~;'o,
I
650 380
I 0 ..
England, America, Austria, Russia, Japan
6Qo to 850
Light yellowish bro..... n to deep brown; fairly well defined annual rings, well defined medullary rays: rift IIIwing (lives ~autiful figure; hard and durable (excepting Amencan): very suong
TMK
Burma and Siam (Indiu), West Coast (Africa)
650
MAHOGANY
Honduras (Central America), Cuba (West Nigeria Indies), S. (Africa)
.80
Light golden brown; annual rings dcfincd b belts of porous tissue, fine medullary ruys; very good figure; di cult to work; durable, fire resilling and hard wearing Rich reddish brown; indistinct annual rings, distinct medul!ary rays; good figure; not durable for external work. Cub3
North America
740
00 Q
0 0 ~
"'"<
Roo:
MAPU
X
E'M BIRCH
England
560 10 690
6,0
1 British hi""
I Tlm~r
tt
L1J(ht reddish brown; indistinct annual rings., very distinct medullary rays, "Curly" or "Bird's-eye" maple has distinctive and pleasing figure of dark" eyes " with curly dark lines; durable (if used internally) and very hard wearing Dull reddi sh bro~'n, distinct annual rin~5 and medullary rays; durable if kept dry or wet but if not subject to both; tough and e\a8tie White to light brown; indistinct annual rings and medullary rays; strOng, tough, not durable
.
and genenl internal and eJ(ternal carpentry and joinery of good quality. Internal work, as for fioors, roof"
and shelving of cheaper grade than above: shuttering. Roofing. flooring, scaffolding.
Doors, panelling, flooring, interior finings, sleepers, piling. Doors, windows, roofs, floors, panelling, slcepers, piling. Used for good class work. Roofing shingl"" (boards), panelling joinery.
Doors, ..... indows, floors, roofs, stairs, panelling, furniture, gates, fer.ces and general carpentry and joinery of high clan quality. class g'cncTul joinery as 0' doors, windows, stairs, panelling, furniture. High clan internal joinery, especially for decorative work, panelling, bank shop fittings, newels ,od handnils, furniture. High elass Rooring, panelling, furniture.
Ht
..
ro<
'n'
Weather boarding, piling: Plywood, doors and furniture.
reqUIred for fint class carpentry and Jomery should be sound, bnght (l.t., free from dIscoloratIOn), square edged, thoroullhly seasoned to SUIt the particular use, free from shakes, large, loq." or dead knotll, warp, incipi"nt decay and other defects which would rcnder it unserviceable for ita purpose. It should be frcc fr,!m stained. "."pwood Dnd the .mount of bright sapwood should . n';'t exceed the following (for redwood): .s per cc:nt: for: first clan join~ry, 7 per cent. for medll.lm class Jomery..nd 10 per cent. for carpentry, thIS amount IS Influenced by the norrnzl temperature of the bUlldmg m w'h,,:h the limber is to be filled. Softwoods.~ claMlfied in three groups. Group 51 comprises Douglas Fir, Plleh Pme and Euro~n Larch. Group S1 includes Canadulfl 5pru~, Redwood. Whltcwood snd Walem Hnn\ock. Group 53 consisu of Europell/1 and Sitka Spruce. and Western Red Cedar.
TIMBER
60
(a) Intermediate supports to ground floors are usually provided in the form of 10Z mm thick walls, called sleeper walls (see below), which are Duilt at a maximum distance apart of 1800 mm, and therefore only small joists are required for ground floors. As upper floors of this class have not such intermediate supports, the jois.:s span from wall to wall (usually across the shortest span) and
I,
therefore they are reiativeJ,y large.
(b) The spacing of joists varies from 300 to 400 mm centres (the distance between the centre of one joist and that next to it). If 25 mm thick boards are used, this distance is generally 400 mm. (c) The minimum safe superimposed load (or live load) allowed on floors varies with the type of building, thus it is 1"5 kN/m2 for a house and from 2'4 to 9 kN/m z for a warehouse. (d) Suitable timbers for floors are referred to in Table 1. Redwood is the best softwood for this purpose. TABLE II, FLOOR JOISTS
Maximum dear span (m)
Size of Joist (mm) (spaced at fOO mm centres)
Maximum dear span (m)
0'99 1'26 1'63 2'03 2'33 2'83 3'2) 3'29
38 by 75 50 by 75 )8 by 100 So by 100 38 by 125 38by ISO sobY'5 0 38 by 175
3'75 3'75 4'07 4'27 4'21 4'64 4'79 S'ZI
Size of joist (mm) (spaced at fOO mm centres) 50 38 63 50 38 63 So 63
by by by by by by by by
175 200 175 200 225 200 225 zZ5
Table II, derived from the Building Regulations, gives the maximum clear span for different fivor joists of Group II softwood (see p. 59) spaced at 400 mm centres when the dead load on the floor is not more than 0'25 kNjm 2 (it rarely exceeds this amount in a domestic floor). Wall Plates.-These are wood members, generally 100 mm by 75 mm or II5 mm by 75 mm which: (a) serve as a suitable bearing (100 to 115 mm) for the joists, (b) uniformly distribute loads from the joists to the wall below, (c) provide suitable means of bringing the upper edges of the joists to a horizontal plane to receive the floor boards and to ensure a level surface and (d) afford a fixing for the ends of the joists. 1 They are solidly bedded level on lime mortar , ,,"'all plates are frequently omitted in cheap work (as shown at I., Fig. 36) and the ends of the joist are packed up with pieces of slate, etc. This is an undesirable practice as repeated vibration tends to disturb such bearings, resulting in unequal settlement of the joists and an uneven floor surface.
by the bricklayer for the full length or width of the floor (see broken lines at F, Fig. 32). Joints in long lengths are formed as shown at G. This is called a half lapped joint or scarj. The vertical cut extends to half the thickness of each plate and after the cut surfaces have been fitted together, nails are driven in to make the joint secure. Intersections between wall plates are formed as shown at H. Ground Roor wall plates arc usually plactd immediatdy over the horizontal damp proof coune. It is the usual practice to rest the ends of the joists upon the wall plate and fix them by driving nails through their sides into it (see u). If the joists "\Iary slightly in depth, their upper edges are levelled by removing a portion of the wall plate as required to form a housed joint (see K and L).l Other forms of joints which may be applied to the ends of deep joists are notching and cogging. A single notched joint is shown at M, the lower edge of the joist being cut to fit over the wall plate (such as may be supported by' a sleeper wall). A double notched joint is shown at N and is formed by cutting both joist and wall plate. A single cogged joint, used at the ends of joists, is shown at 0, the joist being cut on its lower edge to correspond to the uncut portion or cog on the plate. Where the joist cut coincides with the cog after two sinkings have been formed in the plate, it forms a double cogged joint (see p) such as may be adopted when joists are supported by sleeper wall plates. Neither notching nor cogging (sometimes called caulking) are much used. Reference is made on p. 57 to a particularly virulent disease of timber known as dry rot. It is necessary to safeguard against this disease by using only well seasoned timber and to provide adequate ventilation. Free circulation of air to all ground Roor timbers is therefore essential, and it is for this reason that wall plates should be supported either (a) by sleeper walls built parallel to and about 50 mm from the main walls (see this construction shown by broken lines at c, Fig. 10) or (b) upon offsets (shown at A, C and 0, Fig. 11) or (c) upon corbels (see L, M and N, Fig. I I). If, on the score of economy, the wall plates and ends of the joists are built into the wall, it is necessary to form an air space round the sides and tops of the joists (see K, Fig. 32), and it is also advisable to apply two coats of creosote (sec p. 56) or other preservative to the wall plates and to the ends of the joists. Attention is drawn to the provision made to ensure an adequate circulation of air under the wood Roor shown in Fig. 32 where air bricks (one type being shown at v) are fixed in the external wall, bricks are omitted in the IOZ mm division walls to form ventilating openings (abbreviated to "V.O.") and voids arc formed in the sleeper wall (when it is said to be " honeycombed ").
, A less satisfactory m e thod of levelling up joists is frequently resorted to i.t., the ends of the lower joists are packed up by inserting thin pie<:es of wood befween them and the wall plate.
b
FLOORS An enlarged detail of an air brick built into a wall is shown aI u. Air bricks are obtainable In various si~«, colours and textur« to confonn with the brickwork; they must ~ well perforated; an alternative fonn of ventIlator i$ I Cist Iron ventilating grate. Sleeper .....111 foundations have bttn referred 10 on p •• 8 A sleeper "'nil " honeycom~d 'Imply by omitting bricks during Its construCtIOn The vOIds may ~ Irrlnged haphuard, or as shownby the twO alternative forms mdle~ted In section DD. All sleeper ..... alls muSI be pconded ",th damp proof courses.
It is sometimes necessary to resort to either offsets (for ground Roors) or corbels (for upper walls) to provide support for the wall plllt,,;s, :IS shown in Fig. II. Alternatively metal bars, called CQrbel brackets (see T, Fig. 32), may be used. These are of mild steel or wrought iron, from 75 to 100 mm wide by 10 mm thick by about 4]0 mm long with ends turned 5 0 mm in opposite directions. They should be painted and built 215 mm into the wall at from 760 mm to 900 mm apart. An alternative form of wall plate is shown at s, Fig. 3~. This is a 50 or 75 mm by 10 mm mild steel or wrought iron plate of any suitable length. It is r:Hely adopted. Whilst joists may be placed in any direction, it is usual to fix them across the shortest span. A space about 50 mm should be left between the wall and the first joist which is parallel to it. When joists forming Roars of adjacent rooms run in the same direction, the overlapping ends on the division walls arc nailed to each other and to the wall-plates (sec y' at A, Fig. 32). The plan of the room shown in Fig. 32 includes a fin::pl:l(e. The construction of fireplaces is described in Vol. II, as it is outside the scope of the syllabus of a First Year Course. In order however to make a description of ground Roors complete it is necessary to make a brief reference to certain portions of a fireplace. A wall is built round the fireplace to retain the concrete hearth (and the material supportin~ it) and to support a portion of the Roor. This is called afend~r wall l and its 'thickness may be 102 or 215 mm, depending upon its height and the load which it has to support. A fireplace may be constructed within a re<:e!o"S as shown in the Figure in which case the Building Regulations require that the hearth:--{I) Projects at least 500 mm in front of the jambs (the sides of the fireplace opening). (2) Extends at least 150 mm beyond the sides of the opening. (3) Is not less than 125 mm thick. If the heating appliance is not in a recess requirement (3) above applies, but in lieu of (1) and (2) the hearth must be of a size so as to contain a square having sides not less than 840 mm long. The site concrete should be well brushed, and all debris below the Roor
I Ground floor joists Ire often trimmed as described on p. 65 for upper floors. This i, in lieu of the fender wall construction, and is to be preferred u moisture (eap<:cilily if the aite ia a damp one) may ~ transmitted from the filling to the wall plate. and end. of the joist. snd mly CIIuse dry rot.
61
removed before the floor boards are fixed. Dry rot may be caused by small pieces of wood, shavings, etc., left below a floor becoming affected (probably on account of dampness) and spreading to the members of the floor. After the joists have been levelled, with their upper edges in the same plane, they are now ready to receive the Roor boards. Floor Boards. Some of the timbers used for floor boards are stated in Table I (p. 59). Redwood is used for ordinary good clas.ct work, whitewood and spruce for cheaper work, and pitch pine and the hardwoods (such as oak and maple) are employed for first class floors. The sizes of floor boards vary from 100 to 25 mm wide and from 25 to 38 mm thil.:k; the narrower the boards the beuer, for then the shrinkage of each will he reduced to a minimum, the joints ~,ill not appreeillbly open, and there will he less tendency for the board~ to cup (sec p. 58). Hence 100 mm wide boards (specified as being" in narrow widths") are used for first class work, 115 mm ""ide boards for average good wurk and 175 mrn wide boards for commoner work. Hoards of 25 mm nomin~1 (see below) thicknes~ are used when the joists. do not exceed 400 mm centres. The sil-e is that after the boards have left the saw and is known as the nominal or stuff sizes. but after the boards have been shaped as required and dressed (or ~~,ou!:ht) the sizes are reduced and arc known as net or finished sizes. Thus a floor board has one side (which is of course laid uppermost) and both edges planed, and a 175 mm by 25 mm (nominal size) board is ref.hu,;ed to 170 mm by 20 m,n net, and a 32 mm (nominal) board has a finished thickness of 27 mm; the net width includes the ton~\le (sec Q, R, v and w. Fig. 34). Boards arc obtained in random lengths from 4'8 to 6'3 m (see Basic lengths, P.56); although 7 m long boards arc available. Th" boards m~\' be cOlwertcu b~· S'L\'IIlJ.( from the 10).(.:1$ sllo .... n In FiJ.(. )0, or from b,mens' thus Sl~ ;00 mm by:iS 10m (~pproxlmalel\') ho~rd$ may u., obtained from one 'l.oo'mm hy 7S mm batten hy 1"0 sa" euts du"n It~ depth C' deep euts ") Jnuone cut down liS thickn"ss (" fl~l cut "). The labours such as reb~t1l1R. IQngumg, J,(rOO\'lng and planinJ.( floor boards (SCl' Fig. 34) arc ca~flcd uut in one operallun by a m"dun" called a PI~nml: and :\1~tch1l11: Machin". Thus boards "h,ch aT!: tongued and J,(roo"ed (sec R ~nd l·. FII(. 34) He madl' as foJ1ows: The sa"n board as It passes hurizont"lIy throuJ.(h the m'Khinl' is first 5mooth finished on th" 10ller surfa~t:. As it proceeds il I~ pLmed ~nd grooved un one "dge,. tongued on tht: other as the boar? IS reduced to the corn',,:! ",dth, and just befor~ It 1t:~"es the machmt: the board IS reduced to the rC
Joints.- Various tdg~ or longitudinal joints between floor boards are shown in Fig. 34. These are described below. Square or Plain Joint (see p).-The edges arc cut and planed at right ang-1cs to the face or side, when they are said to be either shot, bUll jointed or straight edged. This joint is never used for good work unless the boards are to be covered by another layer of boards to form what is called a do",h!e boarded floor (p. 64). Rebated Joint (sec Q).- A 10 mm wide tongue, one-third the thickness of the board is formed along the lower edge of one board and fits into a slightly wide.
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FLOORS rebate formed on that adjacent. This joint is rarely used for edge joints, but is sometimes adopted in good work for heading joints (see below). Tongued and Grooved or FeathtTed and Grooved Joint (abbreviated to "t. & g." or "f. & g.") (see Rand u).-This is used more frequently than any other for good work. A narrow projecting tongue or feather is formed just below the middle along one edge and a gmove along the other. The tongue is slightly smaller than the groove (thus for a 10 mm wide tongue the groove is approximately 12 mm deep) to enable the boards to be fitted closely together at the tOp and bottom surfaces when the tongues are engaged in the groove. The tongues are sometimes slightly rounded off so as to facilitate the laying of the boards and prevent them being damaged during the process. Rebated, Tongrad and Grooved Joint (see v). This is a good but expensive joint and is sometimes adopted for hardwood floors where the boards are to be secured by nails which arc required to be concealed. As described on p. 64, floor boards are usually fixed to the joists by top nailing, i.e .. the nails arc driven through the entire thickness of the boards. This gives a somewhat unsightly appearance which is avoided if suret nailing is adopted, i.e., cach board is secured by hammering one or two nails through the tongue into eaeh joint. Splayed, Rebated, Tongutd and Grooved Joint (see w).-This is another joint which is secretly nailed. It is an imprmement upon that at \' owing to the thicker and stronger tongue. Ploughed and Tongued Joi1l/ (see x). Grooves are formed or .. ploughed" in the square edges of the boards to receive hardwood tongues or" slip feathers." It is rarely employed unless very thick boards are required and where the ordinary tongued and grooved joints would result in an excessive waste of material in forming the tongues. Htading or End Joints.-Wherever possible, the boards should be sufficiently long to reach from wall to wall of a room in order to avoid end or heading joints. Where such joints are necessary, as for large fioors, they usually t(lke the form of the square joint shown at P. Each adjacent board is cut to cover half of the thickness of the joist below, tht: ends arc closely butted together, anu four nails are driven in, two on each side of the joint. Another form of end joint is called the splayed or be'l:tlled htadlng joint (see v); the ends arc splayed to give a tight fit, and twO nails are hammen:ll in at an angle as shown. Rebated heading joints (sec Q) are sometimes specified for good work. The appearance of the work is spoilt if the heading joints form nne continuous line over the same joist. They should be laiti to break joint as shown on the plan at H', Fig. 32; sometimes they are arranged as shown at J' when not more t"an three heading joints appear in one line, but the appearance is not so satisfactory. (NOlt.-The boardt utcd to coY"r th" floor thown al A. Fig. )2, would not r"quiT" headmll joints, as 5" m lonll bouds (see p. 6,) would be used; the headmg joinn at II' a nd ( ha"" be"n shown to il1ustrat" th"ir application.)
Cramping and Nailing Boards.-The Joints lT'ust be as close as possible before the boards are nailed. The best means of effecting this is to employ
I an appliance known as a metal cramp, the plan of one of which is shown at
A,
Fig. 33. ('mmp,nf;! i~ performed in th" following manner: After the top edges of the jOists h~,:" bun levelled, staning from one Will, the first board is laid at nght angles to the jOists and nailed. F,"e Or SIX boards are laid loo"ely upon the JOistS. Two cramps are placed lemporaTily oyer joists which are some 600 or 900 mm from the
METHODS OF LAYING FLOQBOAl'-DS, ETC
C1Vl.MPING
,i .JOIH _ _
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FIGURE
33
"nds of the bouds. Each cramp is fixed 10 the jOlsls as shown at A, the ann D i$ rotated in th" d,rectlon .. f Ihe arrO" ", "; thiS causes E to rOtale lO .... ards the joist in Ih" direction of the aTTO" "2". "h"n the groo,ed surface on F. and the sharp rnet~1 pomt' at F (which proJ".:t from Ihe Side aod under Ihe tOP plale at C) (8US<' th" cramp to j<:rlp the Sides of the jo.S!. A rough $tr,p of ,,000 is now ,nserted between the floor board and the plate (' to prott'<:t the edge of the board. the urn R is rotat"d in the dorect,on of the arrow" 3 ". and this causcs the plate c to mo"" forward as shown by
TIMBER the arrow H to exert (;onsidenble pr(Ssur., on Ihe boards untIl the joinu between them are completely closed. The boards aro: then nalltd a~ described helow. the cr~mps and the strip of wood are remen,d, and the oper"tion is repeated on the next fi\o: or ~;x bo3Tds. As the work proceeds towards the oppo~lte wall, the lasl fe" lenJo:th~ of hoards cannot be cramped 0" in" to lack of sp~ce These boaru~ may h., brought up I\l.(ht by using ~ pie<:c of Roor bo,ud which i. mclined wilh the upp<:r td"e aj.[ainst the ""II ~nd Ih" lower cd..2" againsl th., prot"cling strIp: "few smart knocks with a h.,avy hammer on th~ upper cnd of the plccr of bOHu WIll dose up the Jomts. Wh"n a cramp IS not avaibblc the joiots bct"el'n the boards mily be dusnl by " jumping them in "or" laid foldm.ll." Tbis method is shown ilt J, Fig. 33. A.~um illS that thc floor has been laId up to K, II board M is nmlcd at" dlSlml<."e I. "h".:h .,quals th" ",dlh of the fivc boards "hen placed in positlnn tIghtly by h,md less (, In I) mm depcn(\lng upon Ihe "idth of the bo.rds; the four bo.m.b, I. 2. ] ;lnd 4~ arc then placed MS shown and forced Into pOSItIon by Jumpl1lg on Ihc bourd ... Whl~h "h"d aero~~ them. The bo~rct.. lOre fin"lly naIled and the operati"n rcpe~tcd. Another method is adopted In tht absence of a cramp, ,15 sho"n at 0, fo-,g. 33 . .-\ metal dOl! is driven into a joist, ~nd the !mards (fOllr "r five at ~ time) are brought close tOflethcr by tightening the hard ... ood "cd.ll"s br means of a hammer. \\'Iwn the boards BTe ~"crctly naIled, and "ach board has ther~fore to be c ramped and n~llcd ~cp~T3tdy, it 1$ usual to crump each bourd "lIh Ihe llid of a stron.!: ~ht~l'l "hich Ii driven inll) the top of a joist cIos" 10 the prOlecting strip and used u ~ Il"cr The blade of the chtsel is forced agaltlst the strip and Ihe pressure closes the jOlllt
The boards are secun~d by oval wire nails (sec A, Fig. 66) the length of which should be 2\ timeS the thickness of lhe hoards. When lOp-nailed, 1\\0 nails arc driven thro~gh each hoard 10 evcry joisl which il COVl:rs, including tl-lO nails lit the ends, The n.lils are ahout 25 mm from the edges, and after Ihl; boards have been fixed, the heads of the nails are driven below the surface by using a hammer ,tnd punch (sce 10, Fij:!. 67), Tongued and groovcd hoards (in addition to square and rebated boards) are usually top· nailed as sho\\ n by broken lines at s, Fig. ) f. Occasionally they arc secretly nailed as shown in the two positions at T, tht: higher position being the better of the two as the tongw: is less likely ttl be damaged. The secret nailing of boa~ds which are jointed as shown at v and \\' has bel;n mentioned all V' 63. The headn of theie are ~1,,() runched. In order that water and gas pipes, ·electric cables, etc" .... hich arc frequently run below the floor boards, may be readily accessible, the boards o\"er them are not nailed hut screwed. In good work it is customary to fix a hardwood margin rOllnd all firepla.:;e hearths, as shown in the plan at A and the detail at J, Fig. )2. This ensures a more accurate finish and a neater appearance than is presenttd if the ends of the boards are stopped against the concrete or tilei, The floor boards, arc rebated to receive the 50 mm by 20 mm oak margin which has mitred angles; if 22 mm thick boards are used, the margin is of the same thickness and the ends or edges of the boards are butted against it. Double Boarded Floon,-Double !looring is sometimeS required for buildings of the factory type (where the floors are subjected to excessive wear) and for domestic and other buildings which require good class floors, As is implied, the floors are laid in two thicknesses. The first covering or sub-floor (or counter-floor) usually consists of 20 mm roughly sawn square edged boards
laid di,t).:onally across the joists to :lvoid their joints coinciding with those of the boards above. The upper boards may be of 20 to 25 mm (nominal) hardwood (usually "Oak or maple) whid} lire fi'\Cd at right ~nglc~ to the joists. (2) Wood Covered Concrete Floors (Solid Floors). ::iuch floors are of concretc, thc~' may he covered with wood boards or hloeks (sec wand x, Fig, 32). Other fini.shes suitable fOr solid floors 'Ire given in Chap. J, Vol. III. Iloords OIl ('oncre!e (see w).-\Vood fillets arc pllTtl~lly embedded in the concrete floor and Ihe hoards arc fixed to them, Special precautions must be take n to pre\ent dry rot; the concrete must Ix: dry, the fillets treated with a preser\",lti,-e, and the top of the concrete gi\'cn two coats of bitumen. Aller· natively the concrete is laid in two laycrs with 3 d.p.c. between (sec s, Fig, 10). Th~ l")ncr~te floor IS Imd to the Ie""] of th~ undcrsido: of the fillcts and the top surf,,~"C O\u_t be' Ic\"d throu!!hout. The fillet~ "Tt· placed at 400 mill centres and kep~ temporarIly in p()~ltion by naIling c ros~ b~nO:I1> 10 Ih"O\ :\1nre concro:te is then pb ~cJ in poslllon !n "!lhm 13 mm of th ~ top of lhe hll~t.. BOlth SIdes of th" fillets
m"y he spl.lyed. alth"uJ.:h It I.' lIlore economic'al If only one .,de is splayed (as shown "I wJ, \,hen one 1"". "f tillo:u lIlay be oh{,un"d f'Om a 115 mm b~' 75 mm sCOlntling.
Blocks on ('oncrelt (see x).- The concrete floor is covered with wood blocks, .. bituminous material or mastic being used as .w adhesive, The blocks may be of well-seasoned softwoods (such as redwood, British Columbian Pine and pitch pine) or hardwoods (such as oak, maple and teak). Their nominal sizes ,'ary from 225 to 300 mm long by 75 mm wide by 25 to 38 mm thick. Two of many types arc shown at y and z, Fig. 32, the formcr being the simplest and is commonly used. The blocks arc fixl;d by dipping the lower portion into the hot bituminous mastic, and then bedded on the conCrete to which the mastic adheres. Whcn the), are pressed down, the li{juid mastic rises in the grooves, as shown by the blackened portions in the illustrations. The thickness of the mastic is almost negligible. The blocks arc laid to various designs, those most common arc of the herring-hone and basket (shown 'It x) patterns. A simple border consisting of one or two rows of blocks is plact:d next to each walL The COllerelt floor i~ finished "'Ih "fllla/m;! lOat (or .aud), u$ually ~s mm thick, conSlstmg of I Cemtnl 3 sand. It must be fiolshed quite level and mUSt b<: aboo. lutely dry before Ihe blocks He fix ...-J. olhen\lle the mastic will not adhere to it. Th" buildmg must be thorou\(hly dry before such floors are laid, otherwise the 5e3SOn"d blocks wtll abso rb mOlsturt and may swell to such an elttent as to cause Ih~ floors 10 T1S~ 10 the cemre. A
Cleaning Off and Protecting Floors.-On completion, wood floors should be trcroeTSed or "flogged." This consists of planing the boards to a Ic\'tl and smooth surface either by hand or machine. Hardwood Roors are afterwards scraped (sec scraper, p, 128), rubbed smooth with glass.paper (see p, 1 :0:8) and finally oiled or waxed and polished, Floors should be protected agalllst damage Juring: suhsequent building operations by liberally covering them with sawdust. This prevents plaster, paint and dirt from soiling and scratching the boards or blocks and the sawdust absorbs moisture,
FLOORS UPPER FLOOR
The plan, section and various details Qf an upper Roor of a room which is of the same size as the ground floor already described are sho .... n in Fig. 34. The bridging joists are placed across the shortest span, and as there are no intermediate supports (such as sleeper walls), their dear span is 3.67 m. In accordance with Table II (see p. 60) the size of these joists will be 175 mm by 50 mm. An alternative arrangement of joists which would be adopted if the shortest span was in the other direction is shown at P, Fig. 33. Trimming.-Where fireplaces and openings (such as are required for staircases) occur, the bridging joists cannot be supported at hoth ends by the walls, and the introduction of additional wood members is necessary to receive the ends of the joists which have to be cut. This operation is known as trimmillK. The trimmed opening at the fireplace shown at A, Fig. 3-1-, has a thick joist, called a trimming joisf, which is 508 mm from the fireplace and spans the full width of the room. This joist supports at one end two cross joists calle{1 trimmer joists, and the latter in turn support two pairs of short joists known as trimmed or tail joists. At the ahernative plan P, Fig. 33. the two trimmingjoisls have one trimmer framed to them \\ hich supports four trimmed joists. Thus a trimming joist isone which has one or more trimmers connected to it, and a trimmer carries cut bridging joists called trimmed joists. The arrangement of the timbers shown in these two plans is J1\ accordance with the Building Regulations (summarised in Fig. 34) controlling the construction of wood Roors adjacent to fireplaces. Trimming and trimmer joists should be thicker than bridging Joists on account of the greater weight which they have to support. It is usual to make the thickness of a trimming joist 25 mm greater than that of the bridging joists and a trimmer joist supporting not more than six bridging joists to be the thickness of the trimming joists. As the bridging joists are 50 mm thick, it will therefore be neces~ar}" to use 75 mm thick trimming and trimmer joists. Joints.-Thc following joints used at trimmed openings are sho\\n in Fig. 34: Tusk tenon joint, dovctailed housed joint, bevelled housed juint, and S(lllare housed joint.
at a trimmed openitl)( ~hould be well deslgn~d and con· On ". H) TcfNenee IS made to the b..-ha\·iour of a load"d wood beam Ilnd to the $trcs~,'~ of l:ompression, tension Dnd sheDr whieh are produced If II. portion of a j"'~t ab",'c (he n~u(ral ""'b .s removed,. th",joist will he less cffeetlvc in reS1S.tm)( comp"~sslon Slre.sn, Jnd if the lower p(lrtlOn IS cut and partially removed the JOist IS weakened to re.,st tension stresses. ThIS muSt not be lji(norcd when notches for pipe5 are made in joists. as a careless workman when fixing .... ater, Ctc., pipet under floor boards may reduce the strength of joists enormously clther by ~xcessl\"e!y notchmg them or by indiscriminate notching. The aim therefore should be to make the jOllltS as SCI:UTe as possible .... ith a minimum removal of wood and reduction. In stren)(th of the main member~. I.t .. the trlmmen (to ..... 1 ,ch the mmmed JOIsts are connected) and the mmmlO& joi5t~ (to" hlch the tTlmme" are joined). J"mts
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h~t"~~n jOISt~
Tusk Tenon Joint (sec I., Fig:. J.t, .1111.1 Q', Fi~s. 33 and 3-1-)' This is the stron!(C!st form of joint usnl in floor con:,truction and for this reason it should be adopted for the connection between the trimmer and trimming joists. The tenon which i~ cut on the end of the trimmer (and passC!s through the mortice formed in the trimmin~ Joist to some 100 to 125 mm beyond it) is in the (1'II1rl'l of the trimmer. The projecting piece or lusk provided below the tenon transmits most of the weight and l:nters fmm ! to l into the trimming joist. The bevelled or slanting portion above the I<"non, c:Illed the IUIfII or h(lunch, strengthens the tenon. 'fhe trimmC!r is brought tight up against Ihe trimming joist by driving a wood wed!(t down through a hole formcd III the tenon; thl: side of the hole (shown by a thick Itn(, in section J']') should he Cllt to the satnc :Ingle as that of the tapered II edge and this hole must be Ion),; enough to allow the trimmer to be forced in the direction ufthe arm\\ until the Joint is tight. A modified form of tusk tenon, called .1 bet'rl/rt! "mll/du'" joint, is sOmetlll1t·S adopted between a trimmer and each of the tl1llllned joists (~s ;tt 1', Fig. 33), where it is not possible to han: projecting knons on account of the hearth. This is similar to the tusk tenon joint, except thaI the tenon docs not prOJect, but is cut flush II ith the outer side of the trimmer. \\"hen the tl:non formed Oil the trimmed joist has bcen inscrted, the sides of the mortice in the trimmer are slightly pan:d to reccive two small \\edges \Ihieh arc driven in to tighten the tenon; 150 mm wire nails are then hammered in from the top and sides of the trimmer and through the tenon. A further modification consists of a shorter tenon (with tusk) which enters a corresponding mortice in the trimmer. Long nails driven in from the top of this joist make the joint secure .
novtlailed Housed or Notchtd Joint (see \IJ.- This is another good joint which is used to connect trimmed joists to a trim1I'er joist. The end of the trimmed joist is formed to correspond to the housing (one edge of which is dovetailed as shown) made in the trimmer to receive it and is dropped into the housing. Long nails arc then dri\'en in slantwise from the outer face of the trimmer and through the end of the trimmed joist. Applications ~rc shown at R' in P, Fig. 33, and A, Fig. 34. Bevelled Housed Joint (sec ;\').- This is a cheaper but an cffeetive alternative to the dovetailed housed Joint ,md is used for the same purpose. It is known as a half-dl'pth joint, as the depth of the housing equals half the depth of the joist. The joint mllst be nailed securely. Note that the amount of timber removed from the trimmer I'aries from nil at the top fibres (where the eom.)ressiun stress is greatest) to a maximum at thc neutral axis. Square Housed Joint (see 0). This is another half-depth joint which may be adopted for supporting short trimmed joists as at s' in A, Fig. 3-1-.
I Sometimes the u .. dusiJt of the tenon is made to coincide ""th the centre of the joist. Although this forms a somewhat strongu jomt, it is more difficult 10 make tight.
66 HEAR..TI4S
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hallro
olhcrI.l15C unJw: sln:ss 1ll;1, he Iran~mllt,.J III tlH: ""lpr"ftin); \\.lll~ .tnJ rl.I~ltn·(1
ceilings m,'\ h,. rendered lide";!I',. on .L«(CI\IIl! of the \jbr;I\I'on prPllu.:nl. Dct:p It IS llnOl'~~.LT\ Illelcf"r~' 10 stiff~n the floor hy p;o\ldmj! HO~S hrflCl""~ Of ,/rr./I",I.{ in U'(ltH1UOIIS nm,; ~nJ ;11 irtcna!s n01 (\(ccuing I'R In apart. Tht'rl' an: 1\\0 tOllll~ of ,,[TUUIIl).!. 1.1, hcrnn,g IKlI\t' and solid. JI"'I1I!? /June ."",rUlltng (sec\, S, anJ J, Fig ..H). Tlu~ I' UI1'llIl"~tllln,lhly lilt: best form, and comprise,; p.lir:> of indinl"d pit:tTS flf \trn",,! II Imh Jrl' I1ghtl~ fitted bel\\ecn tht: JOi~h. The sil.c of c,Kh pi<;u' \ ;lri<'~ frol11 :=;0 11111\ 1·\ 32 mrn to 50 mm by 50 mm, .Ind th,'~" ,Ir" ",u'urcd to the sid.,.,ol til,' l"i,h b~ !UK (IS mm nad at COll,:h end. 1 Prmlu",1 th,' \\,III~ ,1ft SUtiitlflltlv ,tnUll!, fllldinJ.: "I·d!!"" ,If" drilen In bd\\Cen th" \,,111 ami tht ,Idpct'nt .!lJl~t. ,lilt! III IiTl" I,ith thl' ,t[lntill\!. a!> sholln; thest an; ,llIolleo 10 f,'m:'l.In .I~ thtY ltKr,·.I~I· th" "llili"n(\' of tIll" strutlm~. Thb form of ~tfllttlng I~ ..,1 ill dfe<.(lle el'cn il tit,· Im~ts "hrink In tht direction of Ilwir depth ami thilkness, for tht deplh ,hnn,.I!!t' tspnlalh t"nds to reduce the InLlITl,IIIOI1 of the strUIS, "ith a corre~pond'n!! Inuca ... e 111 COI1Ipression. .";olid Slrulllll'/: (sec I' ,lIld ~, Fig-. 33). The simple... t f. tu become loose as their length is thl'n k ... ,., Ih,m the clear di~LlI1(e hel\leen the Joi~ts. To make the struttin~ effectin: It is u"le~".tr) to Ii\ a lung CLrlul.H ste,,1 or \~rought iron rud (varying from 13 to 25 II1Ill in diamder)throuch the \Ihule "f th~Joists and ncar to the strutting-,:ls shlll\n, The rIld i~ threaded thrlluch the holes which have been augured thmu\:th th..: Ilcutr.tl nis o! the joist~. The nut is tightened after the struts hal c heen fixed and ag.tin tightened hy me,IIlS I)f a spanner bdore the floor hoards arc laid. This form (If strulIlng (tulh rod) II nvu Jt/dum adopttd. H e arths.-Huilding regul,lIlOns stipulate that the hearth in front IIf d fireplace shall project at least 500 mm beyond the front of the jamhs, hal'e a minimum thickness of 125 mm and shall extend at least 150 mm beyond each sidt of the opening, They also re'luire that no combustible matenal (other than timber fillets supporting the edgcs of a hearth \.I here it adjoins a floor) is to be placed nearer 'than 250 mm vcrti(;ally helow the top of a hearth unless such material is sepoarated from the underside of the hearth by an air spa(;c of not less than 50 mm, One method of supporting a first floor hCdrth is shown at F, Fi~. 34· The section at f includes alSo mm thick concrete hearth which is finished with tiles to gi"e an overall thickness of 175 mm. The hearth is formed in situ
juists haH: ,\ Icnuclln 10 twist IIr tilt SI,Io;\\.I\s.
I It is a common prac1ice to milk .. shon ""'" _cuts at th .... nds of th .. Plr<:rs to r«cll'c the nail. (see Jl to al'old (10 It i. claimed) th .. nallllphttonK th .. tlmb .. r ThiS .hollid nOt be done al the holdmg po ...... r of Ih .. nlil, is thus r ..dllcl"d
(or ~rm
PLASTERED CEILINGS
Plastered ceilings arc the usual type of finish to joists in domestic work; students should bave read " P I:Jsterin~ to Walls" on pp, 3 I 33 hefnre prn(;ceding 1\lth this sectIOn. For a joistcd ceiling, the wood lath and plaster finish 1\;1S the traditional method. Ril'en laths 38 mm wide, from 3 to '3 mm thick were nailed to the Joists 10 mm apart, the coar~e stuff was Ilclllaid on to the laths so that the plaster penetrated the gaps and spread out behind them. This gal'e a good mechanical key and resulted in firSI-tlass work free from cracks which are sometimes common with present-day board finishes. Woot! lath and plasterin~ and lime ba~d mixes halt no\\ been replaced, Icry largely, by met.tllic lathing or plasterboard covered with p:ypsum plaster mixes :E'xpandfd ,\1ftaJ I.alhllle (XP\I), IIhich should be protected from corrosion by gahanizing (if condensation is e:\pected) or by stove dried asphaltum paint, is nailt:d to the joists and given three (;oats of plaster. XP:\1 is made in sheets
68
TIMBER
610 to 680 mm wide and 1·8 to 1"75 m long, the thickneu variet with the joist spacing, ~.l. 0'56 rom and I'Z mm for joists at 350 mm and 450 mm centrCl fe5pectively; 0"7 mm metal ~ing u~d for the usual domestic joist centres of 400 mm. The short way size of the mesh is 6 mm and 10 mm, the former for hairless plaster, bolh being used ..... hen hair is added. The sheets are fixed with JI mm galvanized clout nails or staples at 100 mm centres. The joints must be lapped al least 25 mm and wired together every 100 mm with 1'1 mm galvanized soft iron wire. For concrete Roonl, the XP:\l is fixed to Aat bars suspended below the floor. 22 mm by 6 mm flat bars supported at 1'2 m intervals and placed at 450 rom centres 3rc commonly used; a 6 mm dia. suspension rod will support '" 5 mt of ceilin~. Render coat and floating coat mixes applied to the lathing can be I cement; zlime . 9 sand; as well as aiding plasticity during application, the lime also mini· mises corrosion; 0'5 kg of hair is added to 0'093 m' of first coat. Such mixes must be allowed to dry out thoroughly before fun her coats are added. The same coals using gypsum plaster (class B or C) can be. I plaster: z to 3 lime: 8 to 9 sand . A sUItable firnshmg coat on both these mIxes IS I plaster (class B or C) : z to -4 lime putty. Special class B metal lathing plaster is also used for undercoats In the proportion' plaster I sand, thiS can be fimshed as above, or with neat class B, C or D plaster. Plult"board consislS of a core of gypsum plaster bonded between two sheets of hea\"y paper; there are four types from 10 to 13 mm thick: baseboard, lath, plank and insulating baseboard. They are all similar except that the latter has a covering of aluminium roil on one side (that placed next to the air space and which is not plastered), and afe obtainable in several sizes; "2 m by 1·8 m wallboard being commonly used. The boards are nailed to the joists at 150 mm centres with 32 mm by Z'2 mm galvanized plasterboard nails. They should be fastened so that the joints are staggered. The joints arc strengthened by a strip of tOO to 125 mm wide jute scrim cloth which is plastered over them as they are being filled. When this has set, the surface is levelled with a coat of plaster between the scnmmed jomts and a final coat IS applied over the whole area; thiS is two-coat work (13 mm thick) and used for good quality work. A cheaper finish is one-coat work (5 mm thick) the plaster skimming follows immediately after the joints ha"e been scrimmed, and the mix is neat class B plaster. The same setting coat is used for two-coat work on a floating coat of I class B plaster: Ii sand. Lime must not be used in these mixes on plasterboard. Insulating fibreboard is used in a similar ~-ay, scrimmed and plastered (prefenbly in one coat) with special low setting expansion quality class B plaster. Plasterboard can also be used alone without having a plaster finish. In thIS case the board has chamfered edges in which a strip of linen or paper reinforcement is bedded in a special fine plaster which is also used to flush-point the joints. The thermal insulation of ceilings is described on p. 14- \\-ith reference to roof construction.
ROOFS Termt. -!\1ost of the following terms used In connection with roof con· struction are illustrated in Fig. 35 and subsequent drawingt. CovuJ.lfg.- The external material laid or fixed on a roof to protect the building. The ,materials used are: Slates, interlocking and plain tiles (see Chapter Fi\'e), pantiles (burnt slabs of day, shaped to a flat S in cross-section, 350 mm by 250 mm by 16 mm), asphalt (as described on p. 17, laid on concrete in two or three layers to a finished thickness of zo mm or 30 mm), asphalt felt (see p. 17 and Q, Fig. )6), lead (see Chapter Six), zinc (thin sheets laid somewhat like lead to form a cheaper and inferior covering), copper (an excellent but costly material laid in sheets), corrugated sheets of asbestos-cement or galvanised ..... rought iron, stone slabt (similar to slates but from 10 mm to 20 mm thick), shingles (slabs of cedar or oak which are from )00 to 600 mm long, from 60 to 150 mm wide and 6 to 13 mm thick), patent glazing (sheets of glass supported by lead covered wood, steel or reinforced concrete bars) and thatch (bundles of stnw or reeds laid to a thickness of about 300 mm). Spars or Common Roftn-s.-Similar to joists but inclined. The distance apan depends upon the coverin/<: material Jnd is usually 400 mm centres for slates. The h~ad of a spar is the upper end, and the foot is the lower end. Spo".- Usually taken to be the clear horizontal distance bet\\-een the internal faces of the walls supporting the roof. Thc tffutive spa" is the horizontal
/USE
A
FIGURE
35
ROO FS distanc~ between the centre of the supports. The .pan of ~p.lrl is Ihl: inclmed dlstanct from support to support. thus in Fig. 37 the span i. the distance (rom ndgelo purim. purim to purim, and purim 10 wall plate. Rut.-The ...crlleal height measurw from the lowest to the h'fi:he.1 J)(linb.
P'tdr.-The slope or inclination to the horizontal expressed either a~ nse .
_
spJn
(see s, Fig. 35) or In degrees. It "anes with the co\'cring malerial in accordam.:c with Table III which gin" the """;",11", pitch :_ TAIILF.
III
RIle (mm)
CO'er1n1 m.lIcr,al
hllloomm run) (~~ n, Fig. JS)
..
-
A.phah and C<>Prt'T Lt-ad and l!:I!K (t-uludlnll drlp~ e'er)' 1000 mOl run) .l"phdlt felt, ("null:att-u a~b..'5'os "nu In," .rrt."tt
Siaies. Lnl/e :.I~'H. ord,"~r' "IJle~, .mall
P.onllk, ~hm~lu, ~~d~r
~h>nli:ln, u .•k P~ltnt
I/luIUI{
tit"",· ~lah"
PI.!II' "I"" .",J Ih~l{h Inl~rllk klllll uk~
-
12 5 I
2~
"
,0 \0
t>t.. 6
" '00 ,0 ,0
"6
'00
,0 ,
~1""mum
-
.... -
Pilch
Anllie
1I
loj'
.,'.
1I
.... :
S:
2q
,6j
HI
"
,6j
.
".
I
"
!
.. \
'0 J:li 30
These anj:(les arc often departed from, thll!<, ,Ilthough 1t:•• tI is commonl) uscd to CO\:. flat roof~ \\ hieh have a minimum rise uf 1'2.5 I.:m flIT I:l' W .. ntl Y, Fi,\(. :,\6) 'I'he Ilndt'r portion of ,in 0\ erhangmg U\CS 15 called thc IU/fit. ....·offit IxJards are ,1'10\\ n .11 \ lic . . 111.1 II. Fit,;, .1"'. and Ih,' nl""'-pIl'l:l'. of "uno illustrJtl.:o t1I 1111
,r,.
I
latter figure to which these board. are nailed are ctJled soffit Harttl. The lower portion of a roof is sometimes tilted 80 u to improve iu appearance; this is accompll!hed by nailing Ihort pieces of wood, called ljWocluts, to the Ipara (see Figs_ ]7 and 38). Rld.rtt Plter or Ridgt.-This is fixed at the highest point to receive the head. of thc spar.;. Illp is the line produced when two roof surfaCC5 intersect to form an external Jngie which exceeds 180'. A lupped t1IJ is a portion of roof betwun two hip' (sec A, Fig. 35). The timber at the intersection is called a hip ro/ttr, and the foot of this rafter ill usually fixed to a horizontal cross-member called a d,ag01l beam \\hich IS lecured at one end to an o"lit tit (see Fig. ]7). A hip nfter supports the upper ends of short spars and it may be requireo to carry the endll of purlinll (Ice helow) "a/Jry is formed by the intersection of two roof surfaces having an eXlerml1 an~le which is less than 180° (see Fig. 35) and the wood member at the intcrscc· lion IS called a valJry raftn. The fut of short spars are nailed to a valley rafler. Jock Rafttrs.- These are short spars which run from a hip to the eaves or from a rid~e to a valley (see Fig. ]5). I'ngr il:\ the edge of a roof which runs from eaves to ridge at a gable (see Fig.
35)· Purims arc hOrizontal limbers providing intermediate supports to spars, and Ire supported by walls, hip and \'alley "hers, and roof trusset (sec Fig. ]5). Roof Truflts are structures formed (If members ft'ameu together, they support purhns in the absence of cross-wallll. See example in Fig. 39. 8oordin.': or Sorking consists of 25 mm (nominalthicltness) boards which are nailed to the backs (upper edges) of spars, and to \\hich 1Iiates and olher roofing matenals are secured. Bourns arc small pieces of wood to which slates, tiles, etc., are secured. rhey are ~enerally fixed by the slater or tiler and are referred to in Chapter Five. Classil1catiun or Roor•.(a) Smglr Roofs consist only of spars .... hich afe secured at the ridge and \\all pl~tcs. The \-arious forms of this type are. (i) Rat, (ii) lean·to, (iii) douhle lean-to, (iv) couple, (v) close couple and (\'i) collar roofs. (II) f)ouhlt or I'ur",. Roofs.- Tn this type addilional members, called purlins, Me introduced to support the spars. {Ij Trum.! Raft",. R'H)ls.~ These compri~c light trUl<<;es fonned hy framin~ tOJ::l'Iht:r spars 2nd ceiling joist~ With intermediatt: members. Th,,} haw replaced almost entire!)' purl in roofs for domeSl1c .... ork. (J) 711plf' fI' F,ft""J R'II.1s consist of thret: sets of members, ir, span that .11't: p'lrtl.lll~ sIIPI",nl.:,lll\ purll"s, 1\ hKh In turn ~re \;Jrned by trusses. SINGLE
Thl'
\.lrIUU'"
forms uf thiS
dJ~~
ROOFS
,m: Illustrated in Fig. 36. The sizes of the
TIMBER spsrs specified on the drawings must not be taken to be economical in all cases, for, in addition to the span, these sizes depend upon the weight of the covering material, the distance centre and centre, and the wood employed. Table IV gives the approximate average weight of various covering materials:TASLE 1\' Material
Welj!ht kg m"
Zinc and copper Asphalt fell Corrugated ,ron BOlIrdmg, 2S mm thIck Shinglel, cedar Corrugated asbestos_cement Patenl glazmg (sl.... 1 (aluminium)
"J.'
"
"
12·0
M~ferial
Lnd (mdudmg rolls) TlutC"h A'phalt, 20 mm thick
'H
Sb,~s
16·8 28·7 '9·1
Pljin Ides
,.,
Stone
sl~bs
33·5 33·5 -0. 0 ~J·o
I'ant,]('~
Int~rlock",J.!
Weighl kgm'
,» 36 .0
47·\1
t,les
86·2
Tables in the Building Regulations ~ive the size of a spar according to Its span, pitch and the load carried; the most usual size is 100 mm b} So mm (i) Flat Roo/.-This is shown in Fi~. 36 by th .. small-scale plan and section at ~. and A, and enlarged details .1,t Q, Rand s. The upper surface must be inclined sufficiently to throw off the water, and, as felt is thl: cO\'ering material, the minimum inclination is 10 mm in 100 mm run.' If the undcr surface is not required to he level, the inclination is obtained by inclining the joists to the required fall \aWards the eaves. If a level ceiling is required, the fall may be obtalnM by 6th~t taIWrlO~ the joists with rhe top cd~e of each sloped to the required fall, more usually the joists are F.xed level ~nd a small tapered piece of wood nailed ,o}1 lOp of each The tapered pieces are called fin-ing pieus or firrings. As sho.... n at R, they are the same width as the joists, and the depth varies from a maximum of 50 mm at s (which is a detail of c) to IJ mm at Q (a detail of 0). Tongued and ~roo\'ed boards arc nailed on top of the firrings, and this boarding should be dressed smooth in order to remove any sharp edges which may cause damOl~e to thc covering material. A fascia board is nailed to the ends of the joiSL~ Th~ herring bone strutting is nccessary if the ceiling is to be plastered, othen< i"e it may he omitted. Bituminous fc:lt and lead are the most common covering materials employed for this class of roof. Lead flats are detailed in Chapter Six. That shown in Fig. 36 is covered with felt, of which there are many varieties.
uad ('(Jured Flut.- The lead details .of the flat shown in Fig. 74 are de. scribed in Chapter Six, and rderenl.:e IS there made to the ~roundwork, I.e., the timbcr construction. The l1at is clil id~d into two by ;I drip and each h.. lf is subdivided bv t .... o rolls. The h()anllO~ i\ gi~cll a falllo .... ards the gutter and I As three lay.. rs o( fC'lt havC' been usC'd. th., ,flI",mum indmauon may h<: n:du(;('d to dat (or lead, i.I., I·as nun in 100 mm run
In thl example, thrf'e layers of thC' f<"lt arC' ustd., w,th a c...t of bitumlttOll' tolutlOn between and on top. ThC' felt (which may bt: tlmllat to thlt dncrib.,d on p. 17) i. in 900 nun wide roili. The firlt IIYu 1.llld d'rKt upon the boardmg, lapped 7S mm II the JOrnl:S ~Ith IIOlutlon betv>C'C'n and nllkd along the Joints It 75 mm Intervalt. Hot IIOluuon ,I now .pplled OVer th" first layer and I .lCCond layer o( f<"lt ,t laid wllh 7' mm joinu (n<)t n.,],.d). Thi.,a blt..... I,.,.,! u~<=r ",uh lIO]ul1on Ind a thIrd la}'C'T of fC'11 is laid aa dncnbl.:i Ind ~wC'n. coat of the hot b,tllmC'n. GrIt (or ,I,te granuln) II now lOUC'd into the aolullon to pr"t~t the felt from the action of the .un ThC' IIltC'racetlon belween the flit and the wall.s mldC' ",uC'rtight by ~'()nflnUlllg the Ilyers of (elt o\('r Ihl tnangular fillet III the Ingle, ThC' upturned MIfe5 of the fdt Ire co\'''red with a le~d covu fllsh'ng as descnbffi. un p_ '43. Roofs of temporary buildlllKS are usually coverC'd with one laYC'T of Cdl. the joists supporting It are laid across the shortesl span. The fall is obtained by fixing firring~ to the tops of the joists. Thl-"Se firrings increase in depth from a minimum of 13 mm at the lower joi~t to a maximum at the upper end (see A, P and T, Fig. 74); deep firrings arc avoided ,at the upper half of the Aat by using deeper joists as shown. The wood constructIon of the drips and roll!; are det;uled in Fig 7.h and will be more readily understood if comideration of this AOit i~ deferred until the subject of lead work is studied The gutter is constructed of So mm by 38 mm gutt" heartH at 400 mm centres. fixed at different levels to give the necessary fall to the boarding. These bearer,; ~rt· supported by the wall at one end and by a 38 mm thick longitudinal fillet or bearer nailed to the side of the lower Joist (see 1', Fig 74). The construction of the cesspool is similar to that described on p. 148. (ii) uan-to Roof (sec II, Fi~. 36). This is the simplest form of pitched roof and consists of spars inchned at 30 ' against a wall. An enlarged detail of J is shown at C, where the wall plate is supported by two brick corbel courses. Alternati\'ely mctal corbel brackets a3 shown ,It T, rig. ]:1:, may be adopled. A cheaper method consists of nailing the upper ends of the spars to a continuous 75 mm by So mm teo./I piece or pItch plate which is plugged with its 75 mm face next to the wall. Plugging consists of dri\'in({ wood wedges (see 1', Fig. 49) called plugs at illlervais into the Joints of the brickwork. The ends of the plugs arc cut flush with the face of the wall and the .... all piece is nailed to them. The construction at the eaves is similar to that at x, except that there is no horizontal tic. The spars arc V.shaped nOlclted at both ends and fitted to the wall plate; this is one form of a birdsmouth joint. AnOlher form is sho .... n al )(, Fig. 37. The depth of the notch should nOI exceed one-thtrd that of the spar. ~otching the spars counteracu the tendency for them to slide downwards. The eayes detail is referred to on p. 74. The roof may be Imardeu as sho\\n at x or battened as shown at Y. (iii) Double Lean-to, Pent or V-Roof (sec ~I and 0, Fi~. 36). Pent means penncd or closed in, and this form consists of t .... o lean-to roofs ..... hich arc enclosed by and sloped from the t .....o outer parapet walls to a party or dlnsion wall o\'cr whil.:h a .eutter is formed. Sometimes tht lower ends of the ~P'lnI arc , 1 hit Ilope I. sUitabl" if Ilatrng is the co\·enng maten.1
J
7' KAt. fOJ. , ..U,MJ-,MO('V
Ii
i
"
Ii
.,
KAU' "OIl. OIT"""
SINGLE RDOFS
iii_
...
i . . . .I......
M DOUBU; LEAN-TO P-OO~
A J(I'U I41:UJ"':-eoo. 'Tl'UTTIH(; ;,
B
1(1"
~LAT~
'"
,. -
JOUU
-.- _u~ -.. -V},'
-C
._---_-'~.
- - 4·15 ... - - - -
SECTION
~LE.AN·TO RDC)F IA
F
,
PLAN
N
CLOSE COUPLE WOF .'~"
NOn .. r'HU:ll.llOJ
I
o 'co "
Fa;lIu: Jf)
,
TIMBER secured to a beam which runs parallel to the main walls, and, if neceM;Jry, is supported at intervals by brick, wood or steel pillars. A detail of the gutter is shown at T and a description of the slating and plumbing work is given in Chapters Five and Sil(o This roof is not adopted often as it is expensive on account of the extra walling required and because the gUller is a potential source of weakness. (iv) Couple or Span Roof (see E and F, Fig. 36) .. It is so called as each pair or couple of rafters is pitched against each OIher and supported at the upper ends at the ridge, as detailed at P. A detail of the eaves at I) is shown at wand described on p. 74. It should nOi be used for buildings having a greater sp.m than 3'7 m unless the walls are exceptionilily thick. The roof is of bad deslJ.:Tl as it has a tendency 10 spread at thc fect (as shown by the thick arrll'ns) and thrust out the walls. It IS not rrcommended, (\) Close Couple Roof(sce I., Fig, 36),- This is a vastly beller form than Ihc last \lescnbcd, for each couple of rafters i~ dosed by a horizont
TAI·!.1e
Ma""mum Span 'm)
s.u (mm)
)')9
so D~ .so b~
4'04
So b,'
a-7 z
'"
.,..., .~
rl~~" (mm)
" ...mom 'm)
"50" S'H
+-
"~
s.z~~ {mml 50 b, !75 ~o b, ~oo 50 b, uS
(vi) CDlIar Roof (sec v, Fig. 36),- ThiS is similar to the d~ couple roof except that the horizontal ties are now placed higher up the roof, and are called collars. The laller may be placed al any height between the wall plates and half. way up the roof. the broken lint"S lndic.ting the position \\hen at the maximum height. Obviously the lower the collar the more effecti\e it becomes in prevent. ing the rafters from spreading and causing damage to the walls. It follows therefore that the dose couple roof is strongpr than the collar roof. but the latter is more economical ill wall height ror, as shown at v. the plastered ceiling may be formed on the underside of the collars and the lower portion of the spars. The dfIWtail halved)Qtnt at L' is detailed at z, A 13 mm' sinking is formed on the side of the spar and the upper edge is dOHIJiled, The end of the collar is checked out 13 mm. Ind the remainder of tne thil.:kness of the collar is do\-e· tJiled ~Iong the upper ed~e as shown so tbat when the cull,.r is fitted to the spar Lt Will be hOIl!\ed to tne extent of 11 mm (see section 1\'11' ), 'rlll' "ullaris then well ~piked or bolted to the spars Th.s j01ll1 ,5 effeCl1H' In "'SlSh1111 both len~.on and (ompr..s,,,m ~trh""S, Thus lel1 wi!. •• bearlnll on !h" upp.,r edlle of Ihe do"et~.led nOldl formed on th~ ~PM, and th" ~rM~ ar~ pre\enlcd from M~glng (10 pr(1du<'e ~ compru""n ~In'.' In the ,'"llar) b,' Ih., 'n<.!,",·d .IDutment "f ,h., collar "h"'h IS fined I!j(hd~ ~I!,un~1 Ih.' \lnd",,,d., "I the 'p.'r n'M "".h end ~n\
aci(d
The siLes of collJrs !>hnuld omform witn tnc SI/CS 01 tie .. gi\"n Jix)\-e (the " maximum span" beinJ,!; the kncth lit cnll,ll), It IS lI"t l"'lJllwnicJI to adopt thc collar type of sin~le mof for sp,Ln" "\U""hne 49 m, DOUBLE OR PURLIN ROOFS
These are shown in Figs, 37 and ],11, Purlins ,lre introduccd in thi .. da~s of roof to provide intermediate supports to th.- comlllOIl rAters. Pllrlm~ are neccssan for roofs with spans of 5', III and \lp\\ard~. othen\i~c fhe ~p,lf~ \\()uld need to h~ increa!>ed to an uneconomical size. rile mJ\imllrn IIIdi:led ~pan of 100 mm by 50 mm spars is 2'4 m and this should be reduced to 1')( m wht'n Ih.' roofs hJ\'e a low pilch and are covered wilh he.!.\)' m.lleria\. Tht 1111r"dllClion (If sulf,ciem purIm); permits the use of comp~rali\'eh ~m,l11 ~p,Lr~, .-/11 tht imglt roofs ll,on" III Ffr:. 36 may hI' ulh"J 10 duuMt rl~1' 1>.1 I}'I (ldJtII/lI/ of one I)r mure sfts IIf rurl",!. Fi~. 37 shnws the plan I flf .L portion of a uouhk roof of tlw ~fll1.1T 1\ pt togt,thcr \\ Ilh a ;.ecliull "I E. A hippnl ,'nd h;IS 1'lCt'rl Llltmduco.;d ~11 J~ I" I'b trato.· Int· applicJtion of hip rafters, Th ,' spar,; ar~ inclined at:;:; (~l'<' ". fl,)l ~lId , \i!Unal.,el) Iht' d~pth of Ih., ntlu,h ." ,h" .. de of rh' 'l'"r.5 .nnea,,,d .n ~c ",' >
In., .'''.; lOr th .. ,'oll~r'~ ch ..i:k"d ou, b,' ~ sllll!l~r amounl ... 01 th ..
In.1I
"h.,.,
~".,mbl~d
b.'11
,•. i ,,,k~
ROO FS two purlins are provided at each sid~ to support th~ spars which have a clear span of 1·7 m. The spars are nailed to th~ wallplat~, purlins and ridg~, and to reduce any tendency for the rafters to slide downwards they are cogged (see p. 60) 25 mm over th~ r-urlins,' in addition to birdsmouthing their lower ends to the wall plates (see x). At the hipped end the spars are cut short (when they are called jack raften) and the heads ar~ spiked to the hip rafters. Purlins are supported by cross division walls of bedrooms, etc. (which are carried up to the underside of the purlins), and at the ends by the hip rafters to which they are shaped and well spiked or bolted. The ends may be fixed to valley rafters in a similar manner. The purlins may be placed normal (right angles) to the spars as shown at E, or th~y may be fixed vertically as shown at Nand 0, Fig. 37, and in Fig. 38. A secure bearing on the WIllis is provided when Ih~ purlins are vertical, and in good work stone pads are introduced at the supports to effecti\'ely distribute the weight on to the wall (N:~ broken lines at N). Joints in 111nl" lengths of purli",,, lire best IIrranged to coincide with and lap at th~ wall supports (se~ Nand 0). Jointing known as scarfing or splicing is resorted to when a purlin is requir~d to be inCreased in length. The best form for purlins is the splay~d or rakin.g lcarf~d JOInt sho~n at R where the lenltlh of joint is from two 10 two and a half times the depth of the purlin. Right angled cuts are made at the ends of the splayed portion as shown. Three or four 12 nun diameter bolts, tightened by nuts, make the joint rigid. A mild steel or wrought iron strap should be fixed at the underside of the joint (see sketch). This joint is also used for lengthening a ridge where the length need only be one and a half times the depth; a metal strap is not required and long nails are used instead of bolts. Filhmg is an alternative form to scarfing. A fished joint is formed by butting the two squared ends of the timber together and connecting them by means of t~o metal (or wood) plates (one top and bottom) and bolting them as for a $Carfe\l Joint. The length of the plates equals four times the depth of the jointed member, and if wood plates are used their thickness should equal one-quarter the depth. This is a suitable joint for strutJ which are subjected to comprC1;~lonal stresses. The collars are usually fixed to the spars immediately below the lower set of purtins, as shown in section AB. These collars are dovetail halved jointed to the spars as shown at z, Fi~. 36. As the span of the coUars i. approximately 'P5 m, their size is 175 mm by 50 mm (see Table V on p. 72). A plastered ceiling could be formed by nailing plasterboard to the underside of the collars and the lower portions of the spars (see broken lines). Hip rafters usually support comparatively heavy loads from the purlins. They must be of sufficient strength to prevent sagging and must be fixed securely. The head or each rafter is nailed to the ridge, and in order that the load from the rafters shall be adequately distributed on to the waUs, it il neccaaary to 1 CatKin, i. omitted in chelOp work.
73
The following table gives the sius in mm of purlins for different spans for tiled roofs:-
TABU VI, PuRUNS (mm) Spae>ng of purllllf (m) Siw of purhn (~)
'"'
'"' I
J"'
Mo. purlin span (m) for :zai"-)o· roof.Jope. (figs, in bradr.eb for )oo_~*. II~)
6) x ISO 6) ;x 2.Z5 75 'X 175
7Sx
~
75
ZZS
'X
1'8) (1'92.) 2.'74 (z'87) 2. '33 h'~) z·66 h'7') a'99{J-II)
1'59 z'J8 z·oz 2.·)1 2.'59
(I'66) (2.· ... 9) (2.'11) (Z·41) h·71)
I'~
Z'I) ,,81 a'07 2-JZ
(1·49) (2.'2.) (1'8<}) (2.·,6) (2· ... )
Purhnl eXceM;na 5 m in I~ath ..... not ~nnm;CilI Tn the .bunco. of crotl._wslls or plrtltion., lrussea ue provided to limit the unlupported length of purlin. to 5 m.
employ a special form of construction to receive the feet of the rafters and to make the angle of the roof secure. If the feet of the hip rafters were, like the spars, simply birdsmouthed and spiked to the wall plates, the concentrated inclined thrust may be sufficient to push out the quoins of the building. This construction is shown at It Ind F, Fig. 37, and in the details at c, Hand J.1 An a,.,k tu or brQU, pllced dilgonally Icross the corner, is notched to the wall plate., and to countenct the throat. tht'H notchea .hould be dovetailed U Ihown by the broken Imea in the plln H. The W1IlI platea IU hslf-Ilpped for the aame reuon, Ind at Ihown their ends projt'Ct some 7S mrn. Thll sngle tie carriea one end of I beam, called. drQ/lon (or dr~'Vl) ~am w~ich is the chief .uppon for the hip rafter. This beam I' tusk tenoned to the Ingle tie Ind Imgle cogged over the wsll plstea. The fOOl of the hip rafter i. connected to the dragon be2.lTl by mean. of an r.blique kftOI'I JOint. and bolt at lhown. After the hip rafter hat been fixed, the whole of the frammg II made nl'd by lIahtly drlvmg down the ~~ of the IWIk tenon. For lowly pitched mob, and where the cavea II not Iprocketed , the foot of the hip. rafter IS aometunea projt'Cteil beyond the outer flce of the Will to the hne of the prOjecting feet of the 'plrl. In thl. cue the rafler " notched over sod I. tenoned nearer to the outer end of the dragon beam.
The lower ends of jack rafters are fitted and spiked to the vertical faces of valley raften (see P and Q, Fig. 75). The eaves details :lire d~rihed helnw. This type of roof in which purlins and collars are employed is often adopted elpet:ially for houscs) on account of its sound and economical construction, It is particularly suited for spans which do not exceed 7 m. Fig. 38 shows another type of double roof. It is similar to the close couple type (p. 72) with the addition of purlins. The 100 mm by 50 mm spars are pitched at 30° (depending upon the covering material and required design), birdsmouthed to the wall plates, notched over one pair of purlins and spiked to the ridge. The ceiling joists or ties are lICCured to the wall plates and the feet of the span as already described, and ;n they are .upported by two sets of I ConliderltlOl'l of thil conllructlOn mly be deferred to the 8eCOfld year of the Coune.
TIMBER
74 hanR~rs
and runners, the size of th~ JOists need only be 100 mm by 50 mm or 125 mm h) 50 mm. depending upon the "ei~ht of the roof co\ttin~. The han~ers and runnen have been des<:ribed on p. 72. Sometimes the runners ;Ire notched o\'('r the ceilin~ joists to afford addltlonal rigiduy to th(' latter. h ,I .mporUlnt , .... , th" 10000U ends of the h~n~n "re n,,' ~cured to the nmnfr" unul aft" the ,1111(:$ or other covering matenal ha\C~ been fixed. othe..... 'ae Iht \ll.Cll/hl of Ihll maten.1 may cause the spars to 53g ~hghIJ)', ... hlch In lurn would depres. the C('lhnlljollll thruullh the hangers It IS the pncuct thc:r.,ro~e for Ihe eatp~n[ .. r 10 nail 1M runnen 10 the celhng J015\1 and the upper cnds of the hanllers [0 Ih" ~p~r. or puTlms, and 10 dder nallmg the lo"u end. of the hanJlcr. unll1 the ~IMler 0. Iller hu comp1e!«I his work
Trimming is required at chimney stacks, dormers, skylights, etc. and thl: is much about the same as that for floors (see p. 65). The name~ of Ihc 'Jriuu5 spars concerned arc similar to those JPplil:d to iklOr trimmirlC'. I,~., Ifwllnmg s/,urs (or rafters), trimml'T span and Ir"mmd {parr (sec . \ and (, Fig. »1), The Jmnl betwel'n the Irimmer and trimml1lg ~p,lr~ Illay h~· nlht'r J tu~k II.'nnn (!>Ct' 1, hI-: ..HI or J ~imil.1T j01ll1 \\ithotLt the tll~k. l:.ee\ ,1Ild ,', hK. 3R). Th'lt hel\ll'l'lI lilt" tlllIHHl·d .HI.I trimmer ~p,lrs ~hould he cllher J dUH·tailed h()u~cd 10m! (st'e '1, he. H) (lr ,I hnl:lkd hdulH_hed Joint de'-'l:flhcd on p. 05. 1 The trim;ning of a f()()1 munu ,I (himnt" ~t.Kk whll:h penelrates a rouf mid"J\ lxl\\ct'n Ihe ta\es Jild ndl.:e IS dl:IJlkl! .II ~, he. 75. Eaves Oelails.2 III~ IlIlpllrt.1n1 Ihal Inc CJ\e~ 01,1 rUI'! ~huuld he lJrdulh .Icsigned. It .1' '"1111" I 1111,..t.tkl: I" lI~l' .111 t'\lx~"I\cI\ deep IJ'lI.l, .111\1 Ih,· .,:Ium~y eITed ,h II I' 1I.!IlH·!< IS "h(I\In ~t ". III.:. -'7, \n t:\(e"~i,, pr',· Icl'llOn "I the 1.1\t~ III r"""I1.n til til<' !'In (Of tht, hllllllllll.: I" .11t"tlwr I:TrUr. h .\ I.:l'nt,t.l1 ,ul,' .,\ til "III~ l' H" ~1I'UlIJ ',t: I,t IHllumurll It.-rth. fha· rlJhur,lIl1m ,..h,.ul.ll>, '''''llIcd, till' ~Impkt lhe .1t'\,111 till" h':!ll"f, Flush, 0rt'n I'rnll'l'III1~ .HI.I d()~t'.1 I'fHlt'('lIng ('a\!" 'lit' lOotl:d on I' 'HJ flu," Fl/;n, 1'.1,) l'\ample ... t:I~ sUlli'll'(1I1) <1n'l' I" .Hler till" ('utl" "I tI" J"I"h ur "'r.l1~. II> \\ !lith 11 10"1 l'lIhl'l tI,nl.·d "r ~CTl'\\ nL 1n tilt' I.lt't·r lkt.ttl tilt" t .t~~ 1.1 l)foJnh slightly Jhmc til.· I>,,;lrdllll.: HI ord.·r til 111I tlte ~Iate~ (~c: ( IIJr"'r lilt·) Tht thldlll"'~ of till" f.ls(i" Ill'l·d IInl C\ll'l'd 2_, mm (nomin.llj, Jill!. II rlclerrctl. Oil., or mllfl' lillt-ti IIlJ\ hI' t"nn, ,I ,IS sho,,!,. ()/,1"1/ "'''IIII'''~' I,,,,. (~t· \. I'l!. Jh). I ht f.'t"t (II Ihl: ~I'.tl' prOWl! 150 l1'n, ,lllIl.lre ,..h.II'",1 ,I~ 1'011,,,", 'Or .I~ IIl(li('.\ll"Il It " an.11 !-te, -, It I" lOot IH:l..:!,S-lry 1" pro,,,11: ·1 LI"'I,' I" .111 "11t'1I ,';1\(',. ,\ Slll1rk "1','11 !"UI"lllllg ",lIl-~ h shl1\\ll "I I I'll.:, 7Z ('1"".1 ",,,,,,'III!! 1·:lnn. rhlfl' ,Ir.: 1\\0 I'}rnh lOt dn"'l·tll·.t't:~. 1./' .• thosl' "nh ~1", .... kl'B ,lI\d thost· \\i,h.,\I!. \" (·\;UII!'!..' (,I lit,· I.tUn IS $hll"11 Jt \ 11e:,:h I he end" (If tb,' r;,/t,'tS itrt: .1.1\\11 10 Ih(' ,,),.lPl· 10 "h,,\~.·. 111\' soffil htl; rd i ... I.ukd to.t" lIl'.tra. 111\11h, 1.1 .....'101 cnn~tructlOn
In ,h.·.,p "UTI< Ih"lnTnmc-d .p~nM'· !Wm"l~ t-o..!!-loonl,·d .nJ "luJ,,01~ ~huuld d"t~r conl1d"'~"Ol (>1 Ih"
" ... ht'J
0310;,1,,, It." nml11·"1I. un,1 (-h.p'" ~ ,'a
is finally filled Ydlh Ihl: edge of the soffit hoard enJl"aging in the gwo\'e prtpared r,'Cent It It Ydll he ohscr\l:d that the brickwork IS set bad. 102 mm so that If the soffit hoard shrinks til \I Idth no unsiJo!:htly gap appears along its length ht-t'Meen il and tht· \\.111, The f.lsu. pmJecls abo\c: the backs of the spar!i.as shown in order to tilt thc bottom cou~ of slates. Another eumple is shown .Il ", rig 71 where a fillet is ust'd to tIlt the siatC1'l, so tile depth of the fascia i" reduced 10 100 mm; the soffit boardlllg is fix:ed to 50 mm by 32 mm bcarer!i naIled to the spars A sprocketed ca"es may be formed by (D) fi,1(in~ the sprockets on the backs flf the spars or (b) naihn~ them to the sidcs of the rafters. . An example of the former is sho'Mn in Fig . .11;. The construction is made dt:ar 10 thc enlarged deUII .It D and the iSometrlt: drawin/;! II, the latter showing !ln~ tnd of a spar cut. the ne\t spar 18 shown \I lIh the sprocket fixed, and the nnt \lith the sprockl:t Jnd hearer lixed. I'hc ~offit boards are funKued, /(u)Q'/__ ed find V·1"mlfd. Jlld .II hipped ends, etc" tilt· ends of thc hoJrds should be carefully lllltred (sec ", Ft~.17)' The bedmould should he ~mbfd to thc walll" scribc" mCJII10 to mark for :tf,:curate fittint:, and 10 thiS case scribing is necessiln- to tnsurc tholl tht' balk of tt>e mould shall lit thc more or less irrq.~ular slIrf.-u.:e of the brtck\\Ork). ,\ hril:k-nn-cnd c()urs(:, projecting 20 mm ib shown. provides a simple and effc(tt\e finIsh and ;llslI f,)rms a fiJt Hch f('r Ihc windO\\. The sprockets shown at " and L. hg, 37 gl\'e I graleful sweep to tlie lower portion of the roof. Ilere tbl:) are fi\.t:d to tht· ~IJ~ of Ihe spars and thc wall plat!;. They arc indined at an an~1c "hieh ~'qual~ th" ddfl:r,mce bet\\een a ri~ht an~lc: and the pilth of the roof (f'.R'., (jO ,,, H). ~rrockcts "hould not bt: .ci'Cn an inadequate slope 1Om:h a~ is ~hn\\n al \1. for. hel'ldes dt,trprockeb and spars unless a Iriant:uJar fill .. t (sho,", n by hwken lines) IS h\.cd, :\ TCHlf II lIh a tlat ~lnpt: IS also diffil:ult 1<1 make watertt~ht at the eales. Thc con!>lrUl:Ilon 'If Ihe ean's is similar to thdt already described, btlt Jttentlfln is draw n to thl' JIIt'rn.ttu e mel hods of supporting Ihe s P'IIPO'>t:) Jlld these l-ntls .tIl: l1~htl~ \ltdgcd, The sprulkets arc sh(I\\l1 in Ihe pbu I I'hl1w 1I.lIlnl .It 1',llh sl,l, "f till' hip rJflerS ;lft' nt·tb· '.In to rrmllk.1 1I1C.ttIS "I li\lnJ! Ihl- IIpp~'r l'nd~ "J Ih .. I\ln ~hurl srrlllket~ al t:.tdl l:OfOl'I .11lI1 tiL\" Ill";trcr~ to Ilhith thl' !.ISU,I 11I\lII~d at tlit: anJ(le) dnd the Olilad emb of thl' suInt h'l;Inh Me 11.1ilcd Onl' "I 1111:~1: ht:,lTl'rs is sho"n al T I->ut h.ls bet:n omlttnl .J\ S III onlet \0 shUll till' IWln ht:l\\eel1 Ihe ~ufiil boards :\ (1<1.111 "I .1 ~!l1H1.1f l·,lIt·" i~ ,hO\\!1 ,It I;. hI!. ;1 1!1'lIIljilllnt: (If 1I1/I'/f/III1II:, This I" thl' brilk\\ork whit:h i~ l"(JIltilltllti up bel\H'l'n ,md til the h;t(k "f the SpArS .Ifla tht· la:ler ha\ e h('t'n n\.cd. ThIS Ii ~hO\\I' in ,III tht· t'i1\U deulls (somcllml's hy Ilt"kell 11Il"~). al1<1. for ob\ioll" H';"."n!. il ., t'spt:tIJlh Iln'es~n ",hen tht" roofs h.l\c "pt:1l t',1\es. 10
" G
G.
W~T
PUUIN .JOINTS
TO AVOIO
DOUBLE P-...OOF
PLAN SHOWING TRJMMING TO _ C>-IIM~EY STACK
'-'D,,.
ISOMETIUC VIEW O~ ROO~
5HOWN
~~~~~~~~~~~~~
IN SECTION B _______
A 15" SO
Ib
PLAjTC:~
TG i .
I
.:;orrlT ~'i
I -
r.R.ICK...~~}N-E~D ,-.o..J~E
5ECTIO N
"
"
B rim
,.
m: r i\'v F S
D
'00 - 15
S P"'N - - -
1l.5 · ' 4 0
- - - - >0O
DETA Il.
lS .
.A,)<., ....
III
1)\
tc Pll.O.![(. - '" t"<::,,or "''': L
,,
.---.-- .",.",1", ' C, H' ,.. ... f
il...EIN r OR.<::£D
CONCUT!:. LINTE L
77
F RAM E D RO 0 F 5 It i. nQl nt'<.;t'lu.ry to hale b".mfillmj,f 011 lOp of the "'all plain. Mild Ihl~ pncun' which" sometlmn earned out cannot he wo $tfongly condemned <';a$H of dr) rol In roof. hal-., b«n IIltnbuted 10 hnornfilt.nR "h,eh has Men connnut"d r". the full thlckn,," of the ".11110 the I»cks of the ~pars and ~rockeu Any defe<:IIVC slatl:1l or OI:her roof CQI·cnn.Q' al thl' POlnl allow "'liter 10 enler. and OW '"I{ 10 the ,,00<1 members bemll" confintii by bnck",ork (or mason!)') they bee_orne .,"uTaud lind rCmaln 5(1, ,",ulunR In defecllYC lImbe.. Adequate 1'"nUlauon,. Just u es~nll.1 fot r()()f umbers a. It ,s for Roo r members (see p. 60) I f dry rQt 15 to be prevented TRUSS ED RAFTER
T R U I I
11111111111 \< .. u 15 ...
,i. (
o
~AfTE~
I_
••
Of HAil <0 ....
1)r.=::::~::;=:=="'''~AIL GUI~ I....
R OOFS
'LYWOOQ
This type of roof (Fig. 38,,) consists of planed stress gradt:d ti mbers fastened together in the form of trusses and placed at relatively dose distances apart It comprises rafters (spars) joined to ceiling joists and intermediate members The trusses are prefabricated and because roofs of this type are more quickly erected and use much le!>~ timber than purlin roofs they have almost entirely replaced them for housing work. The trusses are placed at centres not exceeding 600 mm 1500 mm by 25 mm (min). tiling battens must be used] and the separate members of the truss, which must he of the same thickness, are joined by plywood gussets glut'd and nailed to each face at the joints. The adhesive used for this purpose is commonly resorcinol'fonnaldehyde (see Chap. 2; Vol. Il l); 40 mOl 12 gauge galvanized nails at 100 mm centres in two rows per member are used (Sl'e c). Alternatives to plywood gussets are 18 or 20 gauge galvanized metal plates which may he either perforated for fastening with clout nails or may have integral teeth in .... hich case a special press is needed to make the joint The trU,;lt trus-<;e~, Ea(h leg of Ihe \\' to pa"s not more th~n 6lrusst'li, The two most popular truss shapes are the \\' or Fink type (see II and D) or the Fan type (B) for larger spans. Kotching or birds-mouthing of the truss should not be allowed. The moisture content of thr timber should he 22 per ernt. or less so care should be taken to fix roof coverings quickl~, Irusses should be stackrd Aat on a le\'el ba~{' before erection. The follo",in~ Tahle gin:s the .. i2l'jl of Ihe timbers in mm and ~pans in m for the t.... o type!> of tru~s SPd((,U at -loo 11111\ (('nlreS lIasKo sizr of lruss nwmbel'l (mm) (·AetuaI51~r J mm Ir.. to • Uo,," for planing)
" , ..,
.,
.~
X 7S ..... )( .00 so X 7S SO )( 100
+4
Spans (m)
{L,.,",., ,.,
R. 0 0
,. Pnch (drgn:rt) "
•• " .., " .., ,., ,., 6
6·,
6,
6,
TO
,. ""6,
,."
"
3S
.6 10·1
,".. n
"
~"'ltrJ
.... LL '( "''' ' ....... T
I l [ V .... T10N
~
=.•
'(UH'
10 ",( ... ,nl
I
I N /I.
TR IPLE O R F RAMED ROOFS
The maximum unsupported length of purlins i~ :; m (,;ce p. 7]) if ~ ... lril\J· gant sizes are to he avoided; if there are no cross UI\j'11In \\,111" ,1\.lilJhl~ 10 pru,ide suppor!s to limit the purlins 10 Ilus span 111L'1\ ~ilher rool Iru"~l·~ (.11..,0 called principals) arc needed, or the Irussnl r,lfla .lTUn,gt:I1It:n1 usnl Ilen~"C a framed mor has three sets of members, '_r., spar" \\hit:h dl,lrrnUlt Ihl' \\elghl of the roof tovl:ring, snow, and wind prt$sun: to th~ purhns whidl tr.ln,rllll Ihis load 10 Ihe trusses, and Ihese Iransfer it to the walk The outll1w 01 the trus,; must follo\\ the roof shape, \\hieh is usually triangular A Irlanc:i..- i~ Iht: .. tronge~t form of framed structure for it cannot be dt:formcd if It:. mlmna" Jfe adequate and properly connected. Thr .tudrnt in thr clan m Buildmg Scirn~e "'Ill hlv(' prob~bl' nrm'u OUt Ihc follo .... ing simple rIprnment In connectIon "'lin Ihe sohmon ,,' Iramrd <,rUdU,,, • .... hen loaded A verllealload 11 applred at thr apc~ {It l",u rnclrn.-...l mcmh"r~ "h'lh .IT" hmKrd al the tOP (representing a couplr of spars). Th(""\ ,,",II., Une'· ~p"·dd rllht" feci Irc not rrslramrd and the un!latisf'ctor)' COUple rOOI {,ee E. 1'111 J/)I ""uld ~l"I In th,. mannrr If thr ..... Us ....ere not luffic,rnlly stronl!. '\ h •. rw.m.1 m"mha ,~ now ronnrcted 10 thr feet 10 p.-od.uce a Itruelurr resembling ~ clost" '·oupk t<>"f I~ i., Fig. 36. In a roof truss add,tlonal mrmbers arr Introduced to brM" Ihe ~lTu(!ure throu ghly
, TIMBER Built-up Roof Truss (-.(:0: F,~. JI}). Th •• II Itlt· The c'umplc sho\\ n I" for .• "ran "I h;lIl .Iud
(,>nllto"-'
\\i,I,' \ . <\ 111111 I'lldl "I 10 It '" "I' 1,;..,.1 al I"M m l'cnlrcs dud '''' Jl;M~nl"l.l fOI the Ilchlc"\l\l'c of tr •• htwn;ll mol!;,,\," Ill.;" (1.1'., mtn\o(;kmJ! tiles ~t'(" ,k"u'rIUIII 1m PI'. '-\0 qt IId\ItTn th~ UlI"-..c.":; tru~~
nltt-l
1II.lke
rhe jom!s are maul' b\ I l mill .II~_ he,lts ,mo IImht:r ~ 1nnl"r~. I"lIl'I.\II,"r are (If M'\eral Ilpes, (Jilt' nt-mg shm'" at J ' ...1 flo 111m dl.l. !]{Ilnl c.lh.1nllnl ~h plate ... ,Ih h\che IrldTlgul.1r to:t:th h':nI olf ,1\ n~lH .l1Il.:k~ if) ".Kh "11k I"1ll'
,U ,
f 0 C 0
v
L T P
A
•
0
N
W
I
T
0
b
"
N
f~ia iJ} •
,
V E
G E
~ . J"O
t
A
tJ
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TRENCH TIMBERING by 50 mm purl in which is notched into the Itrut, tbe pUTh" gives support to the intermediate 75 mm by So mm spars .... hieh arc at 450 mm ccnlf" fr)r Ihi!! comparatively light-weight roof. The main tic of two 7S mOl by 50 mm tImbers So mrn ap;lrt 15 jo;n~d to th~ foot of the top chord by a sole piece plJced centrally imd UI>C on C:
79
lua,", at 400 mm centres which at one end are tonjil:ued and nailed to the pole pllte Ind at the other end they arc notched over and nailed (0 a gllt/" plate which is spiked to the tie beam The &e<:tihn at B dnd plan at c. Fi~. 73, should be carefully studied :"'ote ho .... the ht:uers are n\ed at varyinlo: kvels to gi\'e the requisite fan to the hoardln~. The cross 1\CCIIOn Ihruu,il:h tht .2'lller at A Fig. 73, mdicat ..., tht levels of the ne<.:e~ary filii, drip. l'le The umner details should he further considered with the ~ubject of Plumbing (ChapleT SIX) (b) Tl1ptrd Gllt/t, (sce J, K and s, Fig. i-'). ThlS;"!tt1 called benust of itll shape on plan. The bo;lrdin~ is supported tn 50 mm b\· 38 mm bearers which arc nailed at var)'mg levels to the SIdes (If tht· spar.. and 50 mm by )8 mm uprighu .... hlth are half.lappcd to the hearers Thl~ \:f)nstruction \.\ill he ht-tter unden;.tood .... hen Ihe lead drl.llls in (,hapter Sl\ are ... IUlll\·<1
TEMPORARY TIMBERING C'ertam form~ of I1mber l:onstruction arc reqUired only as H:mporary supports of work Cilrried out durmg prehmmary bUlldln~ operatum.s u: in tht erection of permanent structures, after which they are rcmo\cd. Timhenng to support the sides of trenches which are to recei\'e w;lll fuund.tions, duins. etc, and that known as eenter;n1!" which is requirtd to l1Upport arches llurmg thelf construction are examples of this type of construction.
TIMBERJNG TO TRENCHES
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80 TIM8ERING TO SHAllOW TRENCHES
The timhenng of tntse I:xcavations is done by the l
I Thi. divi.ion i. purely arbitrary; .ame authori'i« h.ve subdivided both nnd .nd d.y into. KOre or more different kind. for the purpose of _ i n g their bearing capacity.
3. Moderately Firm G,ound.-Where the soil is firm, except where it is inclined to be loose in patches, Ihe limbering may consist of the simple arrangement shown at n-otherwise the trench may require a temporary support as illustrated dl E. The wide walin",s at D provide a continuous support, three struts being used per -l- m lenglh of waling. The arrangement at E shows poling boards held in position by walings which arc strutted. The poling boards are placed at a distance apart varying with circumstances; in the figure they are shown at 450 mm centres, but this distance may he reduced to 300 mm or increased to I m. The timhering is done in easy stages for it is not advisable in this kind of soil to defer it until a length of trench is excavated equal to that of the walings, as a section of the unsupported excavation may collapse. Thc folio" ;n~ IS the procedure ad,'ptni ..\ sh"n knClh IS l'x(:~vated sufficient to enahl" the iahourcr to IIlsen and It'mporani) ,trUI .• p.llr of polmg boards (thus re"cmhim~ A). Th,~ '" rcpeated untIl ~utfiCIt'nt p"hn~ ho",ds ha\!.' been placed which oould be sp~nn~d hy !lll' " .. iinJ.(s A ~ldT " .• ill1).: IS th~" pla.ed ~iong each SIde and strulled agamst the bo3rds as sh"" n, after whl~h the tempor .. rr struts can be removed. Temporary 51rutl!nl! is show n by brokcll lm('s al f. Ir is 1111t necessary 10 dTlve wed~~s dO\\11 hctw(·cn th,' walm;.: :md boards "'h,ch ha"e become loo$(' Or ha'·.,. been SlrUtled a cr"3tCr d,stanc" ~part then usual. An example of thIS 1$ ~hown at Ii
•
~. Loose £arlh.- The arrangement of the timbers is similar to that shown at (; (excepting that sometimes the sheets are placed about 25 mm apart) and is described below. 5. Loose and Waterlogged Ground (sec c). - Horizontal sheeting is necessary, for unlike the soils referred to in the first three classes, it is not possible to excavate in loose soil for several metres in depth before resorting to timbering. The sides of the trenches dug in this soil begin to fall before 300 mm depth has been reached, and hence the need for horizontal boards or sheets. The following is the sequence of operations; The excavation is made to a depth slightly in excess of the width of the sheeting to bt: used, when a board is placed against each side and two or more temporary struts are driven between. The excavation is continued for 225 mm depth or so and a second pair of boards is placed tight up against the bottom edge of the first set and strutted. The condition at the end of a section at this stage is shown at H. This operation is repeated until four sets of boards have been temporarily strutted or the required depth has been reached, when poling boards are placed at a minimum distance aparl of J.g m centres and strutted as shown at G, and the temporary struts removed. When the foundations have been completed and the walls built to a height of two or three courses above Ihe ground level, the timbering is removed and earth is returned on both sides of the wall and rammed solid.
8.
;
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CENTRE M FIGURE 41
TIMBER
8. CENTERING
A centre is a wood member or frame used as a temporary support for an arch during its construction. The removal of this support, known as "striking," does Dot take place before the mortar between the vallssoir! of the arch has set. A centre must of course be sufficiently rigid to support the weight of the brickwork or masonry to be constructed on it, and, in addition, provision must be made to permit of" easing the centre," a term which is applied to the operation of slightly lowering the'centre before the mortar has set. A centre is supported on vertical posts or props, and the introduction of folding wedges between the heads of the posts and the centre permits of its easement and also the adjustment of the centre to the required height to receive the arch. The term centering includes the centre, together with the wedges, props, etc. . The shape and details of a centre depend on the type, span and WIdth of the arch to be supported. The following illustrated examples should therefore be considered as typical:Turning PieCts.-The simplest fonn of centre is for Rat arches and those having a small rise and width; it is called a turning piece, and, as shown at A, Band 0, Fig. 41, it consists of a solid piece of timber having its upper surface shaped to conform with the soffit of the arch to be supported. The Rat. arch at A is that shown at A, Fig. 15, which has a 102 mm soffit and a 12 mm Tlse. The turning piece is slightly back from the front face of the wall in order that it will not interfere with the bricklayers' line and plum-rule. The turning piece rests at each end upon a pair of folding wedges,' and these are supported by props which rest upon a sleeper or sill placed on the brick window sill which it serves to protect. These props are strutted apart as shown. Reference is made on p. 24 to the method which i~ adopted to ensure that the arch joints radiate to a common point. A turning piece for an arch with a 65 mm camber is shown at 0, Fig. 41. Centres.-Arches which have wider soffits than 115 mm are" turned" \Ipon centres which are constructed of ribs and laggings; one of these is shown at E, Fig. +1. The laggings or narrow battens are nailed across two 115 mm by 25 mm ribs which have a 65 mm camber. T he centre is completed by nailing a 75 mm by 25 mm cross-member, called a bearer or hearing pieu, to the underside of the ribs at each end. The sizes of the members vary according to the timber avaihble, , Studen" often make the lI\ituk~ i;' examinations of sho,,;ng the wedges with IhC'lr lenath parallel 10 the length of Ihe lurmng pie« .. IllS ob,·iOU! that" hen III ,h,s pos,tlon the wedge. cao.n()! be adjuued becaUle of the bnck Jambs.
thus the thickness of the ribs is sometimes 32 mm and the laggings vary (rom 7S mm by 16 mm to 50 mm by 25 mm. Both open and close lagging are shown at E. The former is suitable for axed arches, and close lagging is adopted for gauged arches. The distance apart of the laggings when open varies from 20 mm to 25 mm, except when the centres are required for masonry arches, when the spacing is increased (see M, Fig. 41). A suitable centre (or a segmental arch is shown at f" and G, Fig. ,401. This arch is similar to that at f, Fig. 15. Both close and open laggings are shown. A suitably designed centre (or a semicircular arch (such as that at D and E, Fig. 15) is shown at] and K, Fig. 4lo As it is not economical to use timber whi.ch exceeds 300 mm in width, it is necessary to construct the rihs as shown .... ,th upper and lower ties nailed to them. Narrow laggmgs should be used in order that they will conform to the curve of the arch. The 75 mm by 25 mm bract' to which the upper ends of the ribs are notched serves as Cl support for the tiled key (which projects below the soffit) and also assists in stiffening the centre. Each support consists of twO posts or props to which IS nailed or dogged a 75 mm by 50 mm bearer at the top and a similar sleeper plate at the hot tom. A centre suitable for a semicircular arch having J. span of ,·8 m, is shown at M, Nand 0, Fig. ,po Each of the two rihs is made of t .... o thicknesses of 225 mm by 25 mm pieces, spiked together, which overlap and have Joints normal to the curve. Such are called built-up ribs. Each rib has double '75 mm by 25 mm or 32 mm ties and three 100 mm by 25 mm struts, mdicated by sand R. the lalter being necessary to prevent the centre being deformed by the weight of the arch. The cross bracing provided by the 100 mm by 2; mm mc1ined brace Q and the horizontal brace T increases the rigidity. The la~~,ncs. \duch must be at least 25 mm thick, may be either open or dose, depending upon the type of arch. . For masonry arches tilt: lag.o:ings m:ly be spaced to allow two per VOUSSOlr, as shown at the right half of the elevation ~f, or alternatively small setting u;tdgl'J as shown on the left of the elcvation may be prefl:rred. The arch in the example is that of Ihe main entrance sho\,n in Fig. 24, and for each of the large voussoirs four sets of wedges would be used. two on each hUllt-up rib. The wedg..:s over the props are insetted between two Stout bearer~. and to facilitate the casing of the centre Ihese ~:edges are somellml"s'-I.!reascd. The props rna\' be hr,,,:cd by an inclined rTl<:mher as sho\, n by hroken lines in the sectIOn A trammel rod (referred to on p. 24) is cut to the net length of the radius of the arch. :\ hlm.:k is n.liled to the underside and at . he centre of the ties, and the lower end of the rod is screwcd sufficiently tight1~, at the centre of the M.:micircle to permit the rod to traverse the soffit of each "oussoir as it is being wed.e;ed and bedded. This assures an accurately cun·cd soffit.
I'P"
CHAPTER FOUR
D 0 0 R S. WIN DOW S. S T A IRS Syllabiu.-Doors, including IOOged and batten«l, [edged braced md battened, framed [edged and battened, framed ledged braced and battened, panelled; frames, and eatings; methods of fixing frames, casings and doors; hardware. Windows, including solid frames with vertically hung sashes opening outwards, fixed sashes, boxed frame with sliding $ashes, pivoted sashes, horizontal sliding sashes; hardware; metal windows. Architraves, skirting, picture rails and angle beads. Stain. Nails, ~rew,. and faslenCrti. Description and uses of woodworking rools.
Joinery includes the setting out, preparation, framing and fixing of woodwork which is chiefly used as internal fittings and finishings. There are several broad differences between the crafts of the carpenter and joiner, although they are usually grouped together under" Carpentry and Joinery." These distinctions are: Carpentry is essentially structural, the timbers are left rough from the saw, the labour expended is small compared with the amount of material used, and most of the work is done on the building site. Primarily, joinery increases the habitability and appearance of a building and any stresses to which it is subjected are incidental, the wood is dressed, the labour is a large item compared with the volume of the timber employed, and most of this labour is carried out in the workshop. Joinery comprises the construction and fixing of doors and windows with their frames or linings, architraves, skirtings, stairs, panelling, etc. and floor Uuards. Doardll ha" e been included in Chapter Three, panelling is described in Vol. IV and the remainder below.
DOORS External doors are secured or" hung" by metal hinges to solid wood frames, and internal doors are usually hung to wood linings or casings. A door plus frame or lining ~nd hinges is defined as a " doorset " in BS 4787: Pt. I. Frames.-A dom frame consist-s of three members, i.e., two uprights or posts which are secured at the top to a cross-piece called a head. The nominal sizes of these members vary but 100 mm by 75 mm and 75 mm by 50 mm are common. The head usually projects frail) 50 to 100 mm beyond the posts, and these projections, caEed horns, assist in making the frame secure when it is built into the wall. These horns may be splayed (see s and the thick brokcn lines in the isometric detail at E, Fig. 42) and covered with splayed bricks to preserve the face appearance of the bric"kwork. A t3 mm to 16 mm deep recess or rebate is formed round the frame to receive the door. An alternative but less satisfactory check for the door is formed by planting (nailing) a 13 mm thick bead or stop on both posts and head, the beads being mitred at the angles (see K, Fig. 42). Joints.-The head and posts of a frame are morticed and tenoned together,
variations of the joints being: (a) closed mortice and tenon, (b) haunched mOTticS' and tenon, (c) draw pinned slot mortice and tenon, and (d) double tenon. (a) Closed Mortice and Tenon Joint (see E).-The head is morticed to receive the tenon on the post. The mortice and tenon must be correctly proportioned if failure of the joint is to be avoided, and the following are accepted rules :I. Thickness of tenon should equal one-third that of member. 2. Width of tenon shou ld not exceed nve times this thickness or a maximum of 125 mm, whichever is the less. (Thus the maximum width of a 13 mm thick tenon would be 5 by 13 mm equals 65 mm, and the maximum width uf a 32 mm thick tenon would be 125 mm 2nd not 5 by 32 mm equal;; 160 mm.) The" thickness" and" width" of a tenon are indicated at E, and the " width" and" length" ot' ~ mnflic(' are shown at F. Wide tcnons should be avoided as they (I) may shrink excessively, causing them to lcavc the wedges (sec below), which thus become loose, (2) tend 'to bend when the joint is wedged, resulting in thc splitting of the mort iced memhers, and (3) require long mOTtices which tend to weaken the members. These joints are glued and 'II.:l'dget/, glue' being applied to the ten()n and shouldcrs (see below) and the tenon is inserted into the mortice. Wedges, as shown, are dipped into the glue and driven in bctween the edges of the tenon and the mortice to secure the joint. :\otice that the mortice is slightly e:l.largcd and bcw:lkd to receive the wedges. Oak pins or dowels, 10 mm to ;to mm diameter, are sometimes used in addition to wedges. This is called a pinn,d joint, and examples of it afC shown in Fig. H. A hole is first bored through the head and tenon, and the pin is drircTl in aftcr it has been dipped in gluc. (b) Hauruh,d Mortia tmd T,/lon .7oillt (see F, Fig. 42).-This joint is 2doptcd when the frame is not built in as the work proceeds. Horns arc not requin:d, , Thueare sCI'eral typ~s of:tdhcsin (SCl' Chap. II, Vol. III). Th~y lOny he (al weather. (b) moisture resisl,ml (I" (c) sum,blc for internal u~~ only. Some are descnbed as dose contact (cc) Rlu"s used 0l~1I11y in pl)"\lood construCtIon where heavy pressure and ;I thin glue lin" are us...! Oth .. 11i ~rc gap filhn~ (G~') glues used m gencral jomery.
proof,
• DOORS and therefore the width of the tenon is reduced, except for about 13 mm from the
shoulders (or abutments at the bottom or root of the tenon), otherwise wedging would not be possible. This abbreviated portion or stump is called the haunch or haunchion, and its object is to increase the strength of the tenon at its root and prevent twisting of the post. The stub mortice made to receive the haunch is called the haunching. Note, the horns are not removed until the wedging has been completed, otherwise the driving in of the wedges would split the narrow portion of the head above the haunch. (c) 1)raw Pinned Slot Mortice and Tenon Joint (see K, Fig. 42).~This joint is sometimes used for large frames. The mortice is continued to the end of the head. A hole is bored through th~ cheeks (sides) of the mortice, the tenon of the post is inserted, a point J on a 45" line from the centre of the hole is pricked on the tenon, the post is removed, with J as centre a hole is bored through the tenon, the latter is again placed in correct position between the cheeks, and finally the dowel is glued and driven into the holes to draw the shoulders of the joint together and the side of the tenon against the inner end of the mortice. This i. a good joint for external work for the following reason: Glue may rooften if water gains access to it,t and in order to make the joints of external framing waterlight and durable paint composed of a mixture of red lead, white lead and bOIled linseed 011 is somettmes used as a jomtmg matenal mstead of glue, As w~dges set in paint are apt to become loose and fall OUI, they ,tre sometimes dispenscd with and the draw pinned joint adopted.
II
(d) Double Tenon Joint (see K, Fig. 44), - This joint, which consists of double tenons, is usefully employed between members of large size, it being more effective than a single tenon in bringing the shoulders of the tenon tight up against the adjacent member. The combined thickness of a pair of single tenons should equal that of a single tenon. A temporary piece of wood is nailed across the lower ends of the posts to prevent distortion of the frame before it has been finally fixed in position. Methods of Fixing Frames.- A door frame may he fixed in position either (a) during the construction of the walling, or (b) after the walling has been completed. (a) Such frames are said to he huilt-in. When the brickwork (or masonry) has been built to ground-floor bel, the door is placed in position according to the plan, plumbed, and maintaim:d temporarily in this position by an inclined strut (nailed to a joist and to the head), Tht: brickwork is now proceeded with, the jambs being constructed close to the posts of the frame. Creosoted wood slips or pallets (see II and Q, Fig. 42) are built il' dry at the bed joints of each jamb at about 300 mm intervals \Iith one near the foot and one near the head. The weight of the brickwork makes these pallets secure, Nails are driven thro\lgh the posts into the pallets after the heads (which may ha\'e splayed horns) have been bonded in and there is no likelihood of disturbing thc newly built waning. Wrought iron slraps (see p) arc occasionally used instead of I
This does not apply
to "
\\C8therproof j.llue "-see Chap, II ,
\'01. III
pallets; these straps are screwed to the posts in positions which will coincide with the bed joints of the brickwork, when they are well bedded in mortar. This is a common method of fixing frames. It is not adopted in first class work as the frame is liable 10 be damaged during building operations and lime, etc. is apt 10 stain it. The arrises of the frame may be prott.;cted by lightly nailing wood strips to it. Frames are bedded in morlar as the jambs are being constructed and afterwards pointed in mastic (a mixture of red lead and linseed oil) to exclude rain and draughts. External woodwork should be primed before being fixed, Priming is the first coat of paint to be applied. (Painting is described in Chap. IV, Yo!. III.) (b) The second method of fixing frames, and one which is adopted in betterclass work, consists of plugging (see p, 70) the bed joints of the brick or stone jambs after the whole of the brickwork has thoroughly set. The 7S or 100 mm deep holes to receive the plugs are formed with the plugging chisel (see 38, Fig. 67) and hammer at 300 mm intervals (sec above), the hardwood plugs (see F, Fig. 49) are driven in with their projecting edges cut off to a vertical plane (a plumb-line being used for this purpose) so that the clear distance between the plugs in opposite jambs equals the overall width of the frame. The frame is then placed in position and securely nailed to the plugs and to the lintel. The fixing of the frames is deferred until the building is nearing completion in order to minimise the risk of damage to the woodwork. They are well bedded in mortar and pointed in mastic as before described. Additional rigidity is given to the frame if a 20 or 2S mm square or 13 mm diameter round galvanised wrought iron dowel, 50 to 7S mm long, is partly dri\'en into the bottom end of each post before fixing. The projecting ends are inserted in morlices cut in the step and secured with red lead mastic or grouted cement (see A and R, Fig. 42). Alternatively, hollow cast iron shoes may be adopted (see I., Fig. 44 and p. 1)0). Door Classificalion.- Ooors are classified as foHows : (a) ltdged and battened, (b) ledged, braced and bauened, (c) framed, !edged and battened, (d) framed, ledged, braced and battened, (e) flush and (f) panelled. Size-s,-The si?'es of doors vary considerably, the following standard sizes being in greatest demand: 2040 mm by S26 mm, 2040 mm by 626 mm, 2040 mm by 726 mm, 2040 mm by 826 mm, Other common sizes are 1830 mm by 610 mm, 2640 mm by 810 mm, 2080 mm by 860 mm and 2130 mm by 91S mm. A satisfactory
si~e of door for the modern dmwing or dining rO-o", " : 0.. 0 mTn by that for b"droom~. box~room •. larders, waler-closets, t"I~., ,~ 2040 mm. External door$ should be larger than internal doon '" "nkr thai they nm) confom, with the scale of the buoldtnj:(, and those of a hou~e m,,> be 2080 by 900 mm, 7~6 mm, and b}" 710 Illm.
(a) Ledged and Battened Door (see A, Band c, Fig. 4Z}.-This consists of vertical boards or boltrns which
8S
LEDGED G BATTENED 0001<.. 0 Fi
CLOSED Moo..TICE) b TENON ..JOINT
L.. T. G t.V-JOINTIiO ON ~ StOll M :T G. (. V-JOINTED ON IIOTH SIOttS N. T G t. "'fADED ON 0.0.11 ~IOI 0:1" G to &E ... OfD ON &OTH llDU
METHOD:S or; SECURING
F-Jl.AME
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86
DOO RS
small, and the shrinkage which occurs is correspondingly reduced. Four forms of joints between boards (known as match-boarding) which arc adopted arc shown at L, M, Nand O. The " V-jointed" type is formed by chamfering both edges of each board, and the" beaded" joint shows the bead worked on the tongued edge. These joints are effective in making the appearance of the door less objectionable when shrinkage takes place and the joints open. They are sometimes only tongued and grooved, occasionally they 3TC ploughed and tongued, and in cheap work they arc burt or square jointed (sec R, .'( and 1', Fig. 34). Two other fo rms of beaded joints arc shown at g and T, Fig. 44; the btter shows hardwood tongues or feathers which arc sometimes employed when thick battens are used. The thickness of the ledges is usually 32 mm (nominal), and the middle and bottom ledges are wiQcr than the top ledge, i.~ . , [75 to 225 mm. When employed for ex\ernal doors, the top edges should be bevelled as shown at B, to prevent water lodging on them. This is the simplest form of door and is frequently used for naHOW openings and in positions where the appearance is not material, as for tcmporary shcds, coal·houses, external water-closets, etc. It is relatively cheap ,lI1d is apt to sag, on account of its weight, towards the bottom of the free: edge. This defect may not become so pronounced if the end and cent ral battens arc screwed and not nailed to the ledges. It also has a tendency to twist, especially if the timbcr is not of good quality and thin ledges are used.
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Pr~parnt;ol1 of Door. -"I'h" ledgcd und buttencd dnnr IS mad.., in Ih~ follo"ing nmnner : The planinJ( (on both sides), !-lrooving, tonguin!<. Ihlckn~.~ltlg de .• m,,,,hine oper"llOns of the tongued ~nd grooved battens ar" as descnbnl on p (" fur tl<>OT board$. Th~ batten$ ar C fined together on Ihe jOlllers' bench lind pencillinc5 ~r" dr;)."n auoss them 10 indIcate the position of each ledge. A cnmp (see Fig. 53) ...Ippli('d ncar to one of the ledge positions and this ledge is hghtly and teml1'orarily n,,,kd to Ill<" hJllcns. The second ledge is tben hRbtly nmled after the cr~rnp has bten ~pphcd n~ar to 11. The door IS turned o\'er on the bench, t ..... o rough pieccs uf wood are placed under the led!(es, ~nd oval WIre nails arc dnven through the battens and kdges. Th(' nalls·~re "f sufficient length 10 project beyond Ihe ledges when dri,"en in, lInd as they p,,,r,,,," the roul!h pl~'CeS, Ihe ledges arc not damaged by spllntenng as the naIls protrud". The door I~ fwally re'"rsed und the nails clil1ched or clenched, i.t., the points 9re bent O'·cr and by me,lnS of" punch (see 10, Fig. 6,) and hammer and driven below the fact: of each k ..I);:..,. The b"l!ens are cut and dressed off level It the top and bottom. The edges of the hattens should be painted before cramping 8$ this prevents water (rom gettlnj{ into the jomts and causmg declY. If this is not done an unsightly appearance results ",hen shrinkage occurs. due to the opening of the joints ~hich exposes hgbt unpamted margms. The backs of the ledges ~hould also be painted proor to fixinR. Hanging aNd Fasul1i", of Door.-The door IS fitted bet"ccn the rebates of the frame, a clearance of I'S mm (or" the thIckness of a penny") beIng allowed between the edge of the door and the frame for the thIckness of the pamt whIch IS applied subsequen tl y, and also for expansion, The width of the opening (he low the head and also near th" ("et of the posts as the frame may not be absolutely square) is measured and transferred to the door. After allowing for the deannee, the door is placed lc:ngrhwlse on edge on the fioor pmpped between the notch on the joiners' 11001 Or tr",tle, and the uppennost edge is pl~ne:l. down (or" shot ") to the mark made during measurements. The bottom IS also planed 10 allow 6 mm delrance between the door when hung Ind the step Or Roor. The door 11 placed in pO$ition between the frame, a wedge is inserted between the Roor and the door Ind forced in untIl the door i. brought square with the fTime. If the door does not fit correctly, Iny irregu1aritlel Ire noted and the door taken down .nd planed w'here necessary.
T~e door is now reody to receive the hin,l(es. The fonn of fastening usually provided for Ihl ~ t>"pe of door,s the T-hi7l/(e Or uQU-garnd (see A. FIgs. 4~ and 43), This is 0 wrought Iron strnp pwoted to a metal plaIt. The kmu;klt of the hinge is a pin round "~ich 'wo sectIons of the. plate and the end of the. strap are .bent (see x, F,g. 43). The th,..,kness of the strap "anes from 3 to 6 mm, and .ts lellglh mcreases in multiples of 50 mm from .250 to 600 mm, measured from tht centre o( the pin. Two Sln'ps arc SeCUre9 eIther aUlllllst Ihe face of the hattens (see" :md G, FIg. 42) or screwed direct to the ledges (see II, FI,I(. 42). The plales of the hinges arc screwed to the door posts. Those shown in the elevations m FIgs, 42 ~nd 43 are calk-d Scotch T-hll1x~s and nre of 3 mm thick gal\,~lIIscd wrought Iron. Thicker honges are only used (or hea"), doors. Other hinges are shown at w ~nd x, Fig. 43 and r, F,g. 44.
I/arr/fl:are or homnongtfY includes hinges and fittings such as bolts and locks; it also includes door knobs and handles (sometimes referred to as door
furniture).
All that may be necessary for thc ledged and braced door is a thumb latch. If additional means of security is required, either a padlock or one or two barrel The former is an external fining (as for an external tool~ honse door) whereas the bolts wonld be used to secu re the door from the inside. Alternatively, a rim dead lork may be used in lieu of a padlock or barrcl bolt, or a rilll lock may he used instead of a thumb latch and rim dead lock. The following is a brief description of this hardware :Thumb Latch (see 0, Fig. 4J).-lt is sometimes called a Norfolk or Suffolk latch and consists of : (t) a back plate with handle and pivoted meck, (2) a keeper through which a (3) bt!am or fall bar passes to engage in a (-t) SlOp. The usual length of beam is 175 or 200 mm and that of the back plate is about 225 mm. Another type of thumb lateh with two handles, each having a sneck which passes under the beam, is shown at A, Band c, Fig. 44, A complete fitting is usually of malleable iron, although for better-class work it is of bronze.
bolts may be used.
In fi~ing a thumb laIC!'. " hole IS mmle in the door through which th" sneck is Pllssed and the hack ph'le IS sere"cd to une fuee of the door. The keeper and p!~te to whIch Ihe beam IS pIvoted are serew~-d to the opPOSIte face of the door, Ibe keeper (which IUlIlIs the movement o( the beam) being fixed ncar to the edge of the door. Thc pl~te to "hich the stop ,s att&.!h"d IS $cre"ed to the Inside face of the post. An ulternntive ~nd less conspicuou. fofn of keeper is sho" n at :..;, and this .is fixed to the edge of the dour. A slmibr stop fitl1ng may be fixed to the edge of J3mb of the POSt.
Padlock with Hasp and Staple (see A, F'g. 42, and P, Fig. 43).- The hasp and staple arc usualiy of iron and the padlock is of galvanized iron, brass or bronze. The staple is screwed to the door post and the hasp is secured by two small boits 10 the door. When the door is closed, the slotted hinged end of the hasp is passed O\'er the staple, and the hinged ring of the padlock (after being passed through the eye of the staple) is " pressed home" to lock it. Banfl Bu/t (gee A aod Q, Fig. 43).-It is made of iron, brass or bronze. The lcn~th varies from 75 to 380 mm, alSo mr bolt being sufficient for a ledged and battened door. The plate is screwed to the inside of the door and the bolt engages or " shoots" in a met .. : ""Ckef or staple fixed on the door frame. Sometimes two bolts are fixed horizontally ...; shown at ", or they may be fixed
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vertically when one socket is let into the head of the frame and the other (similar to S/) is let into the stone or concrete stcp. Ri", Dead Lock (see R, Fig. 43).-This consists of a steel case (containing a brass bolt, spring, etc.) which is screwed to the face of the door, and a staple which is screwed to the frame to receive the bolt when the door is locked. The key required to operate the bolt is comparatively long as it is needed to actuate the lock from both aides of the door. The lock may be obtained with one or two levers (see below). An escutcheon (see R') or holed metal plate is sometimes fixed on the face of the door opposite to that 10 which the lock is attached to prevent the "keyhole" from becoming enlarged and damaged by continued action of the key. A plate Jock or stock lock may be used for an external door of this type; this is similar to the above lock but the metal case is inserted in a wood block. (b) Ledged, Braced and Battened Door (sec A, Band c, Fig. 43).- This is a ledged and battened door to which inclined struts or bracts have been added. These braces increase the rigidity of the door and prevent it drooping at the "nose," a defect which is common to the ledged and battened door. These braces must incline u.pwards from the hanging edge, otherwise they would be useless in counteracting the tendency for the door to droop out of square. The position of the middle ledge should be such as to allo'w the braces to have the same inclination, otherwise the appearance is not satisfactory; the appearance resulting when the braces are lined straight through is sometimes preferred (see E, Fig. i3). The width of the braces varies from 100 to 175 mm, and they are usually out of 32. mm stuff; they are housed and not tenoned into the ledges (see detail G, Fig. i3). An alternative ledged, braced and battened door, stlitable for a cottage where a simple type of door is required, IS shown at E. it consists of alternate wide and narrow battens which are 25 and 32. mm thick respectively. See the detail plan at F which shows the battens tongued and grooved and V-jointed, and the T-hinges (similar to that at x) which pass through the thicker batten. The ledged, braced and battened door is used for similar purposes as described for the ledged and battened door, but on account of its greater strength it may be selected for larger openings. It is made as described on p. 86, the battens being nailed to the ledges and the braces afterwards fitted to the ledges and clinch-nailed to the battens. Hardware.-This door is generally hung with T-hinges; those shown at A are 560 mm Scotch T-hinges, and another form is shown at x. The furniture may consist of a thumb latch and a dead lock as already described. Alternatively, a rim /o(k or .a rim latch may be used instead of a thumb latch and a dead lock. Barrel bolts may be used in addition, as shown at A. There are many variations of latches and locks, the brold difference between
each beinl: A "'m latch ia fixed to the face of a door and conailtl of I cuina which tontaina one 1Mw1l.d bolt or latch (which i. operated by a handle auac hed to a apindle) and a ema1l1ockina bolt (aee u).
A rim Ihadloc1c h .. one bolt only which il actuated by a key (see R). A rim locll hu two bolta, one controlled. by a handle and the other by a key (see T); it is fixed to the face of the door. A mortice latch has only one latch (or bevelled bolt) and the case is fitted within the thickness of the door and is only vilible on the edge of the door. A mortice locll ia .imilar to the rim lock in that it has two bolts, but the case ia oflly seen on the edge of the door as it is fixed in a mortice formed. in the door (!lee H).
The rim latch shown at u is a steel case about 12.5 mm long which contains a brass bolt and a spring which acts upon the bolt to maintain it in the staple when the door is closed. The mechanism is similar to that of the latch bolt of the mortice lock described below. The small locking bolt is used when required to prevent the door from being opened by the knob from the outside. A rim lock is obtained in standard sizes varying from 12.5 to 2.00 mm long by 75 to 100 mm deep. A typ:cal example is shown at T, Fig. i3. It has two bolts, i.e., a " dead" bolt operated by a key and a bevelled or latch bolt operated by the handle and (when the door is being closed) by the action of the bevelled end sliding over the edge of the staple. Mullani"" of Rim and Mor/iet Locll.-The internal construction of a rim lock is similar to that of a mortice lock. An interior of a mortice lock' is shown at j, and the following description refers to (I) the lock bolt mechanism and (a) the latch bolt mKhanism. (I) The lock bolt i, of brass or phosphor brom:e or gunmetat and has a pin or boll ,lump auached. to it to form a PIvot for the three thin brass lrous (heflce this would be described as a ., three lever lock ") which are fitted over it; each lever has two recesses, K and L, with a narrow connecting slo! through which a small {roer dump (connected to lhe bolt) passu when the bolt i$ operated.; attached to each lever is. a fine metal spring. When the door il unlocked, the lever stump occupies the upper ponion of recus K. To lock the door, the key is inserted in the keyhole formed in the pholphor-bronze bUJh which has three thin raised rings called u·ards. the key (see , ke tch) bemg shaped to fit thue wards. When the key is turned, it causes the bolt to move outwards and the p:voted levers to s ..... ing upwards un!il the Ilot between the recess i. opposite to the lever Stump. After the key (indicated by broken lines) has been rotated untIl it i, free of the lo..... er edge of the bolt, the lever sprin~ shoot the bolt into the staple (in the case of the rim lock) or strilring platt (..... hen the lock is of tile mortice type-see H), and the lever stump now OCCUpIes the upper portion of the rKen L when the levers have rotated downwards. To unlock the door, the operations are reversed, the key forces the levers upwards and the boh imo the lock in the direction of arrow" I ", ..... hilst the lever stump passe, from recess L to the upper portion of recess K after the levers have dropped. (2) The latch bolt is operated either by the handle or by the action of the bevelled end of the boit upon the tlaple or bent" lUll .. of the striking plate (see H) when the door is being closed. The handles usually consist of two knobs, one of which is permanently fixed to one end of a steel Ilo/ltd Jpindle and the other is loose. The spindle is passed. through a rose plale (which i. acrewed to the face of the door) and through the bush lind follower of the lock (lee x'). There are various devices for securing the opposite or " loose" knob, an effective one being showfl at J' and x' and con,ists of a small metal lIey which is pivoted by a countersunk screw let into the end of the loose knob; the second rOle plate is passed over the projecting end of the spindle, the loose knob i, fitted over it and pressed against tbe rose plate until the laller is brought tiahtly up aglinlt the face of the door, when the key is then dropped into one of the .Iou in the spindle; each rose plate is now 5Crewed to the door 10 make the handle. secure. Oblerve It J that one of the feathr Jprings Ica I
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DOORS uP<'n one end of the latch bolt lind this causes the opposite end to protrude. The fol!ower acts upon the crank rolltr; the latter i~ fitted to the crank which is pivoted lit the crank ltllmp at one end and the other end bears upon a proj«tion on the end of the latch bolt. To open the door when the lock bolt is disengaged, the handle is turned to cau.se the follower to bear upon the crank roller which in tum causes the crank to rotate and operate upon the latch bolt and move it horizontally in the direction of arrow" :lI " until it is clear of the striking plate. When the knob is relcaled the feather springs force the cnnk and bolt to asswne their original positions,
A further reference to mortice locks is made on p. 100. (c) Framed, Ledged and Battened Door.-This is similar to type (d), described below, with the exception that the braces are omitted. The door tends to become distorted because of the absence of the braces, and it is In little demand for this reason. (d) Framed, Ledged, Braced and Battened Door (see A, B, C and D, Fig.44')' This is superior to any of the foregoing types and consists of a framing (which must not be confused with the door frame) strengthened by ledges, braces and battens. The framework consists of a top rail which is mort iced and tenoned into two vertical members called stiles or styles. The middle and bot/om rails or ledges arc morticed and tenoned into the stiles and the braces are either housed into the rails at about 38 mm from the stiles (sec B) or are taken into the corners and tenoned into the stiles (see A). The former is the stronger construction, although the method shown at A is often adopted because of its beller appearance. These bracts musl incline upr~'ards from the hanging post (sec p. 88). The battells may be joined as explained all p. 86, where reference is made to the joints shown at sand T, Fig. H. The upper ends of the battens ,Ire let into the top rail (see section vv at ;\1), the side baHens are tongued into the stiles (see sand T) and the lower ends of the batlens cumpleltly cQt:eT the bottom r(lil l as shown at A, Band c. Detal1s of the various joints arc shown in Fig. 4+ That at h shows the joint between the post and head of the large (125 mm by 100 mm) frame. It is double-tenoned to ensure a tight fit at the shoulders (sec p. 84). M shows t1:e haunched tenon joint between the top rail and the stile, and the housing of the brace as indicated at c. The rpiddlc rail has 3 pair of single lenulIs 2 and is notched to recci\'e the lower end of the top brace (sec N) and the top end of the lower brace. As the rail is comparatively thin, it is not advisable to form these tenons as pre\'iously described, but rather to make them flush with one face. when they arc called barefaced teno1l$. , The practice, sometimes adopted. of makmg the bottom rail the same thickness "s the framing Dnd letting the lower ends of the baw'''' into it is unsound. for "Dter ,,,11 lodgc on the rail and rot both it and the bottom of th( battens. • These are aometimCi clll1ed .. double tenons," a:lhough this description is not quite correct. A double tenon joint :as shU}'n at "'. Fig. 44) has both tenonl ill the thickness of the member, whilst a meroMr h:l.\'ing a paIr of single tenons hu btlth tenons formed in liS
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The bottom rail has also a pair.of single barefaced tenons (see 0). The lower tenon may be haunched like that shown at M. The tenons are dowelled or pinned, in addition to being wedged. These dowels are of hardwood and are from 10 to 13 mm diameter (see 1'.1, Nand 0). One is inserted through each tenon and at a distance from the shoulders of at least twice the diameter of the dowel to prevent the wood from splitting when the pin is driven in. The framed, ledged, braced and battened door is a very suitable type for external use and it is particularly suited for factories, warehouses, farm buildings and buildings in which the doors arc subjected to rough treatment. That shown in Fig. 44- is typical of the type used for farms. The figure also includes a portion of the roof details. Preparation of Door.-The sequence of operallons in framing this door •• brieRy: The rails are fitted loosely into the stiles. thc braces are placed in position, the battens He accurately filled and slipped into the grooves of the &tiles and tOp rail, the tenons are wedgcd and pinned (a.cramp beingysed as described on p. 102 to tightcn up the joints), and the b911ens arc nalied to th ... ra.ls and braces. The door frame should M securely fixed as explained on p. 84. The feet are shown secured by do"e\s. Alternatively the door posts may be filled with tlUt iron .hotl (see 1..). These prov.de a good method of fixing and also protect the lower ends of the POIfS from damage such as m~y be cau5ed in factorics, fannsteads pnd similar buildings. The ends of thc posts are shapcd, painted and fitted tightly into the shoes which are then screwed to the posts. The frame i. now fixed "ith the do"els let into the mortices previously formed in the step lind run In with lead or cement. lIanging and Fmttning of Door.-Heavy wrought iron Scotch T-hinges are sometimes uscd for hanging this type of door (sec p. 8b). Alternat"'e!y, 6 mm thick wrought iron strap hinKts or bal/ds and glOdge!TII hooks are used, espeCIally for large doors (see P, Fig. 44). One endof thc ttrap 's bent to form an eye. Two straps are required and arc secured by 10 mm Or 13 mm diameter bolts which are passed through the rails and battens. The door is hung by passIIlg the eyes of the straps o~'er the pins or gudgeons which arc welded to back pfat~s bolted to the frame. Sometimcs dooT"$ are not pro\'idcd with frames and arc hung by eng~ging the eyes of ehe str;lps in gudgeon hooks smithed to wrought iron lugs (see Q). The !ug~ arc secured to the stonework, morticc, being cue to receive them. After insertion. the IUl{s He "ell caulkcd with lead and the reaSOn for the dovetail shapc and ra!(g«l surface IS 10 give a greatcr key for thc lead and incrcase its holding power. The heavy caft ir(ln ''''IKe (see w. Fig. 43) is another type of fnstening used for \'Cry large doors. A pair of these hinges '5 bolted 10 the door 'Illd the pins on them engage in IO(kets fixed to the frame. B,,1/ hj,.g~J (see Y, Fig. 43) He often used for hanging this type of door. The flanges . ?r !Wlgs of t~e hfingc! nrc made of c,ither c~ht Iro,n, n"lalJeabl~ iron or steel'la~d thher increase III r 3 mm umts rom L5 to [50 mm onl{. • e nuc e cons.sts 0 f a centra pm W rch passes through ahernan"e eyes of each wing to form five segments. The" ings have COUntersunk holes to rece,ve the heads of the screws used to secure the wings to the door and frame. The door is hung by butt hinges in the following manner·: 1t;1 fitted into the frame and trimmed so as to leave II uniform clearance of J'S mm (seep. 86). The door rs removed and one wing of each hinge is screwed to the edge of the hanging Itde. This is done by forming slight housings in corre<:t position on the sti!., to receive a wing of each hinge which is screwed to the door. The door is again placed into ehe opening. wedged tempor_ ar,ly (p. g6). and brought to the reqUIred position. The housing. for the free wings are marked on the post, the door is re\TIoved and the housings are fonned. The door is placed finally in position and the wings of the hinges lire screwed to the post (aee ..:, Fig. 50). In order that the door shall swing freely. the centre of the pin of the top hinge should be 5 mm beyond the faU' of ehc door and that of the bottom hmge should be 6 mm dear. A description of the JktT~ butt hinge shown at z, Fig. 43, and iea application is given on p. 100.
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PANELLED DOOR Hardwart.- That for this door may be as previously described. If provision is required (for purposes of ventilation, etc.) to enable the door to be kept slightly open and yet secure f(om unauthorized entry from the outside, then a door thai,. as shown al v, Fig. 43 , may be fixed on the inside. This fitting may be either of malleable iron, brass. or bronze. The plate to which the slotted shoot is attached is screwed in a horizontal position to the inside face of the door, and the staple to which the chain is fastened is screwed to the post. The free end of the chain is in the form of a stud which may be inserted in the slot at the end farthest from the staple only when the door is dosed. The door may be opened to a maximum of 100 or 125 mm, when the stud is passed along the slot, and the stud .,;annot bc removed from the outside. (e) Flush Doorl (see Fig. 45}.-This is thr most pupu/ar type 0/ door, particularly for internal use. Two of the many va rieties of flush duor are shown in Fig. 45. That at A is caBed a laminated flush door ann cunsists fA a core of strips of wuod glued together under great pressure and fa ced on each side by a sheet of three thin layers or Vn/tn'S of wood, called plyu:ood (see below), which is also glued under pressure to the core. Sheets of pl)'wood can be obtained up to 2'5 m in width, and therefore a flush door has the appearance of J slng!e panel. As shown at E, thc core consists of 32 rnm wide softwood strips or 16 mm wide hardwood strips. These strips art arranged \\ ith the Jl:rain alternating, as shown; this reduces shrinkage and distortion. A hardwood edging is fi\ed to cover the core and the edges of the plywood; this prevents the latttr from I,cing damaged, particularly at thc striking edg-e. A laminated flush door is heavy and requires mu(;h material, and anuther type, (;aHed aframedftush door (sec B, Fig. 45), has been evolved and is extensively used. It consis!s of a wood frame comprising stiles, wp and ballom rails, and thin il'1c:rmediate rails, and this frame is covcred on both sides by sheets of plywood. T!lC 75 mm dcep top and bottom rails are tenoned to the stiles, and the thin (25 rmn) intermediate rails arc stub-tcnoned to the stilts. The joints of the framing are glued and (;rJ.mped, and the plywood sheets are glued to Ihe framing under great pressure. Lock blocks arc prm'ided as shown at B for the insertion of a mortice lock. An alternative form of hardwood edgir.g to that at E is shown in the detail f. The finished thicknC5S of h()th types of door is 4S mm. (f) Panelled Door (see Figs. 46, 48, 49, 50 and 52).-A panelled door consists of a framing or rim which is grooved on the inside edges to receivc one or more panels. Types of Panelled Doors.- Several designs of panelled doors arc shown at A to !I (ioclusive), Fig. 46. 'fhe members of the frame not already mentioned include the mun,in, which, a,t c, is the short vertical piece between the bottom and middle rails. I\"ote in e\'cry case: ( I) the stiles are continuous from top to hotlom, (2) the top, bottom, middle .. ud inter:ncdiate rails arc joined to the stiks and (3) thc muntins arc joilled to the rail~ (~ce later). 'An extended dnenpllun
IS
ill,·en.n Chap. I], Vol III
The nominal thickness of the framing may be 38, 44' or 50 mm, depending upon (I) the size of the door, (2) the situation (external dQO~ are usually thicker than those fixed interna1iy), (3) the type of lock to be used (a minimum thickness
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of 40 mm is necessary for mortice locks), (4) the thickness of the panels and (5) the size of the panel mouldings. The panels may be rolid (as shown at j, R and v, Fig. +6) or they may consist of laminattd wood t such as plywood ar,d laminboard (see N and A', Fig. 46). The minimum thickness of solid panels is 13 mm (nominal), whereas that of plywood consisting ofthrcc veneers (termed" 3-ply ") is from 5 mm to 13 mm. L A detailed descTLption of the manufacture and uses of plYI<·tKJd and similar veneered products is given in Vol. II] Briefly, ply"ood consists of three or more thin sheet, of Columbian pine, birch, o"k and mapl" arc some of the t,mbers used. Round logs 3re CUI into from J' $ !O 1.'5 m length!, steamed. ~nd subsequently each is placed horizontally into iL machine called" rotary vI/ru" CUlla "hrch J.lrips it at the rnds . The machine rOtate. the lo~ aRaln$t the ed/o(c of " 10nJ.l knife" hich extends Ihe full width of the m.clune and cots th c limber into a continuous sheel,
wood which have been carefully dried, glued, pressed and trimmed otT.
TYPES OF DOORS (, PANEL MOULDINGS MII.- -
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SIX PJ..NSL
PANELLED DOORS Treatment of Panek-The finishes which may be applied to panels are many and varied.
The panels may be finished with simple or intricate mouldings,
or they may be left plain without mouldings. Elaborate mouldings may harbour dust and are difficult to keep clean. They may be expeIlsivt:: tu produce, esped~ ally if mitred by hand (see later). As will be explained, most doors are now machine-made, and in their manufactu re it is the aim to eliminate as far as possible labours performed by hand . The following are the various panel finishes Square.-No mouldings are provided, the edges of the framing next to the panels being left square (see J an'\ K, Fig. 46, and 0, Fig. 52); 1 shows the corner slightly rounded by sand-papering and is called" pencil-rounded." The panels are known as square sunk or flat (see E, F and H, Fig. 46). Chamfered edges, as shown at Land 1\1, are an alternative. These finishes are much in evidence, and, provided the panels are weli proportioned, such simple treatment-has much to commend it. Solid or-Stuck Moulding.- The mouldings arc" stuck" (meaning" worked ") on the edges of the framing. Various examples are shown at I. to y (inclusive), Fig. 46. Note that in most cases the width of each mould is equal to the depth of the groove prepared to receive the panel (see the broken lines at R, sand y); the operations of moulding and framing hy machinery are simplified when this is observed. The joints at the angles of solid mouldings arc scribed to give 45° mitres 'or intersections. Scribing is the shaping of a moulding which is required to fit against a similar but continuous moulding. This is illustrated at c and 0, Fig. 47, which shows a bottom (or intermediate) rail scribed to a stile. The latter has an ovalo (or quadrant) mould worked on it for its entire length and the shoulders of the rail are hollowed out to fit accurately over the ovolo mould on the stile. Tbis is shown dearly on the plan at c which indicates the shaped end of the rail separated from the stile; this results in a 45"0 mitre as shown at D and E. This mould and the solid llluuldings shown at L to u (inclusive), Fig. 46, can be machine-scribed and are therefore comparatively inexpensive; whereas those at v to y (inclusive) can only bl;' mitred -by hand and are accordingly expensive. Planted M/Julding.-These are separate moulding!! which are" planted" round the panels adjacent to the framing. Examples of these arc shown at A', B', c' and D', Fig. 46. The mouldings are nailed to the framing and the nails must not pass through the panel$, otherwise the panels will crack owing TO the 'internal stresses set up when the limber shrinks. It is important to allow for the free -movement of the panels (when the wood shrinks or expands) and then~ should be a space of from 1'5 to 3 mm between each edge of the panel and the groove; the clearance in each of the examples shown in Fig. 46 is l ' 5 mm. " Panel pins" (~ee F, Fig. 66) are used for fixing these moulds, as the small heads are inconspicuous and cause the minimum damage to the mouldings.
93
Planted moulds are formed with mitred joints at the angles (see A and B, Fig, 47), each adjacent end of the moulding being cut at an angle of 45°· Planted mouldings which finish level with the face of the framing arc called jlUJh mouldings (sec L, Fig. 49). Those which project beyond tbe f:lCp. of the framing are called bolectjon fllOuldings (see F" G' and H', -Fig. 46, P, Fig. 48, and K, Fig. 50); these are usua!ly rebated over the edges of the fram ing to cover any shrinkage which m ay take place. Occasionally the panels are made with one face flush with the framing; these are termed flush panels (see c, Fig. 46). A bead (see E') is usually formed on the yertical edges of the panel to render less conspicuous any openings which may occur if the panels shrink; these are called bead butt pmJels (c). If in addition a similar bead is worked on the' horizontal edges of the panel, such are called bead flush panels. Raised Panels.- The central portion of the panel is thicker t han the edges or margin. That at n', Fig. 46, shows the panel chamfered from the edge of the moulding to leave a flat or " fielded" central portion; such is called a raised and flat or raised and fielded panel. That at P , Fig. 48, is known as a raised, $UlIk and fielded panel. Sometimes the edges of the sinking next to the central flat portion are moulded, when the panel is said to be raised, sunk and moulded. A raised and chamfered panel , when. square, is chamfered from a central point down to each edge of the moulding; when the panel is oblong, the chamfered margins meet to form a ridge. Sunk Moulding .-This is formed below the surbce; the sinking is usually continued to form a sunk panel and the portion of panel enclosed by the moulding may_ be below or flush with the outer margin. The panel is thus formed out of the solid. Examples of panels and mouldings are shown in the elentions in Fig. 46. Students arc advised to cultivate the habit of drawing details involving mouldings to fuB scale mther than make sketch details which are very frequently far too smalL They should realize tha t it is not ulways necessary tQ show mouldmgs consiSTing of many small members and fil1ets, for very ofte n the si,mp1cr the mouldings the better. In t his connection it .should be pointed out th:::t whil~t mouldings of hardwoods may have sflmn ",~mber$, those of M>ftwoods .Muld not, for they ~re difficult and expensive to make and disappear when two or three coa ts of paint are appJie.!.
The construction of panelled doors will now he considered.
Single Panelled Door (see Fig. 48).-This is suitable fonhe main entrance to a house. The construction of the joints of the frame has heen described on pp. 83- 8 4. The outside edges of this frame may be pencil rounded by sandpapering them, or they may be ovolo or agee moulded and thus rendered less lioMe to damage than if left square. External doors are uSlla\ly prepared with 50 mm (nominal)l thick framing, , As previously mentioned, an allowance from the nominal sizes for dressed (finished or net Ol' wrought) work must be made. The usual anow~mce for work which is given a smooth finish (as for painted work) is !'7 mm for each dressed surface' plus 0·8 mm for sll)ldpapering tach surface (see pp. (n and IO<}).
DOORS especially if they arc fitted with morti~ locks, although there is no constructionaJ reason why such dOOB of average: size should exceed 38 mm in thickness if they are fitted with rim loeb. In the illustrated example the door is So mm thick 90
account of the thick panel which is necessary because of its large size. Full size details must be drawn to the finislud sizes. In accordance with the footnote ,tated on p. 93 the usual total allowance for painted wo,:k is equivalent to 5 mm, when both faces arc dressed and sand papered. If great carc is exercised in dressing expensive hardwoods, the tot:!.1 loss when dressing both sides may be reduced to • mm, and this allowance has been made in the details shown in Fig·48. The joints of the framing of the door may be either (a) morticed and tenoned or (b) dowelled. (a) Morticed and Tmoned Jrnnts.- These are similar to the joints of the framed, ledged, braced and battened door shown in Fig. 44, and are illustrated at Hand L, Fig. 48. The width of each tenon is 58 mm. The grooves formed along the inner edges of the framing to receive the panel are shown. The depth of the grooves is usually made equal to the thickness of the panel, although it should not be less than 13 mm (see P, . . 48, and the details in Fig. 46). A I
clearance of 3 nun is shown at p to allow for the free movement of the panel (see p. 93). (b) I>ouHlled Joints.- Typical dowelled joints are shown at J and M, Fig. 48; that at J shows two dowels used to connect the top rail to the stile, and the detail M shows the connection between the bottom rail and the stile where four dowels are used. The dowels, which are machine.made, are of hardwood. 'their diameter should not be less than about one-third the thickness of the framing, and a common size is 125 mm by 16 mm (see 0); they are placed at about 50 mm centres (see M). The ends of the rails are bored, glue is applied to the edges 1)f the rails and the inside of the holes, and the glued dowels arc inserted; the ~tiles a~ bored, the holes are glued, and projecting portions of the rail dowels are inserted. The dowels are grooved (see 0) to increase the holding power of the glue. Only well seasoned timber should be used if the joints are to be dowelled, otherwise the shrinking and warping of unseasoned timber may cause the dowels to snap, followed by-the destruction of the joints. This method of jointing is almost universally adopted fOT doon mad e by machinery as it IS a cheaper Conn than the mOTtle"" and tcnon Joint on account of thc savmg of timber and I~bour which results. Whilst there is still much prejudice ulta;nst tho;-
MITRED 6 SCRIBED JOINTS
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DOORS doweJiM joint it i. being increatina:ly recognized thlt modern methods of production have evolved • door, having dowelled joints, wPlich is eminently aati.f.ctoryconaider· ing its rel.tlve low COlt. Dn.tlc changa h.ve taken place in the m.king of doors; most imponed doors .nd thouSinda of doou made daily by mass production methods in this country have dowelled and not morticed and tenoned joints.
The door shown in Fig. 48 has a 22 mm (finished) thick raised, sunk and fielded panel with bolection mouldings on both sides (see p); alternative mouldings may be selected from Fig. 46. Whilst certain timbers, such as mahogany, can t)e obtained of sufficient width to enable this wide panel to be formed in one piece, it may be formed in two or three pieces carefully jointed together. This jointing is done by shooting the edges of each piece to a true plane so that the adjacent edges will make a good fit throughout the length of each piece; the edges are glued, fitted together, securely cramped until the glue has set, when the panel is planed over to a smooth finish; this is called jointing. Any panel exceeding 280 mm in width for an average good quality internal door should be jointed in this manner. Attention is drawn to the construction at the bottom of the door to prevent the access of water (see Q). An oak (or similar hard wearing timber) sill or threshold extends the full width of the door opening, well screwed to the floor and bedded on mastic. The large groove on the inside serves to catch any water which may have penetrated and which escapes down the two horeholes. The top of this threshold is approximately on a level with that of a door mat (assuning that a "mat well "-which is not re'i0mmcnded as it is difficult to keep clean-has not been provided). There is therefore little danger of anyone tripping over the threshold . Incidentally, small sills or projecting weather· bars are more dangerous in this respect than are deeper and \\ IdCf sills. An alternative method of weather exclusion is shown at H, Fig. 48, the wrought· iron weathcr-bar being let into the dovetailed sinking and secured with molten lead, run in hot and afterwards well caulked (consolidated with a blunt chisel); this lead is covered flush with the top of the step with cemeot mortar so as to exclude rain·water which may otherwise cause discoloration. The moulded weather· board is tongued into the bottom rail as shown and should fit as tightly as practicable petween the door posts; thir. throws rain clear of the threshold. Hardft'arf.- The door would be hung with three 100 mm butt hinges as described on p. 90. It would be fitled wilh a 75 mm four·lever upright /IIortice lock with striking plal~ (see s, Fig. 48). This type of lock is necessary, for, owing to the ahsence of a middle rail, the usual type of mortice lock (sec H, Fig. 43) would he too long, and the two handles should be of the lreer type as shown, for if knob!\ were used (as illustrated aT x , Fig. 43), injury to the hand may be caused owing to their dose proximity to the door post. The striking plate serves a similar purpose for a mortice lock as does a staple for a rim lock, and is housed and .scre\\ed to the rebate of the post after two small mortices to receive the ends of the holts ha\'e been cut in the post. The prOjecting lug on the plate is slightly bent so that, when the bevelled latch bolt strikes it as the door is being
closed, the bolt will gradually be pressed in. This furniture may be obtained in bronze, brass, chromium plated or oxidized ailver metal, bakelite. etc. A Cylinder Rim Night Latch with staple (see M, N, 0, P and Q, Fig. 52) would be required in addition to the above lock. This is one of many patent locks which are on the market and the complete latch consist! of a bronze cylinder fitting N, the latch 0, and the staple P; Q shows a section through the latch attached to the door. The fitting N comprises a separate circular rim with its inner edge rebated to receive the circular face plate which is cast on the case (see Nand Q); the case contains the cylinder to which the spindle is attached and this cylinder is caused to rotate within the case by the action of a key. The latch bolt may be operated from the outside by the key which is inserted in the cylinder to rotate both it and the spin~le for the latter to cause the bolt mechan ism to function, or the bolt may be shot back from the staple by turning t~e knob of the latch from the inside. The locking arm (see 0) is used when required to permanently fix the bolt so that it cannot be operated by either the key or the knob, and thus the bolt may be fixed in the staple to afford greater security or it may he fix ed when it is clear of the staplc. The directIons for fiKlng this cyhnder latch are as follow8; A 32 mm diam eter hole is bor~d through the door, the centre of thc hol e being 60 mm from the edge of the door; the cylinder fitltn!: N is passed through the hole from the outside, the back plale (~e Q) is screwed to thc back of Ih ... door; two long screws are then pa~ thrOU.Q:h hol"8 in the back plate to sc:<:ure the lUll attached to the case; the end of the spmdle IS .,as$ed throu!'(h the bush of the latch o. and the latter is screwed to the hack of th" door. The staple is screwed 10 the edge of the door.
One pair of antique bronzejlush bolts may also be provided (see s, Fig. 43) These are not so conspicuous as the barrel type, as the back plate is screwed through the stile in a housing formed to bring the plate Rush with the face of the st ile. The end of the bottom bolt slides into a metal socket (5') let into the floor or step, and the top holt engages in a socket fitted into the head of the frame . Sometimes ,\ leller plale, prefe rably of antique brom:e, is required (see" and L. Fig. 52). The flap opens inw:lrds and is suspended on a horizontal rod round one end of which is coiled a sprin,g which forces the flap tightly against the back of the plate. A mortice. approximately 150 mm long and 50 rnrn deep, is made in the door with the horizontal edges splayed downwards (see L), and the fitting, wh::h entirely covers the hole, is secured to the door by means of two screws which are threaded to slUmp.~. A door chain as described on p. 91 lIlay be fixed. Ooor Casing or Linings.-Whils! external doors are hung to solid frames. it is customar y to fi, internal doors to c;lsin~s or linings which provide a suitable finish to tPc openinv;s. Casinv:s arc thed either to (a) pallets, (b) plugs or (c) grounds. (a) Pallet pie(l's or slips, 10 mm thick. are built into the bed joints at the jamhs of the openings as shown at Q. fig. 42, and 0, Fig. 49, and at intervals as described on p. 8.. This method of fixing is very general.
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DOORS (6) A cheaper and less satisfactory method is to plug the Jambs. Wood plugs ( .... hich should be of hardwood but are often made from pieces of floor boards), shaped as shown at F, Fig. 49, are driven into holes f.)rmed in the mortar joints; they are driven tightly up to their shoulders and .... ould take the place of the pallets shown at D, Fig. 49. The plugs indicated at 0 would be used for the fixing of architraves (see p. 120). (c) Grounds.-As implied, the purpose of these is to provide a groundwork for the casings and architra\·es. This method of fixing is now only adopted in the best practice. The simplest form consists of 20 mm thick pieces of undressed timber (when they are caned rough grounds),1 and are usually i5 mm wide, although this depends upon the size of the architraves. They pTtlvide a continuous means of fixing for the casings such as is not afforded by plugs or pallets. One edge is sometimes splayed to afford a key for the plaster (sec A, E,], K, L and 1\', Fig. 49). The jamb grounds are fixed in true alignment on each face of the .... alls to plugs at tntervals, and the head or soltH grounds are naIled to the lintel (see A). They project about 20 mm beyond the jamhs, depending upon the size of the brick or stone opening and that of the door. In good work, the head grounds are haunched tenoned and wedged to the jamb grounds (see P and E), This preparation is all that is necessary for 102 mm walls; for thicker .... alh;, however, So mm wide by 20 mm or 25 mm thick short horizontal backing PlletS are fixed to the edges of the grounds (see A, C, K, Land N). These cross pieces provide extra means of fixing the wider casings and, if the ends are dovetailed and fitted into notches formed in the grounds (sec A and E), they are effective in preventing the grounds from expanding and twisting when they absorb moisture from the plaster, which is applied subsequently to the walls. The backings are fixed near to the top and bottom of the jambs and at about 600 mm intervals. There arc three types of casings, i.e" (I) plain, (2) skeleton and (3) framed, ( I) Plain Casing$.-Thesc are usually prepared from 38 mm thick boards and arc suitable for openings in walls which do not exceed 215 mm thick. They may be either single rebated (see D, G and H, Fig. 49, and II and K, Fig. 50) or double rebated (see A and h, Fig. 49, and 11, c and D, Fig. 52). Alternatively, in cheap work, a 13 mm or 16 mm thick stop is nailed to the casing, when the thickness of the latter may then be Teduced to 25 mm (sec J, Fig, 49). Double rebating a wide lining gives it a balanced appearance which is noticeable when the door is open. The soffit casing is grooved or trenched to receive the tongues formed on the jamb linings (see G, Fig. 49). This groove extends to the outer edge when softwood is to be used and which would be painted, but if the linings are of hardwood and subsequently polished the groovc in the soffit does not extend right across but is stoppcd to house the abbrcliiatcd tongue as shown by thick broken lines at 0, Fig. 49. (2) Sheft/on Casillgi (see Band L, Fig, 49).-This type consists of a skeleton I Thnc are di$1lnct from fHoughl grollnds which are used in conjunction .... ilh architraves (5Ce M, FiR_ 49)·
jamb and soffit framing comprising 75 mm by 32 mm stuff to which 13 or 16 mm thick boards or stops are nailed to give the appearance of a double rebated lining, The short rails of the framing are tenoned to the long member-;, and the latter of the soffit framing are tenoned to the jamb framing (see B). The short rails should coincide with the backings and be nailed to them after the long members ha\'e been secured to the rough grounds; the stops are then nailed to the framing, An alternative detail is shown at M to introduce a dressed or wrought ground which requires only a small architrave. Skeleton linings for thick walls arc cheap and effective, although there is a danger of the wide stops splitting if they shrink excessiyely, as movement is restricted when they are securely fixed at their edges, (3) Framed Casings (see c and N, Fig, 49),- This is the best form of lining for openings in thick walls, It consists of panelled jamb and soffit frames, and the construction conforms to the principles of panelled door construction. The treatment of the panels should be in keeping with the design of the door. This casing is fixed to the grounds and backings as described for a skeleton lining. Casings secured to grounds are less liable to damage during the subsequent building operations than those fixed to plugs or pallets, as they arc not fixed to the grounds until a:'ter the plastering has been completed. Although internal doors are generally fixed to casings, there are certain exceptions, Thus, heavy internal doors (such as the framed, ledged, braced and battened type), as used for warehouses, etc., are sometimes hung with straps and gudgeon hooks fixed in jamb stones (see p. 90), and the casings are then dispensed with. Another exception is shown at F, Fig, 43, where a frame and not a casing is used. Internal coal-house, etc" doors are often fixed to frames instead of casings. Two Panelled Door (sec s, Fig. 46, and Fig. 50).-The construction of the framing is similar to that described for the single panelled door with the exception that provision has to be made for the middle or lock rail, so called as the lock is usually secured to it. The height of this rail depends of course upon the design, and whilst it was the invariable practice to make it at a convenient height for the door handle (which is approximately 840 mm to the centre of the rail), this htight is now often departed from. The position of the middle rail in the door shown at B, Fig. 46, is such as to give two panels of equal height, whilst the centre of the lock rail of the door in Fig. 50 is 1'4 m from the floor. It will be observed that, whilst the appearance of this latter door is satisfactory, the position of the lock is not conveniently accessible for small children, If this door is to be fitted with a rim lock, the middle rail will be formed with a single tenon at each end when the rail is only 100 mm deep as shown, atd with a pair of single tenons at each end when the rail is 175 mm or widen. I( however, a mortice lock is to be used, the door is often 50 mm thick, and the ends of the lock rail will be prepared as follows: If it is a narrow rail, the end to be fitted into the" hanging" stile will be prepared with a single tenon and the opposite
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end will have two tenons (to form what is called a twin trnon) which art' equal in width to that of the rail less the depth of the panel grooves and with a space between them equal to the thickness of the lock j for a wider rai", the end secured to the hanging stile will have a pair of single tenons (as shown at A, Fig. 52) whilst the opposite or " striking" end may have four lenons. usually called a pair of twin tenons (see Fig. 51), in order that the preparation for the lock will not weaken the joint. This latter fi~urc shows the mortice lock in position. Note that the combined thickness of the twin tenons eq uals one-third that of the rail. Mortice lock$ are now available "hieh ,lTI." on I" " rum thick ,mu they obviate the necessity for using twin tenons unless. for some ~pecial r~;lSon. " brge lock is n:quired. Another type of lock;s trian,l!ul"r or \\.-dJ.:,,-shapl·d ,-nJ neccssitatt,s for its accomodllUon the removal of unly ,I s.m"ll purtlUn of the tl·non.
A marl ice lock is iHuslrated at II and I, Fig. 43, and its mechanism is described on p. 88. Note that the steel case is fixed to a steel Jure-elld to whieh is secured a br,lss jare plale by two set-screws. It is necessaT) to keep the hottom of the door at !cast 13 mm clear of the Roar to enable it to pass a carpet with underfelt. It is advisable 10 screw to the floor a 10 mm thick hardwood slip with splayed or rounded edges in order to minimise drau,li:hts (see j, Fig. 50), Alternatively the door may be hung with a p
varnish by finger marks. These can hc obtainc(\ in various sizes in bronze. o~idiscd sil\'er, etc. (Sl'(' J. Fig. 52). Doors shown at c, E, F, G and II, Fig. 46.-A detailed description of these doors is not necessary for their construction will be readily understood on reference to the details shown in respect to the single, two and four panelled doors. In every case the stile~ are continuous, the rails are either tenoned or
DETAIL
OF
ql HA~E
I
"".1
"
51
Manufacture of Panelled Doors.-Most doors are (0) man ufactured by machinery, some arc (h) prepared principally by hand. (a) Machine-made Doors.-Reference has been made on p, 96 to the enormous number of doors which are machine made. Mass prOOuction has been responsible for a large reduction in the cost of doors and this is the chief reason for their popularity. In the manufacture of stant!:ard doors t.he whol.e .of the operations of plamng the timber reducing It to the correct Widths, forming the Jo1Ots, glUing ahd finally c ramp10g the m~bcrs together are done by ma~hlnery. It is also e:mployed to trim the door to the ~i~" of thc frame, form the lock morllce and. Icrcw the hlOj:lc, to th,· d"". Many of these doors are dowel join'ted, as shown at J and M, Fig ~!l, and the following i. a brief deKTIption of the operations involved in their manufacture: The timber is sawn to suitable scantlings, artificially seasoned, taken to the planing rtylchine where it is surfaced on both .ides and edges, sawing machines cut the door panen.. sules and nili. into correct widths, rails are bored glued Hnd dowelled by a machine," orit! oPeration, stiles an: bored by a machine, glue i. sq uirted imo the dowel holes in the stiles, rails WIth their proje<::ting dowels are fitted into the holes in Ihe slIles after the panels ha\'e been .Iipped into the grooves and, finally, the assembled members Ire cramped together to complete the door.
-
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I'.'""ION OF MUNTIN
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DOORS
102
(b) Hand-made DooIS.-\\'h,I.t mac:hmtr;' his fl,m;Nn~ most of the oprrauont ",h,ch .c~ funnerl} pe:rfortnN by hand. there I. Mill. dmulOO fur doon .nd "mllar (ramc,""ork ... h,ch require. (:Ullm If1lOI,.In, of hand prcplluuon. TN. Ipphn plrtICUlarly to the hlgh«1 qUllhty fram~ and pancllrd doon and 'hOM: .... h,ch Ire nOI of "andlrd I'lt. The Opl'nholU ,"voh'fliarc: (I) .ellm. 0\.11. hl fo""mR "",r1I~n and tenon., (3) IIuln8 .nd wedgmg up and (4) clalmng off. (.) SCI/I. <>Ut.--llill II the ."prodU<;U(fl ' " . board (ulled 'I~lfll" OIt out on ont fa('C' of ,h., board, and the honzontal KeUOn, called Ihe fndllr ,od, •• detailed on the rnu-.e The pl"ce~ of IImoc' II) be used for the various member1 should he carefully tclected to "h'Htc "a,le dUr.nM ~O"'·ChlO". If machlnCr)' II oot 4.'a.lable, each pl«e I' <'ut do"n by mea". 01 ~ rip \d" (<)th hm"h The Jo.ner pcne.ls h,s cha",clen~ll{ mark, CJlk'd a f"u lid, /tIn.1t (~ •. " F .nd c;. F'R, H), on the face Ind thll should 41 .... ~)s POlOt 1!'''4rd, the bt·.t ...lilt Thl~ edlle. ulled the fau I'd(l'. IS th"n drellscd b)' a ja. k plM)1' ~nd sub"'rflctl (/rid T""",u, --The ~t,l ... UI' no .... mortll'l'd If a mnrtlsmlt' machme II nO.....llable.the morticesn" made .... ,th ~ mOTuse chl-.el (, .... p ,26) ~nd nlollkol (..ee 23, hil- 671. A mortlSC IfLIUlle ("'. FIIl_ 1'171 II uvd '" ", .. be Of m.rk th" mon,c'" un u~h ~~ of Ihe slIle. Ihl' polOlS of Ihe Ilaul/:e ,,",lOR ~"I 10 the ",dth of th" ~h"d .... h"h • h"uld "'l".l orliT-th,rd th(' thlckneu o( Ihe "uff These m<)rll~" lire dl"a~, II~UlrCd frutn Ih" fdee udt'of each ,tile Ea"h mortice II clIl half,,,,.)· thrOURh. comm.. n
t.,
compleled from Ihe rIce edfft' In ••im,l" manner; • plflnR Lhiscl (3S. Fig 67) i. uaed to fiOlm off, The So nun deep nub moMlCei are formed 0" the l"l1111U feet',,·., lhe lenon•• t Ihe ends of Ihl' munhnl. 1M end~ of Ihe nIl. ITt ~uaed from the bce Ilde ., .hown I' II, F,g. S) The .. mort.ce Imes" .n: rip llI"'n d" .... n '0 the" haun~h III""'," Ihl' ,. "asl"" II remo,'~ •• nd the" "uK" hnl'S ., Ife llI"n do"n 10 Ihe shouldl"" h"es "(see c). The panel fi{n)O"e " thl'n formed. by means of. ploujoCh ()I, FIR (7) on Ihl' lscc edge from ('nd 10 end of each s{lle, Ihe top fll .. edge of thl' bn1tOm rl,l. h.. th ed/lel of Ihe middle rail. the bottom or face edge of the tup raIl and both edgel of I'"h muntIn; Ihl' plough ITOn must be of the proper s.u. be vt dt Ihl' c"rr",,1 deplh (I) mm 10 Ihl! CI'I'). and Ihl' ploucll must al ..... }". be work .. d from the fact ~Id(' of e.ch mt"lnber_ The I.. "on lhe~ks (outer ponlon.) Ire now remo, .. d by U$lOg Ih., tenon u .... (I). hll. 6;1 101 urrfu11y CUI do"n Ihl' centre of the 'houlder lme5 to LomplN~ the ~nd u ,t\<,.... n III I). I· II!:. SJ I"he Il'nOnl on the mu"t'n, ar~ fonned ,n a ""nll"r manner Afe"r lh" eomen of Ihe end~ I)f Ihe tl'nor,~ h,,\(" b<-en dm"l1ed off!lO thaI they rl'ad,ly I'nRage In the mortl~"', Ih., "hole of the. mm1ber~ arc ",,,..mhlcd eemporanly 10 &ee If the jomls I1t a~'-ura!(·I\'. and th" IrumlOlI ".pUI ~sld,' pendlnlllh" pr~p .. rallon of the pands. The pan"l~ arc then lI",d~ The d"",-1I51<"'5 MC laken frnm Ihe rod or rramlllg, one face and ~dJ:1' Me plan.,d ""h Ih~ trYlO1l pl,IO~. ~nd Ihe fa~ .. and ('"dRI' mark, arc put on thell<:. A panel R~U)ll' In.., p. 12.~) I. u,,·d '" mnk Ih~ ."qulTed ",dth, Ihl' pwnd IS CUt II10nK Ihis hne. and ,h .. ""d~ are .qUJtL-d and, 1,11 tn Ihe enn siZt:. Th .. panel" no" /tIJtIl~I~d or lI"UK"d; Ih.· mu11"I" -u p'ne or ""'w I!TtM)\'ed 10 the requ ...:d IIZ(' (5« Ii • F'II SJ}--i. shpped .. Ionl( th,' ,'dj{n 1)( the p~nel 10 ,nd.,-'ate any "x.ccs~,,~ly Ihlck pl,,·e. "h,eh a.c "ased b\' pl.HlInll The four pand" H,· mud~ ill this manner, the .. des lTe smoothed br d ~muolhmR plane (I-rt' p. 12.6). RI,'" PJJM:r II ruhbet! a":TO'Crtn of 11 mm dllmetCT hoi"" alun" lis j"nRlh 1010 "h,.h 4 7 _~ mm by '.1 mm munt! .t.-clt~per P"R I¥ 10.e'IW; thIS peR is attached by a chaIn II) a ~h"e, Ih" Ja .... ~ "f .... h,eh p ..... uHr the t\~nl!:e of Ihe bJr I" "nabl" Ihe ,hoe 10 Ihde .IlonR II; a, Ih.- other end o( I],,, b .. r Ihere is II ""till h ..ad .... h,eh I~ threaded to allo ..... the "orkmJl: "I' a 'K''',," "h ... h hd. a r("< tM'l!'\llar plate al unc eot! h"",ol( J~""~ "h,ch slide ~lonR Ihe bar A."oll" "hen Ih., melal r.. u ..... d for larl(~ (r,,,,"nR'" Th" d ..... IIlak,'n 10 P'e(:'" Ind both "d~'S .)i the t.. n'.n~ .. nt! Ih" In~,d" of Ihe mort,c... arc ~Iu"d; ,t,~ ~I one" r,'uvmbl"d; th.· ~'~'''P IIlhen u"''' Commenung allhe mIddle r~,I, tht· ~ramp ," fixed In 10" fM)~.t ... n J~ o;h_ n ,.t J th.· .. h'le I~ ~lld ~Inn.lll< ... t1<'''' If ,h" d""r.5 mould~d. Ihe 'HlnJ o,..,not"m~ "~T\' ",th Ihe t)PC. Thu~. If Ih(' pdn"l • IT" to ha'c ...,11" moult!mtt:t. the faa' edl(CI of tho: $III", r~il, and mUl1lins .... ,111'" "",uld.·d I
-
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WINDOWS Ih~ ar~
SETTING OUT " HAND PREPARATION OF DOORS B C D .•. _ ..o~ .....,~""o
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moWded edJrft of 5111o:~ .. ,II M C(lOlmuOl•••. Ih06C L'n thl!' <4.1. ",lib.. .U,~ In Ih"m (IK<' hI! 49) lind those on Ihe muntin. ",II 1M- 5Crt~ to tho: ra,1 mould,"~. If pl.nud mouldlllfl" are ro:quLrW, they IT" (ormed br planr. 10 tht r('<)~lt,on an the two 10011'" P'C'C<'I ITf " ~prunll' ,nlO pi ...... ; 1M- mouldml/S no: n.,1fd 10 Ihe rrammll and th" nail h"..:1. IIU' punched b.ch paoel" Itu(l'd m Ih •• m.o~r.' Th" "lK'uuun "".)].,,] " " ....... nlll ,he c_,ng ,"",II b<' "nden,.><><1 from rh .. for~,,""nll des.:npuon (,''WOW lUll are pap;ared "h,,'h 11.\1;, Ihe reference number of the Job, to~.. tht:f ,,"h the number, length. and nom",.. I"nd fin"hed ",dths of the lules, nilis. ele., compr,.",J,:( th~ door The..e 11th arc n~,I.,hlr rnr the "OrklllCn responslblt for 'lC'tUnJ,:( out and prcpH;nllthe UtH'U~ TT,~mb~" allUl'1lblrd
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TIMBER. WINDOWS A \\lndo .... induucs Ih~ fram~ and one or more sashes which are glalcd. The frame may ha\e solod ""OOJ tno;:mhers or it may be constructed of compar.uiHly thin pieces 10 form \\ hat IS ca~lt.:d a mud or boxtd framt. The sashes rna} be filled or made tn npcn. The IdueT, .... hen associated with a solid fr;lme, mOlY be auao;:hed by hlllges In o'nJhlc the sash to open either outwards or inwards like a door, or it may lit: hingl'u at the Im,er edge to open inwards, or it Olav he hung at the top edRe to open ouh\dTd~. Another t) pc of sash is pi\'oted at Ihe centre 10 open .... ,Ih the upper half S"IOlo:lnlo: im\ards, and another form consiSls of one or mure sashe~ which shde honmnt.l.lly. ~ashes \\hen made to open in a cased frame slide \'ertL(:Jlh'. In order In pro\id\! su-fficient \cntllJtion thc Building ReJ::ulations stipulate th;lt the minImum area of thc openahle par! of a windo .... or \\indoW's shall be onet"cntieth of Ihl' floof area of tht: room. The Regulations also require thaI some par! of the openahle area shall be: no! less than 1750 mm above the floor. The \\indo\\ area is frequently at least equal to one-quarter of the floor area and m05t, if not all, of t".e sashes are made to open. , As PH" L()u~l)' mrnt,,,nw. Ih~ e'{~nal\'~ uS(! of ..... ood"'orktnff mach,n~ry has chmtn.. cd mMt nf the lahour. formrrl~ dnne h, hand, and ~\'en ,f "andard machi;,e_madc d'>OnI U drsenbed .n p, 100 ~rc nOlI TfttuIT"d, m~ny of the oper1ltlon. dttatled on pp. IOl"ob "uuld n., pt'rform..,d hy machmrs, Thus the slllel, nIb and muntIn, ",ould n., cut ,nfO knlo(lhs and ",dth~ h, the nrc"iar SOT!'. they would be £Ie-cd and rd~"d on a rUT/au plrmrr and tak~n to a un,form ",dth and thlCkn.., ... nn a Ihld~"'m"l( ",arll",t'; tht rcnuns " .."Iil he formw hy • u""""'1I' ",... 1<"" ~n.J th ... lTl.onic"s by • nfflrtisi,,<: ",ad",.,,; if rl'1.l,n~d. they "ould be !I(1lid moulded on Ih., sp"U/ic mouldutllt'Nuh",,,, '\1.oy of thH(' "pt'r3u<>ns can be d"l>~ hy I eomh,nt"d Inlehmr called 4L 1('''' tal }1I",a, The panel, ",(.uld pia"", Planted muuld,nJ;!~ oould be prepared on thc 'pmdte be finished hy A "","Id.'r ·\flt:r belOit u~bled and crJImpe.l. Ihe door .... ould n., It" .. n I smooth fin"h h~ a sand /'0/><'''''1{ nl(l(hm,. \\'h,l~1 snme of rhc~~ IUffcr aod morc c'pl'n,,'c ma"h",u atC nOII\·a,l.bl~ tn fhc smaller ~hop" then' ar~ cnmplTat",'ely fe .... firm' "hn ha,'r not 3 c,rcular U" and rnorh"nlo( InJ t~non,nJ;! lTl.a~hme~ .• nd are ther~hy cnabled to reduce some of (he rdat,,'ch' COlt:)' hand
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\\oo,.J",orktnlf ",achmel In ducnbtd io Chap I. \'01. III
I04
WINDOWS
Those windows which aTe to receive extended treatment here are (a) solid frames with vertically hung sashes which open outwards, and (b) cased frames with vertical sliding sashes. There is also an introduction to mild steel window frames. (a) Windows with Solid Frames and Vertically Hung Sashes Opening Outwards (see Figs. 54. 55, 56 and 57).-Sashes which are made to open like a door are called casements, and the window is usually specified as a casement window, I t is adopted extensively. Frame.-If the window has only one sash (see A, Fig. 54), the frame consists of two vertical posts, stiles or jambs, a head and a wood silL If it has two sashes (see B, Fig. 54), the additional vertical member is called a mullion. If the frame has a horizontal dividing member (called a transQme) in addition to mullions, the appearance resembles that shown in Fig. 22, except that the members are of wood instead of stone. Details A, Band c, Fig. 56, show typical joints of a window frame. Note that the jamb is haunched tenoned at each end and the head and sill are morticed to receive the tenons and wedges. The outer shoulder of the lower end of the jamb is scribed to the sill (see B and section EE at c). These joints are sometimes pinned as described for door frames. The frames may be fixed as described on p. 84, the horns being removed if the frames are fixed after the wa1ling has been completed. The bedding and pointing of the fra'mes must receive special attention if they are not to be built in recesses. The head and jambs are rebated, 13 to 16 mm deep, to receive the sash. The inside edge of the frame may be square, pencil rounded, chamfered, ovolo-moulded, etc., as shown. The capillary grooves are referred to on p. 107. The sill is sunk-weathered to cast off rain-water. Special attention must be paid to the bed joint between the wood sill and the stone or brick sill, as it is pacticularly vulnerable. Precautions taken to prevent the access of rain at this point include (a) the provision of a metal water bar, (b) lead tucked into a groove formed in the sill and continued as a covering to the brick sill, and (c) a mortar tongue formed in the groove of the sill. \Vith reference to : (a) A groove is formed in the brick sill (see Q, Fig. 58) or stone sill (see L and 0, Fig. 25, and Detail T, Fig. 54) and the 25 mm by 6 mmgalvanized wrought iron water (or" weather") bar, which is the full length of the sill, is partiaily inserted and bedded in cement mortar. The groove in the wood si1\ is filled with a mixture of white lead ground in linseed oil and the frame is firmly bedded on the mortar spread to receive il wilh the projecting bar engaging in the groove. (b) The brick sill is covered with lead (no. -l or 5 weight) which has been bQssed (shaped) by the plumber and the frame is carefully placed in position with the upturned portion of the lead fitting into the groove of the wood sill (see 0 and E, Figs. 56 and 57); the efficiency of this joint is increased if white lead mastic is spread along the edge of the lead before the frame is fitted. The lead projects 13 mm beyond the face of the wall and the outer edge is turned under to give a double thickness which adds to its appearance, increases its
stiffness and makes it more effective in throwing the waler clear of the face of the walP A water bar, as described above, is sometimes used in addition to the lead, the upturned edge of the lead being dressed over the upper edge of the bar. (c) This is adopted in cheap work and is not a reliable method (see 0, Fig. 54); the groove may be rounded (see It and B, Fig. 16). In a mullioned and transomed window the transome is the continuous member and is tenoned into the jambs; the upper and lower mullions are tenoned into the head and transome and the sill and transome respectively. Scantlings of Frames.-Heads, jambs, mullions and transomes are generally either 100 mm or 75 mm by 64 mm, 100 mm by 75 mm or 115 mm by 75 mm; sills vary from 100 mm by 64 mm, 109 mm by 75 mm, 115 mm by 75 mm, 115 mm by 90 mm, 125 mm by 75 mm and 175 mm by 75 mm. These sizes may be exceeded for large frames. For ordinary good-class work it is usual to specify redwood for the head, jambs, mullions and transomes, and either oak, teak or pitch pine for the sill; for first-class work the whole of the frame may be specified to be in oak or teak. Sashes.-The members of a sash 'Jr casement are similar to those of a door, i.e., two vertical stiles, a top rail and a bottom rail. In addition, a sash may be divided by both horizontal and vertical bars or horizontal bars only. These are called glazing bars or sash bars or astragals. The construction of the sashes is illustrated at H, J and K, Fig. 56, which show the top and bottom rails tenoned and wedged to the stiles. The project~ng ends of the tenons and wedges are of course removed before the sash is fixed. The joints between glazing bars are'shown at M and N, Fig. 56. The scribed joint at M shows the horizontal bar to be continuous and mort iced to receive the tenons formed on the ends of the vertical bars. The chamfered mould on the latter is scribed to the moulding on the horizontal bar. This is the commonest form of joint. The franked joint at N shows the continuous horizontal bar mort iced to receive the halved and haunched tenons worked on the vertical bars. Another satisfactory method of jointing glazing bars is halving and this is shown at M, Fig. 59. All of these joints are glued immediately before assembly. In both the scribed and franked joiots the continuous bars may be either hori_ zontal or vertical. dependmg upon circumstances. For casements, greater stiffness to the sash is obtam~d if the shoTt horizontal bars arc made continuous and the len/-lths of vertical mt'mber tenoned into them; for vertical sliding sashes (see later) it is customary tn mah the "utical bars continuous; in the halved joint both horizontal and verl!~'al bHS are continuous-.
The ends of the bars are tenoned and scribed to the sash stiles or rails. The sash is rebated for glazing; these rebates are from r6 mm to 20 mm wide by approximately 6 mm deep. The glass is secured by either puny2 (see Figs. I If the frame is sct back to fonn a 102'5 mm outer reveal, the iocreas~d width of.l~ad should be secured by a lead dowel formed in the mIddle of the brick or stone sill (s~e p. 152). , Putty is whiting ground io raW linseed oil.
.ol
DOWS tU.'."HISII'1II ~~~~'f:~~l1lOO~n 111; .... 0 OF fUIo\f
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106
WINDOWS
54 and 55. and D and P, Fig. 56) or small fillet:J called glazing 6tad~ (see E and G, Fig. 56). Note that the rebates for the glass arc on the outside when putty is used and are on the inside' when beads arc adopted. The glass is usually shut glass! and is specified by its thickness; i,t., 2, 3. 4. 5, 5'5 and 6 mm. Glass for small panes is usually 2 or 3 mm thick. Polished plate glasr is sometimes used for glazing windows in fint class work, the usual thickness is 6 mm although thicknesses up to 38 mm are also available. Small metal sprigs (which arc without heads) are driven in as shown in the various details to temporarily retain the glase in position until the putty is set. Glazing heads should be secured by small scrc"''S-'' cups and screws" (see J and R, Fig. 58, and 0, Fig. 66)rather than nails to allow for ready removal when broken panes have to be replaced. The glass should be well bedded in putty before the beads are fixed to prevent the entrance of water. Scantlingf oj Safms.- These vary with the size of sash. Small sashes may be 38 mm (nominal) thick, average sized sashes should be 44 mm thick and large sashes may be 50 mm thick. The stiles and top rails are generally 50 mm wide with deeper (63 to I}O mm) bottom rails to give added strength and an improved appearance. The glazing bars are equal to the thickness of the frame and are out of 25 or 32 mm thick stuff, the latter being reduced to 25 mm finished thickness unless the sheets of glass are large. The bottom of the inside of the opening is shown finished v.ith a 25 or 38 mm (nominal) thick u,'indow board. This is tongued into the wood sill (to prevent any open Joint showing when the board shrinks). To prevent it casting or twisting, it is secured to plugs driven into the vertical joints of the wall or nailed to 38 mm thick hearers plugged to the top of the wall. Tiles may be used instead of a wood window board to f.:>rm an internal sill i these may be white or coloured glazed tiles (about 10 mm thick) or they may be square quarry tiles (about 1.5 mm thick) bedded on cement (see F, Fig. 16). The following items, not already referred to, should be considered in conncetion with Figs. 54 and 56. The panes of glass arc comparatively small and the design is particularly suited for houses as the small sheets conform in scale. A satisfactory proportion of pane is obtained if its height approximates to the length of the hfPOtenuse of a right-angled triangle having both sides equal to the width (see T, Fig. 58). A reasonable size is 280 mm high by II}O to 200 mm wide and has been adopted in the elevations A and B, Fig. 54. The vertical bars may be omitted to emphasize the effect of horizontality. The windo ....'S at A and B are not built into recesses such as are shown at E, Fig. 8. This is a weaJmess for, unless great care is taken in the -bedding and pomtlng of the
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I Beads Ire plKKl outside when double II'lazlnll' units are used (see F, Fill'. SS)· I BrleHy, sh~I.la.. is produced by fusinll' a mu:ture ofund, ai!icates of.ooa and iLme, elC. The malenals are melced In a furnace .... here, alone end, che molced II'lua IS dr.wn up a lower and CUI 10 sIze (sec Chap. IV, Vol. IV). I Polished place II'ln. IS formed by casting the moleen malerial on co a mecal table, roUIn, it 10 a Uniform Ihlekne:u, and aubsequenlly plnd;n. Ind polishing II smooth by machinery. It IS al., produCfli d,rect by the " lloal " proce:u. FIGURE
55
J
WINDOWS frame, water 111;1\ J.:Jin culLin. c: between it and thc w,IIL The rc,,~on \\ ny du' frame is shown in a Mlu,ut" .IJlIlh is on an'Qunl of thc imprO\eJ appearance \~hich resuhs whell the maximum ,lmount of the fl.Jrnc IS npo-.nL Sound~r (011~truction j" shu\liI in Fig. S5 and also by broken line;, at I Fig. 8. The frMllt: is checked fO rcccil c the plaster (see F, ri~. 54-) or J (mer Illould, sudl a-. I~ shown at 11. Fij.!. 5." 111,1) he prolidcJ to hide ally shrink'l,gc CTJth \Ihidl ,IPI'C.ir :'\ouct' p'lrti~ular1} thc small ,groOICS III I'll" rcbJlc of the frame and In duo' rails and stiles. These are capablc of arrestmg ":lIef which would other"lsc proceed b~ LJpill.Jrit~ bet\lccll the SJsh and the frame to the in'>HJc. The fT'Hl\e shown at I) and f, 1-iJ::. 50, is I,ider than those .. hL\\1l in Fig. 5.. , and this makes It possihk- for the sash to be ~et fanhn h.u.:k ;llld Lhe uilder~ide of the head to be thro~tcd; exceptin,g in he;lI'Y storm~. lhi" throat IS etfel:ti\c in causmg the rain to drop dear of the lOp rail. The alternatilc dt·tilil" shml n at E and G, Ii!!. 5(" h,IH hl:en pro\Tu to result In an excellent we.nhn resisting Ilinuow. (Jill" uf Ihe t!i~o1U\al1la!!es uf l:i1sement \llIldll\l~ i" the c'Illdnsion of the wooll IIhidl 111.11 I,lkl: plaLl: tl) cause tht· ~,Ishe" to .. i,lIn ., IIr .. hind." \\"hen thi" IIUUTS. Ihl' ."Ishl·s ,ITl' "l:,lscd " (thl' fd~c;; hl·inl! pl.H1t"l! 10 n:rnOl-e the e"l;es" t:mher) ami Ihere I~ ,\ likelihnllu of rain and \\ind l'ntl"Til1l' Ihl' enlarged ck;!r,l"ln' .. hen tht." timber ~hrinh "uhsequenll~. Det,ub E ,Ill.! G ohviate thl'se lkft:l:I,,: Ihe l:O\er tillet I\hidl I~ screwed w the SJsh 0\ t'rhlps the frame 13 mm Jnd ellahk-s ;1 (1 rnm de;tr;!nl:e 10 he prondl'd whi(h is ;tn ,Ilkqu;!tl' ,dlnll,Hlee for any npansion of Ihl: timhl:T that may Oleur: III addllinll, the tillt-IS ,Ire ctfeui\<: in excluding r,lin Jnd wiml. The thm;!ted hood or drip Jilhl. ton,e:ued tl> the head, atfords .Ill addition,11 protection. Thl' ";Ishe~ rna~ be nude thicker and shaped to indude the fillet. 2nd the he,.d nl thl' fr;llIlt· 1Il,l~' Ill' 1Il,lde Ltr!!er §O that th ... hood m,IY he furnwd out of the wbd The det,lils "hO\ln in J-ig. ~5 ~rl" abo recommended ftJT adoption in huiJdin!.(s IIhich arc e'lptl!led tll sc\ert~ 'l~e,lIher conditions. That at n shows a rl:hatcd JJrnh "hieh gin":; a 20 nun cover 10 the fram~. The window has a large ti\ed pane Cf1n~isttng of a double glazt:d unit (two sheets of glass separated hy a , mm scakd air S(Mce), a side-hung opening sOIsh ,md a sma\!er top-hung one. Duubl ... glal.in~ reduces heat losses from the room. The sashes lire lipped to Ki"e effeelil'e weather protection. The usc of d.p.c.'s II here the ca\'ity is brid~ed ~hould he noted at B, t) and 1:. Some of the window hoard~ are shown finishetl .. ith hed moulds whIch are returned ,II Ihe ends. The~e moulds are usually nailed to plugs and to the II mdow board,; after the latter have been secured. Large moulds are fj,ed to ~pla~tJ ~Tounds .. 11I(,:h are plug~ed to the 1\3U (see R, Fig. 58). The internal soffits ~nd jdmhs uf the opt'nings are shO\\ n plastered. These are called plastN'td Imlllgs. and 0110 pbster IS easily dam.lged al the edge:> a lIatisfactory finish is prf)\ided when a c()mpJ[;Itive!~' hard material, such as Ke(:Tle's cement. is useJ w form the arrises. A Keene's cement arris is al least 50 mm WIde in each direction, and narrow lillings may be enmel), covered With this cement instead
7
10
of plaster (see e, () and K. Fig. 54, and p. 32). Wood angle bead, (ste 1 and :\t, Fig. 63) or ,l!al,anized steel beads are often used instead of cement arrises (see pp. tu 123). The britk linte! IS shO\\n at II and '"" Fig. 54. supported on a mild steel angle. Thi~ i~ nOI nften USed 1m .I single or double light "indo .. , whtre the sp;!n is rc1atlleh sma\! and the hriLk head is usually built directly on the head of the: frame, but such support (or th~' i1hername forms shown III Fig. 12) comp:ies with the principles of ~ound constrllction ;!nd must always be applied to \\ ide II indOI\ s. The hci);:ht of "mllolls "b()\e ilflor le\"t~J ~hould he gi\"tn (onsickrati')Il. That shown in section c, Fi,e:. H. is satisfaLlon for J house. L"pper-tloor I\indOllS of the LotL.!!..:l· tlPC should 111""IS nl:Jr III th.., e,lles J~ possible, and .I ~Jt!S t"ael!Jn' treJlrn\'n1 ;if II1\" he,II.lls shown alisf,lCtory 'IS they arc ,Ipt t\l hl · \\ Tenchl:.! otf and. when fixed to upper tlqor \\induws, difficulty IS e"penenced III cl ... ,ming the e"terna! face 01 tht" !..:l.b~ frolll the inSide. A big imprultlllent UJ)(1Tl thl' bUll lunge for han,gingLISl'l1K'nh i, the f\/ension or deamm: lime'" Ilhlch IS il!lI"trated in Fig. 57; tht IIpl'tr linin..: i~ ~Iwwn at" and the lower hinge is "hOlln JIll . .-\s shown in the 1'1.111. Ih\· ",,~h ..:.11l he opened to giH~ a dearance of from 100 to 125 mm bel\\een it and thL' h,IIIIl·. which is sufficient to enable the outSIde of the \lindo\1 to be dl'an,,! fr"m thl: lIlside (see Jlso isometric sketch). The lertical edge of the free Sliit ,lItd tht adjdcent rebate on the jamb ~l1ould he ,,:ightly splayed to peTllllt of the opening of the casement. These hit1!!~·" ,Ire made of ~teel or \\TouKht iron which is shl'rardi;;fd, a process of reTldtrin!.( t)w metal rust proof hy the ;Irplil:ation of a powdered zinc. ('cul'lI/ull Fasteners (see (. and sketch).-The pl,n, tfl II Ilieh the pivoted handle i" all'K'bnl is ..erewed to the inside face of the free ~ti!t ,lilt! the projecting point nt thl' hMlllle (when the sash is dosed) er,~ages III ,I ~lotteJ phlte which is scrcwed tl) till IrJllll' ncar to the rebate. This type is also known as a wckspur faSltner and IS obl'lined in "hcrarJized iron. bronze and aluminium aHoy. lnsf'nll.'nf Sluv (sec I). pl.ln and sketch).-This form is called a peg stay and consists of a bar."holcd al about 50 mm centres, which is pivoted to a small plate Ihal is :Ie rewed to the inside face of the bottom rail; there is in addition a peg or pin plall' which is screwed to the. top of the wood sill. As is implied, the object of the stay i.. to IllJintain the sash when in the open position, and this it do<:s when the peg IS engaged in one of the holes. This fitting is made of sherardized iron, bronze:, etc. Fixed Sashes or Dead Lights. -One of Ihe sashes at s, Fig. 5-1-, is specified to be fixed. Su(h sashes should be well bedded in lead mastic and screwed to the frame.
",,,
CASEMENT WINDOW DETAILS t _ lINHl
" /
.... lTfR.NAT1V[
'~' HE FIG S4
DE TAil
50-44 r,n-)!') TOP U1L 01' S....1It
/
D
~t;.~~,(:~"a~ - --jl - t.J- +---II'; JAM'
SO"'4
~,..if:t=jj't PUTTY SPkIG
,~.
/lLTERNATIVE
"-10
COVE~ ~lll(T
JOINT BnWHN STILE
h ... CHAMNCE U'TWHN 1MI-I to ~IVIME
niLE OF S... SI-t
r ,
e..
~!f!;;~TOP """Il ,
E
DETAll'S' - +-if-SEE FIG 54
.... lTERNATIVE
--ttt-- D ET A I L ~H
'T'
FIG 54
15120)
B
0"1<. Sill
.v ;'",",,~;;,<~CO;;.II~~O~D I lll
DETAILS OF CASEMENT
JOINT Uf'HEE"I JAM!! e.. Sill
SH ""LSO
'M',Ki-S' ~
SClI. l llfO JOI NT
Ei::;;r::g:::;;::,.. ~
•
WINDOWS
1"9
It i •• CQIlUl'Ion pnclIce to dl.penH! with. (:aKmtnl (or. find Ji,ht .nd to fix the .1_ directly to the frvnt; the mullion, jamb, Mad .nd all bei", rebated for this purpoI4!. In.n ekYlltion NCh . . ., FI,. .54, thll would .pod the 'ppaonnce of the window, u the" .ighllinn" of the lop and bottom nil' of the cuement would not .. 'lne through" With the top and bottom ",hI !ina of the fixed Ii~t. the upper and lower Pinel of the fixed hShc. would be hlstler than the mtennedaltn and, In addition, the .httlt ..... ould be widc~ th.-n those In the hinged _h.
Window. with Solid Frames and Cuements Opening Inward•.-As it is almost impossible to make this window weather proof, its adoption is not recommended, and for this reason a detailed description of it is not given. The frame is rebated on the inside ra receive the sashes which swing inwards. The interference with curtains, etc. cauaed when the sashes arc open provides an additional objection.
(b) Window with Cased or Boxed Frame and Vertical Sliding Sathes (see Figs. 581 and 59).-This window has a pair of sashes, both of which should be made to open for the purposes of venti'lation and to facilitate cleaning. The sashes slide vertically within shallow recesses formed in the frame which is built·up with comparatively thin members. A pair of metal weights ('ontained within the frame ill connected to each sash by means of cords or chains after being passed over pulleys fixed to the frame. Without the weights, the upper sash when lowered and the bottom sash when raised would of course drop to the bottom immediately the sashes were released.' A satisfactory appearance ill obtained if the sashes are divided into panes' of the proportion shown at T, Fig. 58, and if the window is three or four panes wide and four panes high (see A). Both sashes are usually equal in size, although it is sometimes desirable to increase the height of the window when tht' upper and lower &ashes may be two and three panes high respecti\·ely. Frame.-This consillts of two \'ertical jambs, II head and a sill. A jamb (see Nand s, Fig. 58) comprises an innn- or inside lining, an outnor outside lIning, apulley stIle (so called because the pulleys are screwed to them), and a bade Im",g (often omitted in cheap work); in addition, a thin piece of wood, called a parting SLIP or ,,"d-ieathn-, is used to separate the two weights, a small partin, BEAD is provided to stparate the two sashes, and an In"n- bead (sometimes called a staff Mad, fiXIng lHad or pard lHad) is fixed 10 complete the shallow recess for the inner or lower sash. The head (see It and 0) conSIsts of an inner and an outer lining, a hl!ad or soffit lintnl, an inner bead and a parting bead, although the latter is sometimes omitted. The solid lill, with staff bead, completes the frame. , hg . .s8 II Inlni/ed to pro~·ide In exlmple of I t)"pu':ll home"'"Urk .J'''''I (Ke p. 16). The hllf fulll'~ dellil, before re:productlon, "ere: dl1l'" n to the finished lizes (see pp. 6" 94, lOS Ind III)..
• :\ fitllng rona'lt,na of • coiled Iprinl and ailed. uuh balalttt mlY be uwd mllud of the "'e'i/hu, cords snd pullt>l. A pa,r of balances ..... ould be UHd per IIo8lh (see p_ I IS). 'WmJ"". in hor~ tlone bu,h:lmlJl (If the commerci..lor factory t)'pe espec,.lly may conlilt of sashes ",hu:h Ife nul d,v,ded b) IIlu.ml ban IntO re:lallvely un:all pines but nc.:h ..lib i, glued .....,th I smile .htrl.
D
PIN PLATE seal'.flO
'0'0
sou.
FIGURE 57
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IlfV""ON
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NOli ... , .... _ , 01' ..... ' 1Hf III.lMNlS ' ....... E In .. 0IV0W" TO 'Hf "''''111(0' OIMi"~' (.. 'Hili AAi S_ IUi T~ THf '_01"-1.' \'UI II.lU i'U Dfl""Li Nlf DilAWN THUS Tiff KAU '"',1ST ... ''''MS _ I It 1_>1 1HU\
I(
INCIIUoTlD ON T>1f
~'N(;
, ..,,
P l '"DlT N .... l ... ' .....Ti,.,....,,1f[ ) ...... 8
VERTICAL SASH WINDOWS A. shown at N and s, the inner and outer lininga arc each ploughed with a 10 mm square groove to receive the: tongues formed on the pulley stile; the outer lining proJect. IJ to 16 mm ~yond the face of the stIle, and the edge of the inner lining is Rush with the face of the stile. The upper cnd of the pulley atile is either housed or tongued to the soffit lining and it! bouom end is housed and wedged to the .....ood sill (see A, B, D, £ and t, Fig. 59). As shown at A and B, the lower end ;)f the stile is about 6 mm below the outer edge of the weathering of the sill, and as indicated al L, the wedge is dri"cn in from the inside between tht stile ilnd the H~nical CUI of the housing, and this wedge is securdy nailed to the stile. The inner and outer Jamb linings extend the full height of the frame (see 8), the inner and outer head linings butt against the Jamb linings at x and y (su 0), and as shown at 8 and e, the oak sill is cut back at each side to receive the lower ends of the inner and outer jamb linings which are nailed to the sill, pulley stile throughout its len~th, soffit linings along the tongued and grooved joints and at the butt joints x and Y. The parting slip extends to WIthin 100 mm (approximately) of the top of the SIll and is suspended from the IOffit lining. A slot is formed in the latter, the slip is passed through it and either a nail or wood wedge is dri\'en through it as shown at K and 0, fig. 58, and A, 8 and 0, Fig. 59. The centre line of the parting slip coincides .... ith that of the partinI'! bead. The back hning eAtends from the soffit lining to the upper surface of the sill and is nailed to the pmb linings (see It. and c, Fig. 59, and N, Fig. 58); occasionally one edge is housed into the Jamb lining as shown at s, Fig. 58. As ~hown at s, Fig. 58, the clear spale betv.e:er> the pulley stile and the back lining must be 50 mm as the diameter of the weigh!! is usually 38 mm. As the equivalent to a back lining is not provided at the head. the necessary stiffness is imparted by the use of 75 or 100 mm long triangular blocks spaced along the internal angles betwccn the soffit lining and the inner and outer linings 11.1 intervals of from 75 to 150 mm, with one placed across each hutt Joint bet\,\,een the jamb and soffit linings (see K and 0, Fig. 58, and A and 0, Fig. 59). These blocks are glued to the linings. The inner bead is fi'ted all round the frame. This bead covers the joint between the inner lining and pulley stile or soffit lining (see K and N, Fig. 58); these beads are often rebated in good work as shown at 0 and s; they are moulded IS required and the ends of each length are mitred. A Ilightly wider and bevelled inn~r or staff bead is fixed to the sill; the bottom rail of the sash is also bevelled to ensure a reasonably tight fit which prevents the sashes from rattling (see M). Alternati, ely, a deeper sill htad (see Q) is recommended. This allows th~ lower sash to ~ ralK"d K"veral millimetrts to permit .air to enter between th~ meeting rail!> of the sashes (see later); this incoming lir is deflected upwards to minimize draughtll and the latter are not caused .It sill level. This is sometimes callC"d .a wlltila/llrg P'«t or drau..l(ht !Had. Inner beads should ~ fi~ed with brass cups and krews (see 0, Fig. 66) to permit of their re.ad), remmal when required, although they are more orten Just bradded (nailed).
III
The parting bead is fitted tightly into a 10 mm square groove ploughed in the stile and nailed. The detaill show. similar bead 11.1 the soffit, although thil is often omitted in common work; when provided. it assists in excluding rain and draughts. Access for U'tights. Provision must be made in each pulley stile for fi'ting weights; such is called a poclttt .and is situated just below the meeting rails of the sashes and ('(tends to about ISO mm aOO\'e the sill. Two forms or pockets are shown at A, 8, e, F and K, Fig. 59. Sidt Pocktt.-The sketch at F shows thIS type which is indicated at A and s. The plan shows the width to extend from the bJ.ck of the inner lining to the groo\e for the partmg bead which it includes; it is about 380 mm long for average sized sashes and must be at least equal to the length of the weights; the bottom end of the pocket is be\'elled at 60° and the top end is V-shaped and bevelled at 60° in hoth directions. I The pocktt-pltct is secured to the stile by .a lerew at the ooUom cnd in addition to the parting bead which is fixed subsequently. The lower sash and parting bead completely cover this pocket and therefore any damage caused .... hen the piece is removed for sash cord renewals is effectively concealed. Central Pocktt. This is a less satisfactory form and is shown at K; it ha~ a rebated joint at the bottom end and a rebated and bevelled joint at the top. This is not such a good type as that shown at F as the outer vertical joint and portions of the horizontal cuts are exposed and any damage caused to them on removal is conspicuous. Sills. -The several forms of sills should ~ noted; that at Q, Fig. 58 is wider than the Sill at ..t to allow the cover mould to finish on it. The water bar at Q is shown at the centre of the sill; it is often fixed with the outside of the groo\'e in line with the back of the outer lining so that the bar will arrest any water before it has travelled more than 25 mm. S~a"th"Ks 0/ Framt. As the weight of the sashes is transmitted directly to the pulley stiles, it is customary to prepare the stiles out of thicker stuff than th.1I ror the linings. The nominal thickness or pulley stiles and soffit linings is either 25 or 32 mm, and that of inner and outer linings is either zo or z5 mm. The sizes of the various members are figured upon the drawings. \".,ntton "drswn to the note In FIll 58 whIch Itat.,s thlt th., d.,lllll. ha"" bHn drilln to Ih., finlShC"d d"ntn.lon •• Ind that theM.u 5 mm Ie.. than th., nomlOal IIln. It should b., nOlcd ho".,.er that th., memb.,.., of the fram., are oft.,n only pl~m:d on Ihelr uposc-d fllces and thul the lollS 10 dressing IS rC"duced to IS mm; the ba~k ImmK i. I.Isually just dressed .Iong liS edg<:s.
Sashes. It \,\,111 be seen on reference to Figs. 58 and 59 th.at the upper sash slides in the re(css formed In the frame by the pulley stile, outer lining and I The ~uta marlr 10 fonn these be"els arc made by th., poelfit duuf (to« p. (16): the V-shaped lOp .,nd II f"nn.,d by ",,,km," ~cond CI.II. ~nd the $nl
112
WINDOWS
parti,ng head, and that the lower suh is accommodated in the recess formed by the pulley stile, inner bead and parting bead. Each auh consists of two stiles, a top rail and a bottom rail, but as the bottom rail of the upper sash meets the top rail of the lower sash when the window is closed, these two members arc called m~ttjng rails. A minimum clearance of 0·8 mm should be allowed all round the sashes to permit of easy movement, and Ihis is often increased to 1,6 mm when the window is to be painted. Join/ bttwun Stil~ and Top Rail of Upper Sash (see H, Fig. 56, and R, Fig. 59). -The detail at H is usually adopted. The alternative detail at R sho""s the top rail haunched tenoned (like a door) at each end and each stile suitably morticed to receive the tenon and wedges. Glued wedges (waterproof glue being l,~ed) and a hardwood pin or dowel complete the joint. The methods of securing the sash cord are described on pp. 113 and 115. JOllll ~tW€l!1I Stile and Meeting Rail 01 UPI'" Sash (see T, Fig. 59).- The bottom of the meeting rail of the top sash and the top of the meeting rail of the bottom sash are at least 10 mm wider (assuming that the parting bead is 10 mm thick) than the thicknesa of the stiles, otherwise a gap equal to the thickness of the parting bead would be left (see Land 1', Fig. 58). The joint between the meeting rails are either just bevelled, or, as shown, they are bewl rebated; the latter joint is preferred, for it assists in preventing the sashts from rattling, effectively increases the difficulty o{ gaining access to the sash fastener (see 0, Fig. 59) from the outside, and enables the rails to separate easily when the sashes are opened. The stiles of the sashes may extend from 38 to 75 mm beyond the meeting rails and these projections are !!haped as required to form horns (or bracktts or joggles), but they are often omitted as they are r.:onsidered to detract from the appearance. The detail!! at T and u show both types. The horned form at T sh
I
edge is usually left slightly projecting beyond this face until both meeting rails are finally fitted together. 1 This joint is also pinned or screwed. A groove is formed down the edge of each stile to accommodate the sash cord; this is similar to that shown at Rand s and is indicated by broken lints at v. Note the provision made on this meeting rail to receive the glass; as both meeting rails are of che same depth, it is not possible to form the usual rebate on the lower sash meeting rail and in lieu of it a groove is formed along the underside of the rail. The ends of the bevelled portions of the meeting rails must be cut away for clearance round the projecting parting beads. The small piece so removed from the bottom sash meeting rail is indicated by broken lines at v. The groove for the cord, the clearance for the parting bead, and the dowel holes have been omitted in the sketches so as to render the details less confusing. Joint betwen! Stile and Bottom Rail 0IIAu)" S4Sh (see w, Fig. 59).-This is an ordinary pinned haunched tenoned joint. The bottom of the rail and the end of each stile are shaped as required (examples at M and Q, Fig. 58). The joint shown at J, Fig. 56 is very often adopted. . Joint between Gla:ling Ban.- The scribed and franked joints between sash bars are described on p. 104 and the halved joint is shown at M, Fig. 59. Glue is applied to the joints before assembling and cramping each sash. Scantlings of Sashes.- The usual nominal thickness of a sash of average size is 45 mm, but the thickness may be increased to 50 or 60 mm for larger sashes, whilst small sashes may only be 38 mm thick. The common scantlings are: stiles and top rail, 50 mm by 45 mm thick; meeting rails, 50 mm wide by 38 mm; bottom rail, 75 to 100 mm by 45 mm thick. Glazing bar5 may be out of 45 mm by 25 mm stuff but a thickness of 32 mm reduced to 25 mm gives the bener appearance. Timber.- The timbers employed in the construction of windows of this type are redwood, pitch pine, teak and oak. The {ormer is most used. although a more durable wood such as oak, teak or pitch pine is specified for the sill. Oak or teak are used throughout for first class work. Hardware.-Ahhough there are many patent devices on the market for use on windows of this description, the following simple fittings have been proved to be quite effective for their purpose. They include sash fasteners, sash lifts, sash handles and pulleys, together with the weights and sash cords or chains. Sash Fastnrn (see 0, Fig. 59).-This affords an effective securicy, provided it is of best quality. The fitting is of brass or bronze and comprises two castings, one being screwed to the centre of the meeting rail of the tOp sash, and the second (or lug) being screwed to the top of the meeting rail of the bottom sash; on the former casting there is a lever which is pivoted at one end and has a solid knob • Student. should be careful 10 show Ihe joinl between the meeting ra.ls corr«tiy. Examlnallon acnpl. and homewgrk shH:ts frequently .hgw deuull wh.ch Ind.c.te the bevel ... nninll downwards from the in.ide w the: outside. Movement of the Ashes would nOI. of course, be poNlble If the mee1inll ra.l. were constructed to luch dela.l •.
, VERTICAL SASH WINDOWS at the oth~r. When the lever is rotated, the pivoted end bears against the free cnd of • Itrong and highly tempered steel spring which i. riveted to a recessed vertICal portion of the cuting, and the dovetailed notch on the lever engages in the tolid curved lug which .. riveted 10 the second fitting. This brings both meeting rails cloeely together and IICcures the window. Stull Lift (see 0, Fig. 59).-This i, the hook lifl type, other forma being ring lifts, RUlh recessed 1ifts, knob liru and hinged lifts. One pair of lifts is screwed to the inside of the bottom rail of the lower sash and at about IS0 mm from each end. They are of course used to raise the bottom sash and arc obtainable in brut and bronu. Sillll Ha",Jl~ (see P, Fig. 59).-When a lash is large (and especially when there are no glazing bars to grip when drawing down the sash) a pair of these rna) be fixed on the underside of the top sash meeting rail near to the stiles. They are not very convenient, as the lower sa,h has to be raised before the handle. are accessible from the inside. The followUlg IImpk o:ped,~nl II df«tlv~ A pulley I. oed 10 Ih~ Mlffil lll1l11a of th~ fram~ unmedlat~ly oyer nch 'hl~ of th~ upper ...h, and In Q'~ or nng il ICrew~ II1to th~ in~r f.ce .nd nellr to Ih~ end of ",ch IlIle of Ihll Nih; • pie« of cord of a 1enKth equal to .bout one Ind a hllr times lhe h~ighl of Ihe windo .... II pllollCd through each e)'~ and over ~h pull..,.; each cord II knoliCd Immtdl.tc1y lbo\'~ and below th~ ryr; the ..... cis of each double curd .~ equ.1 .nd I bandle i. oed 10 ",ch, To opcn thr top ...h, one rrod of tach curd I' pulled to dill .... th~ Nsh downw.rds with th~ lOp knol be-nng upon the ,ye, Th~ Nih 11 clotoed by pulling on th~ other end. of th~ curdl which bnnaa the lo....t t knoo apm" the ~yes to lift
........
As mentioned on p. 101}. in order to conveniently slide tbe sashes and maintain them in any desired position when open, it is neassary to fix to tl)em sash cords which are fastened to weights situated in the casings after being passed over pulleys fixed to the frame. Sash Ar/~ P",Il~'s (see A, D, D and 1'1, Fig. 59). This type consists of a 60 mm dia:nctcr round groo\'ed brass pulley (or SMtl'tV) having 12 mm diameter steel axles which rcvoh'e in brass or gunmetal bushtl (6 mm thick annular bearings) mounted on a metal (iron, gunmetal or rustlesssteel) case which i, Ranged and co\ered with a brass or bronu plate; the pulleys may be.s, 50, 60, 65 and 75 mm in diameter. Tlti, hollow-rounded groo\'ed type of pulley is suitable for flax cords, copper cords and metal chains of the form shown at w'. Square groo\'ed pulleys are adopted for certain he...), chains. The COR wheel type of axle pulley (ha\mg a fixed a:de with a toothed portion which bears the chain and which revolvel on ball bearings) may be selected for extra heavy sashes. The 125 mm hy 28 mm face plate of the pulley iSlCrewed Hush with the outer face of a polley stile with the top of the plate from]8 to 60 mm do .... n from the head (see A and B); the mortice for the pulley case and the housing for the Range and face plate are shown at D. The pulleys project about 8 mm beyond the outer external flce of the pulley lIile (ICe A), and the size of the pulley mUllt be suffiCient to allow the weight to hang clear of the casing. Two pulleys per ush Ire required.
113
Weithts (see N and 5, Fig. 58, and A, • and c, Fig. 59).-These are cylindrical cast iron weights, 38 mm in diameter and of varying length in accordance with their weight; thus, a 2·3 kg weight is about]oo mm long. The obp:t of these is to counterbal.mce the weight of the ....hes. The top of each weight is holed to receive the end of the cord. OplnWIU differ u to the weight reqUired per tuh, but uusfaclory raul.. Ire obtained If HId of the: IWO .... ellhu for the: rop talh " from 0' liS to 0'5 kg Iwm:in Imn hal/lhe wtlght of the luh, and I( ~h or the tWO hallilm .alh .. ~ighl' i. from o'as to o-s kg light" than /wI/the wright of th •• suh. Th~ .... elghl of elch IlUh II d~trrmintd by means or •• prlng btl.nce, and dur .llowance should be m.d~ for Ihe w~ight of th~ ,I •• 10 be used .nd IhlU of the paint.
Sas/r-Cords and Chains.- The weights are secured by either cord, or chains which Ire passed over the pulleys and attached to the sashes. Best quality stout twisted or braided cotton cord is usually specified for ordinary work. It is obtainable in sizes of " 30 m" or " 5+ m" in length; its thickness varies {rom 5 to to mm, the former being suitable for weights of less than 2'] kg,and the latter for weights up to 2] kg. The cheaper cord stretches and, therefore, each length should be well stretched before being fixed, otherwise it may elongate to such an extent as to limit the movement of the sashcs, i.~., the wei~hts of the bottom 515h may reach the bottom of the casing before the sash has tra\el1ed to its full height. Certain brands of the be!t quality are greased and are guaranteed to be stretch proof and damp proof. Tht defecl of flaJ[ cord is that in course of time it frays and ultimately breaks. A stronger and more durable cord is that kno ..... n as coppu wir~ cord. It is sohl ill 30 m lengths and the si~e is specified according (0 the nlimher ; thos, a " ~o. ] " cord is 6'5 mm in diameler and consists of thirty-six strands of copper wire ..... hich Ire .ubdivided into six segments; the Slrands in each segment ar~ intertwined and the segments in turn are intertwisted together. One form of sash chain is shown at w', Fig. Sq. This;s called the thrttand-tu:6 II"k coppo- chaltl, as it comprises a series of thrtt links or plates (each 1 mm thick) ...... hich alternate \\ith a pair of links; the overall thickness of the fi\'e links is 6 mm. Each link has t.....o holes and loose fitting pins or rivets pass through the fi\'e links at each connection. The chain can be used in conjunction with tr.e ordinary axle pulley shown at s as it readily accommodates itself to the sharpest cun'e. Special fittings are used for connecting the chain to the .....eights and sashes. One fonn of connector to the weight consists of a hook which is simply passed through the eye of the ..... eight. The sash fitting comprises a plate which is scre .....ed to the edge of the sash and a pin is passed throulth the brilckets on this plate and the holes of the chain links. The chain i. an improvement upon, hut is more expcnsi\'e than, the flax cord, and chains hive been kno ...... n to last for mnre than thirty years before requiring attention. Chainll used in conjunction with the c~ ..... heel type of pulley used for \'ery heavy sashes are of similar construction to the abo\'e, but the links Ire of rust proofed stttl connected by means of phosphor-bronze rivets.
.., DETAILS OF WINDOW WITH CASED FRAME SLIDING SASHES i
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VERTICAL SASH WINDOW Fwrtg Cords to Sasllts and Wnghts.-Two methods of fixing the cords arc shown at Rand s, Fig. 59; that .hOlAn at S IS the mOlt common method. A better way is shown at R where a groove i. ploughed to a diltance of from 15°10 250 mm (depending upon the size of the aaah); this i. continued by a to mm diameter hole which is bored to a depth of about 100 mm and is terminated by a 2S mm diameter hole fonned at the edge. The cord is secured by threading it
through the smaller hole, the end being knotted and hammered into the bottom hole.
Sash BalanuJ.- This fitting, referred to
In
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with weights, cords and pulleys. A cased frame is not necessary. but inner, outcr and parting beads must be fixed to the solid frame to form the necessary recesses for the: :.al>111:s The balance vcry much resembles II steel tape used for surveying purposes with a face-plate attached to the balance casing. The balances are obtainable in various sizes to suit the weights 01 sashes. :\Iortices are formed in the jambs just below the head to recei,-e the casing'S of the balances; the face-plates are Sl.;rewed to the Jambs and the looped ends of the metal tapes (coiled springs) are scre..... ed to the edRes of the sashes. When the top sash is pulled do ..... n the tapes from the two balances are dra ..... n out, and ..... hen the lo .....er sash is raised the upes in the other two balances are coiled up. ·\nother type of balance I~ ~hOVoll in Fi~. 2i, \'01. III Manufacture of Windows. Th., pr.,p;.roit.On of th., fr~m"" and Juhn IS donf' chif'fly by ma(;hlnf'r"1 Mnd rompa .. t,,-.,Iy fe'" "'lnd""1 lTe no" f'nt.rrl~ m;ld., by h~nd Standard CIIKTTIent ""ndo",., complete ""Ih frames .nd S;lJhe,. n., nocked by manuf.l(. lurer. of ma ... produced ""ndo"'~ Th~ \·anou~ opt"ullOn. of setllllll "ut, prepannM Isscmbtmll, Illulnll lind wo:dginJ! up. and Til-anini! off In th.· maklnlt of the frdmf' Qnd nshn of. '" Indow Ire .. mIl .. 10 thf' mlll'ufaClurt of doon d.·I~,lo:d on pp_ 100-· 10J.
General. The .... indow sho",!) ir Fi~_ 5R is shown fixed in a bmldinR whic.:h is faced with 50 mm bricks ha\·in~ 10 mm mortar joinu and finished at the openinR .... ith stone dressings, I.f'., stenc head, ~ill and }Imhs. Note that the inbands and outbands of the \;lUer course wllh tilt' brick.... ork and that the \ertical joints btt"een the stone and brickwork arc irreJ::"ular. If ~tone dressinJ::s .1fe not desired, the rece$bCI may be _112 mm deep as ,>hown in FiJ::. 8, "hen the outer face of the pulley stile conforms with Ihe facc of the outer rneal. \\'hibt Ihis undoubtedly ensures a weathertight joint l-.et\\cen the frame and brickwork, the iippearance is not so satisfactory, ;1.5 ;III but a narro\\, marRin of the frame is concealed. hence the openin~ are often pro\idtd .... ith square jambs which permit of the whole of the outer faa: of the frame ht'inJ:: e\po<>ed (see JI. and !<, Fi~. 58). The defect in this constn.lltion is referred to on p. I 10. One of several methods adopted to prc\'t'nt .... ater Riiininll: Ac.:Ceu bdwten the frame and hrickwork is .hown at 0 and 5, ",here a narrow 'Itrip of le.d (or felt) is fixed al the jambs and head. The If'.d lit the head II j;utl b.,1\\een the 4n;h ~nd tho: rl';nfQrcf'd ,'JOuete Imld .... hen the lauer IS bfOmJl fixed, Ihf' final dft' •• nll m-f'! tho: fr~m., br-,nj;l t.lo~ ~I ~ 1~IN "ollie Thf' If'at.ll,mnllill the jlOmb~ II fiu..:llult !lntoT t<.) Ih.· f"unj! of the fT~me ",hen a Hru~.1 Kroo~"C .. ronnal ,n el<.h ,Mmb. tht' It'11d .. tud...·tl tOto It .ntl PHurf'd "'I .. IC'Iod ",c:d&n (11ft 0, F'I. ''I) dn\-f'n "' at about 300 mm 111\<;0.1, ..\rtte th~ fume h ..
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Windows with cued framo and sliding $Uhes (often referred to as" double hung sashed windows ") are most effective in excluding rain and draughts and are superior to the ordinary casement windo..... for exposed position•. Windowl witb Pivoted Sashel l (see Fig. 60).-This type consists of a solid frame and a sash which is pivoted to allow it to open with the top railswinRlng inward,. The pivots (sec later) are fixed slightly abon (about 25 mm) the horizontal centre line of the sash so that the sash will tend to be self-closing. T.he construction of the frame is similar to that of the casement window except that It is not rebated. Both inner and outer beads are required (sec det ..ils at II. 1 and K) All lIhnwn, the ush is in the middle of the fr.lme with the upper portion of the 011.1" bead and the 100:" portion of the '''''" bead fixed to the J'Qm~, and the up~r half of the III"" bead and the lou'" half of the OUI" head nailed or scre..... ed to me sash. These beads should appear to be continuous '" hen the window i, closed, and they should be cut correctly to enable the sash to he freel)' (jpened "nd closed .... hen required. A method of setting out thc splay-cuts for the beads is shown at J. As indicated, a \'erticAI section of the complete windo" is sct up. Thc sash is inclined to the required maximum opening position (this varies from 10' to 20 to the horizontal) and the inner and outer heads are drawn. A line (" ~ ") is drawn throu~h the centre of the pl\ot joimnJ:: the points" 1 " and" 2," ~hich, are I) mm abo\c and below the heads, and two short lines are drawn at ri~ht An~lcs I(l it and a<:To!'.:> the widtb of the frame beads to givc the nils. Wi:h the centre of tht pi\'ot as centre, the lrcs indicated by broken lines are"dra"'n to gi\C the correspondlll.'( points for the splay-culs on the sash beads. The I) mm c.:learancc.: bttwct:n c,I(:1I of Ihe pr:t1ll1S " I " and" 2 " and the sash beadb permits of the remo,,11 of the ;;,1sh when required. The unucro;ide of the head of the frame is il>lightl}-' splayed (about 6 mm), and the lOp head and the t(]f' of Ihe $.Ish are made to conform to it, to allow the sail>h when openc.:d to de;!r the frame. Hardware. The \\indow tittings conSist of pivots, cyelets, cleats, catches and p.lttlll \cntil"tine ~caring. Sa.h P,('O/~ Of C,."rrt'1.- Of the varioull forms, Ihat shown at \t, Fig. 60, con!ioist.~ of a br;1!io5, malle..!bl e iron or ,fo!unmetal pin or stub mounted on a plate, scre\\cd to t"c inner f;Ke of the sail>h, and this engaRes In a melal socket the plate of .... hic.:1t i ~ screwed to the inner Lice of thc fralne. One pair of fillin~s is required per ..... sh. The "ash pi\ot sho\\ n at P conil>iS1S of a pin or stub plate and a blotted plate or ooocket. :\ pair of Ihe,;e fitllnf(s is h\ed to Ihe edfo!~ of the ...ash and frame. The pin pl.lIe rna} bc tiwd citho to Ihe frame or Iht' SJsh. If the f()rmer, each sockt'l platc must be <;cre\\ed 10 the edge the S
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VERTICAL SASH WINDOW slot do,", "\.lards (not as .hown It p) and in.... ard.; a p:roovc for each fiuiop: must also bt: formed along each inn('f bead attai,:hcd to Ihe sash and continued to thc .10t of the lOCket plate (sec broken lines It 1); .... hen inKrting the sash from the mSlde, the ends of the pi,'otl are cngagt'd in the bottom of the groo\'o;, the sash is pushed dO'>l""n"ards and outwards until the slots on the socket platt:!I hne been rCOIc:hcd. Altcrnat;\'dy, each pm and lOCket plate rna> be screwed to the .ush and frame respecli\'dy; when thiS is done, the socket plate is fixed "ith the open end of the slot uppermost (as shown at to) and the groo\'c is formed in the frame. These P;\'OIS arc not so readily fi'(cd as the typc at \I, and if thc SJsh is pilrli.llly open, it can be easily remo\'cd from the outside. The r-'tenl 'YiM' Ihown at Q is an improvement on the ahm-e centres. This consists of a J{Unml.'talscrell> bolt or PI\'ot with three plates T, li and v. A holC' is hared throu~h the middle of the lash and frame. As shown at It, plates T and l" are scfC'wed to the edges of the Ilile and plate \' is screwed to the frame. The pm IS thcn lnS('rtW n) screwin~ it throulCh the threaded block on plate T. This is an effective fininJ( as il can be easily "I[ed, the sash can he readily removed ",hen required. and it il a lecure method of han~in~ the sash as it cannot Ix removed from the outside unless the bolts are withdrawn. The size of the bolts
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uri" from 7S to 100 mm long and from 6 to 10 mm di.ameter. :\ pair of these finlllJ.:~ IS required per lash. ('a/rhn.· · A simple form i. shown at s, Ihc latch fitting being "I[ed in the mlltdle of Ihc inner fdce of thl! top rail of the SJ.sh and the stnking pilole being screwed to the undl!rside of the frdme to rccelH' thc end of Ihe lalch; a spring retdins the latch in the fixed position until Ihe sash is required to be opened, "'hen Ihe IJIl:h 1\0 rdC'dSCll hy depressing the ring. Alterndllvl'iy, the ush mdY hc securc.:d by sm:lll barrel or flush bolts, as des· cnbC'd for doors. A~\'tlt's and efta' s. A simple arranj(:ement \\hich permits of the opening and dosinJ.: of Ihe sash consisls of a lenJo:th of cmd which is attached at each end 10 hrass or brom:c eyelets scre\\cd to thl.: insidl! face of Ihe top and hottom raill. The cord must he of sufficient length to belay It round a metal de,lt fixed at a coO\'enienl point on the pmb. One form of eyelet is sholln Jt N, and a cleat is shO\\n Jt o. If the sash catch s is u~J, tile tIIp end of Ihe cord is £OlStenC'd throuRh the hole provideJ fOf it Jnd therdore only Ihe eyelet at the bottom nail is rC'lJuired. There dre mJn), pdlenl Je\ ices for openin~ Jnd dosing pi\'oted sashes, one
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METAL WINDOWS of d:c simplest consistlOg of • \crtical 5t~1 rod \II hieh has ;01 hinged arm con· nected near its upper end and i~ lower end pas.sinJ{ through a gunmetal ",jnding box; the arm is Stturcd to the botlom rail of the suh. The sash is opened and closed as required by turning the handle of the winding bolt. Pivoted sash windo .... s are comenient for lighting and ventilating high rooms, as they can be conH'mently openw and closed (rom the floor level. They are sometimes used for {actorie&, warehouS(:S, laundrits. staircaKS, etc. A pivoled sash is often used u a fanlight over a door. Windows with Horizontal Slidint Sashes (tee FiR 6t).-This type of .. indo.. is falrh common, "pee,,1!}, In cerlaln of the nonhern COU"IlIn. II II generally known aI I }'Q~lI:IhiTt ughr .•• lu~h "'IOdO.Of ..... a charauer,s!lc feuure of many of th., old.,r .lOn., bu,lt houses in that rounty. Compal1llu\"~I)" f~" .r~ no ... mad~ IS II has ttrta;n undnlr_ IIbl~ fntun:s, I.~, an unutllf~uor)" apf>ellnllnce and II tendency for the slldmg !IIIsh to Jam -\, ,ho"n In the de'·lIlion III II, the appearll~ is marred on ~ccounl of the" lil!'ht hnes ., not bell12 contmuou,. Ihe top and bottom 1111;1. of the slldln.!!" lIi.. h ne nol pre~en! in JIll: fi;ud hght; lru. cau-.el each paIr of panO!!l in Ihe fixw III/hi to ~ of three dIfferent hel.l(hts. The...... mdo", an: aull 'pcclfled for ahenmonl lind elUent'OIlI 10 bUlldlnR'- and ror replacements The wllld •.," " Iho'" II m a R'KlJlar coursed rubhle ",all. It con~lIts ora fixed iiI/hI ~nd ...holnjt: sash Deu.1 It shn", •• he melhod adopt"d for pt:rmllllOl! mo'·emenl of tho.' l.ish .-\n,.k bHd (or .1I,,,,r,), "lth rounded Ngt:, " utllf:rted :n the oak 'til lind ulends ror Ihe full ",dlh be:t"u"n jamb.. (Ht t: and i00i); a corrnpondmfl" but .IIJ(htl~ ",der J(roo\"e •• fortned on the 10"'et Ngt: of Ihe bottom rail of lhe: lliuh. The hud of the fnome I. rebaltd thl"OU"hout Ita IC"nJI'lh 10 reccne the top rail of the ...h (I« p. ~nd the ASh i, retamed m postbOn by an ,"nrr bead planlN on the jambs and contmL!l':d round Ihe head and 1111 -\ •• f:, mm elcaranc~ shoold be: pro,·idw all round the saah to penmt of free mO\~mcnl RII.n and d,..URhll ne ucluded by lettmg a bead Into Ihe jamb", hlch engages In a RtoO'e 10 lhe stIle (sce 1..) and teballO/i{ the lilies of the fixed Ilghl Ind ,lldlOR ..... h (s", \I). A barrd bolt II Renerally UKd to KCure Ihe .1,dlO.II ..... h
Ii'
METAL WINDOWSl
These are of galvanised mild steel, bronze, and aluminium alloys; they inc:bde fixed lights, ~ide and top hung casements opening outwards, inwards and pi,·oted. Ther~ are many sizes and types,' with or without glazing bars; simple examples are illustrated in Fig. 62. A fixed light consists of a frame only, and:oJ c:ascm~nt hu a ush which is attached to the frame by means of two hinges. Tht details show that the Jramr a1ld JOJh orr DJ 3.2 RIm Ihlck m~tal and tlrnr U(II01lS art idnttl{alm HZt and ,hap. They ar~ of Z.. sc!.:tion. 25 mm deep with 20 mm "ide flan/ol'd, one of thc latter ha,·ing a ~hliht rroJection beyond the web to allo,," the salin ,md frame to on'rlap 6·4 mm l'oth int~rnal1)' and externally. The horizontal and verli!.:al member.; of the frame .1I1d ush are wclded together at t~e COTnI!'T"S. Th~ hinge. are of th~ extcnslon I~·pe similar to that ,hnwn in Fig. 5i; when h.lly ~xtended Incy Vhc a 100 to 12; mm d~aran #' Ott"etn the sash and frame I I
Se-e Chap. II. \'01. III rOf • fuller ~nptlDrl Ind addlbONlI enm.1'1~. F..e. Module 1 _ rall,e lind Wao nn,e (~1.et.l Wlndo.. "-:>c.).
enabling the outside of the glbS to he cleaned (rom i~lde the room. Th~ st~1 hinges are provided at the top and bottom of the sa..h (see A, E, G, Hand K, Fig. 62), the fixed arm bemg riveted or welded to the fram~ and the mo,·ing arm (rotating on a hard weanll,g pin of phosphor-brollle or st,linless steel) is fixed to the sash. The skeu:h at " shows the position of the partial1y extended hinge rel:ltive 10 the frame and sash. The sash is fined With a casement fastener, or lWQ-polnt ha1ld/~, and a casement stay, both are of brOllze or RUllmet.a1. -\ t.... o~poinl h3ndle IS .ho'" n 10 Ihe 1"'0 omalJ-scale e:1e",UII)rIs.at ... dnd £ and Ihe pl"n "t" It is mOUnlN on II pin ~II.lChed I<> 11 b~ek pl~t~ "h'lh .. riHlcd or .. elded to the lOner ftanJfl': of th~· sash. and 1$ 110 c"lIed because of Ihc polO!> fomlN lit Ihe: no..e b,· Ihe nOllhcs (I« s). .""Isho"'n, Ilhm bronlc ~tt1kmj.l "I~(l {;lhOUI 2\ mm hy 10 mm IS ~UTed 10 Ihe mm:.flanl(" of Ihe franIC!" lIS obJccl I~ lo.p',,'enl Ih.· no,,, 01 the h3ndle COnlaellnR Ihe Ranl{e·and d~maj;:1II1{ the p"'nl \\'hen the )lOSltlon of Ihe nose I~ ;11 shu" n, " tl~hl lit bel'" kn the sash Ind the: rr~me: .hould result; the cJc~r;once: ,hO',n i~ c".lltl1entted to m;,ke: Ihe dCI",I. tl.,.... A. n"'.:d, ":nlll~l1on c~n be afforded hy enM3MIOI1 Ihe tlanMe of the f!llme (lind .tnkioK plate) 11\ .·"hcr nOlch" I .. 0'" 2 "; lin opcn1ll1l up 10 25 mm," .. idlh nn thus be mamlamed Addlllonal venulaUOIl can of course be oht~lnw by JI'PlymM the c~~emenl lIay. Th,s nl;O~ be;o pel{ st;oy hce 1l. hI!". 57), "h"n.l pm pl;lIe or h,.Ip-I:n ,,"hout Ihc pIn enll~l{mJ( In DOle of the h..,l~ of the bar -\ betle:r form IS the 11",""1: 11-1.\· (con."lIoll of a ho,,;
nil
Fixing.-The metal frame may be fixed direct to the wall or it may be screwed to a wood frame or surround. The w:ndow shown at A, Rand (:, and detailed at G, 11, J and K is fixed direct. EiRht 8 mm dia. countersunk holes are provided in the web of the frame 10 recei,·c the fixin~ screws ($ee~). If it is to he fi,ed to maSQnry. terrJ.-cotta or concrete. 13 to 16 mm dia. hnles arc cut in the pml!·, head and sill orposite those m the fr:ame. These are prderahly p1u~£:ed w;th lead, althou~h hardwood plUKS or r~wlrluRs :are more oftcn used. The windo\\ is then placed in correct positIOn and the frame screwcd to the plugs. The frame i,. fin;II1~· ,e:routed in with cement morlar and pointed With mastic. The delaib Co and H show these fi,inp;!O. The details:at J and K 9-how an ~hernali,·f' mf',h"d of fi'(inr.- tht' framl'" hv means of 100 mm by 16 mm by 7 or 5 mm lugs (provided by the manufacturers) .... hich are hent up 50 mm and have slotted holes in the bent-up position to give fixin,g adjustment al\owinc; the horiJ;Ontal part of the lug to be placed in :a eon~·enient Joint. If ne<:e5Sllry, holes are cut in the jamb~ of the wall at the correct position. a1d the lugs are inscned and firmly cemented in. The frame is secured to the luJr.' by 7 mm dia. fixine- oolt:l. The above method conforms to Ihe best practice, as windo .... ~ should ne'·er
IZO
ARCH ITR AVES
be fixed in posItion until the roughest work has been completed. OtherWlse damage may be caused, not only luperficially from daubs of set mortar, etc.,
but sashes may become distorted and g\ve rise to leakage. It is, however I the U&\.lal practice in cheaper work to build the metal windo"". In as the construction of the wall. proceeds. especially if these ace of brick. Typical fixin~ details of a built-in frame are shown It J and K, aJready mentioned.
The lug. are bolted to the frame and the window is pb.ctd in position. It i. kept level and plumb as the wall i, built, and the lugs are securely built-in with mortar. The lug. are shown bedded in the horizontal joints (see A, J and K). Lugs are also built-in al the head and sill. A vulnerable part of a metal window which opens outwards is the outer Hange of th~ top horiwntal sash m~mbt:r wh~r~ it contacts the fram~. In an e.lC:poRd position 'A-"ater may enter hert: enn if th~ sash is ught fitting. It is ad\'isable thereror~ to throat the underside' of the head and adopt wide exttrnal jambs by fixing the windoW3 well away from and not nelilrer than So mm to the face of the wall. Th(' more elaborate type of window has a projecting metal stnp, fixed to the top of the frame jUlIt above the sash, which senes as a protection. Criticism IS dlrect~d against metal windows fix~d direct in certain types of bUildings bKau~ of the mean appearance presented by the narrow frames. This is emphasized if the colour of the painted windows contrasts with that of the adjacent walling. Hcnce, as shown at 0, E and F and detailed at L, S, 0, P and Q, metal ".,indoW8 arc often fixed in wood frames. The latter are rebated, or double rebated as lIhown, 10 receive the metal framCi. The sletlframe is ~dded In mas/j(. affd Ihis must Iu rull d"ne to prl!f.'l'nt the mtra"CI! of waler betlum tilt two frames. Th~ metal frame IS then screwed to the surround, 8 mm dia. holes are pro\ldeu in the former fo~ this purpose. Putty is used for ~Iv.ing standard metal windows. Ordinary putty (whiting ground in ra"" linseed oil) alone is u»cle" for this purpose. as it will" run," and gold size is added 10 enable It to set. Small m~tJl ) mm dia. sprigs are sometimes used to retain temporarily the panes of glass until the putty has hardened, thtS(' fit into holCi in the web (see G, etc.). Alternati\'ely, spnng wire dips are UK'd ill lieu of the spri~. Steel windo".,,., bemg gahaOlzed. are \'ery durable and compare ra .. ourably with wood Cl5CmCIlb m exdudin~ weather. l ' nlike those of wood, they are not affet:ted by atmlhphenc I:hanges and consequemly do nOt Jam, a dcfel:t com· mon to certain hadly constructed wood ca~ments due 10 swelling. :\letal windows can be coupled to~ether. to form composite windows of large ,Ize, with metal mullions and Iransomtl. Such a window may also consist of &C\'eral frames and sashes h'l[ed In a wood surround WIth wood mullions and, if requir~d, wood tranM)mes. Special types of metal wind<)ws are a\'ailahle for S(;hools, hospitals. commerCial buildinlfl. etc. These, tOJl:ether with metal doors are de.:nbed In Vol. 111.
ARCHITRAVES, SKIRTI NGS, PICTURE RAILS AND ANGLE BEADS The fixing of certain joinery work can only be completed after the Wills have been plastered. Architraves, skirtings and picture rails ate examples of such work. ArchitraVH,...These are used for the concealment or the joints between the casings with their grounds and the plaster at dool1l and occasionally windows, and to provide an effective fini5h. Casings or linings have been desc ribed on pp. 96--10) and various se.:tions of architraves are shown at Hand N, Fig. 49; architraves are also detailed in Figs. So, 52, 6) and 64· An architn.ve consi$ts of twa \'ertic:al and one horizontal members with mitred angles; they are nailed along both edges to the grounds (at plugs) and edges of the casing. Vsually th~ feet of the architrave are continued down to the floor to which they are nailed, but in first c1allS work they are often finished ..... ith plinth or fOOl blocJu (see Fig. 64), These blocks are slightly thicker and wider than the architrave and higher than the skirting which is housed into them, and their shape roughly conforms ..... ith that of the architrave. A tongue is formed at the foot of the architra\'e and a mortice is made in the block to receive It j the: tonl{Ue is glued and securely nailed or screwe:d to the block from the back. Plinlh blocks provide a suitable finish to the architrave and skirting and serve as a protel:tion to the moulded architrave. The size and design of the architra'-e depend upon the size of the opening, the quality of the timber and the .:eneral effect desired. A 100 mm (nominal) wide architra\-e is usually sufficient for doors up to 9 15 mm wide; for lar~c openings the width should not exceed ISO mm if in one piece as it is liable: to split whe:n shrinkin.e;. The plain architra\-e shown at s, Fig. 6), would be suitable if the door has square or chamfered panels (see J and L, Fig. 46), but a more elaborate archLlra\'e would be preferred if, for instance, the panel mouldings were of the section shown at ~-', Fig. 46. Certain sections. 5uch as those at L, Fig. 49, and P, Fig. 63. should be avoided unless well seasoned good quality timber (preferably hardwood) is used, otherwise unequal sh rinkage will occur, resultin~ in the members curling or twisting on account of one-half of the section being much thinner than the other. Simplicity 10 design is a characteristic of modern construction (see also p. 93). Skirtings o r Plinths are provided to protect the wall plaster and to cover the joint between the floor boards and plaster. Several sections are shown in Figs. 63 and 64. The size varies, but the depth rarely exceeds 175 mm unless for very large rooms. The best method of securing skirtings is shown at Q, Fig. 6J, and B aT'd E, Fi.e;. 64, where horizontal rough grounds arc plu~ed at about 645 10m intervals in the \'crtical joints of the brickwork. Skirtings ..... hich are 100 mm or less in depth only require one set of grounds. When two rows of grounds are fixed, the space between them IS not . Iways filled with plaster, and when it is, care should
, ARCHITRAVES, SKIRTINGS PICTURE RAILS 0 ANGLE BEADS
PICTURE
1t"'1 L
110-20 W ... HUID IN
,~ U !
PLANS OF ,JOINTS D[TwEEN
of' t.. °G"
"'J<.CHITJ<.I'V tnr AlSO f1GI,.Q S
T
'0'
S~~TrNG
""1 ANGLES
SKIRTINGS
122
be taken by the plasterer to ensure that thc facl! of the plil:!lter does not project beyond the grounds.
to
The cheaper and morc:: usual method of set:unng skirtings is to fix them direct which have been dri\-en into the Hrtical jOints of the wall at about
plu~s
645 mm intervals. For deep skirtings the plugs are staggered, .... ith the plugs fixed a]tt.:rnatd) near the floor and top of the plinths.. The skirting al R, Fig. 6]
is sho\\n plugged to the wall. It is the general pr:Jclice to fit or scribe the lower edge of the skirti ng to the floor, ....-11Ir.:h may be uneven. Snlbm~ ,~done by I"b~'inlllhr PI,","," of skl~tinlo: In \>05111on and p~ckmll Or ""djj:H1U up Ih~ l,mn ,"nd untd Ih"II'p .. dg~ I. len- I ; COrup~Sks (su F,!,:. 67) ar .. t~hn and, "lIh till' ('loon' •.• p.ut ~4u.,1 w ,h" hCllo(ht Ihm the IO"e!1 JKImon of Ihe flOOT IS bdo" Iht' "'>lInn) ~dg<, of th~ ~klTlml:, dr,,,,,, along Ih~ fa<:t of Ih~ Sk,rlllll: "ith Ihe pn,nt' .. \ th., <:omp.l» m a "'rl1c~1 plan<:; ~s Ihe If"',-r pOlnl follo"s Ihelrrt'j!ldariuC'S of Ih,· fI"or 11'1" mh.,r IllMks ,I p~r~Hel hoo: on Iho: plmlh; tho: 10\\0:' edge of tho: sklrtmg
s.
"t,·
.. Ih"n •.•"" .llo,,~ thIS lTrq.:ubr 1m" and fl,...,r" ~~sur"d "hen the fom,,,r ,5 fi""d
Ihu~
a IIghl fil b<:1"0:"" Ihe Sk,rl1nll dnd
:\ gap Imariabl} appear5 lx-h\een this hottom edge of the skirting and the tluor boards due to the combined shrinka~e of the skirting and the floor joists. '['his allows both dust and currents of air to enter ground floor rooms from thc sp;ll;e below. \ smJl1 <10 to 13 mr'l) quadrant co.cr mould as shown at R, Fi/;!, 6], may be bradded to the floor to prC\"ent this; alternatively, the gap may be tilled with a m;lIeri,1i called "llIllie u;ooJ which is pressed in whilst in a plastic condition, smoothnl o\cr "ith ;\ knife and sand-papered over when set to bring it tlu~h with the fan of the skirt mg. A bt:tter, but more costly method. is shl)\\n at Q. Fig. 6.1, and F, Fig. 64; a tongue is formed on the lower edge of the fiklrtlllJ! .md this IS titted into a grome formed III the flooring. Se\'cral Joint:> hen\ecn the ends !If !;kntlllJ!s are shown in Fi~. 6]. The cht:apdt mdhud is to minl' the cnd~ .It huth e\ternal and internal angles as shown at " Anotht:r cheap Intnnoll.10int tOllsists of scrihin~ one end Lo the face of the otht:r "hlch holf; heen tI,!.!htly J.nd slll1J.rely fitted into the an~le. A better Joint for internal an).:les is sho" at z; une piece of the sklrtinR is grooved from the bottOlY\ cd.!!c ~ the hottonl (Jf the IIllluldmJ!, the end of the adjacent picce is tollgued and tht: moulded portlllTl L:i :>eribed to that of the first piece. A joint used In \ery ~(Mld ,\ork for hoth internal .. nd e\ternal allJ!les is sho .... n at A'; tile thin hard\\oud tross-tongue is ,l.!lued and the joint is assembled before the piete" ,Ife n\.ed to the ~rollnds. The Inltr{'d and rehated Joint at B (:llso called a Iipp'J jOint) i~ a /l:ouJ form lor e\.temal angics, (foss-hraJdin,!.! a~ !>ho"n is necessar)". As illllieatl'd in Fig. 1I4. sklftin~s ·He housed into plinth hlocks. If the latter ,Ife not pro'ided, tho.: ends of the ski1!inJ1:s ~ho\Lld he let into archLtra\es, other \\Ise cr.lcb .... tll sho\\ \\ht"n shrinkage OCCllr~. Thl' deSigns of "klrllnp', aTlhitnl\t:s ;lnd pJnd mouldings when ;lssoci
'1
moulding w. Fig. 63, architrave 0, Fig. 6) and panel mouldings v or c', Fig, 46 form an agrct'able combinat ion; the chamfered Or bc,"elled edge shown at Rand s, Fig. 6] is preferred when a simple effect is desired. Alternative ski rting mQuldings an:: shown at T, l" and v, Fig. 63; the cavetto ski rting at x, Fig. 6). pro\ides an effcctive finish, but the labour in formin g Ihe trenching in the floor to receive I .
I•
DETAIL AT FOOT Of ARCI1ITRAVE
l t===jnrt-iin
B
A
"
." ""'"'"'AAVE---L
PLINTH aLOCK.
~OUGHGWUN~
~S.,.z5
,,
, ,
,
,,'
SItIUING
--.
E LEV A T ION
St<.ETO+ SHOWING
C ~ s!.AlE.
P l. "t-I
+
loa!
..
zoo!
E
AJIt,CHITRAVE. PLINTH eLOCIC.. 6 SKI~TING
FH;,·Rf. 64
PiClul'e Rails. The$e arc often omitted in the modern h OIl~c, e~pe(i'IHy in rooms \\h ich Illa) be only 2'5 m high; they have may the efreet of ~poiling the proportiolLs h~ bre3.kin~ up the \\011\ surfaces ;lnd "lowering the cei]ing:s." \\ hell the\ are required, a satisfacton finish IS obtained if thev an! fi"\l'd at Ihe level of'thc top of the door afchil ra',~".1» sholln at A, Fig. 6). :,1,.ltcrnati\·e sections Ihrou~h picture TJils arc gi"en at H. j and K, and the plug: aud rouJ!h ,ground (t\\O forms) fi\:nJ!s are included; plug~ arc generally us{'d and arc dri\en ;nto the n~rtical.!Oinh of the \\allinJ!. Angle Beads. Extern;.l .Ingles of pla!>tered walls hJ\c to he protected ,l,!.!"in~t dutnJ.l!;c to tht" plJMer .ITTises. '1' .... 0 mcthods of accompli~hlll.l!: thiS .HC shown.lt L and \I. Fij;:. (,3. !'lugs are drin'n in to the joints. the proJectmg ends .Ire cut off in true ~lign1l1t:nt, .lnd .6 or 21,1 mill "ood beads are n,uled to
,
STAIRS them. The plaster should be cut or qlli,lud as shown, but this is often omitted. An application of this form is sho"n in detail in E, Fig. 61. Another type is the gah'anized steel an~le bead nailed into the brick joints. The more costly Keene's or Parian cement arris has heen referred to on p. 107 (see "'I, Fi~. Sf) and described on p. J2.
12 3
.... "'IILlI. IXA""III ". ('M'" J VOl 2.
Col
s
T
A
s
R
TIM8f~
VOI~
STAIRS A staircase is a set of sleps or fiightleadiog from one Roor
to another. Timber and stone are two of the many materials used for constructing stairs (see Fig. 65). Each step consists of a horizontal portion or tread connected to a front part knO\\n as a ,iu,. The goill.~ of it step is the horizontal distance between the faces of two consecutive risers. The riu of a step is the vertical distance between the tops of two consecutivc treads. It t- 1S been founo that. for comfortahlc usage, the ue~1 pruporliul1~ uf it stcp are such that going plus twice rise equals 584 to 610 mm. Thus at F, J05 +(2 x 152) = 609 mm. The Buildine: Re)!:ulatim:s require this figure to be between 550 and 700 mm. Timber Stair. The simpk internal e.\.lmple shown in ::>cction at A and plan at B has a total rise of 11",6 mm and there are six 191 mm risers. The risers andt"attached treads span between two 250 mm by 38 mm strings which are plugged to the side walls. The treads (see D) and the risers are housed 13 mm into the strings and glued "edges arc used as shown at (' to make a tight secure .wint. Triangular ~Iued blocks (si" fJCT stcp) are also required 10 stiffen the CC''l.SITuction. The detail al {- also sho\\S ho\\ the risa is tongued, glued into the adjacent treads and screwed. The distance be'"een the outer faces of the strings is 840 mm (to suit a space IJ mm greater between Ihe walls); when this latter is increased to 915 mm as is common in houscs, then additional support is required 10 the steps running centrally bdow Ihe Hight. This compriscs a 100 mm by 75 mm raking bearer whi!.:h h.ls 150 mm hy 25 mm thick timbers nailed to it to fit tightly under the treads (see Chap. II. Vol. Ill). The simple handrail detailed at E is of So mm dia hard\\ood fixed to steel hra!.:kets plugt;::cd tu tht: \\al\ .loS indicated also .It A. The Duilding Regulation, state that the handrail ,hould he fixed at a heiy;ht not less than 8fo mm as shown at A. Stone Stair. The steps are made of hard i1on-~lip stone ~uch as York !landstone. The elevation at F and plan at ,; Jl e uf a shrJrt Right sHch as may be required at an entr3nct'; it is made wilh selid STone sleps. The:;e haH': a ~ore or less re!.:ungular shape as detailed at II, but p:Ht of the soffit is chamfered as indi;:;ated bv the broken lint' .1nd 5h(,\\n al!>/) at J. The chamfering is not essentid ho!re bu', it rlduce~ .... t'i~hl and gi,-es 3 neater finish on Ihe underside ~holJlci ~he soffit he o[l<:osed 10 "iew J!'. in open Ill,o\'hl .lairs. fhe steps rest on brickwork at lither side as noted at G and J. The elevation at~· (which is actuallv a 'lCction throu!;!h a returned .• inforccd concrete landin~). !'.hows how care h3S
.... ,,,., ,~,AO
, .. " . . . . IJ'~IIIJ
OM
0'
.. " , .
· 51"0"''''
3 l'
"-,,
r-," "•• '''~.
(
-.
"MO
O{TAll'V'
FASTENINGS been taken to course the steps in with the brickwork
5(J
All
to ;lvoid
wI
bricks.
The balustrade on the open side of the flight is formed of mild steel or ~rought iron members and the handrail :1 dr .. wn at K The 20 mm square sla,ttla,ds or baJustus Irc placed in pockets in the step as shown at H and fixed hy lead which is run into the holes. Note that in accordance with the BuildinJl: Regulations the height ot a balustrade to a landing must be at least 900 mm for I private stairway (1100 rum for a common stairway). Similar steps 10 these can be made in reinforced concrete and they can both be built 102 or ISO mm into walls to cantilever out <;0 as 10 be unsupported on the outer edge. Care should be taken to provide sufficient \Ieigh! of wall above the bearings to .. tail" these steps down. Further ~xamples o( stail'1 ar~ gi\'en in subsequent volumes as (ollo"s Stone and reinforced concr~te in Chap. III, \'01. II. Timber in Chap. II, \'01. III. Rein(orc~d concrete and steel (including fire escape stairs) in Chaps. II and III, Vol. IV.
ScreWli.-Thne UI' scl'l'l,,1 form8 of sere"" but Ihose t:hidl)' used for fillin. woodwork arl' the flat headed (SCI' K) lind rnund_hl'adl'd (see L) cypes Theil' are made of wrouaht .ron, .1«1 and brllt. and a. IhC' thrud II 1'fi"I'CI;\'O: in cuniog InCO ... ood. thC')' arl' IOmeriml'S called rmod 1lT('f
NA
LS.
FASTENERS
f.
SCREWS
,,,~;' '>- . VJt:ii~~~';';~~~~==~~'. 1>. ~t ~~~"~-~2~d;
A adI lililit 1l1lAA"""'1
..
OVAL WIItE NAIL
IO'AD
II!III!
CII'.CULAR WII'.E NAIL
$fCltON
WROUGHT N,A,ll
SfeTlON
SECTION
-I!-
PANEL PIN
_
NAilS, SCREWS AND FASTENERS SIC('I or wrou'thl uon faslenin~ used In cJ.rpentr~ and Joincn indude onl and circular wire n,l1ls, CUI da~p nails, wrou~hl nails. hrJdl;. H.I! dod TlJundheaded screws, cGach scre\\s, corrugated fasteners and holts. The biter i~ deu.ilcd at J. Fi~. Ro. and other fastcnin~s are IliustrdlcJ In Fig. 6b.
•
Wire Nails. Th"" aro: O:lIh"r nul (Stt \) or ,,,,ul.,r \5n' II). (h"I""rc o~Ils .Ir~ u ....-d for ~t"o~r~1 purp' .... ~; rhc)" .I.r I"u~h .. ",j ~ ... ""I hahl,· In spIll ,h~ w,KKI "h,·" dO"rn In; Ihc d,~hl ~tlJlIo .... .l:r<""u. ur IKrr..llnOI In Ih" ~1"In ,"H~d ...· Ihr .• holdlnij power" nr ~blilly ,0 .llTlp the fihT<'~ <>1 Ih" wn•.u ml .. "'h,,,1-1 Th ...· nn' d',,·~n. Thn arc nhl~In;lbh: 10 .,,,,0:5 '·.Ir-Inll from l, In I~O mill ~oJ ~rc •. ,Id hy ""II/:hT. rhe \,trculn "all ,hown ~I " II nOI '«-n "u~l"d by ,,,"l ""t" 0",1~. Wroulht Nails (sc,' n)-TdPo:rrd m bo,h \\ l,jlh ,md ,hlckn"s5 10 form ~ poml. u""full~ emploled for fixmlt Ihm membrrs. ~~ ahrr p"nl·lr.ll1nlt Ih" mJle,,~1 Iho' poml ~dn 0.' r,,~d.Jy h.mml'rrd mlu [hI' ,,0<><1 'Jr t:knt:hl'd h",' p. Sh) Th,' .,z", "'"rl' frnm :~ ,.) 100 mm Spike. ~rl' u"l'd fur ..,curmlt lar~"ood membel •. "'I,' n,,,I. "h"h """"",d J 2~ mm '0 1,'n~lh Jnd "roulthl nail. "h,ch ,H" luolte' rhao 100 mm ...., .1."sln,·,j ... ~plk". Floor Brads (see ~.I , -Tk"5" \\t'rl' 00'" u'Inl lot ~"'UTlnl: """r b"~rth InJl k .. ", 00" ~n ro:pl.eM b\' o,~1 n~,]. Tht: knvlh I~nu ImOl lR 1<> 7~ mm JoineM!' Brads Dr Sprill (~ II f Th""" '"'":mhl,, floor br~J,. hUI rh.· ~I"'", .lIe fmOl (> 10 ~o mm , .... \. ano m .. d .. of.rft hu.... nJ c"pp'" Panel Pons ·...... e) l Th...., unall Is. cl,,"UI,11 01<"('1"'" ,111' g"m'ull" u ......J fur n~",g h.lrJ"uod m.-mh<"rl fu.u~lIy moul,j,o,:" Needle Points (~n' c) ·I·h"..., .rc ""..I pln~ u~"J f
,If"
grt""~"
.,1'
6
SECTION
.
FLOOII. 8"'AO
UCTION
" mmmmlI:'::O=~~ 8
K ~)II\\\\\\\\\\\\
flAT HE .... D SCUW
J.... (...O" L 'IS $I \ \ \ \ \ \ \ m\\\ ~OUNO ~E""D
ol'''@N /
'cup
HCTIO .... SHOWlt-IG
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C JOINERS' SRAD
PO..... T
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D De -l i \ \\lm:m'M
J MHHOO~""CONCEAUNGSAADS
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\Ou"ItE HEAD
COACH SCREW
"'£""0
wma4\A~ .~ a (L(V"110N \ "VV'V'V'V Pl.A ....
£Nl ...IlGfMfNT Of
.
S",W EDGE
OIVU,GENT P... THIt.N
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CORRUGATED SAW EDGE ~ASTENU.
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MITIt.EO JOINT
tun JOINT OF FASTENflt ,toPPLlC,t,Tl0N
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Sonu,-,-\s Iho"" ,II k. Ih ..· "Ir~u!~r flat hl'~d (which II O ... ,'~"" ,he ... ·rC'''drl\t'rll~ IJPcred J.",o 10.0 f'I'"0[; Ih" Roll h,,~J c .... be brouj;lht Ilu,h ""h Ih~ limber; "'5 "hl.unabl" In "ZCI "~rymvlrom 6 10 '50 mm 10nR ~nd from I h 10 .t. mm m J •. lm"lct It" J',,"lrablo' I ..... J In, h~ld"o..
TOOLS A hole .I,ghtly smaller t!l.o the: d i~r of the lop of the cup, i, fOfTl'led by • ccntre b,t In the requtrled pos,tIOn , ,Imlt alue " pillcni round tM holt and the- cup
(Ke 46, F'I. 67) 18
dnvcn in.
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R...d-4Ntkd (10« L).-Thne arc ...mlar tQ thoK dncnbed .~, Cllccpt thaI h hud " .Imoat hcnllipMric.l They 11ft eenerally IIIIItiI fo:w Ulna: metal to wood, ~., loo::t. and •• mllar blI.rdlu.c • CrMCftl/-..1 DJ Fa$tltlWfl'.- -\\'alU\ nails and hnld, arc dnyen Imo IOf,,,,,ood diCI. heads "II: dnven ,bout 3 m m be low the lurface by I h .. mme. on , Itcel pu....,h (II« 10, F it. 67) and the: ho la ne filkd or .. $IOP~ ...... ,Ih putty beron: the .... ork II pamted For hudwo
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WOODWORK I NG TOOLS Whilst machinery has very largely ditoplaccd hand lahour particularly in shops ",here standarJiled units like doors and windows are made, the Joiner is asked to perform many ta~ks necessitating the UIC: of haod tools. The follo\ling are in ~encral use and arc c5sc:ntial parts of a kit ~ C lll55i fie:at ion.-II.",d loolR m,,}' bt da ... hed 1010 IhOk required fur Cd mllrklnlf lind Kllln.lt OUI. (2) .. ultlOlf lIod ~hll'IOR, (J) bonna-, (4) Impellln.lt. (5) abudlnl/. (6) cramp_ Inll .lOd hnldlOR. lind (7) mIKl:ll .. rK"O\I'" ~I,,~( or Ihef" lIrtc "hO\ln In hR 67 (1) M arlUn, and Sell ing OUI Tools.· -The..: ",dud.· ruks. m;lrklnJ( knlf"" 5tr~'Rhl edj:!e, try .... uar~. mitre, i>e\-el. c;ump;osses. call,pe~ wnd If~U"'"' kwiC", (scc I) \I •• d" ~.r box"ood ~O tm r"ur-fold. I m four.fold. nc 1t1ur/""", Artl antlClltlln" J\n,jr {Ke ,). ,-·l·..c:d ror kltlnl( out lIu;urue I'ork (IC'~ p. 1021, Ihc ~"I (or polOll belnll usc. d fur pncklOR po'nl~ fwm thl' rod and Ihe Ih,'rp edge belOj:! U~CllI0 CUI tM., shoulda, 1'1", II""",. St,m"n/ F:d)!, IS ~ 75 to 100 mill \I ,dt howrd 13 mill th."k. 2 or 3' 5 m lung" IIh one edRe pcrf«ily "IUd,e ;lnu th~ (liher bevc:lJed 10 dISUOIIUIf;h II frOlm Ihl' true cdjl'e; u~d ror tt'tltlnl!: lurf..ces, mllrk.nllllnc:l, elc 1"", -"'I"'''' (~ 2" For ..·tI.nl( OUI "Rhl unRIci. lind I«Unll .... u .. 'e .'Ol/In dunnR Ihe pl~nlll).! up .. f "uff; obl~lO .. hk \\lIh 115. 150, 1'10. 225 "nd 300 lonll' mCI .. 1 blold" •. _l, IMj/<'r '<.Iu."e i. III .. ) R-quln'd: cnnf;llh of .. mah'll::"ny hl .. de .. h,d, i. uSWllh 51l nlm b~' 6 mm by 760mm 100111 tenoned to 1I400 mm IO",II.tock. -\ .\1urt SiI'drC"D' FI'la lJC"f,,1 h;osil sleel hl"de "xed "I 4~ 10 ~ '10K'" ~Iock; Ih.~ II a uKful 'pol for fCllmfl OUI 45 'nll'lo:I.
Bft..,{ (He 3).-The bilide \;lin be fCCIIri'd '" wny a nfl le ; uso:d for Km....: out WIIII:In olher Ihan neM ..... gln; the b lada are. us, 367 aod )00 mOl 10"':. C_JjlUIU (Me S). ,UKd fOl mark"'R p&r~lle l Imes 10 'rrquur AUf..:a .u~h u senbo.ng Rlmnp 10 ftoon (HI' p. 1:Z'l) Ind mouldmp 10 \lall,. and fot ducrlb nll CIl"t1ts and Ktlma off dluancel; 'lOCked 10 ISO, 175, lOO, :uS and 350 mm "&H. ,l, /1'."._11,. u..ed for Mnlunl: larJIC areu Ot" ~m:les; COT\IUIl. of 1"0 meta l head. each havlog a 75 to uS ITLIn poml. ,,·hlcn Ihde ,,1001111 hanl\lood I lid:; the POIOU CIIn be fixed .. dt'tllred lod one of them rna)' be repl..:-ed by .. peOCl I sockel. ClllllpoJ are used fOt" mcuutmg dlJmeterl of cun'cd .uriaees; OHt$ldt ClI l h~ ...., used fo r external dlmenslOfIS, conSist of '" p;olr of hinged . Ied c un'i'd legt which a re s haped 10 a fine polnl; ,,,ridt ~1It1lptn. for inSide mt'tl. uremCnlS, hllve IWO hmRed dod Idpe red legs "hich fi nis h "'Ih pomll wh ich t urn oUI", rd •.
Ca u,es \lTC 10015 used 10 mark one of more 1H'It'S on Ihe wood pdTIIlIellO the HIKe; Ihe \-",nella ,nduik Ihe m.rlllnif pUJIC. cutnn, pURe, moniSt' !lIluJte .nd panel g;.~. ,\1(lrlmq( GIIJIXI!: (~ 4).-1'he ho led adjustable beech head rO:CCIHS Ihe Slffll, ntllr 00'" end of" h.ch "a lleel nurlung loolh; after Ihl' Slffll h"s betrl SCI .nd Ihe Ihumbscrt'\\ II lChtt'llw. the face of Ihe head (Ihat nrarrll lhe loolh) 's pl"ced "1I""IOlllhl' timbe r dnd Ihe poinl .. pr"5SCd dO\l 0 10 ICQ"", I Ime on the .urf~ce ils Ihe htad Ir-~'-erset Ihe edge . ,,,ltinl( C""Jlt Simi lar to the m~rklOJi "",u~ except thai 11 has '" steel CUIIU m pl .... e of Ih" loolh; uSC"d for ~U lllng p" .... Ud tlTlpS from Ihm 51uff such ;11 \'enullI ~od for m;,lrkmll' ............ Ih.· f!nI.n .\tartlY Gm/flC" f_ ",).-Thll hal a mo\ublt pin attached 10 Orlt' "nd (If .. nrllU s l'de and 1 pm fiud to Ihe "em . ......, d'5t11ncc bt'1\I ttn Ihem may be adjusled from 6 to So mm The 1I00uge Ihu. ",nable. 1\\0 panlUcillOt'I to be mark .. d and IS emplo)ed for settlOR 01.11 mortl .... and len<>l1I; Ihe POlOtS of lhe fl'lIU/lt' arl' KI to thl' "'Idth of Ih., morlifC and Ihe he:od IS IMn adJusled 10 Ihe: r""lUlred dlstanc .. (rom Ihe mo\"ablt' pm P"n~1 Gt"'~t.- Th ill' I.rger th~n bUI r",,",bl.,. Ihe mark"'l( RaUl/e; "is ust.lall), m4de by Ihe JOIn"" th .. ltem belOR ~boU171 omm 10nR Th.. p.n is fiud aod I~e ht'ld is adjusted hke Ih., markinJ.: R~ U ICI'; II il used in Iht' conllruction of door pan .. " (2) Cultin, a nd Pl a nin, TooIs.-Thesl' compnse 5<1\11, e:hisel., I!:ou ges, plone$ Dnd .pok"'h~vcs.
s.wa.-1'he man)' \'ariel,'" IOclude Ih", crosa-cut sa", np saw, lenOn .. W, do\-t'tIIllllIl', t'omPUIi saw, pad 18\1 Ind tJ,o.. .. ". A a;I\I ba~;I ~prinj:! 511,,1'1 blade \I,lh a wood (usually beech Or ~ppl .. "ood) h~ndlf K<:urdy n'eled 10 II; tbe 10\l"r edge or froni oi th .. blade IS dlnded IOtO fin" letlh; Ihls (Umnj:! .. dRI' II usually specified a(cordlOR 10 Ihe number of P"'"/' (nol rHlh) prr zS mm; Ihu5;ol A. C aod o. Flit 67. Ih .. numbtr of POlOts per ~s mm II •• x, four aod leo rClipectIVely. The teeth are bent .. lternately 10 ,h.. nRhl and I"fl of Ihe blade; Ihl,,, called ,tiling lace II); In adllillun, the blade, of Ihe la'lCe r ...... s Ire grouod Ihlone r ~I Ih~ b"ck (opposit~ ed.lte to Ihe I .. elh) Ihlln ~ I Ihe CU lling cdNe. T he 5elllni/ I. done by meanS of thl'..,ft Itt (see 20). \ a;I'l should be Ibm 10 ,nold wast" of m~ l erull Croff·fut Stm- {Ke Ill. ·Th" iJ "'JM:nllally UMed for CUttlO.It acron Ihe fibre. of Ihe \lood, bUI alllO "'lIh Ihe "tim, and 10 (";IT1'Cnlr~- for .lteol'ral sa"'lnll'; II il mad", ... lenl(lh. uf 500 10 710 mm; the number of poln" II 5, 51. 6, , ~nd 8 per z ~ mm; Ih .. ~'il:hl poml N " is comid"red be., (or hardwood,. a K'tn-POIOI saw for bolh h .. ru\l ood linG 5Ofl"ood. and I fi,t'·polOl U\I for ro"'ll'h caTpl'ntl")'; Ihe leelh are shaped a~ 10 Ihe enta'Red sk.. leh ~t
A
Il,,, &m.-Th •• is only used if machmel"}' II unn .. ,labl .. for (UIlIOII' limber alonR Ihe
Il'r~lO; 11
resemble. Ihe ((OS,·"ut sa", " 710 mm 10nK, ;lOd has leeth Ihapt'd as shown al C pu".I. pe l a~ mm PIOII,I Sat< i.lke ihecTOIlS-cur \11th" finl'r bl~de ,md Iccl h shaped 11.1 at A: 1680 mm bl;ode \\llh I~n or l"eh'l' POIOIS per 2~ mm II oormal; II is u...,d for IIccunlf work-aod m.lt'lId of the I.. non .... \1 for CUIlIOJI pan"'. and slmll,., "Id.. \lork T,n,," Sm, (5«' 131. I-or finn \lork Ih.. n both the ~f(_-CUI and panel5a\lI, u..ed for CUllinII' '~nons ~nll \lhc~. clun CUI II rI~ded; the J~O mm blade .. preferr"d "hich •• ~t.ffcned by the bra.. or ,ron bar on Ihe top edjlC II has len or 1"'t'II'1' polOll per Z5 mm 3nd Ihe leelh (called ~ le(lh) U~ shaped as .ho"n ~I o. [)Q,,'r/ail Sm~ (~t' 15) ·Tt". hili a zoo. US or JOO mm Mad .. \lllh fourier" polOlS per 15 Olm; u-SI'd (or ~'ery fine work, III for formiog dOHlal1 j0101I
,,,ti, (UUI
JOINERY
126
CON{lflJI or T",",'l/l.'j(", {6«' ,6 .. "0 17).-For c;ullmg ",un'\'3, it h .. irottn:.hangnbk
bl.od",,; th., Ittlh a,...h~ped U II! c. Pad." K~·lrol.. S-m (I«' lin -For '''nn,"g k,,~'holu lind "mll;!r cur\'rd work; it i. 1M In.... llnl aot", Inc blade un be, p_-d n~"llh",ull'h Ih .. hllndlt "Mn nm In use; tht tccln UTII' ,.mllar 10 thOS(: 01 th.. comPIIP taw HOle $mc (so..'C H). ·t:tcd for CUlllnlf curn-d \lork "lIh "'\Inops "hl..:h lire too quick It> "" ntROUutcd by tht l"tlmp"." 6;1" Fmmr Strr~.-II .imlh., bu. 10000I-'1:r lind ,uon!!", than Ihe bow sal' Chit.Cls ha\'c fOTlCcd ",,0:1 blarlo:!l wllh ;Ish, boxwood or he~.... h handln; .,..~h bl"d" i, b.;\'elled on th" hack lind h ... I cuumt!: C'dl{t; L'ard to T.-.nO,,' thm layeR '>1 shann~ of "ood In ahapmll surf"",". formmg morh"..,., et~. ,'''nout kmd1l mdude Ihe pannl/. firmer lind mon.".: <:n .. d both "d...os. 11 15 uMd for formmlf pock"I' in I:>.-l"cd wIOd"" Iran'eII (k.., p. ".); oblo"n~ble on ",d,h. hom 3b 10 6. mm.
Gou,e, ~re cun'cd lhlad~ pnxluun,v: ur~ul~T cu,.. I'~r'nj:!. fim,,,r ........ kel. etc., J,t:0u"..... ITt' oblam.lb1e; lh.1I shOlln ;11 }" .. ,In und IIDUl:'e for h('"~n' work; Ihf>k' .ll:T JH mm. Plane. Jfl' "" ~;oIl"d a. (hey "r,· ehu:lly u~ed for ~h'''I0~ nr sllloothonR pl.m .. $urb~e~ ~ltcr I..h" umber h.,~ lx....·n ,."'n~ IhcI ,rc of rtl) "nod (bt:l-..h) lind (hl mr{,11 (ea,t ""d, JnlnmcIa] ~nd mall,,~h1e Iron). (a) Wood Planet.- -Of Ih" many ')J'<". Ihc ja<'k. t~onll ,mJ .mOOlh'n)l pl~nn (Mno"n /nn.-h "1",,,.) _Ir" "".... ntl;oI IIcnl~ of kll; .. ,me of Ih,- olh"rJ .If" sc·ld,,", u...,d ;u.-l.. I'I",,~ (~ ...,. <1 "f,~r II has I"fl Ih" U\\ i II elomm,""os Ihe "". ,m,rks ,md I,';,.·,·, Ih,' surb"" ~uftki"ntl~' smoolh for Ihe ,ub· .rc.ju"nl tinl~hlO,,: ... Ilh th .. IrylO!! ,md 8mCIIllh,n)l p"'n..",,; "nm~ist1 of II _Iood. douhl" ,rnni, "cdJotl' and handl ... The 'I~nd~rd bt...",h,\()(>lr.· bcolOll: adjuslt'd Th" Irnns conll~1 01 ;I (IIlIi",! i,,,n (t·) 'lIId n />.1(1. lOr '''/I "OJ" (I)" hleh ;!f,' m"d" of nul'!' hie •· .. ~t ~Ied; Ihel "Ir m.Ld,· in 1':lTi"U~\\HJth., I",· flo mm II~,' b"IIlII populi.r, Th" buttom rd.ll" of ,he ,·UllmJ.r ,mn I~ r.mnded .1~ ,I " rcquln-d In remon' ~h"nnJ,f' "hit h hh"uld o~ thld'e~t III Ih,' nnlr,' "nd fin"r ," the rdl!e; Ih,s ,-d).:e I~ d"uble_hel·dl .. d (...e rnl~rl:"d • .-eu".. thmu/.:h Ih .. rdl!e ~tl;). ,h~ fl,o,d,,. 6n.-~1 b.:1O).: .IUfhlll 1",]]0'" IIround .,n.! ~ppr"!I. Im~h'I)' 2< , Ih" 1h"T,.,."i~ 1I",,1~ " .Ibout .11'; Ih" Ih"kn".. of the .roo rn<'TUxt Irum l: mrn WI th .... I"P tn nhnul. mm 111 the 1"1" "C 'he .l!nn,""" held; Ih.· i."n i •• Ioncd In wll"" m""'mr'll of Ihe II..,."" ... h,,,h on' ... h .... II 1.1 ,he h.,ek Iron. Th" borlt ,rtln (F) I~ of unlf"rm thlckn~ •• of ~hout .1 d""n 10 OIlx;ut l j mm frum Ihe bollom. "h,'11 it IS ~llllhll) "un",! .Iud r"dU(;"d t" 10 '111<- l-dgo:: "bnt~s "1.11 itL ,In~(-hl·tl tl' ,I" It<>n.or 41 'i,ea ,h ... ••:R''' v. h"'h ~..,nne<" hf,lh plat,,~ t~rtl""f /,t'C' J): the d'~I"n ..'e Ih~1 the fdll" ,t ft. .. CUlllnJl proj",," bo"yond Ih~1 "f ,h .... blK"k ,ron ,~ "alkd th .... , Mnd this drp ..·r.d., up..... Ih. cnar", eer Cor tb.· v.ood to b.: i''''IIN ..u,d ,I" :1",;'n"111 nl tlll' d".ired ",h.~""Il: the:., "l'l'rm"m.oottl·. ) mm f
I.
,,(I"
In'"
U,.
Ihe surface of the "'ood by 1M j"ck plane: .nd for fotmlllR Ion. ItrliRhl cdsa. It 11 tl,~ largat ben~h pllne (Ih~ 11_ belOR s60, 600 and 660 mm).nd retembln thej.ck plln,,: the ~I of 1T(.on' .. uswolly 1·6 mm for IOft"oo(1I Ind 0·8 mm fof h..d"ood •. S",ool~,..,.plm,e (5« l:9).-Thll .1 IDr nn •• h,ng plane used to Jmooth Ihe "ood IIfler Ih~ 1"ck Ind If) .n.il plan« hal,· betn operlted; Ihe lIock .1 onl) 100 mm long Ind It provided .. ,Ih dnuble iron, leI u for 'he Ir)inll pIli" .... Rr6nu Pilmr (~ J8),-l'~d for formong rebatn and hal 0"1,.. I sin)":l,., eumn)": iron from 6 to ~o mm Wide find hI' • wedll'" lind placed on the ,ke\\ Holitnt' 1,Itd R.",M P/flntl (we: )0).- Thr fonner .. used for makin.il eonl'ex lurflen on Ih,., hmbrr (Ke cni3'11cd &t<;uon Ihrough Ihe ,olt lit 11:). Ihe edkr of the .ingl,., Iron cOflfonns 10 th,., CUrl·C. ronuI'e Burfae~ a~ mad.· by tht round pllne (Ke enllrged t«.lion l). Buui Pln"t (~ )}).- Thla mouldlOJI plan~ " 'hll r<'<{u,~, and 1"0 or Ihtff d,ffc,."nt .izes should form parI of II kit; "'S used for fonnlOg a half·round mouldin!t \lllh II qlu,k (I",k'nJ(1 on edR'" of members; the SlrlP leI 1010 thc IIOle of Ihe nock 15 of boxwood to tHiSI "c~r. II .k,.,tch shoWlIlff Ihe IIpplication illflvcn II" SOIr. ~louldinff plan.,., .uch u 011:«, 10rO$, r~. IISlnlgal, 01"010. etc., hnt pn,cueillt., fallen intn d,_uw, III rnouldlll.lC' are m ..de mort' cheaply by machinery. PI"'jl!h PI""" {ate } I) ,I u....d fnr fOrmll\,lll/rOOI'C:S ... lIh Ih,., II"rlln from } 10 16 mm wIde. and up 10 j1 mm dcep; Iht .11111"1 .... Iron. se<:ur"d h~' a "edge, panet down 101 nanO\\ mouth III Ih" mt'lll] run""" ""relied 10 Ihe "ock: thr deplh of the grool'e '"~ rt'gulaled by Ihe mtlal thumb- ... ,e" I\hlch dcpr".,u nr mls'os II mn,,1 IOleplecc (nbout 20 mm \lide) \\hich OJ><:r.llu b~-"'cen Ihc runner and "ond fen,e; Ihe .. ood nUll and acrew bars >Ire 1ll1l11ipu(aII'd 10 .ldJuu Ihe I\ldlh ~I\\«n Ih", fen"c ~l'Id Ihe runner I t required; th .. ploUllh IS pro",ded "'Ih Or e'lt'hl Irons of different I' ,dlh,. Rmlftr 0, Old 1I"0...,./n·, Toull, (ke jl).-LHd for mereasln" the deplh of /Crool'n (,.,,,rJ..'W) furm"d prCl'I"u$lI' b~ an<>lner tool; Ihe $lronll:' Iron .. from 3 10 13 mm wide. S".,ltr.hm·r (5CC H) - l'~ed for pL.minff ctrcul.. r work hal'inll' quick eUTle~: thr "on (ICC 0) has ll1n t"perl-d tunp p,,<.ro.ll Ihrouuh the siock; II II :tdju"eJ by lapPinit' ellher ,h ... proJ,-..tlnu ends of Ihe WIIIII 0. thl' bl.,dr (,e.: leCllon "I :'>OJ (Omp"III'I"",.-'i'h,8 I. II ImOOlh",£ pl>lf>e ,,"h II conle~ ""Ie: and So mm ",de double irons for pl~nlllll' l'urn_-d lurlole.,.: II I I nOI much used Too,IIi"l! PIIII.r.-l-Kd fur prep~rinR ~urfK~ of limber "h,eh ~r'" 10 be !tlued lo!C"ther: In 50 Iltm ",41,· ~"'I:1c 11"011 h;l. II 1It'.r.IIM ed,::t·. 1"0"1(""':: ",oJ (;,,,,,,,,"1: P""'~I (ub.o knn\\n liS If/(IuhilfllpolaMI)_ ---l'",d to form tonllues ;rnd ~rO
,Il(
(b) Melal Planes.- \Iost of Ih,- 1,,>0<1 pl~ne. d,.,;cn~d ;,bme are ~I&O obl,un,oble in m"'~1. such ", e.IM 11.'<.·1. anrnmel"l. m"I1""ble i.on or ;llumlrtlum Snme of Ihem Irc ~n tmprOI,m"nl upon th" \\ood pl.lnn. hUI ,h,., ,,0tJd j~ck pbn,· e5pl'C1,,11) IS ~ull eomlurrcd III be thc hrn lor liS purl'''''' ·m.· mel.II pJ.,nca ~re mOre fr~,v:i]e Ih~n th.."c of wood l(rlul S"'w/ll P/trr ,.0 1<1 2~O mOl m I"nl:lh uf 10k "'Ih ,'uU"n f,,,," .11 It'e +4).- ThiJ '. ".~ usd'ul lur ~mall IIork which i. not readily de'H~lble ,,41 for prq"I"rul).: m,\rel "fh"rd"".>d m"uldlnc<; II" IIdl "wled fnr planing a.:ro» II-.t lin in; 'I J-..I~ "nly;o ·';"Ill.· ~o '"m ",d,' ,f'," ·,t ("'.III,·r ",dmrd "I 11 to 20 ; Ihe he,d ,.f t], .·'tIl,·r II upl','n""" T" .,,,.. mol,- !h.· roh,·,·. I]", Iron ('<'I hle-h IlOIlI:I ",.,nlral ~I",IIC plICed ~'n lhe ml.Illl'ro~UlOt: I.. ,-e, co'l' 1I0:r"", ,hr c~p ("h"'h h~ •. _ knu"kle jotnlll~ fillc.-d Ol'n '. 1>nd "h"n n,rree'::' pl.Krd, preuute n" Ihe (,'r $pn-:"•. ~ "",. p<>IlII"n; II-.e cJf,.;.- af lh "uttrr if otnut:hl 1".It;lllrl \I Ilh ·h., ",nulh II>.o.t.·J, " m", ,,:11,'\ t...- I .t ... ml mO''t"menl .,r tho 1..le. and th" dll,an .. e bell"'"n Ih .. edt:t· ,'f ,he ,'utter and lh,' ('''"' "I the mHUlh " r~I!U_ );,t .. d ~~ requlr .. d by ,h,., milled In,"\ Or nut ~ho"n belo .. Iht· "'Icr. Olher Iln"'lel of mtllil planu ,"dud,' Ih t",lh'Il" (Ih" edge ,f the: iron Ii cl05e
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50
. )H£L .. 'IT
SCALES VAMlUl
JOINERY up 10 Iht ,It>~ of fhe plane and .5 then-fon- u""fullo, pl'1M'f11l' >urf'K;n al the tnd~ of .ehal,'" h:tc.) dod the should" pf"lWi"hlCh '5 II foml ot rcbalt' pb"c uKd lor plamng ."halrsm h~rd .... ood ~nd putlcularl} the end~ 01 mrmbru su"h as ,h ... ~houldcn or nuls,. (J) Borin, Tool •. - ·Tha.c mdude the br.ICC and b.I5, aUII"'. RIm! .., and brada.-!.
/JTtlU and H.u (~ 45 10 ~o).- .\ hUll' hold. " cuner or bit uK1' l"1,rioUi pallern. Indude rhe IfnJ' .,,,,/n (8), ,//#·/1 /:,,"'tl (resembletl ~ !fOUge "ith. SCr"" ~OO) and th~ "UK" X,,"I,, "h,ch hoi' ~n ~u~"T<'d .h,'nk R",dm,' (...~;u) The small st~1 bladl' II Ih~rpent'd for makmll o.nl.lll hoi.",
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(4) Impellin. Tool. includc hamml'rI. m.nell, Ierl'"dnH'Tllnd naIl punchu J/nm"'t"J.-That Iho"n aI, I 's callf'd Ih" 11''''''''1(1(>11 hm","t'.; the h".,d (u~u"lly of til.' 11('('1 ","h I temptrf'd facl' .nd pcnl') is "I:dgl'd 10 th~ .haped ~~h Or h.cknq .h"fl; of the man) ~'ze •. that ""th thr hrad "'I:ilth,"!, apprOXlmalcl)· 0·45 I.JI II II..,.t u ...·d for 1I...""rll purJ)05l:'.O The ciaR h",,,,,,u (I.) II made ,,'th hncl. "1-.r.:hlOll frt"'Kll at klllo 0·7 k.w:; Ihe cld'" I. us.rful for In·l:rJOIf back or ""hdu,,inll n"II •. \tufftl (se~ ~ ,) l'Kd for drl\'mlt chlSorls and knO<.klOll (r~OIln" IOQ'l'lh~r; Ihc I~p.:-r~d m"rtl'l' 10 the bn,ch h"..f r"~..,"·I'S the .hlthtly tapl:rl'd a.h or bu~h ~hafl SHtl
Sro,,""t h ..-.: SJ) Thc "'0 lonk... r f'd/l:es Oflh,s [ 6 mm thick "~el plat" Irl' turned Onr to foon a .h/l:ht burr on e~"h "de; It ,. uSt'd On h..d"ood .urfleft to remov\:, mar'" left b) pbnmlt Raft" T"o Itrades of th~ IIN'I h.lf-round ra~p Iho"'n II "J Irt' u.ed 10 prepilre U.lT\f'd 'urf~"I:'; Ihe coal'll: and fine files Ire about :150 and 100 mm Ion. rt'tpttl,,·el),; fl~t ril_p' I.e also obllmllbl...
(;I,IJ!.p"p.," .... 1 .. , "· ..,,,·d ,,, ..J·/'<'f>t""'If. I~ Ih,· tinal .. r....·6~ "pplred I<> "ood surfaces ,III,·, Iho' ~Url",C ha~ be"n pl.,n ..od hI Ihe J.... k, Il"\mll ,md ~mno-thlOl'( plan!:. and scrap<.od, II IS 1...1a .....t (Joi' ..m·rall) ""h Ihe !.!r~m I b, Ihe TllI~ IS a pltte of cork round "hlth IS ".app.:-d ~ plI."'I.eof ·p .• P<'r 'I'hl~" ~ ~tronjol paper. mw ~Ide of "hrch 15 co;oled ,,"h "n .. br,,~"·t:; ,t ,I "bum~bk m 'a.".u, IIr.,d,·, .md UffU~lIv "ppl""tron oft"oor,hrN' of Ihl"n IS ncn·s",,~· b.·fore Ih .. ~url"." I~ ,,,n,pl.·h·d 'Iahot;:an~ .. nJ cnl.. m otht't hard_ ,,<>Ods should Ix: d .. mp.cd "'th., hllk hUI ".lIer and all""cd tu dr" "'·fon: Ihe finer grade of JI~l>I-pap"r IS applied. [h" r",.". Ih,' j,[r.olll "hl~h h." bo:,·n d"pren,od bllhl: coaTSt'r paper (;""dIf,mr-PI,IO" , ... ns. ~hIWI~, ""' h,,'~ tn tW/{Tflund I-ttfore bemR sharpl'n,.! on Ihe ",lstune .\ h"rd Jlr" lion" {I• • arh"rundum "'I""nj,[ 0..1,,,: ., used for Ih,. pUflJOSC Oilslrm" .. nd 11(>).' (~l~). !'here ... ,. ,,· ...·r,,] n"tur"l .",d .lftllltl~1 OIl-Mones and Ihese '·ar), "onSlderahly In de!.!rl'e ul li",·"e"' , "e!l-kn""n '.''''·hO:~ MI' Ihe .\rl.anfhls. C:arborundum. Indl .•. Wdsh,t". ,,,,0.1 Tur~o:' ... Itm 4u"I,I'· ",I ,hou\d Ix usee ",hen marpen'nlf thc luol~ SI'/J SImI' ("l,(, l7) S,m.J,lr II> UlI.wne~ .",d uwd Iur ~hJrpo:"mf,: !.!UU!.!o:iI (6) Cramping and Holding Appliances ",.IudI' T-~Tamps. G-~·umps. b ... nch hold. (asls .. nd mllre hl,,,,,k. T-umll/J Thl~ h .. s ixrn d" ..... h-nl "n p 'Ol .md ,. ~h""" "I I. hr;:. 53; It .. ull':n ~ITh'lr~""lIId p~n,,1 muuld",!.!". "'''. Thl' I.,nl:ch 01 m" ... ldm.: '''' pl.",·d lin Ih,· hlf"k ,,,,h Ihe ml",ldLod f.."" oun, .• rds. tM sa" ,5 pl,........ d III th,· lUI. ,,,,d thl' m"uld"'10( I' ..."", ,"[h Ihe ""fre "uti """"lng U a !.!tI,de ., ",I/Tt /HI, In Ihc 10m, "I a d",,,"d "I(h I"" ~Id" P'~'<:~" hall"l1 n'ru",,1 nlllT., ~'Ub and .ecllr.,.,j 10 a ",~"j IwJ p',·H· I~ .. m" limn u...,d I ... lark.... mOllld,n~ The muuldmg 's pla~ed In 11'1" bo, .md .n",k .. !.!,d I" "'''''''.:1. d", I."..., ... " .. pl .....Td :terou Ihl' hooK and o:nll~"'Cd m t ....· t"u ~h"rt ,ul' .. 'lId ,''', ""1"',, ...... n dooo.n Ih" ",ould,nJl :\ ,,,,'u Itlftpfrl u>o<'t.l 'n trln"'",,!: Ih.· • ul 11111 ..". .. no.! s"_I1~ I'*, Jn~<·"u'·nll~ Iho'" .In· "'['I.lhk ••1 ~uh,no\lally merO: .. <1111: outpU(; whlisl 5OfO\'whm he ........ r th3n "rd"",T\· h'''lol 1",,1 •. p''''''r ",.. IH .ITe e~"I\ h,mdled ,,"h mu~h I,," f~llllu~ tu Ih,' ""l"f~'O' Fath 1'1""'" t.H,I,. ]1r"... "..I.'d \\lIh ,I s",,~h. usually on Ihe hJndll' and Ih"rd!)Tt, ,,"",enlo:nll) ,.pcr~I"" I'"rt"bk I",\\e. tool~ ~hldlv used (or ,~,"..dworkm!.! mdud., .''''' .•. Ind,·r ... $~n·wdr"·.·", h.m'",<'N. pl,u,,,s. d .. 1I5. "tl'. Sume of them ~rr $hown on F'll. bll' P,,~/,rhft Fltrl~'"c S""., Th,·.c ate pro~ld,·d ... "h '-"r"I,,~ hl.d,·. SImIlar 10 tho··~ drscnbed on Chap I. \",,1. III. Iho: ~'II' ... ar~ f"'n, 1 ~o IU JoolIIOl d,.,mo:tt·r ~nd Ih" eorrl:$n"n d,'cp r .., h ... " ,s pro\',df'd ,,,th pondonj,[ cuts Ih4' ,·.m Ix f"","·d ~ro: r. ......, ~o I" 1,,0 handln. one.ol Ihe "'~r .• ",1 "nl' I)f1 Inp Th,' hl ....I<: .. prm,ded "lfh a !{\lard "h,ch Thu~.
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TOO L S co\er.. Ihe leelh, Ihe .... f~,ly of rh" operdlnr .. Ihu,. _u,.~..J. H,I'. U"'iII-Iur .md '1)"11.,1 hl~de. :I re m'cr"h~n~eablc, unJ h"nce ,h., 11101 ~'an h,' u ....·d I". ~nwmg '''Ih ~ml dU"~~ Iht liT"'" as d";red It ,s d"",,ed th~ t II porl~bk de~lru; ~"" "~II ~UI 1"0 lImes Id'in Ih.m Iht ordmal) .....005;1" The rxampk III , " mounle1<>1", d'dmele r, g'nn~ ~ m,,'lmIUlI \<·rll".,1 "UI III' flo mm; mh"r bldd~.. ;or" anllillble, indud n~ .. plan.. r for 'mooJlhon.l( IInlher unJ J sihn>n r .•• bod., .,Ilrn,,¥.· d", (ur UJllmg ~IOO", hlll'k, C,UI Inm. hr"nze .md M,b,.'1vld,..1 ftlr ,h .. o~rah'-C' 10 nUHC' Ih,·,..,w I)"cr 1m, mdle" •• 1 h,·tIIl( I'U! Th.· sol .. pl;"e h", an ~n.:k ;odJunmcnI '0 1/:1"" 1x'\'C'1 cuts ,md another IldjUstlllenl III rq.:ul.'lr Ihe ,·ullin.: (kplh Lndnload. Ih .. blad.. ~"oh'C'~ dl 3.00<> re,,,IUli,,,,. p.'r 'llInuu' w,lh an "'put of '.050 " ... ns, It c~n be fined ""h a jfuidC' 1I11 ....:h,,·d In Ih.· 1',1) ""re"'! ,'" Ih.· ,0;01., pl .. lc fur nppmRlong lenlrth~ o( umber. PlJrl
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The example shown al 3 has a 'p",dl .. spe('d on full load of lf~ re,·olullon. per mlOule "'Ih Mn IOPUI oi 280 ".nl. It hat a reH"lnlls"'lch for "'lhdr~"Iflg IICr .."s Mnd c~n be used for dn\"IflIol ht'.J:aR"'l headed melal serC'I" and nUI$ up to .0 mm dla. It hal 1\\0 ~pe('d. 10 gi"e IhC' corr«1 dnvC' for Ihe dlfferrnl malC'"al" belOl{ drilled Elutrll" Ro/.)oy P",'(IUSIO" DrIll (I« 4), ThIS" ust'd for both nonnal dnlhns: and pt'rcuulve d .. 1111\I{. tilt: t'hangeovtr being made by ~n adjultlOR rmg '" rt. .. front of thC' mach.ne "eill'hll nf ,...1l'"UI\·e dr;"e are pronded 10 fol,ve lilt' corrC'CI "tlghl 10 lUll the parllcular lob WhC're limber fixmgs a~ mlde 10 conerC'le the machinC' enables Ihe corn'C1 IClion 10 be gi"en for dri lling through the wood, and by adjusllng, IUII.l/hl 1010 Ihe concrele which require. percuuive IClion for effieienl drilhng Tht' dnll 15 doublC' ",sulated ro. operator prOI«uon-th,. means Ihll II doe. nOI ~Iy enllrC'ly on earlhlOJt for II' "fety al the" hole of the body •• made of in.ulillng mattnll POltable Elu'rI't PlontT'.-Theae Ire melll pllnea, one Iype hsnnlol a IOle whIch II app rOXlmalely 500 mm by 175 mm Ind a cunmg Iron or cuner blade of 100 mm Wldlh. It hlll"O handl". one near the heel and Ihe olhC'r or prelllure hllnd:e near and above the ~ A IngRer .w,lch " hOUKd .n 1M hftl handl." and Ihe blade IS rndlly adjulled for depth of cut b) meana of a thumb ser.,,, and fixed by a "''''R lock,,'g nUl Thi. eleclrlc planer pbo" un limes .. fall .. Ihe jack plane dncrrbed on p, 126. Por/able 1:'lu/nc Dr.III_-Th~ Ire employed for lorming hoI" (If vary"'g diamelC'rI; like the btKe and bll (p ,d) an 1:leCUK drdl h .. a chuck which lIahtly the bll of .ize and th.pe reqUl~. a secure gnp bema _U~ by rotat"'g the chuck by meanl of a ifni]] key AI m .. nlLoned above. Ihe d,,11 .a UKd for borlOR small dlameler pilot holea for Kre"', but much larger holes can be dTilled Ind, by fixmg. lpeclll.t\achmC'nl, Ihe "ze of hole un be up 10 loommdlatnt'ltr, ThC'lmaUertype i. one -handed bUllaraer doll. ha"e
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o:oJ and ~iJ~ !or two SI<.I ... ) h.lndles and, on add,tlo", Ih" mo .... fJO"".ful tool ,~sullubh d'sh-sh"J)("d on lOp to penni! of br"ast-prcuur... . Th .. ~umple 1It 8 15 " snMII VI:ocral dUly droll ~nd II In" forl'runn.." of thc IU<)I~ dcscnbt-d abo,'c It j, rap.,bll' (If driliong 6,. mm d,~, holes In ~tcd ~nd .6 rnm dIu. hnk~ In hard\\ood; on (ullloo.d thc bit rotutr5 III 1,400 rc .. oIulion~ per mlllUU: ",th.m Input (.f lila ",,,ns \\'h .. o the <;urren! ,~ .,,,!,h,,d on 11 tlows throu~h tnt: coils, !Ie[{lnll" up a maj;l_ nrllr IidJ UIUStnK rOl~t"m uf Ih" urm~lurc "h,eh tr.lnsmll' '" l(... ~r~; Ih,,~c "po:.ule arlin (n. ,-, .. ,J",!! ,ond Jlso a spIndle ""h the aUilehed chuck 'I'h" Jrllll~ ~n "II,nsuJdled modo:l "ml. the.<:for." d, ..... s not rt'l) upon ... arthmg for ~"fd~-, ,h" "h"k bod. bt·tnJ.: of onsulnt"d maler,,,! In ,"0".1 Qrll"rutor (Onl~LI ".Ih any "k~I"G.I p"rt. Th,s ~"lllpkIC """'Iope of InSulal."n '·'''.I''s<:8 ~ sp<:e.al nylon chuck spindle "h,ch lS
" IId" . C"""J~r-"uH,~.J Twl hee II) Thl~" .I perLU""" loul' p""Lr"d by a slnall cartndl(" .·xplus,ve. It L~n bt< used tur att"Lhlnf,l door ,md "mdo" r..unes, baw:ns, pIpes, bntLket~ ;,nd Londu.t Lhp~!U brld, Lonerete and slOnc. It d,mIllJh's Ih., dnlhng of hn1es for these: fiXings and .t Lan .. Iso be u~"d to dn\C fa8temnl1S d'll!
, \t.mur.Rtur~d hI to.IEA-Aku"nll:es ... lt""hafl, Seh,'dll, Wurdr,," Ltd on Ih" Lountry.
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and mark.·ted
CHAPTER. FIVE
ROOF S),f/lJims. III"
COVERINGS
Bnef dCSCrlplH'n of thl"" prq'"r",inn ;1111.1 ch"r.lc'<"rl"ics ,,' ,bin;
~ize.;
lerms;
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hip and ,-.111 ..·,· dl"ud5
Pla;n and in,erlncking
into ("0 or Ihrel." se,-IIOIlS. ~""h nf"hich'5 c"t<"fully_~plit!O form Sbl~5 oflhe requlrcd Ihlt"kn~'''; the ~-h"cl IS dr'ell firmly" dO"rl Ihc Rt~m "and pTls~d ;lfll"r ~~(h suceeSS"l" lap un " un,,1 the ~plil " compiele TIl<" Ih,dmc," of Ih,' ,1~le, "Mil"s ac<:o,.dlll~ In Ih" '1u .• hl\ 'Illd .. ord"r " reqUlremenls. \\'chh ~I." ... s , ..." fHlm 4 10 II mm. and for bcsl qualilY \V"'~lmorlalld slatc, " .. ~ per .10 rom . (c~d" hcrn"" 5 mm 'hKk) r5 prcfcHcd f)rtmllil 's Ihc fi",,1 npl1S11ioo. p);IU'S e:l<"h slale on 1m: ''''/I'nll" or Imrht (~t'., G, Fig (9); Ihl" '!~I~ is hdd ",!h ~n Irregulolt edge o'erhangln!{lh,' cdJo:c of Ih .... lion und a dean ,·dJ!c ;< fonneU "s hl" mnkt,s 1,,0 or three do" n" ard him's wllh Ihe .,",lIttle (sc(' H. Fig. 6
SLATING
Formation. Slale is .J hard. fine-grained sl:dim~ntar} Jrgilbecous (clayey) stonc. Originally, Ihe partidl:s of clay were deposited 1)\ water and suhjl:tled tu vcrli .. ~1 1"r;:~SUIr;: 10 form 5h~k (inunnedialc belween eLl), and sl,'te); thi" was subsequl:ntly changed into !;latc JS ;, result of tremendous lateral pressure and heat. Owinj:!; to the latter action the ,;bte is bminuted, ha\ inj:!; numerous parallel planes of ciCflt'ugC, so that large hlocks arc relldily spht into comparati\eI) thin sheets or larninJe knuwn as slates. The cleavage pbnes are nhliquc to the original hedding or st'dimcnl;lIion planes. Thus at tr.e llonistcr and Yew CraR mine:; (Cumberland) th~ .mgle of the beddinj:!; planes is about 35 . whereas that of th~ d~~\'a~(~ planes is approximalel~ 70 (see A, Fig. 69). Slate is quarried in Wal~s (!'cnrhyn, Dinonlic, Bangor and Ffcstiniog-). Cumberland and \\'estmorland (Honister, Buttennere, elc.). Lancashire (Burlington) and Cornwall (Delabole). 31st) 10 Scotland (Aberdeen, Ar~yll and Pt"rth). Quarrying.~SIa!e
i. Obl~In~t!lrotn l"llhu 0Pl'" qu~rr1Cl1 or mlm's. Thus Ihe Penrhyn. (or Vdmhdhl and Delabnle slale is qu;orril·d. wh,lsl thH from FfUlmloll and Ilonlsl ... r ,g oblamed from undH~round "~\'Crn' "pproochcd by "allenn Cunpo" dcr or p:Cligllll'" 1& used 10 bl~sl Ihe rock and dislod,t;:c huge blocks Qf ~Iale. Convt:rsion.~Afttr Ihl' blocks h,,'"e heen reduced in size by the use of Ihe mailel, chisel. C1C .. 10 pcmlll of their ron,"en;enl remm.,.1 from Ihl" mine or quarry, they arl" tranJiported 1<) the ~,mmill fnr sa"ing, sphllin" and dr~~'In).l. S"'''ng.~A d;amo'ld or o.:ircuhar sa" (see p. 36) IS used 10 d"ide cach hlock InIO Sl"<:I;OnS "hieh arl"" irom 'BO 10 600 mm ",de and up 10 )60 mm Ihick Thl" sa" cutS:1I1 .Hragt: raIl' (\\'eSlmonand "1~1e) <)f 3m per minute SpfitlinlI.- The sa" blocks art: now rt·uu~.-.J to ~!~t.." !lI~h lire .. WUI 15 mm Ih;~k, "nd each ,lab is dl'"lded by hand lab<)ur into Ihm lammal" or slatn A" 'phUff," "'Ih Ihe .1~b reslinR aJ(~in~1 the sid .. of onl' of hiS leJ(s. dr;,"es a chisel into th ... I~b:ll onl"" of Ih .. '3"n ends (sec c, FiR. 69). Thl" chisel u ..... d for \Velsh .Iales has a hT
Sizes. -Sbll"$ "", proouu'd in a large number of s'u.,.; SOm" lJf Ihe la'Rer qUJrrles un be obl~med In no I"ss than th'Tl"-I,,"o 10 200 n11n by zoo mm Common ,izes arc 600 mm to 300 mill, Soo T'"Im by 250 mm, 4So mm by .llS mm and 400 mm by 200 mm; L.rJ(l"r ~nd ~pl'~i~1 517l"' can bt: oblain~·d ~t ~dd,t,onal co,t ThO' WeSlmorland. Cumberland and ;\orlh Lancashire slales are general)" produced m "h;lt arc lennet! " r~nd()m si7.(:~." Random slalts Hl" frolilloo to 600 mm lon~ ~nd are proportIOnate In w,dth, Ihe ~\·er./{t' "id,h helng half ItS length; Ihe,"" Me" s,~.,u" afler ~lnR drcssed. i.t., sorll'd lnt" IIZes 600 to ~oo mm, SOO 10 450 mm ant! 450 to Joo mm lon/{, These ~I'iI" arc usually Ilid In rel/ullir r/,milliJlilll! rlJ"~UJ (sec p (39) for "h,ch mixed Ji~es are requIred. PrXI!.ItJ ar" small-slLed random_.; Ihe<" arc 2~5 II> 300 mm Ion/-! (" besl p~gllin "J and ISO In .lSO mm lonll ("~econd pe).li(;N"l. wllh proportionale "idlh~" ~upply o"cr I"enty ~nd Ihe B~nJ(or slale~ ~Iand •• rd ~;Zl"1 var~-mg from f>oo by 350 mm
, Sel' p, 68. Felt ~nd lead {o,"ermg fnr fbI roofs " dOlCn~ On pp. 70 'Ind '48 resp~cli,dy. P.nt;I.... , Itahan and Spam.h tiling. 510n .. slallng. sh,"~I .... , eoppe' lind zinc eo\'enngs. nbestot 5h~u and thatch lITe descrlbcd In V,,1. III L.:hl"l:"ight Inetal and asbesto. she-e.;nlfl and deckingt arc Included in Vol. IV.
In add,l;on II> c!a,,,f\'inj( sldl~s according 10 Size, Ihey arc d;\·,dcd into three or mo~ gnod"s kno\\o as" \.Iuahlics," i.t._ .. firs15 ,. (or" bests ")." seconds" and" Ihlrds" :\~ ~ rule. Ihese lerms r.. fer to rhickness only and nOI to ".Iue. for, m cert~m quanie .... bt'~1 .,
'3'
ROOF COVERINGS
13 2
TOOLS {., PREPARATION OF SLATES
'ii ,/ly Jla/n ~rc \\'c I5h .Iales "h,eh nm~ III .,7.., from 600 mm by 360 mm to JOO mm mm ~nJ are w Id br" count," ....,., per thousand Qw" n .Iak. arc Welsh sillin "h,ch arC from 600 to 900 mm (increasinl/:" by So mm) lo n l( and are sold by ,..rll(ht.' by
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•
20Q
Characteristics.-<\ good slate should be hard, tough and durable, of rough tc\ture, ring bell-like when struck, not split when holed or dressed, practically non-absorbent and of a satisfactory colour. Those which feel greasy art" ,l!cncrally of inferior quality and any showing white patches or marcasite (iron pyrites) decay readily, especially if subjected to a smoky atmosphere; patches of lime also adversely affect durability . When left immersed in water to half its height for twelve hours, the waterline on the slate should not be more than 3 mm above the level of the water in Ihe \·essel. In slatts of poor quality, the water IS readily absorbed and rises se\'era\ inches up the slate; such slates are easily destroyed by frost action (due to the absorhed water freezing and disintegrating the slate). If a dry slate is kept in water which is kept boiling for forty-eight hours, its increase in weight should not exceed 0·3 per cent., and if a spceimen of slate is immersed for ten days in a solution of sulphuric acid it should not show any signs of flaking or softcning. 2 In general, Welsh slates are blue and Westmorland slates are green, but there are certain exceptions to this. Thus Bangor (Carnarvon) slates vary from blue, blue-purple and purple; Dinorwic or Velinhelli (Llanberis, North Wales) slates vary from red (maroon), blue-grey, green and wrinkled (purple with green markings and slightly furrowed surface) or mottled (blue-grey with rather indefinite green markings); Penrhyn (Bethesda, North Wales) slates, similar to Dinorwic; Festiniog or Portmadoc (Wales) slates, uniform blue-grC'y; Vronlog (North Wales) slates, various shades of green and grey; Precelly (South Wales) slates, green, grey and khaki. Westmorland slates include those quarried in Cumberland lind North Lancashire as well as Westmorland; those from Buttermere, Coniston, Elterwater, Kentmere and Tilberthwaite are of various textures and many shades of green; most are light green, others are a darker green (olive) and at least one is grey-green; those from the Burlington Qt:arries (Kirkby-in-Furness) are dark blue in colour; Cornish (Delabole) slates are green, grey-green, green and rustic red. Some of the Wrlsh slates
,.
~Imil.
SCAUS:.....wous . UAWIO fIIMlJdIiC:IM:
QI'\/IH
FIGURE
I'l9
I The practice of wmg the follo ..... mg lemu when ,pcclfymg s lales SHOUW 1If. D1SCOUIl.o.GEJ) n, ..... ith few exceptions, they are not nO\\ used in the trade, i.e., " smalls" (Joo mm by 150 nun), .. doubles" (JJo mm by 165 mm ), ., lad,es "(400 mm by 200 nun or 400 mm by 250 mm), .. countessn" (500 mm by 250 mm), "duchnsn" (600 mm by JOO nun), etc. I B.S. 680 for Roofinl Slates lIVe. full details of these
,es...
I SLATES are very duf'2h&l:, whilst the best Westmorland slates are practically indestructiMe; the attrw::tive (lI)loun and coarse texture (with apalled edp) increase the artistic merit of the latter alatea. ~ti_ 01. Slare. _ Site _ in Slaler', Va1'd..-Thi• ...,.,.,11. of holinlf and cultin, the ,lata to vanou. wpn md liza. With the C1ceprion of """II random, (neb of whICh nuly be .ecured at the heed by one .,.,il oniy), each elale II lixed 10 the roof" hy two .,.,il. (_ p. 13..). Thil hobng iI done by the ,I,ter either by (/I) hind punehinK or (b) machine drillina:. (.) HMd PIu.dIi...-Tbe poJItlon or the holel i, marked on the .Iate by. ,/llIIle diclc or _tlttl, thil ill a piece of I,th through which two naia. are driven It • dittance apan equal to that between the bottom or tid of the alate and the centres of the nail hotel. The ~, -..: oc ~ (_ J, Fi,. 69) i, uKd to punch each hole by .trikin, the alate with the .pike. The.mooth or bed ,Uirace of the elite ,. uppennoat when it is bet". holed .a thlt whoen the ,pike penetrate!! the ,lite "",,11 piece..rc bunt off round the null,;n and on Ihe uoderJlde to fonn , rough irnlulu c;ourlteninking of the hole; .. the 'latet arc /i.",ed on the roor WIth the .urfaee h.lvlnl the rough edges uppennoat the head. of the n.,l. an be
driven in Awh with the eurface bec:ause of thil counter.inki",: otherwile tM head. would project to cause " ndlng " of the alate. lbove them and thill would admit nin or .now. ~b) M4dn1N Dril/....- Th,.,. perlonned by the portable slate 1toIdi• ...at/UM Ihown at 1'01, Fi,. 69 which an be bolted to, bench or clamped to a plank. Mtff the mKhlne has been cl.mped I bock ,. fUed on the plank on each auk of the midline and at the c:orreet diannce from it, the di'lInc:e betw~ the bncb betn, equal to w lenJlh of the elate; the alate i. pla«d betv.'etfl the bncka, with the: .mooth .urflK% uppcnnoat Ind one edge .pil'l,t the pille .howI'I m the sketch and which i, 3. mm from the po,nt of the dnll; _the hal'ldle ,. "vero I partial tum, the dnll detCtl'ldl Il'Id puncturet the alate, the POll'lt ,. w,th· drawn by revening the ha",,!le, the "!"'e i. removed and rcpla«d w"h the end. rcveraed (but with the smooth .urfla .t,1I uppcnnoet) . 1'1<1 the wcond hole ,I drilled. Thi. i. I much qu,cker procell than hand punchlnllnd i, 1_ li.ble to crack the ,llta. A cwtt•• innt, dot or drtu, .. ,roll (tee III) I. used ,"",hen ,Iatet h.lve to be cut to cen.in • iza or ahl,ptl on the job ; II II oftero UKd on the roof, the a1lteT drivinl the potnted ends uuo I spar or otbet convenient mem~r. After bell'lnulrited to the: reqUired wpc, the alate " placed on tbe iror'l with w edge to be cut projt<:lmg the r~ql"red amount, and I (ev.' sman blo,"", wllh the pe neatly tnm off the edge. The Iw",,,"~, picll or /l«1c
133
made o( ahtimony, Ie.d and tin or copper and zinc, and are harder than copper nail.. Aluminium alloy nails are also used in good work. Galvanized wrought iron nails (see D) and zinc nails are orten used for cheaper work, but they are unsuitable for industrial and coastal districts. The former arc invariably u$Cd for good work for fixing laths to the spara as the zinc covering offers a protection againat corrqsion. Naill arc specified according to length and weight, the size depending upon the thickness of the Ilates, and the length should equal twice the thickness o( the Ilates plul 2S rnmi if too small, "tight nailing" results, and this may cause damage to the holes and ultimate cracking of the slates. The following gives suitable length.! and weights o( nails ; -
TABLB VII QualIty of SllIet (Re p. IJI)
........ Beat
01"
medIum • .
Rlndom.
l...math (mm) J'
""
Coppcc or ZII'IC (per 1,000) (lo,) 1 ' 27
3' 18 .. ·.5 4
Compoeition (per 1,000) (lo,)
.... a'95
5'-45
Galvanized Wrought Iron (Gauge) th,ckl'l_ (~)
.., J.J J.'
Sometimes 32 mm nail. weighing 1·8 kg (copper) or 2'3 kg (COIJlPO) per 1,000 are used for thin small slates. TERMS.- Variow terms used in slatillg Ire ; Batk.- The upper and rough surface of a s1ate (sec 0, Fig. '9). Bed.-The under and smooth surface. lleQd.- The upper edgt: (see 0). TQi/. - The lower edge (sec 0) COlUse.-A rOw or layer of slates (sec A, Fig. 70); the couraea are equal when the .Iates are of uniform size but vary (rom a maximum at the eaves· to a minimum at the ridge when random. are used to form di,.inishing COIlTSts (lee p. IH, and I, Fig. 71). BmuI.-The arnngement of slates whereby the edge joints between the slates in anyone course are in or ncar to the centre o( the slates immediately above and below them, When the slate. are o( uniform size the edge joints Ihould run in straight lines from eaves to ridge-" keeping the perpends " (_ A, Fig. 70). Thisil accomplilhed by uling a wide lLate, called, slate Qttd Q Judi, or a hal( slate (in inferior work only) at the beginning of every alternate course. But such mechanical neatncu il not ,Iways desirable, especially if Westmorland or Cornish randoms or peggies are laid with diminishing courses, when a Ilight deviation (rom straight lines results in a more pil~.. ing appearance (lee J, Fig. 70, and!, Fig. 71). Pitch h.. been referred to on p. 64), and the minimum pitch for " large,"
ROOF COVERINGS
134
.. ordinary .. and .. small" sizes of slates 1$ ltat~d. Comparatively large slates should be uaed on roo& of about 300 pitch. On steeply pitched roofs most of the weight of the slates is carried by the nails and therefore the alates should be small and these should be secured with stout nails. Hence the .tec~r the pitch the smaller the ,Iatea. lAp is the amount which the tail of one slate cove'rl the head of that in the course next but Ollt to it; this applies to centre-nailed slates (see below). When the slates art: head-nailed (see below) the lap is melUlured from the ctntre of the nail hole instead of the head. As shown in the various details in Fig. 71, there are THR£E tlrjclmnm of datu at the lap. The amount of lap varies y,ith the pitch and degree of exposure of the roof; thus for roofs with 300 to +s' pitch, the lap should be 76 mm; for stttper pitches thr lap may be reduced to ~ mm; for flatler pitches than 30" the lap should be increased'o IJO mm to loomm , and in exposed positions (such as on lhe coast) " lap of I So mm may be necesllllry. GQug~ is the distance between the nails measured up the slope of the roof (which is the same as the distance between the tails of each successi\'e course). The gauge depends upon (I) the length of slate, (2) the amount of lap, and (3) the method of nailing, I.r" centre nailing or head nailing. Centre-nailed Slates (see A and c, Fig. 71). -The gauge equals length of slate-lap, thus for a roof covered with 460 mm by 230 mm s!.ues and
,
60 6mm 1&1"d" With a 76 mm lap, the gauge _4. -7 _. ...
,
192
mm, T he position
0
r
'!he nail holes measured from the tail of the slate is shown at P, Fig. 6cJ, and equals the gauge, plus the lap, plus a clearance of 13 mm; the dearanee is necessary to allow the nails when being driven to clear the heads of the slates in the COUTU bylow. Head-nailed Slates (see E, rand G. Fijo':. 71).- -The hAes are pierced 26 mill from the head (see 0, Fig. 69) and, as mentioned alxwe, the lap is measured from length of slate-(Iap + 26 mm); the centre of the hole. Hence the gauge elluals _. =-"-"'''::-''''-
,
thus the gauge for 460 mm by 230 rum slates with a 76 mm
460 mm-(76 +26 mm) -
,
la~
""
""179 mm .
In both centre and head nailing the holes are approximately 32 mm from the edges. Comparison between Head- and Centre-Nailed Slates.· Head-nailed slates offer a better protection to the holes as there are two thicknesses of slate~ onr ",ch. They are not readily damaged or strained when being nailed as they have a solid bearing in the form of battens or boards. Their tails are more readily lifted h;.r a hi~h. wind owing to their big leverag~; this allows rain and snow to blow betwttn them and the ucessi~ mO"'ement of the sbtes may gradually damage and increase the size of th~ holes until the slates Ire 1\tlmately
displaced and blown off; hence lar~ slates should not be head-nailed, especially in expoeed positions. More head-nailed slates are required to cover a roof on account of the reduced gauge and therefore this method is more expensive than centre nailing. Centre·nailed slates are leas likely to be stripped because of the reduced leverage, and for the'same reason, there is less likelihood of drifting snow and rain finding access. Large slates should always be centre·nailed to give greata rigidity. Less slatea are required and the method is therefore more economical than head·nailing. Defective slates are more readily removed. There is greater likelihood of rain entering the nail holes if any of the slates above them are cracked and if the roof has a flat pitch, as there is only one thickness of slates over the nail holes. There is a risk of the slates being strained and sometimes cracked (which cracks may not open until later) by careless nailing owing to th," IIpace between the middle of centre·nailed slates and the battens or boarding below, and especially over the inter.;ection betwttn sprockets and spars (see c, Fig. 71). Centre nailing is morC' common than head nailing. Dbninishing Course Work.-The roof consists of randoms which are laid in diminishing C')urses from a ma_'IOimum at the eaves to a minimum at the ridge. The slates are sorted to give carefully graded courses, those in each course being of the same sixc; thus a large roof may have 610 mm or longer slates at the eaves and peggiea at the ridge. The gauge ,"aries with each coune or every second course, but the lap is uniform thrtlllghout. A very pleasing appearance results, and as shown at J, Fig. 70 the bond is irregular. The method of determining the gauge is explained on p. 139 (see also E, Fig. 71). Margin is the exposed portion of a slate and equals th ~ gauge multiplied hy the width (see A and D, Fig. 70). Boording or Closr Shuttr.g (see p. 69).-The wual thickness is 2S mm (nominal); it should be tongued and grooved although shot or butt jointing is Ukd for cheap IJpeculati\'e work. As detcribed below, the boarding should he c.wered with felt before the slates are fixed. Boarding is sumetimes referred to as sarking, although this term is more often applied to felting. Statlff/! 8Qttnu or LAths.-These should be sound, sawn redwood and of the following llizes: 38 mm by 19 mm for small slates 400 mm long and down~ wards, So mm by 19 mm for ligbt slates 460 mm long and upwards, and 50 mm by 2S mm for heavy slates +60 mm long and upwards. They are fixed to tne boardmg or dirtttly to the spars, to the: re:ljui,ed g-augc: apart by gtalvlln'ud ",rought iron nails which are usually +4 mm long. They are sometimes creo· I()ted for preservation. (.vlmttr·/Jottnu as shown at D, Fig. 70 and G, Fi~. lire also used; these are generally 50 mm by H) 'TIm, spaced at 400 mm centr('1l (or equal to the distance apan of the spars) and secured with JIl mm galvanized wmucht iron na,ls. TiltillJ.: Filltts 0' Sprj1lging Pitcts.-These are triangular or tapered piec" of wood. from 75 10 150 mm wide and up to 75 mm thick, used at the eaves (~ Fig. 71) to tilt the lower COUBel of slates in order to usiat in excluding rain and
,I
H
SLATING snow by ensuring dose Jointl at the laill. These are often omitted if fa1\(;\.boards are used (see Y, Fig. 36). They are also used at chimney st:l.cks, ctc .. which penetrau: a roof, 10 caUM: waler to f;all a\o,ay 4U1d.ly from the ,"crltcal surface... Damp Proofin g.-Pro\'ision must be made 10 e'l:dude r,un and sno~ \o\hit:h may be blo~n up bet~eell the slales alld to prcvenl Ihe entrance of ~aler hy capillary attrat:tion. Such Indudes either (Q) c()\cnnJ{ Ihe buardin~ or lipars ",ith felt or :.imil.ar malenal, ~hu.:h is the mO!.1 USLa.t1 syslcm. or (6) lon:hing the underside of the slates. (a) Roofi"1! Ftlt.- ThiS is Similar to bUI thmner th,," Ihc fihrous asphalt or bituminous felt descnbed on p, 17 and is oiJtainJhlc 111 Roo or 900 mm Wille rolls, It is either laid upon the boardm,:: With the Joints runnin,R from ea\es 10 rid~e II( parodlel to the ridge. or, for du:.tpcr \\Ork, the hl/,mlin,:: IS flm;lIed and Ihc lell (called un/torohlt Itll, bceolusc uf its wughne:.s. tlllc t (0< dl!ut n;lib ") dlrel't II! Ih,· 'plUS. The former is sho .... n iit d. Fig. iO. and th" IJltcr JI A. Fig. -;1. Tltc joints are I.lpped So to 75 min in e.ldl C.l'>C, .md It 5h,)uld he lapp,'d O\Ct th" ridRe. The edgc of the felt IS dOUI-Il,lIlcd to Ihe hll.udmJ! ncr\, 7_, mill or to each spar when laid directty over tht'm. (h) Tr,rchml: ur l'u",11II1: or TIFrlmi. (;I)I!lilime murtar. III \Ihil'h de.tn hill!.: o.\·hair has hcen added UI increase its alon~ the uppcr cdJ,:!c of c.H;h crus,> batt'_'n; thi" I1M!cr;,,1 should he .... dl pressed in het\lt:ell thc shllcs ;IInl thc mort;!r tillch ~pLI~'cd olT (~"c n. Fig. ]1-1). ('(Jmparin~ the t~o methous 1-"<':\1111': .111<)\1'> Air to enlcr and l'in:ulate und.:· Ihc slolte5 and round Ihe bJtlt:n~. ;1 r"JIIH'l' .. ht'al Il)s,>,'~ .. (the Ir.iIlSffiN.lOm of heat dnd cold throu/o!h Ihe TIll/f). II I~ l'.:~d~ ti""d, hUI I~ morc c"pcnsiH' t!un torching. 'i'on:hinJ,:. prt:\cnt~ \cnlibl;ull. d!HI 10 pmlonged \\tl wcalhcr II rcu.ins moisture whll'h mn Ill.' Iranl'm;III'" to the allpn'nt h;II1I'n1\ and roof mcmhers and set up dt"l·a~. 111 cours.: of tlln" H,:fl'nOl mJtcn.11 dl·ICrlllr.Uc:s and drops off le:l.\in~ gaps through \\hich ram .m.! SIIO\\ may cntcr; If h"\Il'\':' hest materia\~ :md .... orkman~hil' ,Irc JPplled. Ihis m("thml enslin's ;1 .. drop-dn' .. root, as is t"\idcnced b\ Ihe thous.lnus of ruufs Iha: h.11l ht·u, Ikill \Iilh IIi tlllS manner and haH; rt'm~incd .... JIt:rlll!hl and 10 RooJ om.iiti"n for a IOil).! pl"rI. Special Slates. ~~':'hJl (;I~CI .ban thOIo" of 1\11;111.11 J;i/(' Jlld \>h.lllt: .Ill re'IIl'" u in order to m .. ",t'lIl1 !.:orr,,!.:t honJ and lllnform to I>hal"l''> \\h,,11 .Ill' m'·'~ ~~':.s ;rrq.:ular. T~ey :ndudc those 11~{,1'oSan to form tlw h"ttom co,,·, .. I 11.", " ... ~b, tI,c tvp lO'HIoe .. 1 thc rid~e. \er~es, hips Jml \.Illl'~s. f)"lIhi, Eat,tJ ('()UTlf;" Slaf,I (see 1-"11:_ j I). :\ douhk (Olini(' flf ~ldll'S I.. 101,.1 at th. ea\'e$, ot"~r\o\' 5C • a~n would ("nter between I~,e -"u~e )inU. '1'1,,,, lirs-I I.• ~tr
135
of slales (or " doubhn~ course ") is compar.llivdy thort and e:qual in length to Ihe gUlIgt plus lap ( .... hen centre:-nailed-see A) and gIJugt plus IIJp plus 26 mm ( .... hen hcad-naile:d- -l>(:e (;). The: practice which is sometimes adopted, of laying the: normal s;ud slates It:n!llh .... ise to form thiS COUTU, is not advocated IS Ihere is OJ ri5k of some of the end Jomts coinciding with the edge jomts of Ihe COurse alx)\e. 'l'up Rld.t:t ("/lUfU Sialts. These are aboul 50 mm longer than Ihe bottom duuhlinJ:: C;1\elo ((mrS(: s12tcs in order to le2\-(" a soitahle marj::'in below Ihe winJ2' of Ihc TIIJ~c tIle (!'oce A. Fi~. 71), '-tf,!!' Slaln,-As Illt:lltil!ned on p. I]]. either a special slate called a" slate :l!lll J h.tIf" or ,! hollf slJte is used at each allcrnate Course III order to glH' corn'ct hondo A ~l.l\l· :l11d J half, ;,IS is implied. is une and a half times the normal .... iuth. thlh lIS SII" .... 111 he 520 mm by .190 mOl if 520 mm by 260 mm slales ;,Irt' il(·m.: u~,'J, ..\ \"r~l' is a \ulnt'Tahle pari of a roof. And these wide slall·S. \\hen ".u,:h I:!' !;c'-'Hl'd l\lIh al k,iSI 1.... 0 nails. 1(111: a much ~Iron,-!:er I<)h than dl) half ~1.11t·S t:a!.:h II!' II hich m;i\ hl' secured \\ Ilh one n~il olll~. J"hr ,lpplic.lILO!l IIf t!u.:S<.: \\ ldc \Ulf)l',, .mil eMh,,> u~u.dl~ furlllnllrlllll.1 slale and a half Ihp sl.1t~ arc sho\\n ,1\ C;. hI!. 6j. ami \.tlle~ "bll''> ijTJ· ~1l1l!\;1r. Open or Spaced Slating.-Hooj,> of temporar~ and .:"rlain larm hUildincs. "t..: mi1\ hc 1'U\l'Tl,d ·.I1lh ,101 It:'> whllh arc \;lid \\Ilh a "rdt:e fr(.m .\)0; III 75 !lun hll\ll'"n 'he sl"pl1ll! nlL!l" \\'hlbt Ihis m"'hnd re'>lIit:. in dn CtllT!nm\ 01 m.llen.ll. il ducl' nlll ~1\ l' .1 "llrop-dr~ ff>of. and I'> nl)\1 !;t:ldom used, . Ridges. S\;ued roof~ Ji'l' tini'>hed .11 tht: nd,-!:cs with shaped pieet:s nudc ill .IJtc. lile. '1"1It: and \to,HL ,',;/lIf. RId::,. (~,." E. h~~. il) .• r" fllr11l""j in 1\\11 PI"Cl''', ca(h fr"lIl 10 to 20 mm thld•.10..1 up to .• b"UI .. 60 111m loni!. tlnc !s a r1.l111 rlTIJlll.':ular II IIlI;! holnl fur '><.:fl·\I<; .mu Ih" Ifllwr I~;J 17~ ur 1,0 nHn \\Ilk \\111L! \\llh a ,01060 mOl roll (hird~m"\llh",1 h(11l'.lIh) 11I1fkni nn -lllf tnp nlc" \s ~hl"\n. tilt, lelp eJ~c of th" \\n.d ndl.:'l' is c·h:Hnl<.:rni JlIJ 1~ lhuul .,1) mill .Ihon: thc l'-llf"n~; Ihe pLoin \1111.:: h bedded ill lIIurt,lr un Ih" 1"1' ~'UlIr"t' "I' "late" .Inti \ nr t'oppl"f "'nt'\\s; lil<" r,,1Icd 111IlL! is j,{'chkd tm thl' ~Iatcl> .l1Id "'" tiu\(,I' cdL!" "f till p1.I!Il \\in\!. III ,Iuditi"n. 1!1I :',;nt hel\\"':11 l'Jlil roll snliun I, "n'l/td \\1111 .1 ""pper or ~nl.lll ... 1.11l· .1"\Il'1 Thl' lomb of JIll" TIde" sh'nlld .. hnJ1.. I,!!n! .. \\il" Iht: lOp 1"lCIr"l' ,'f ,,111\'~ Thl~ fldc" I~ n"l r 1\'1/ mUl'h u'>ctl. ":,,,,'Ih un .Illlllillt of ils irulllfcfl'Il1 ,!ppCJr.II1H· 'III., Hid::,. ,In 1I1.,Jt· of .-1.1\. mould",1 tn;, \-.lril·11 of !'.!IIu , ... lind klln·hurnt Tltl' h"lf-I ,OJ.I rilk: Id •.-l",\\r. .11 .\, 1'1';_;1 allJ tht' h,,~'-ha"k ri.1!.:t: il1ll>lrolt.-.! II CO. he:- ';"1 ,11~d OIl ii, II!.:. -2 J:: 01 I- sl., .. lur) h~ll'n. ""'f.ldnlllu 11;/"'11 "I/"flIIS Ihal ,.f ,h, ,I"fl". tt~e~ ;ITt· 11.11· III ,I, !"I1r k"J.:'hs, tl'I' \\ld'h \.!TI"~ fll'111 ~30 I" .i!Ho 1I1In .l1ld th~ d,!,1..n~'~s 1"[10111 I. ~~ lUll! . .-\ \' rld l n.I\'llIe 0\ f\al'l'l'd "I n·h.llc:d Iflinl.'~ ~hll\\n;ll '-. i"1.L:' ;0: 111111 i~ =2 mm thlt1.. ,"" Iht' ".nlCs .hould "l('1 he 1, $ Ihm 17.:; mm~ Iho; anglc" :-.Ie~ Ilhe \\;n;,:" \'.11
r.,,';
SLATING DETAILS
SII.H(l-t OF "IDGEIN OHAtl "Go
"G.,I
FtC1Rf: 70
to suit the pitch of the roof. As shown, the riJg~ are bedded and poilll:ed in cement mortar which is preferahly waterprooft:d, and the In.nSH':r5e joil'lls are
slated roof, and 3re commonly employed in Yorkshire and the Cotswold district ...-here compar,lIi\ely thid. slates from local stone form the covering material. uod RiJ~s .Ire described on pp. 148 and 150. These form a suitable finish if Welsh silltes are used, but the lead is apt to stain certain green slates. Hips a~ finished with either half-round or V-shaped tiles, sawn stone, lead, nr cut and mitred ..loitcs with lead soakers. TiJ,J /lips (see 1\ and K, Fig. 70) are commonly employed, and whilst they pro\'Kle II sound finish, the appearance is far from pleasin~, "-pccially if the roofs are small. As st )wn at K. the tops of the jack rafters finish lc\"et with the top of the hip rafter, the ends nf the battens are brouf!:ht oyer it and the slates ITe rouJ!:hly mitred. A hip hook should be screwed to the back and at the foot of the hip r..ftcr to prc\cnt the tiles from shpping (ace II). Hip tiles, like those for ridgcs, should be: of a satisfactory colour. Sav:-n Stont /lips 3Te formed of pic<:es of similar tection to that shown al B, Fi~. 70; tht: dihedr,lll an~le between the win~s should conform with that of the
formed of the ume material. It ;1 nOI ",i.e to bed the ndR" solidi) '\lIn morUl~ 'IS ,h., h;11 b.",," Ihe ...... u,., of wood ridf[n ~conllnll defecm'e on Kcounl of lilT bclnfl r.u'ludt:d . \,",;I~I the flanged jo,nl II C IS effectiH: ~nd _ oftm ....:I, •• dpl"S re~ of t:hnc ptn:t', n" unllJl;:hlly Ind the •• mple bun JQon! " pt"f~",u The hOlm Jl;:I\n ;0 "1I1irnlR:ht J'lb If formw '"Ih I/UOd maten:"! lind np«ulh ,I II ~u· IS ..-r1rd undn eKn }OInt ,l.h"rnlt...e:). (('n'lln m.okn of nd~ Ilk I'" oblillorl"bk "'~"mlli mleTTllll &lORn> and these pro,"idt • sound juinl Ind. ndRt' \\lIh In u ... nleT~1td outlUlC, The .p~r. IIn~e of the ridl/II: i. ImpH"ed .f the: t'kI one or 1\\0 IU'e 1I\1:n I allIIN lilt up" .. rd .. ;'s ~ho" n lind J. F;jI. 70 The-wend p,ce" ,.,.., .. soltd rrded."
II, ,.
',C<:"
Ridge tiles can he obtained In se\'(~ral colours and they should therefore he can:full), selected to h3rmoruze \\ith the: slating. Ston~ RiJXts (see 1'1, Fi~. 70) are sa"n out of the solid. They arc from 230 to 150 mm wide, about 38 mm thick, and from 300 to 900 mm long. The joints ar~ rebated in ~ ,,-ork (ICC sketch) and the pieces are ht:dded, jointed Ind pointed in cement mortar. They pro\-ide an effective fini~h to a Westmorland
TOUf.
1]6
SLATING uad Hips are described on p. 1 SO.
Cut and Mitred Hips with Lead Soams provide the best finish to a slated roof; the method is sound, especially for pitches not less than .;s", Ind the appearance is effective (see 1, Fig. 70). The construction is shown in the ~ction at f and the plan at c; it is customary to provide two 100 mm wide hip boards (which are mitred over the hip rafter) to form a good bearing for the slates and a fixing for the soakers, against which the ends of the battens are butt jointed; alternatively, the top edge of the hip rafter may he bevelled and finished level with the top of the battens which mitre ag::linst the rafter. Both methods provide a true line up the hip rafter to which the edges of the slates are cut. Wide slates (slate and a half) an~ used and these must be carefully cut and mitred as shown. uad soakers (see p. 143) are placed between the slates; as shown at G{tnese soakers are square, measuring from 300 to 360 mm across the diagonals (depending upon the size of the slates); each soaker is bent over the upper edges of each pair of mitred slates and twice nailed 10 the hip boards; the soakers Jap each other at each course. The mitred slates must be securely nailed (especially in exposed positions) otherwise they are liable to be stripped by strong winds. Valleys.~It is customary to form" open" valleys in stated roofs. These are covered with lead and their construction is described on p. 150 and shown at P, Fig. 75. An alternative and suitable finish is provided by cut and mitred slates with soakers as described above. Another very effective, but expensive, finish is the" swept valley"; the sharp angle at the valley is blocked out by meanli of a 250 or 300 mm hy 25 mm l:-oard which is fixed above the valley.rafter. and this makes it possible for each course of slates in the adjacent roof surfaces to be uninterrupted at the valley, as the slates are continued round to form a series of curved or swept courses. The slates forming the valley are cut and packed underneath as required. As swept valleys are more often formed on roofs which are covered with plain tiles, a full description of this finish is given in Chap. Ill, Vol. Ill. Verges.-One of se~eral methods of finishing at \'erges is shown at II and E, Fig. 70. For the reason stated on p. '35, a slate and a half should be used at each alternate course. The slates project as shown, and in order to direct the water from the edge and prevent it from running down the face of the gable wall, the outer slates of each course are slightly tilted upwards. This titt is formed by bedding a course of butt-jointed slales (called an underclQilk) on the wall in cement mortar, and the ends of the battens are laid on this course. After the slating has beer. completed. the open edge is well filled in with cement mortar and neatly pointed, as shown . The undercloak may consist of a double layer of slates. Preparation of Roofs for Slating.- The groundworit may consist of either(o) horizontal slating battens only, (b) boarding and felting, (c}boarding, felt and slating bat:ens or (d) boarding, felt, counter-battens and slating ballens. (a) Horizontal Slating or CrOff Battens (see D, Fig. 38, A, Fig. 71, and
'37
Fig. 72).-This is the most common method as it is the cheapest. It is quite satisfactory and a drop-dry roof is assured provided either felt or torcb.ing (as described on p. 135) is applied to prevent the access of rain, snow, wind and dust. (b) Boarding and Felting (sec wand x, Fig. 36, and F, Fig. 71).-The boarding (described on p. 13;) is nailed to the spars and then coveted with felt (see p. 135). This provides II drop-dry and draught proof roof, although dampness has been caused through the penetration of water through the nail holes. Heat is less readily transmitted Itlrough this roof than that described at (a) and therefore rooms which are partly in such a roof are relatively warmer in winter and cooler in summer. (See also p. 1;1.) (c) Boarding, Felt and Slating Battens (see c, Fig. 71).-The boarding is fixed, felt is nailed to it, and the cross-battens are then fixed to the required gauge to receive the slates. Although expensi-ve it is not a satisfactory method, as any rain or snow blown up between the slates lodges on the upper edges of th~ cross battens causing, in some cases, a rapid decay of the battens. (d) Boarding, Felt, Counter-ballms and Slating Ballens.-This is undoubtedly the best method and is adopted in first-class work (see D, Fig. 70 and G, Fig. 71). After the boarding and felt have been fixed, So mm by 19 mm counter-battens are nailed running from eaves to ridge at the same distance apart as the spars; the slating battens are nailed to them at the gauge apart and the slates are secured to them. Any driven rain and melted snow gaining access pass down between the counter-battens to the free outlet at the eaves. Besides providing a perfectly drop-dry roof, heat losses 3re reduced to a minimum and this construction is therefore very suitahle for opcn roof!! !!llch as are rl'quired for churches. public halls, etc., in addition to domestic'buildings where the expense is not prohibiti\·e. (See also p. 141.) Certain of the details in Fig. 71 not already referred to are described below. Centre-nailed Slating.-This is illustrated at A and c, Fig. 71. Detail A.-See p. 74 for the construction of the eaves and this page for the groundwork An additional top batten is provided at the ridge so as to tilt the ridge cOllrse, otherwise the tails of the short slates comprising the ridge course would ride on the course below. Nou that there are THREE thicknesses of slates at each lap. Students in examinations Jrequmtly make the mistake oj showing only two thicknesses at the lap u:lth ont t"ickness betwten laps; this of course affords no protection at the side joints. The double eaves course projects 38 to 50 mm beyond the tilting tillet and the felt overlaps the edge of the gutter. Detail C. ' The sprocketed ea\'es has been referred to on p. 74 and the groundwork on this page. The distance between the slates at the junction between the sprocket and spar is rather excessive; this would be reduced if smaller slates (say ~oo mm by 200 mm) were used as the sweep would then be more gradual. Head-nailed Slating. E:o:amples are sho"n at F" and G, Fig. 71. Detail F.- The prOjecting ends of the spars are cut as shown and an asbestos gutter is fixed to them.
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The close borording and felt have betn previously de.cnbed. lktail G.-The Iprocketed caves i. aimilar to that detCribed on p. 14, except that the inclination of the apars Ind sprockets art soo and 300 r~pec· lively and the projection is only 2)0 mm; the ground ....-ork i. described on p. 137. The space between the slates over the intCBeCtion of the spars and .prock-cts is wide but not 10 serious IS the defect purposely shown at c (already referred to), as the slates. being head.nailed, are not 10 liable to be damaged whilst being nailed; this space would be reduced if the sprockets were given I steeper pitch, and auention is drawn to the gradual sweep of the portion of the roof shown at K, Fig. 37, which is produced when the ideal and trad itional pitch of the spars and sprockets of 55 0 and ]SO respectively is adopted. Other examples of head nailing are shown in Figs. 36, 37 and 38. The detail D in the latter figure g\'\'cs a good example of the lower courses of slates having an inadequate fall due to the flat sprockets. Provided the window could be kept lower, a sounder job would resu\! if the feet of the span were continued and a small tilting fillet used instead of the sprockets. Diminishing Coursed Work (see J, Fig. 70 and E, Fig. 71).- As explamed on pp. 131 and I]S, the random slates are sorted and laid in graded courses dlmmlshing from a maximum at the eaves to a minimum at the ridge SlalCl in each course are of the same length, but the width may vary (see I, Fig. 70). As the lap is th~ sam~ th'Olllhowl, it follows that the 'gauge decreases from the eaves upwards. The gauge for head-nailed slates is found by the rule stated . mean length of slate and slate above - (lap+-z6 mm), h h r at E, I.t., - - :1 were t e app 1-
PLAIN TILING DETAILS SLIGHT CAMlEl
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A R I 0 G E T " I L
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cation sho ....~ a uniform lap of 63 mm (which is adequate for a pitch of So ') and the length of the suceessive upper courses to be 460, +30, 400 and J70 mm; the gauges of the 460 and 430 mm courses are 178 and 163 mm retpectivcly as 00 4 +37 0 - (63 + :16) shown, and that of the 400 mm course _ li8 mm. The
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gauge for centre-nailed slates, as in ordinary slating, is 13 mm mote. Whilst the above example is a simple illustr:ltion, it should be pointed out that the reduction in length is excessive and very large slates would be requi red at the eaves of a large roof if a more gradual reduction was not made; sometimes the COUrKS arc diminl:>hed at e,'ery second course. Westmorland slates are usually laid with graduated courses and a \'ery attractive appear:tnce results. The slate ridge is des.:ribcd on p. 135; 11 sawn stone ridge or a hog-back tile ridge (provided it was of a suitable colour) would be more ple~l\i"g in :lppt'~r:lnce. Procedure in Sla ting a Roof.- The follo .... ing is the normal sequence of operations in slaling Ihe roof of a building .... hich is assumed to be detached and has gabled .... alls ;The meta l ea ..es lJUuers are fixed Immed,atel)' after the .... ood ...ork It the e&\'et h i' been completed . the bauens are fixed li t the gJluge apan. commencing from the
E A V E S E T
139
L FICU~E 72
-
'40
,
ROOF COVERINGS
eava; .tacks of alate! hnml been placed .t .uibble inktv.lI up the roof by the I,bourer, the alater proceed. to fix them, oonyncneinl .t one end of the: eaves .nd anduIUy ",readm,lonIlPNdinaUy Ind up the roof until 1M rid~ i. re.ched; the oppoeite .lope is coveftd in • .amilar mannn; the rid~ tilee .~ Mdded, jointed and pointed horUontally and. 1ft true .hani1W'nt, Wifh exception of the md pieces .00 thote ,pintt c;:himney·,tKU, which .~ &iven I Ili,ht tilt upw.rd., II previously cxpJllined. If hip. Ire required, the apcci,lIy cut hip al.tts will have b«n dresKd to the eornect at.pe and &tze and. theN are the fint to be filled in c.dI COYrw; if the hip' Ire to be cut and mitred, the lcad _ke ... (prepared by the plumber) .re find by the al.ter .. the ,lllina proceed.; if hip tdes .re required, these Irt fixed in c:orreet' .lignment, commmcin, II the CIlVft Ind neatly mitring WIth the rid~ tiln. If the ~rca are •• ahown .1 S, Fig. 70, the underdOlika Ire firmly bedded In ament n'IO.rtlr before the batten. Ire fixed. Finally'. the luncrI Ire cleaned out Ind the undeR.de of the roof i. torched. Of COUtle, If unteanble fell i, 10 be find ,n liw of to~n., !hi. il done before tIK- batte:nt .,e find.
PLAIN TILING Plain tiles are made of clay or concrete. If or clay, this is very finely ground, moulded into slabs and subsequently dried and burnt. Like bricks, both handmade and machine-made tiles are produced in a wide range or colours. Handmade tiles have a aand-raced lurface, they have a better texture, are tougher, arc leM liable to lamination, and are more expensi\'e than those which are machinemade. The size is usually 26-] mm by 165 mm by 10 to 13 mm thick (see A, Fig. 72). They have II IIlight camber or sd (3 m radiuI) in their length which enlluret that the tails will bed and not ride on the backs of those in the course below. A tile has t ....-o (sometimes three) stubs or nibs which project on the bed or underside at the head in order that it may be hung from the batu:n, and each tile has two holes formed at about 25 mm from the head and 38 mm from the edges. Special tiles are also made, thus: ~aws tius (165 mm by 165 mm) and ti/~ a"d a IuJlf (267 mm by 2.f.8 mm or wider). The latter are used at alternate courses at verges and swept valleys. Terms, such as bond, gauge, margin. etc., used in slating are also applied to tiling. Plain tiles are laid in regular bond, and the preparation of a roof to receive the tiles is Similar ta the methods described an p. IJ7 .....ith exception of .. boarding and felting," as thil i. impracticable for tiling on account of the nibs. The naill used are similar to those described on p. 133, and J8 mm long coppn naill are used in moat good .....ork. Unlike Ilating, every tile is not teCUred with nails unltu for roofs in expo5fil poaitions. It is usually lpeeified that every tile in each fourth course shall be twice nailed. The double eaves course tiles. ridge course tiles and all verge. hip and valley tiles mUSl also be nailed. l In MlfT\e techniC1lI collevn. plain tihn(l: ,I p~f"rr«llo 11,,"nJj: I f ' fint ~·t':Ir wubjC'C1 of. Buildm, Courw.nd h~ I bnd mt'fltion of II 'I made here. Plain :iln and other roofing mlter,al. aff IIYrnmore exlt'flded tre.tmenl,n Chap. III. Yol. III IndUltnal and Ii.hl .. ",.hl roof aht'etln, an d deel"n. a ... de-cnbed In Chi" VI. V,,\ 1\'
Pitch, Lap and Gauge.-As I plain tile is a relatively small unit, a large lap is not practicable, and therefore the usual lap employed iii 6J mm. Thi. necessitates an increase in the minimum pitch to 45°. For reasons p~viously given, this angle should be avoided, and a pitch or So" to 55" adopted. The gauge equal. lengt:-Ia p _ 267-~3 mm = 102 mm. As in slating, lMre rnwt be THRO thidmeues of tiles at the lop. Typical eaves and ridge details are shown in Fig. 72. Eaves Detail (see c).-The spars forming the simple open eaves project only 75 mm, and a tilting fillet is fixed to them to give the necessary tilt for the lower courses and the doubling eaves tiles. Felt damp proofing is shown. Ridge Detail (see 8).-The top course, like that in slating, is tilted by using a thicker batten at the ridge; the'length of this course should be such IS to gi ...e a 102 mm margin, and in the example it is 216 mm. Either the hog-back ridge tile as shown, or a half-round ridge tile (as shown at A, Fig. 71) provide .. suitable finish, and these tiles should be bedded, jointed and pointed in cement mortar or mastic as described (or slating. This pointing material may be coloured to conform with that of the tiles. The underside of the tiles is shown torched, but untearable felt (fixed as described on p. 135) may be used if preferred. Lead-covered ridges should never be used for tiled roofs on account or the colour which, as a rule, contrasts violently with that or the tiles. Tiled verges m:1y he constructed in a similar manner to that shown for slating at E, Fig. 70. Hips are often finished with similar tiles to those used for ridges, but such are unsightly. The best treatment is that provided by bonnet hip tIles; these are curved and bond in with the adjacent tiling. Purpose-made V-shaped hip tiles which course in with the plaintiles are al§O employed. The best form of valley for a tiled roor is the swept' valley where each course of tiles in the adjacent sloped surfaces is s\\ept ruund 10 a suitable curve; this is constructed as briefly explained on p. 137. Another good form is the laced I \'alley .... here wide tiles are used at the intersection and each course is lifted to gIVe a lat'ed effect. The most common method adopted, especially for .peeolali\'e work. consists of forming a lead valley as shown for Ilating in Fig. 75; this is not desirable on account of ils unsatisfactory appearance, for in general, lead work in a tiled roof should not be exposed to view as its colour clashes wilh that or most tiles.
INTERLOCKING
TIL E S
In terlocking tiles (sometimes called single-lap tiles) are the lightest type of roof tilin~- --weighing 36.6 in comparison with 63.5 kg.'m l for plain tiles. Hence Ihe groundwork of spars and purlins can be lighter than for plain tilirg 'Set-
Chap. iII, Vol III.
$
Till N G and 7S mm by 50 mm spars II 450 mm c~ntres ar~ sufficient for spans up 10 Z m. Int~rlocking tiles (see Fig. 39) are machine mad~ of concrete in vlrious sizes and sections, the 380 mm by 230 mm type It D is typical. The tiles are troughed as shown al A and D, have one nail hole, two nibs which engage behind the 38 mm by 19 mm bauens, and the undertide also has projecting lugs which fit into the troughs of the tile below. They can be laid with a slrli!ight bond or they may ha\'e a broken bond like plain tiling and slating (~.l. at A, Fig. 70). In th~ latter e\'~nl, special left and right-hand ttles arc used for Ihe fini.sh at the nrge. 4S mm copper nails arc used for the best work, each tile in alternate course being nailed except where the roof is exposed and steeply pitched when all the tiles arc nailed. All the ea\es and ridge tiles and those at Ihe valleys. hips and verges mUlt always be nailed. Pitch, Lap and Gaug~. Interlocking tiles arc laid with a minimum head lap of 76 mm, they also h~!\'e an interlocking side lap of 26 mm as shown a: A. The minimum pitch is 30' when the gauge is z80 mm and the head lap is 100 mm as shown at E. For pitches of 3S and upwards a 304 mm gauge and 76 mm head lap can be used. Note that unlike plain tiles there are only "l'(} thicknesses of lile It the head lap as indicated at c. Eave$ Detail (see E).-The eaves project:tls mm and small sprockets arc used to give support to the felt at this point. The truss (see pp. 77 and 78 for dellCription) rests on a 100 mm by So mm wall plate to whith it is spiked and the ca\'ity wall is dosed by a ZIS mm brick course and one of half bricks as beam filling. Ridge Detail (see E).-This is quite simply arranged as shown. the top batten is slightly thicker to enlure that the top course sits tightly on the course below. The ridge tile is btdd~d as d~5Cribed 3bove for plain tiling.
'4'
Verge Detail (sec A).- -This shows the use of a plain tile as an under·c1oak and a special left·hand \o'erge tile to finish the edge. The treatment is similar to that already described (or a slated verge. Abutment Detail (see 8).-Thi5 occurs at a chimney stack and shows the use of a simple lead cO\-er Rashing which must extend over at least one of the raise:d portions of the tile. (Sec also p. tSo.) Hips are made with third·round tiles similar to those for the ridge, the imer· locking tiles being cuI to the line of the hip. Valleys are formed by using purpose-made troughed valley tiles nailed to short timbers nailed bctwttn the jack rafters and parallel to the valley rafter. The single lap tiles arc laid to project o\er the valley liles. and after being cut to rake to form an opcn valley about 100 mm wid~. morlar beddin~ is pointed in along the cut edges. Thermal Insulation of Roofs. It is important to prevent the undue loss of heat throujo:h the roof and the Building Regulations include a clause to this effect. The ",,",mum requirements for a pitched roof arc that it should have slates or til~s plus felt with a 60 mm thick quilt of glass (or slag) wool over the ceiling (or between the ceiling joists). In the case of a flat roof havlOg boarding not less than 16 mm thick a 46 mm thick quilt must be in· corporated within it or within the ceiling to it. Insulaung quilts are obtainable in I m wide rolls from zs to 7S mm thick. comprising a paper cover~d core of slag (or glass) wool. An alternative is shown 10 Fig. 39. where the inlulation consists of loose vetTl'\lculit~ (an expanded fOITTl of mica) 70 mm thick. Another insulating material IS 38 mm thick ~xpanded polystyrene insulation board fixcc\ to the top of the ceiling jOists.
C H APTER S I X
PLUMBING S>"lIab"I:-Bn~f
dr$(."nption of Ih~ manufacture of milled and east .heet kad; character;.t,,:s; "'elghl' of 'h«1 lead u~ for noou. purpota; tennl; Indudin.ll roll., dnps. RashmRs and $08.ken. D~'IIII. of Ind"ork at gUI1~n, R"I'. ehlRlne~' shlcks, rld~. h,ps and \"Il1I .. ~·s, R,,,,n~'\aler Plf'C'S, Domrshc "aler S<'n'io.::rs, Tool •.
Cha r acteristics of Lead.~This is a heAVY metal, weighing approximately 1374 k~ m3 ; soft, \ery malleable. tough and flexible; easily worked and readily cut; \cr}' durable (pruvided II is not subjected to certain acids and not in contaci \Iith Certain cements); is bluish Wey in colour with a bright metallic lustre when freshly cut, hut this tarnishes when t!xpoScd to the air. Lead has a hlf:h ((Hffi"""' of lin,ar 'XpanJlon (it being 0'000029 per C, or approximate!) t\IO and a half times that of sll.'1:l) and it therefore readily expands and contracts Ilhen subjected to considerable \ariations or tcmperalllrc, It is because or this charactcristic ttl"t very larj(e sheets of lead must bt- a\oided (especially if used to co\'er ,-ertical surfaces) Olnd ample provision made to permit of thl>. mOlellu:nt. In Ihis conneetion. defects such as wrinkl1n~. bul~lng and crdckmg \1 III he avoided if the OT~Q of tod. P'''U of shut Itod IS IIm,l,d 10 2-23 m~, ami 'I olliv trco (If tht adJaul11 sidtl of a ..ulongulaT shnt af<' fix,J. Attention is drJv.n to 11'11' \·arious details shown in Figs. 73. 74 and i5. which make provision for mO\'ement duc to c>;pansion and contraction, Weights of Sheet Lead . Despi te the chan~c to metric units, le"d is s(kcificcl by numbers accordin~ to its \leight m Ib, per square foot. Thus No. 4 lead \\ei~h~ 4-19 lb. per sq. ft, The wei~hls recommended for various purposes are.
Lead is chicRy produced from an ore, called galena. which is a compound of lead and sulphur. The principal sources of suppl~' are the Cnited States of America, Spain. Australia, Canada. Gt!rman}' and :\lexico; comparatively little of the are is now obtained from English mines,
I
Manufac tu re o r Lead.-Gne of S<'H'tal melhods of ,bSIr.tCllng Ihe leud i. 10 smelt the orr In II l'urnau.. 10 remo,'e CerlJm ImpUrities; Ihe melal .. run 1010 POlS, lunsfcrred 10 lURe cnp~r pMl., remelted 10 .. hmlnal .. furch .. r ImpUrlll"'. and the s"fl ... fined met,,1 " fin~lIy l:J~t IntO blIrs CIOlied pi1(" Thne pil/s ',,:11th from J/l 10 H ka;: "ach .ond J'" u~<,d for the mjl"uf~Clu.e of sh .. n •• plpt':t, ett Sh""l It'lid I' u...,d for ('oH'rinR roofs, ~'"'r' ...d~, elc Th..-r... ar .. 1\\0 nlethod\ of manuf~ctunnl/ .hNI Ind. ; ..... {,,' nlllkd or rollfl:! .h..... , I.. ad, and (6) (,," .h.... , I.."d (.. ) ,\IIIl..d,,~ R"fltd Shut 1....",/ -ThOi' PIllS I>f I..... d ~n· m .. h«f ~nd C~II 1010 s\ahs from I' ~ 10 2 '2 m lonlr. I '2 to I'll m ,,,de, and .. ppro,lind b."d" P(.,p~r~d. and 1.. , ..H..d .urr."e bc-onl( ~llll"htl' bdu" the: .,dfln of ,he b."och. depc:ndmlt up"n thl' r"<.jultrd ,h,,'km'.~ of Ihe I..."d Th .. mollen IC'tId " rournl into II !rouKh. >Cffi", .."uia. on ""'lion. "hl(h .,"'ends 10 ,he full '\Ldlh I>f ,h., Mn"h 10 "h,ch II I. hmi; .. d .. , on" .. nd; Ih .. trouRh " rOl.lled to up Ihe I..ad on '0 ,h., ... nd b..d aotlthe ltad IS push.,J h,r.... rd b, m .... n' of. 'Ink .. or b .. "h",h run. nil I/ulo.., .. n ,he ionR "d ..es of Ih .. fram" .. t a h""l/hl cortelpllnJIIlR to Ih .. rC, t"mm .. d. cut to Ihe rrqulrf'f' lenltlh, ~h~p'·.1 u re'lulTtd. and tiruoU .. jOlOnd bv iead·bu,nlOlI or .. )Idenn~.
.I."
tl~,~,
p>l"htd mof.. "od ItUlle,.,. IIlps ~nd Tldl!"~ ..'I,.,.h,lll(s
So;ik"T~
'\0. 6, 7 Or 8 Iud '\0. t) or 7 Iud '\0. 5 I... ad J or,. kid
'0.
I.ie:hter ,\ctghts th"n the ahme arc often adoptcd in cheap work. and It IS not uncommon 10 nnd th;il for such \\ork :\'0. 5 lead is employed for flats. The thicknc:>s and colour coJe of the various~rades arc shown 111 brackets thus: ~o. 3 (1'25 mm, .e:reen). \'0. -+ (t·R mill, blue), 'Jo. 5 (2'24 mm, red). :.Jo, 6 (2'5 mm, black), :-';0,7 (3'15 mm. white) and ~o. R (3'S5 mm, oran~e), Terms, Tht! follOWing' terms are used in plumb1l1~ Bum"g means" workinl:; up" and is appl1ed IU the labour in dressing lead to ""ricus shapes when formin.e: rolls. drips, cesspools, etc .• hy means of the bossin~ stick and other lools dcscrihcd on pp. 156 157. Care must be taken to maintain a uniform thickne5s of lead when performin~ this operation.
, Th .. rool. of Ihe \l~nche."·r CtnTral R.. t.. r.. I1,,, I.Ibr •• ~- and th .. To"'" Iiall E"'''OIioll. \laneh .." .., (compkted 10 IOUh.' ar...0Hr..d ,,,th .... 0, ~ rm/ ,hul Ind and th .. 1('lal "tl,hl of I... d und ",as apprm:om"tl."i\- l';'l k]l
'.'
SHEET LEAD Bwmng-," IS the method which is somc=tlmes adopted to 'JC:curc the edl(e$ of lead cov'crings of projecting stone mem~rs. A groove or ,atld IS formed in the stonework (see At Fig. 76), the edge of the lead is scraped clean ami turned into it, and secured by molten lead \\hich is poured Into the raglet and afterwards consolidated or cau/lted by using the caulkin~ tbol shown ;it s, Fig. 79. The lead is poured down grooves formed in a narrow board (which n::slli OIL t:dJ.{O! upon the cornice and i. placed against the face of tile parapet) and delivered into the raglet; the hot Iud healS the turn-m of the covering and unites wilh il. This method is not now commonly employed owing to the dittil.:ulty experienced in raismg the temperature of the edge of the lead covering to that required to effect complete unity bet ..... «;n It and the mohen I~ad, and the method adopted for fixmg cover flashings to brickwork is often pr~f~rred, i.~., we:dges are driven in at about 300 mm intervals and the joint is afterwards pointe:d with mastic or cement mortar (see below and p. 148) Sold" is an alloy'O£ lead and tin, and used by the plumber to join pic:ces of lead and form Joints between lead pipes, elc.; this operation is called soid"mg. Coorst or plumbing sold~r is used for uip,d JOInts (see p. 155) and consists of 2 parts lead and I part tin, fin~ sold", used for finer .....ork, is a mixture of I part lead and 2 parts un; ordinary sold" is a mixture of lead and tin in equal parts and is used for forming cop~.bit p"ntl (see p. 155). Coarse solder is either heated in a meltmg or solder pot (u, Fig. 79) and poured on the joint by means of a ladle (M, Fig. 79), or it is cast mto narro .... IIrips which are about 300 mm by 32 mOl by 0'45 kg and in this form the solder IS applied to the joint by using the blow·lamp (..... , Fig. 79) to melt the strip. uad Burning or Wtldmg.- ThiS is the proceu of uniting by h~at (fusing) picco of lead in which gases (such as oxy-acetylene, oxy-coal gas, etc.) are utiliLcd ilnd sp«ial blow-lamps employed. It is a method which has been developed in recent years and used for certain purposes as a substitute for soldering. Nails a1fd Nailing. -The nails used for fixing leld ..... ork to wood are of copper, :15 to 32 mm long, with clout (flat) heads. The term clOIl nailing is applied when the nails are at from 25 to 75 mm intervals; in opnt na/bng the nails are spaced at from 75 to 200 mm. Soams are thin pieces of lead (not more than So. 4 grade) which are placed between slates. The size Ind shape varies, thus tbe lIOakers described on p. 150 (see c and M, Fig. 75) are 175 mm wide, bent at right Ingle5 with an upturn of 75 mill. and a length which vlries in accordance with the length of the slates, whilst those described on p. 137 are square. They are either nailed to the boarding (at their headl) or the tops are turned over the slales. Only light lead i. ulled for soakers to prevent the tilting or riding of the slates. Flaahing••- Theae are narrow pieces of lead which are required at the intersection between vertical faces of wall. or framing and pitched roofs, flat., gutters, etc. They Ire c1at1ified into: (I) HorUontal Coon Flashings, which are usually 1So mm wide strips h2.ving their upper edges turned as mm into the raked-<,ut joint of the brickwork (or
'43
ragkt formed in the foIon~work) and the IOw~r ed~es lapped over and cO\'ering the uptllT" or upstand (vertical portion) of the lower pIL"CCS of lead (see Fil!;c§. 73 and 74, and p. 148). (2) Apron Flashings, .... hidl Jre provided at the: front of chimney-stacks, dormers, etc., and are from :zoo to 300 mm wide; the io"cr portion is dressed over the sbte:s and the upturn /s let 25 mm IIItO th.e raked-out jOint or t"a~lel (see A, 5, Land 0, Fig. 75, and p. 150). (3) SttpfHd Co.:rr Flashmgf, .... hich are from 150 to 200 mm wide and ha\c their upper edges cut into a series of steps; thc hori:wnlal edge of each step is turned 25 mm into the rake:d Joint. They arc fi\cd at the: sides of bnck chimneys, gable walls, etc. (see A. B.• , (; and s, Fig. is, and pp. 150 and 1St). (.) Raking Cot'~r Flaslllngs, which are used in lieu of (3) when the walls .Ire of stone. The upper edge of the Rashing is let 25 mm into a raglet forme:d parallel to the rake of the roof and this top edge is therefore not stepped (M'e p. (5 1). Flashings are in lengths cut across thc width of the roll and the maximum length therefore varic8 from 2'1 to 2'7 m; they are secur~d alOng their upper edges by lead wedgcs. IAad Wl'dgl's :::re tapered pieces of lead of the size lnd shape as shown at 0, Fig. 74. Tiley are made either (a) by running molt~n lead into a mould and cutting lhe tapered sfrip into short pieces when cool (such are called casl lead wedges) or (b) by folding pieces of scrap sheet lead and beatin~ them inlo shape. They are used to fill flashings and are driven in belween the lum·in of the Rashing and the upper edge of the joinl. In the ca!~ of hori20ntal and raking cover flashings, the wedges are driven in at about 300 mm internls- HO mm mlllCimllm (!U'I" R, n lind Q. Fig. 73); one or two are provided at each step of a stepped Rashing (see A, Band •., Fig. 75). The raked-out joint between the wedges is pointed with eitber cement mortar or maslic. The section at N, Fig. 74 !how! a wedge in po!ition. If used to secure Rashings in stonework in lieu of burning-in (see abo~'e), the edge of the lead is bent and turned back to completely line the raglet, and the wedges are driven into the folded edge. Oak "edges are sometimes u~d in cheap work. These are apt to become loose when they shrink. TackJ, Tingles or Clips are strips of lead used to stiffen flashings and prevent their free edges being lifted by a strong wind. They are from 50 to 75 mm wide and are placed at a distance apart not ellceeding 760 mm. As shown at M, Fig. 74, each tack is filled in the Joint, and it is sufficiently long to turn over and grip the free edge of the flashing by about 25 mm. Tacks are also required 10 ICC'Jre hollow rolls at 610 mm inter\'als (L, Fig. 74), and welts Ind ridge coverings at 610 to 1200 mm intervals (sec B, It and s, Fig. 75), the fixed ends of the tack, being clout-nailed to the boarding (or ridge) as shown Copper tacks, being stiffer than lead, are used for first·c1us work (see below).
144
PLUMBING
Joints.-As already mentioned. provision must be made to allow lead to expand and contract, and the Joints between sheets must be fOfmed 80 as to permit of this movement. The various joints are: (I) laps, (2) roils, (3) drips and (.) welts. (I) Lap Jolnts. - These occur at a maximum of 2-' to 2-7 m apan (depending
upon the width of the roll) for flashings, upturns of gulters, ridges, hips, "alleys and lead coverings of pitched roofs. .rhey arc also called posslnKs. The amount of lap (distance that one piece co\crs the adjacent piece of lead) is usually 100 mm for cover flashings, upturns of gutters and aprons, and 150 mm for stepped and raJu~d ftashings, ridges, hips and vancy•. The side laps of lead covering pitched roofs are in the form of rolls or welts (see below) and thc lower edge of each upper sheet laps Ihe lOp edge of the sheel below illo form a horizontal joint. The "mount of lap al such horizontal Joinls depends upon Ihe pitch; it is usually 150 mm when Ihe pitch e).ceeds 45 ,and Ihis may be increased to 230 mm for flauer pilchcs. Ahernatin:ly, horizontal wellS may be used instead of wide laps, bUI Ihese may detract from Ihe apP'"arance of Ihe roof. When the slope of a roof is less than '5 ' the horizontal Joints he,\\,et:n the sheets of lead are usually in the form of drips (see below). (2) RDlh.- This form of joint is required on lead-covered flats, pitched roofs. ridges, certain forms of hips and long gutters. They "Te placed at inten-Jls varying from 460 mm to a maAimum of 760 mm for A"ts Jnd similar construction. There are three kinds of rolls, ,.~ .• two forms of covering wood or solid rolls and a hollow Toll. Solid RoIls.- One form is shown at P, Fig. 7). and J. Fig. 7-4.1 The wood roll is shaped as shown and is nailed or screwed to the boarding. One edge of a sheet is dressed into the angle between the roll and boarding and continued beyond the crown as shown. This is called the und"riOQIf or und~rsht'tt. Its edge is secured with 25 mm copper nails at 25 to 150 mm apart (depending upon the quality of the work) and the edge is rasped off. The edge of the adjacent sheet is .....orked into the angle, passed over the underdoak and continued 25 to 50 mm on to the flat of the roof or bed of the gulter. This is known as the oowclOQIf or owrSM~t. The second form of solid roll is shown at K, Fig. 74. The undercloak is dressed and secured as abo\'e descnbed, but the overdoak is brought over to within 7 to 25 mm of the flat on the other side. This method was generally preferred in the North of England. but now both forms of solid rolls are adopted equally there. There is a difference of opinion as to which of the two methods shown at J and K is the best. In the former, water may gain access between the sheela by capilbry aUT2&tion. Whilst this is avoided at K, this practice is not recom-
mended for exposed positions on the free edge of the overdoak, having an inadequate gnp, may be lifted by strong Winds. The treatment at the ends of solid rolls is referred to on p. liS. Hollow RolI.-This type is adopted for hest work in connection with leadcovered pitched roofs, and especially if cast lead is to be used;1 il is also suitable for COvered surfaces, such as domes, where wood rolls could not be employed economically. The roll is supponed by " stout" (preferably from No.8 lesd) lead tacks or tin,il:les \\hi<.:h are 50 mm wide and 150 to 175 mm long; the~ arc placed at 610 10m apart, and one end of ta(;h is secured to Ihe boarding by two copper dout nails, the hoarding having been slightly recessed to recei,'e it. Coppcr tacks, bein~ stronger than lead, are used in superior work, each end being secured by two or"ss scre\\~. When turning a hollow roll, the edge of the underdo",k is upturned ,·enie:ally. the tacks arc fixed and their free ends are turned o\er the 1I1llIerdo:lk, the: ed).!e of the overdoak is upturnt:d and also turned o\'er the underdoak, and the II hole is finally dres~d to Ihe form shown in the illustration. 11011011 mils are nut suitable for fiJt roof~ as tht)" ;Ire liable to he damaged if trodden nn. Rolls ;.Ire J,I.!JIn rcfcrr<.:J to in the fullo\\ mg PJgcs. ()) /)rips or S'''PI an.' formed nn tiJts and in gUllers which exceed 2'-f m in Width or length, ;md they "rc plJced JCrfll)S thc fall. They .Ire gencrJII~' 50 mm and sometimes 75 mOl Jl·Cp. Three forms uf drips .Ire shown it Q. Fig. 7), Jnd 11., T and I'. Fi,,~:. i-f. Thc 50 mm drips at Q ,md R shl)\\ the upper edJet: uf the 101ler shcet (called the ,/lid,,· shut) dressed into the ;Ingle, contlllUcd up thc step fir drip, and dressed inltJ the ",0 mm \Iide shilklll reoate funncll Jlnng the ed).!c of the ho:nding to which It is dose copper-nailed . The ohJcct of the rebate is 10 ",,"aid a rid.e:e in the lead. The 101\er edJee of the upper sheel (calkd the of:tnhut) is dressed oler It. "nd hke tht: roll at J, is continued on the Rat or hed for 25 to 50 mm. The 75 mm drip Jt T has thl' mer,.hccl slupped short of Ihe AJt; \\aler cannot thereby gain access hy capillary Jllrallion. but like the roll of ~lImLiar construlllOn, the free ed,ll:e of the overthect IlIJ} be disturbed in a high gale. A ~econd method of prelenting capillary attraction is sho\\n at t·. \\hich illuslrates J" cJpilbr}" woo,",~" formed along the step and Into \1 hlch the IJndc~hee( is dre:;scd; II hilsl this construclion is excellent in theory. it is very fUely adopted in prJctice. Drips are further considered laler. (4) 1I'~lts or SlQmS are often employed for jointmg sheets of lead cm-enng vertical and sleeply pitched surfaces and for jointing lead and copper dampproof courses (see p. 18). A welt is illustrated at R, sand T. Fig. 75. Like hollow rolls, the edges of the adjacent sheets are upturned With 50 mm II Ide lead or copper tacks between, the tacks being fixed at from 610 to 1200 mm intervals; after being folded as sho\\n at R. the upturns arc dressed down as closely IS I 110110.... folll , 6J mm dl~meter, Ire emplo\-ed on Ihe roof or the l.lbrary refer",d 10 Ihe rOOt note on p 141. ~nd Ihele ue KCUr~ by I!O mm b)' 1~ mm copper IPck. ~I .60 mm inltn-.. I.
In
PARAPET GUTTERS
COVEIUNG AT WALl.
B
Q n-so SECTION TH..au
(MINIMUM FAll 12,.. 'M 1000..... )
SECTION TtW)UoGH CESSPOO\..v·OO FIGUIU! 73
".'-
PLUMBING ~iblc
all to thc R,II. The ~pa,"(,:s bt.,t\\c\'n the folels han- tll:t:lll'mrh;l~i/Cd to ,1'10\, the ~onstrucllon mort: ck;lfly. Jnd the finished appearance of a IICII morc d05d} rcltmbles the ~kel!.:h at T. The width of the seam ~'arit."S from 3l to 75 /lim. Wchw Jninls arc not liuitdble for flats or low.pitched Toofs, but like hollo" roils, they are vcr} df«II\'(' for .!eep or curved 5urfac(:s. Detail 0, Fi~. i5. !lhows a !>CClion throul{h a \Iell which may he tmplo}'cd at rid~cs in lieu of ISO
mm laps. The 1'001 of
Int'
M,m"h"lrr TOWn 11..11 bu,h.ltnll (loti: fooJn"'" on ",. 1..1) ,,_ ..
bo PIlCh, ;lnd the dlecu or ....sllead He joined at Ihelr slopmlt ooJ,!rS b\ v.dn "hich are 70 mm "Ide. Ihe horiwnlal jO;'lla consist of 165 mm ",de laps and tht ~hecl. 3re se.;-ured by fUming the 101" cdjtel oler the board,"!: to "hich th('y are dnM' coppt"r. n3,kd; each board Jmmedi~tdy ~ho\'e that to "hl<'h Ihe.' upper edJ,:e uf the sheet "31 nailed lIas remOl'ed ('I bcinjlleft lOOK (or th,. purp..",e) "nd, "rtcr na,ljn~ the Ih~t. Ihi. board I'''' replaced lind n~,led
Gutters. -There are thr« forms of lead-t:O\·tred gutters, i.e., (0) parallel parapt't gutters, (b) tapered parapet ~ullers Olnd (c) V-gullerll. (a) Parallel Paraptl (}UllffS.- -As i.. implied. this gutter is situated behind a p.arapet wall and at tht: bottom of a flal or sloping roof; it is also known as a 0.1,\ 01 r",uXh )::ultl:r. The I::uller IS of uniform widlh throughoul and mUllt he at least 255 mm II ide to afford adequJte foot room. A lon.l:: gutter is divided into seuions, h;\ving J. roll .11 the highest point, and drips at inlerl"al" not exceeding 2"..1- m apart; it is )i:i\en a minimum fall of U'S mm per metre. In Fig. 7] it recei\'es the drainaJ,!c from a sloping roof. and in Fi~. i4 i~ associ;ltcd Ilith a lead flat. The timber details of the gutter shown in Fig. 7] are referred to on p. 78; a part plan is shown at c and a longitudinal section is sho\\n at B; a So mm roll IS placed at the highest point from \\hicb tbe ~utter fall!; 25 mm to a So mm drip and the lower portion falls 25 mm 10 a cesspool. A usspool or drip-box is a lead-lined receptacle, situated at the 10llesl end of a gUller, from which a lead outlet pipe, suitably bent, discharges the water into a rain-water head where it is conveyed by a rain-water pipe to a gully and drain. Rain-water heads and pipes are described on pp. lSi ISS. The minimum depth of a cesspool shoutJ he 150 mm. The wood framing, its support and the chamfered hole are detailed at 0, Fig. i]' The lead lining is in one piece. two sides being turned up 300 mm against the lIalis,-a third side bein~ turned up I So mm and dressed J8 :TIm into a shallow rebate formed along Ihe lower edge of the gUller boardin,g: to "hich It is nailed, and the fourth side is 5 to mm long, J60 mm of which is turned ..-ertically with the remainder dressed over tht: tilting fillet and roof boarding to which it is nailed. The lining is bossed to the required shape from a TL'Ctangular piece of le40d before it IS placed in position, and a skilled crahsman wi!! do this without resorting to folded or "dog-eued" angles (Re p. 148). It is boled and dressed over the chamfered hole formed in the wood bottom, and the outlet pipe,1 havmg been formed to a 'Th" .,U (11th" p'pe of roof lud• .:e.
TUY
be drtenrmt'd by alltJ"'lnJ( 10 em' 01
p,pe,,~
to lo,g m'
sw,iO-nt:d( !lend ,IS d,:scribcd on p. 148, With 115 upper end cnlar)::cd by means of a '''110m fir turnpin (:.ce E, Fi).t. i9). is either soldered as shown or lead-burned to gi\"t~ a firm wa-tcrtlJ:(ht joint. A galvanized wire or copper balloon or dom~ is 5Ometim" tixed inlO the top of the outlet pi~ to prevent it from being choked by !t:aH~s., etc. :\ j;mJII lead ol'erfto\\ or warll1ng pipe should be pro\'ided as shown to sent as a templJrary outlet for the water in the C\'ent of the pipe becominJ,! choked. As t:ertain mortars act chelmcally upon and destroy lead, it is ad\isable to CO\'cr thl' h~aJ o\'erflow pipe Ind the portion of the oUllet pipe wbich passes through the \1 .. 11 with larred fclt (!oCe Band 0); alternativell, these pipes molY be ~1\en " coatin~ of bituminous paint. The lower section of the gutter is cQ"cred •• ith lead after the cesspool has been hned. the co.-cring consistin~ of thc bed, a 125 or 150 mm upturn or upstand J~ainst the •• all, and an upturn aj;!aim.t the pole plate whil.:h is continued over tbe tilting rillet to about t So mm on the slope of the roof where it is open coppernailed to thc boarding .Ilong its cdge. ThiS lower end is dressed 100 mm down the cesspool, dnd the LIpper end fOlm! tht undcT"!Ihf'el of the drip which has been described on p. IH. The nc\t section of the gutter has a similar (o\-ering; the lower end forms the over..heet of tht drip and the upper end is dressed o\'cr the roll 10 provide the underc10ak (see 1'). The CO\'cr Rashing is fi\ed. commcncing at the cesspool end, after the oPPO· site half of the guller has lx:en lined in a similar manner and finished with the upper end of Ihe top section formmg the overdoak of the roll. Enlarged details sho\\ing the laps, tacks and wedgcs are gi\'cn at 0, p and Qi the detail al A shows the relative heighls of the roll, drip, etc. It will be seen that each piece of lead forming a gutter (and cesspool) is fixed along two adjacent edges onl)'j the other two edges being free to allow the lead 10 C\pand and contract. S..ou: Boards should be pronded to gunl'n In order that melted Ino" may h.ve frH pataa~ to tho: outku and to prot«t IhI' le"d lIpinst d .. mll~ by tnfflc; .... ,thout boIIrd •. the snow on the j;L:uue.'r ,mp..des (hI' fib ... of watl'r a. the .now' thaws on the undl'n,dl'. lind th" may <:au... the w~tH to rise above the lead co\'cnnjl and penetrate the roof. A snow bo"rd may eonsl.t of two 100 mm by So mm longitudinal bHren, extendin.'! the full lenJi:th of the lk"Ctlon. to the top of "hich arc nailed So mm by 19 mm tnmS\'erlle l"th.1II about IJ mm apart.
:II
~uch
Anolher example of a par:Jl1el gUller is shown in Fig. H and a further example is shown at G, Fig. 24. (b) Ta~,~d Po,o~t Guller (see J, K Jnd N, Fig. 7]). -The wood details of Ihis guller are described on p. 7R (I« also "). This f!Utter, tapered on pl.an. is divided into sectIOns by a roll and drips as described above. As s"'own on the plan ..:, the lower ed~ of Ihe slating has to be cut p~ralle1 10 the tapered side of the gutter. The section at N shows the width increases due to the fall of each" bay" of the gutter and the drip. The sbape of the gutter on plan is de\'e!oped by transferring to it from the sectlon tbe various widtbs at the lower
J
""J
NAlU£l~l1 A"fU.NTU...
LEAD FLAT DETAILS
lv" ... '''''''' "'"
""
'<--'''''''' (ND OF aou.
T
10'"
, !W'""""
>~O
u
LEAD WEDGE
N FIOUIll 74
I
\
/
PLUMBING and upper ends of each bay. The section 3150 sho",s the lead turned up 150 mm Jga;ns! the wall and about 230 mm up the slope. The li1tin~ fillet is fixed with ill ~ower edge 75 mm abo\'c and parallel to the Intcrse<:\lon between the gutter and roof boarding. The details of the cesspool, drips, foil, flashings, etc" are similar to those already described. Another example of a tapered guuer is sh<>y,n by broken lines in the elc\'ation in Fig. 21 and the section at ~'. Fig. 24. the section being laken throu~h the gutter immediately above the cesspool. (c) V-luttus. - -This type is formed along the 10\ller intersection between two sloping roof surfaces. The groundwork may consist of bearers fixed to the sides of the spars (at various heights to suit the fall of the guner) as sho"n at T, Fig. 36, when the construction resembles that of a tapered gutter, or Ihe lower ends of Ihe spars of each slope may be birdsmoulhed over a pole plate as sho ..... n at A, Fig. 73, 10 form a parallel guuer. Long lengths of such gutters must be divided by rolls and drips as above described. Cast iron and other caves J::utters are described on pp. 154 155· Flats (~e Fig. 7i). The wood construction has been described on p. 70. It hOi:! been mcntioned thlt the minimum f~1I j
clip or pi ...'<::c of Iud (whi(;h has been left on the undercloak when trimming It) "hich is turned over it (sec Q). Form.ng '~ad nalt.-The follo\\lnjl: IS Ih~ order n \\hich leadwork fot Ihe Itst at " 'I ould ~ cx~uted Cesspool" .Ih oullet pIpe (.though the fiS:I1"1R of the latter ma\· be dderr«l), I(Uller. lo"cr $Ide bliy '11th underd03k, lo"ct mIddle b~y, lower I,d,· bay 'I IIh o,·er~IO/Ik, upper I,de b~)' 'I .th undercio~k. upper middle bay, .nd upp"r IIde bay" ,th o,·ercioak. The CO\·U "ash,nl! II then fixed In !hc mortu JOlntl whIch have b«n pre';ou~ly raked Qut for at lea.! z5 mm preferably ~fore the mort.r h .. let; the finl lenllth of flashmR to be fixed il !hal over the upturn of the RUtter. commencing III the c.,..pooI end. ~nd "rter oompleung those at the lides. that .Iong tho: top end i, fixed; the H4shmSI are wedged .nd Ihe morlu jo.nll .re po.nted with cement morl.r or 011 mastic. Forming (I CeJJpooI. I- A p.e« of IO'ud is cut sufficientl), larlle 10 form the bue .nd "dC-Sllnd.t " ~I OUI bych;dk-m.rllin.llthe hnes llOOIf "hlch w,lI be formed the angles al the base and •• de. . (l"on.-f.ead mud "ftU be ,,,,,,lred rv Krvet! Willi (l1r"tilt or Jh(lrp ob~ct a~ this al once "e~kenl .t$. Shallow llmovu are formed .101'111 the 1>:1 ... hnC"\! b)· plKmR the loCumg-'" luck on th<'r1l ~r.d .harply Itrik,".11 ,t with the oo...ing m~lIet. The lead .. tumc:d with the bnnam upwnd •• nd lIently tapped parallel to wnd . bout ~5 mm Ins.d., the ba.... I.nes; thl' 1."Sts In ",ffenmllthe blR Ind k«pmJo: It firm. The le~d II turned over ynd the .. des are bent uflwnds on the gromes, thO' cornel""l bemR lefl Each corner .. then IItpanotely bos5cd up by usmg lhe manel . nd boainlE IlIck. the (ormer beinlf inSide th~ " box " (<<"pool) .1 the boSSlnR I"d, .a applied 10 work the .uq'th'.I.... d IlraJUfllly from the bouam up\\ardl. CITe mUlt be taken not 10 dr>lR the lead from the cornet Or C'UIe the ba.e to lift; i( acre• ...., Ippe'l""I, " must be It once knocked out or the lead will pucku .nd .pht. A. It II I{I"1Iduallr boaRd UP".ros • .ame of the IUperPunUS lcarl at thlt top should be ~Ut off to O'n~ble thc remainder to bou up molt' ell,ly_ Thi. process i. repeated lit all ...""Ornen and the "des ~rc ~ut off 10 the rellum:d h~Ilfht. Th~ cesspool i. holed, dreued In posillon" requlTtxl and the WIer pipe conl"lC(:ted to ,I u .Irndy described. Bntd"w IAtJrI p,,oet.-The (0110'1''". describes the bendlOlf of. lead pipe .uch IS that .ho\\ n at Q, F'll. 74 The pipe " .lightly he-oiled 1I the pcMltion whefe the bend 1110 be formed; illl then bent ovltr the knee lind thll Hlltenl the pipe It the tllrool; the long dummy (Y) (aee F'I(. 79) ,. now used '0 .pproxlmltely restore the pipe to I Circular secllon by ,nsenmll the" 'Iraillt"ht end " (head c') Ind workln, it up Ind do\\n unlillhe thrOilI i. Ifnldually broUllht out; the bendin, luck (c) " then .pplied 10 nch side of the p'pe lit the bend in tum, workinll hom the throat to the Mltl until the circulu section hH been rou.llhly r~M:.'ned. The bobbin (F) Ind weight are mlerted, the former being of the proper IIU to IU.t the pIpe and the l.tter IhJhtly Ie.. ; • piece of rope .. au.ched to the weight Ind plsaed Ihrou,Q"h the bobbin .nd pIpe; when the rope II lliven • Kries of sh.rp pUnl, the weiRht IEndu.lly drives the bobb.n throulfh the bend, .nd u i! doc:. so the ,.,ttrior i. brought to • uniformly Circular oorlt. The PIpe " sfl1l.n heated and the lime opc:ratlQlu Ire repe:ated, care beinll t.ken In workin,Q" the bend with the bending ltock that s uniform thickne.. il malnt.med. AI the radlu, of the bend increases, he.d D' of the dummy il uK
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Ridges (see a, H .and J, Fig. 7s).-uad·co\·ered ridges are.uitable for Ilated roofs, although lead is apt to discolour green slates. The detail.t H ghow1 one method. A 50 mm wood roll i. nailed to the wood , See p. t56 for. d..sc:ript.on Dnd Fil(. 79 for Iketch.,. of the plumbonr tool ••
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PLUMBING ridge; a pair of So mm ..... id~ lead lach is nailed to the side of the ridge (kC B) at 610 to !'l00 mm intervals; thc lead c;o\'cring consists of Slrips which aTC from 450 to 508 mm Wide and 2'13 m lonl(; it is p3ssc:d over thc roll, well "orked into the angles, and dressed o\"cr IhC' slates for 150 to 175 mm on each side; thc frce ends of the tacks are then turned o\"l::r the ed/l:e5 of the lead for about 25 mm to prev'cn! the lead from being lifted hy the wmd. The hnmantal jOints arc generally lapped I So mm (a pair of tacks being provided at each), althoUJr;:h in best work they may be welted as sho\.\ n ;U D. An altcrnati\'C' method is sha .... n at J where the lacks (which pass o\er the top of the ridge) aT!: nailed to the wood ridge hdore thc \\ood roL is fixed. The treatment .n tht enll or Ihc nd,Rc abuuint: against Ihe chim"e)' ~tack i~ ~h')wn at o and dCiCrihed on p. 152. Hips. Lead may he u!>Cd at the hips in thc follo .... lng mJ.'lner. (I) wood roll .... ith cOlHtnUOU" kat! co\·erinj:.: as 5hOI\11 for ridf.:c~, (2) CUI and mllr~'(1 slales .... ,lh lead !\lukers, and (3) .... ood mil with kJ(1 suakers. (I) Wood Null tu,h Cimtmll'llIi l.tod C/f"lt'tn~. This IS 1-uTIIIJr to Ih(' riJ~c detail eM:epllng that tht: dihe .. lral anl!k i...... idcr. The ~tnp~ of lead :If(' naikd at the head .. under the lap" ~nd Jle ~bo '>t:curcu hI tht· lead t~ds. (2) ('lit and "'hfrrJ .'ilolrJ ruth 1"0'/ .'i"oken. TIll'rt are 1.... 0 llH:llulil .. "I usin~ soakers, i.t., (0) ~lnl!lc-tOllrsc 'IOakcrs and (II) \Inllhle-c"ur~ soakl·n., (Q) This IS the arrafl~enlt:nt .... hu.:h I" ~hn\\"n ;It , .tnJ e;, Ft~, iO, alld dcsnihcJ on p. 137. It pm\"ldc,> an e'a;elleTII finish til a sbtnl roof and 11 ,ldopIell in Ihe Oest work, (b) In Ihis methoJ, tht Itllf:th /If Ihr JUukt'rf If 26 1'1'" I"ngt' than 'hut ('I 'hI' slatts; the horl7.0ntJ.l \Iidth of e.lch win.c: should ~ "lighth more tllJn tI\I' ~1.1tl· btll," in order 10 covcr the joint, anll it tapers \() ahout ;0 rllm al thc hL,ld, .... hich is narlrod. A soaker 1<1 plal:LJ "I ('wry Qf't"l1l/t c"u~sc. and IIlod"r(' .n ever)' other course the 10 .... cr p... rlion (Ifl.lr,l.!tn) of c, ch ~nakn Ii e,po,>nl \0 lil'w It is not ofttn atlopt<:d. (J) U"OIllJ Roll te:ilh I.t:aJ '\"IflJ{f'rl, S')aker~ :lrt prm Ilk" a: elery course, and throy Irc shlpc:d to p;ts.;. Iwer the mil and 1M,'!y,l'l'11 th(· ,lall'S :It the \linK';'. The len~th of soaker roqualith wakl·rs. (I) ()f't'n "aftt} (;Ilfftn (lk:e I', Ftj.!. is), I'hi .. 1<1 Kcnerall~ Cmr1fl\("J amI prondes a lOun': hUI unanr.tClll'C InokUlr.: linish. TI,,: 1e... II" 111 2'1) m II'nJ::III~ with 150 mm laps, anti the .... idth I'> ,Iholl\ .. So mm. tWIIlK drl·,,"C,·d 'ller tilt' boardinK and liltilllo: f.lleh ,1.'0; sho .... n; it i:-. I'1:l:ureJ hv d,~' Loppn I.:lilill~ up cadi side alollj;.! the tdge, and the end", arc kft free, I'he dl',lr II,d,h t~t ....een the cdgt's of thc slates ( .... hich arc l·ut to tIlt: r.lkl·) ~IHJuld 1101 1'Ie k'lI.
dama~cd by anyont procctding up the vallty when carrying out repJ.lrs, tiC. If the roof IS hatten~d and not boarded, it is n~cessary to fix a 250 mm .... id~ hoard (call~d a lin' boord) on ~ach side of the intersection, and for the full extent of the ullroy, in ordtr to receive the lead, The ends of the slating battens arc cut to Ihe edges of the5e board'!. (2) Surd I"olfry Gutfm (see Q), The width of the 2'13 m strips of lead are only about 254 mOl as the c.:ut ed,l1:es of the slates are only about 25 mm aparl. Whil51 the appearance is an impro"ement on the open \'aliey gUller, it is objected to for the reason th,lI Lt is hhll~ to become ch"ked by lencs and rubbish which may accumula:e :lnd choke the vallty, callsin1! .... ater to back up and pass o\'cr lht" k,uJ. (3) CuI o"d .\f""J Slotes mfh SnllJurs The construction some~hat rt."St"mhlu that for cut and mitred hips \\ IIh ~ingle-courr.e soakers (dtserihed on p. 137) in thdt wiue slales (slJte and J h.M) arc cut 01 tll(· requisite Icad .... ork \I) t .... o chin:ne~ stJck~ .HI' ~h(J .... n III Fil!. ,:,;. One "lack is ~h()lln intercepling ont of the slopcs f)f a ru of Ihe l(,oId J!TlIduaJ:~ I\ork IIJl\IJrds to dn irre.c:ular Cllr\"l~, and it is the pl:lctin- to neath' Inm thc ends ;1'> ShOll1l whcn the bosstn~ has been completed. The ;lpron i~ 1CI:\Ir\·J b~ It"t! wt'dll;t.'S (sec ,\ ~fld II). Ll'ad tackll are pHJI ided a~ shnwn .11 ,\ tn securt' the free elil!c, althou~h th("~c an;: not nec~ary it the apron I~ ~hort Jnd especialh' If thc emls :Ire lalkd down by slates J.S indi(;;,led at II; !hl' Idl"ks m.I\· he cOfl!inut'd lerllc.llh and let into Ihe joint (as Sh'hlll) 01 !til'" IIlJ\ he "hort dill.! luileJ at their upp.:r ends to tht· (Op 1,;llIl·n. 1";Il,l.! 1c'ngth
SHEET LEAD and 26 mm I~ if the slates ITC centre-nliled; in addition, the length (excepting the upturned portion) is increased by 26 mm for nailing to the roof boarding (sec rot) or for hooking over the hC20d of the .Iatc when secured to a batten (tee c). A. shown at A, f, Nand 0, each soaker laps that above or below it by an amount equal to that of the slates. The stepped cover flashing is formed out of a ISO
the cut bac.b and the wall; each Itep illttured with one or two wedge. and the JOints lI.htch r«eive the tum·ins of the Iteps should be well pointed as before descnbed. Sometimes the pieces are shaped with vertical front edges and not cut back as shown. Thell(' are not so attractive in appearance as those shown. (c) Single Ctmll,nunu Slcp~d Floshing.-Soakers are flOt used, and in lieu of them the Iteppcd flashing is continued and dressed ISO mm over the slates. In appearance, therefore, the 10Yl"f:r portion resembles the aprOn at L, whilst the upP.tr portion is similar to the flashing at N. This method is not as sound as either (0) or (6), as water may be blown between the slates and wings of the flashing or It may enter by capillary atlraction, and it does not look well. Its use IS on the decrease, except where pantiles or similar interlncking tiles are used as a roof covering (see H, Fig. 39). (J) BucR.-The lead work here consist$ of a gutter and cover flashing. As shown at "1', the angle at the Inters«lion is blocked hy a triangular piece of .....ood which is shaped and gl'cn a sligh fall In both directions from the centre (see o and the broken hne at c). A tIlting fillet should also be pro'ided (altt"ouRh (hill is often omitted) and this shollid be tapered as indicated at 0 and I\: in order 10 preHnl tht' shlles lInmcdiately above the ends of the ~uller from ridin~.
or 175 mm ..... ide strip to the shape shown at N; the as mm WIde upper horizontal edges bcin~ let into the mortar Joinls and each is secured .....ith onc or Iwo wedges; the size of the steps depends upon the thickness of the bricks and the pitch of the roof, but the distance from the" water lme " (see F) to the lower edge should not be less than 50 mm (at f and s, thIS is shown to be 6.J mm). A rUing co..-ct fl.ashin~ (see p. I.U) is adopled for slone chimney·slacks as the absence of horizor.lal Joints at from So to 75 mm apart preclude the use of stepped cover Aashings. The above continuous Aashings are not so liable as those described !:lelo\\" (6) to be dislodged by the wind. (b) SoaJurJ u'llh S!tp~d FlasJr.mt 1" Smtlt SI,ps (kC Band (").-The SOlkcr!l are as described abovc. The (;O,er Aashmg is nude of scrap pieces of lead to the Ihapc shown at c to gi,"e a 50 to 7S mm lap; it is because of this lap that this method is preferred to (0) abo'·e. as water does not readily find access het"een --..:
PROTECTION OF CO~NICES 20_ THIC" AS'H,',lT / LEAD n~'
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PLUMBING The sketch at K shows the piece of lead which has been bossed (or lead~burned) to the required !Iha~ before fixing. The I So mm wide cover flashing is shown at E and the ends arc returned (see It. and F). FlnUh at Rid:, (II«: B). The end piece of lead ridge covering is turned So mm up the wall and the central piece of cover flashing-called a saddk-pieuis turned over the ridge to (orm a cap. Genenal.-A roof is made watertight at the: intersection between its slope and brickwork or stonework (as at J and M, Fig. 36) by using an apron flashing with cover flashinJi:. Similarly, any of the three types of flashings (a), (6) and (c) is used to exclude water at the intersection between roofs and gable walls (such as that shown in Fig. 21). In inferior work, cnrtnrt mortor filldl are used instead of leadwork at such intersections; these are triangular fillets formed on the slates and against the brickwork or stonework; this is a very unsound substitute, as sooner or later the fillets crack (and sometimes fan away), causing the roof to leak. Protection of Slone Cornices and String Courses.-It is especially necessary to protc!.:t the upper projecting courses of stonework against the action of rain-water which is converted to diluted acid in polluted atmospheres. The twO materials generally used for this purpose are (a) lead and (b) asphalt. (a) A lead-covered cornice is shown at A ~nd c, Fig. 76, NO.5 or 6 lead being used. A raglet, about 13 mm wide and 20 mm deep, iii cut along the face of the stone parapet to T(."(:ei\e the edgc of the upturn which is secured either by burning-in or \\edges (see p. 143). If the parapet is of brickwork, the upturn is secured by wrdJiCcs in thc usual way. Exceptionally wide cornices should have free upturns which are protected by cover flashings. The lower edge of t~le lead is doubled and dressed over thc fillet or nosing to project ahout 7 mm to allo .... ,\ater to drip clear of the moulded stonework (similar 10 that at B). The Irans'"erse joints between pieces of the lead (which are 2'13 to 2'74 m long) :lTe welts similar to that shown at 0, FiR. 75. /"ad dols (also knol\n as douels. rints or butlmu) arc used to secure the co\'enn~ ;'golinst thc action of the wind; do,etailed square or circular holes are formed in the cornice at about 900 mm lCf'lreS (sec e); Ihc lead afler bein~ hossed is holed. mth the edge of each hole turned up slightly, and a met,11 dot mould (sec B', Fi~. i9) is then lIsed to form tht dOl by pouring molten \cad through the small hole ill the mould (see A and c); sHmetlmes the" cup" of the muuld ;5 !'<;mi~ph"ricallo form dots hilling cun'ed IOrs. These dots may be formed hy Ie.ld b\lming: (see p. '43); thc edge of Ihe le.. d at the hole is turned dOlln sliRhtly and the hole in thc cornice is filled with molten lead from a strip of lead held over it and rt"du!,;cd 10 a molten !';undillon by the flame of the lead burner; the molten lead is finished flush \\ith the co"erin~, and the dOl is made inconspicuolls by li~hdy hammerinJ:: it and clean in!!: II nff. (6) Asphalt is often used in modern cnnstruction as a w,-erin!!: material. In the example sho .... n at D 01 small channel is formed at the hack and the lOp surface of the eOfOlce IS ~il-en a slia:ht fall tow.lTds It; the channel falls sli\.!hll~ to ....ards one end and deli"ers into J ratn-water pipe. A 25 mm deep dOletail
groove is formed along the full length of the cornice and about 75 mm from the front edge (I« B) and a 25 mm Iquare eaglet il made alon& the bottom of the paeapet (or each stone is formed with a rebated joint before being fixed). The No. S or 6 lead flashing i. bossed as lhown It B and the hot asphalt is applied, fini.hed lmooth to a thickness of 20 mm, well tucked into both grooves and rounded off at the outer edge.
RAIN-WATER GOODS Rain-water goods include eavn gutters '(or .pouts) and eain·water pipes (or down-pipes). They are made of cast iron, lead, asbestos-cement, enamelled iron, galvanized steel, aluminium or plastic materials. Details of cast iron gutters and pipes are Ihown in Fig. 77 and an application Is shown in the perspective sketch. EAVES GUTTERS
Ea"cs gutters are provided with a loclut (or Jauctt or JUmgt) which receives the spigot end of the adjacent length. These are genel'lllly " outside" sockets (see A, II, 0 and v). although" inside" sockets are also provided (see v). As shown lit 8, the matimum length is 1·8 m, t:tdudi"g the flange which is from 38 to So mm .... ide; shorter lengths c~n be obtained, and where necessary pipes arc reduced in lenJ::th by means of the saw. They are made of various shaped Stttions, i.t., half-round, deep half-round, agee, etc. A deep half-round gutter is shown in section at E and in oblique projection at A, Band D; this is a very good form, ~ing simple and of satisfactory appearancr, and it can readily be painted hoth inside and out and so presened; it is sometimes provided with a bead alonR its outer edge similar to Ihat shown in tnc middle section at H. Other moulded forms are sho.... n at II; the disadvantage of these is the backs are inaccessible for painting if and after they have been fixed to the wood fascia hoards. They are moulded in numerous stock sizes, thus the half-round gutter i~ obtainJ.ble in sizes \";I.rying from 100 mm by 50 mm to 300 mm by 150 mm. ~ote that these sizes arc r.Ttrrna{ sizes (see E and II). The thickness is 6'4 mm (" e1(tra heal)' ,2:radc 'l S·z mm (" heavy ~rade "), i·8 mm (" medium grade ") and 3'2 mm (" ordinary" or "liJ!:ht eastinj.!s "); the latter is used for cheap work. the medium J!:r;lde is used for a\'cra,2:c J!:ood work, and the two heavier castinKs ne only spc!.:ifit!d for special work. Special Fittings. These include e"ternal and internal angles (see A), stop ends for ~kets (c). stop ends for spigots, outlets with nonles or drops cast Of. (D) and union dips (c.). the latter beillg used to connect two Spl,2:ot ends. Supports. Eal-es gutters arc suppClTted by wrought iron hrackets, generally twn he-nJ!: rC(luired per I·R I'll length. That sho.... n at \I, Fi~. 77, is twice screwed or nailed to the hacks of spars (sce llso" and v, Fig. 36, A and D, Fig. 38, dnd >', Fi/!.71). The one at 0, Fig. 77, is IIlIce scre ....ed to lhe sides of spars (suitable
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for the type of eaves thown at x, Fig. 36). The t .....o sho..... n at N, Fig. 77. are scre.....ed 10 wood fascias and are ailed" fascia brackets" (see Q, Fig. 36, and c. Fig. ;I), and that ahown at Q, Fig. 77. is suitable for fixing direct to stone '1A-alls where the pointed end of the bar is driven into the bed jOint and the c:urn~d bracket is adjusted to the required height by means of the nut and back or \nck·nut which are screwed [0 the rod fi'(cd to the bracket. Jointll . . ;\ ~ction through an outside Joint is shown at v, Fig. 77. The jointing m:r.leriai is red lead mastic or putt)' (powdered red lead mixed with lin!lttd oil) and is applied to the inside: of the socket after the gutter is placed in position on the brackets; the spigot end of the adjacent pipe is placed inlo the socket, the wrought iron 6 or 8 mm di.l. K,dtt' bolt is inserted and the nut is tightened until the hcad is flush with the inside of the f.\:uHcr; this squec7.es out Iny cxcess of mastic which is wiped off. Whilst the above is the commonest form of Joint, some ~\Itters are specified to ha\'c inside sot.kets; the<;c arc necessar)' if the I;:xterior of the gutler is not to be Interrupted by the lOCkets, as is sometimes advisahle for moulded gutters. An inside joint is also indicated in section at y Trough Gutten. - These are large cast iron or galvanized steel gutters \\ hlch are used, especially for factories, :lnd simi!'lr buildings. instead of lead parapet and V-gutters. DOWN PIPES
The size of down-pipts ,·aries from 50 to 300 mm illi"nol diameter, those: :;.peclfied for house:;. being gencrally 60 or 75 mm. and are in 1·8 m lengths Indwlng the sochts (sec J). Short lengths are also obtainahle. The thickness is similar to that of eavcS gutters. Special Fittings. These include swan-neck hends, rain-water heads, off:>.:t bends, shoes, .md .. ingle. double and Y-branches. _,'f,wlI-nulr Bind (s.f:C 1- and pcnopc:(,:ti\·e sketch). --This is necessary to connect the nozzle-piece or outlet (see 0) of a f.\:utter which is fixed to an O\crhanging cavcs and the top JenRth of.t duwn-pipe. Rar'l-u:attr Htad (or Hop",r IItQd ) (sec pl. These are obtainable in many sto..:k SilCS and designs; they arc used to recei,·c water from p
•
water only. A nuisance may be caused by the water splashing over the gulliet; such is prevented i( ollti-splash sho" (sec v) are used, the projecting plate (sec s«:tion) breaking up the flow. Boots are similar to shoes but have legs up to 300 mm long. Sinclt, /)OWll and Y·Brandttl arc used (or connecting two or three branch pipes to a common down-pipe; a single branch is sho .... n at o. The above bends and shoes may be obtained with or without lugs cast on (sec below). Cast iron pipes are also made of rectangular and square sections in sizes varying from 75 mm by 50 mm to 100 mm by 2.00 mm. Holderbats (see later) are made to match. Supports. Rain-water pipes are supported hy means of (o) spikes which arc driven through tars or l"Cl, or (b) by holduboll. (a) Down-pipes can be obtamed with or without lugs cast on. Those with lugs cast on (see K) are used for ordinary work. All cast iron pipes should be fixed at a d,stance of 50 mm from rhe fact of the .... all to allow the backs of the prpes to be painted, otherwise the mctal will corrode and rain- .... ater .... ill escape through the holes or crach .... hlch eventually form to caU!le disfigurement and dampness, The pipes are mamtained at this distance by rhe use of either cast· iron bobb1ns (see T) or hard'-'>ood hobbins; two of these are required at cach lug and the pij>CS arc secured by dri\·in~ stout spIkes (see l") through the holes in the ears and bobhllls into wood plu~s whn;:h hale been fixed in the wall (see K and x). (b) One form of holderbat is shown at s. These are cast iron supports which arc suitable fur fixing into Joints of brick ....ork; Similar supports for fixing to stonework ha\·e dovetailed lugs (shown by broken lines) which arc let into holes formed to recei\"e them, 3nd secured by molten lead ..... hich is caulked. The lugs project 50 mm from the wall. Each length of pIpe is secured by slipping the triangular pocket which is cast on the lower bead of the socket o\"er the triangular pin ..... hich is cast on the holderhat. This pro\·ides a neat and effective support and is used In good work. Alternatively, rain· .....ater pipes without ears (as shown at 1) may be fixed by dips (see R); the wrou~ht iron band or dip is secured by a screw and nut to a pair of lugs after it is passed round the socket of the pipe. Joints. Down-pipes arc often fixed with dry joints (no JOinting material being used), and the lengths of the pipes are made rigid by lead or wrought iron wedges which are driven down between the spigots and sockets. Wood wedges should not be used :as they arc apt to expand ,lIld split the sockets. The section at L shows a Joint with red Icad pUlly; a shon piece of yam gasket (rope) is wrapped two or three times round the spigot and tightly packed to prevent any mastic from entering the body of the pipe, and the putty is neatly finished off with a fillet • The .uhlecl of dnln"II"~. ",h,,~h Includu SOIl· pip", 1. lualed ,n Clurp_ II, Vol. II. IppJII:lhon of '"t~rnal ....illnd WI~I~ plpe"'ork. om"p,pe Ind lingl~ .Ink I) Item. CfC_ II d~I•.-rlbed In Ch"p_ II, Vol. II and In geuter delill 10 Chlp_ X, Vol. IV . Th~
DOMESTIC WATER SERVICES The joints between heavy cut iron pipet; (such as soil_pipesl) may consist of (.) moltr.n lead. (h) lead wool and (c) lead wool and molten let1d.
Two of
these joints au shown at z, Fig. n. (4) Molten pig lead i. run between the spigot and socket, and then caulked to consolidate the material; a piece of yam gasket is tightly packed before the
joint is made (lee right of section).
(6) Lead wool (fine ItJ'2J\ds of lead, twisted to form a ro~) is packed into the joint and well caulked. This forms an excellent joint and the material is convenient to handle.
(e) The lower haJf of the joint is caulked with lead wool to within 38 mm from the top and the remaining space i. filled with molten pig lead which is subsequently caulked (see z).
Plutic Rain-water Good••- These are made of polyvinyl chloride (p.v.c.) and are used widely in domestic work. The gutters are in half·round or rectangular sections and are jointed by push fit gutter brackets to leave a gap of 3 mm between lengths to allow for expansion. Asbeatos-cement Rain-water Goodl.- These are strong, durable and light and need not be painted. The jointing material IS a special composition provided by the manufacturers. Enamelled Iron Rain-water Gooda.- These are enamelled both inside and out and therefore painting is eliminated. These pipes are obtainable in eight standard colours (black, brown, green, etc.). A bituminous compound is the jointing material.
DOMESTIC WATER SERVICESl The water for domestic services i. carried in pipes of copper, lead, galvanized steel and polythene (this latter for cold services only). The use of lead pipes has diminished greatly in recent years, they are in any case unsuitable for drinking water which is soft because of the danger of lead poisoning. Lead is still sometimes u~ for conver!!inn ilnd alterlltlon work for wilste pipes where its elise of manipulation is an advan~age. Galvanized steel is cheaper than copper and is used more on the larger industrial schemes, it is also adopted in some hardwater areas for it can withstand the hammering needed to remove the scale deposits which occur in such districts. Polythene is cheaper still and is !King increasingly used for cold water distribution; tubes of this material have the best resistance to bursting, this can happen to pipes on thawing out after being frozen. Most internal pl~mbing work is carried out wilh the light·gauge copper tube conforming to B.S. 659, it is a convenient material, obtainable in long leng!!ls and having a good resistance to corrosion. Lead Pipe.-The various joints formed between lead pipes include the wiped, taft, block and Siaem joints. The following is a description of the first two:I ThHe In COfIsidered in gTnter detlll m Chap. X, Vol. IV.
155
Wiped Joi",t (see A',
Fig. 77).-This is generally considered to be the nrongest joint for Iud pip" and i, therefore employed in first-claSs work and especially for water pipes which have to withstand high pressures. Solder (see p. 1.3) con· sisting of z parts by weight of pig lead and I part pure tin is the jointing material. The joint i. mlde IS followl: The end of each pipe il prepared .. shown In the hllf-section, tNt of the upper pipe (when it is in I vertical pocition) being r ..ped. down on the ouuide to lelve • shlrp edge, and the end of the lower pipe beinlf diglrf/)' filed on the ouuide Ind then opened by hammering I tan-pin (E, Fia. 79) Into il. Each end il painted with loil (I blaek powder Conlllllnl of Ilmpbtack, .iR Ind whitma, well mixed with hot wlter) for at lellt 75 mm. depending upon the .iu of the jOint.' When thil i. dry, e1Ich end i• ..:nped. with the lhave hook (G, Fig. 79) for I distlnce of J8 mm or more (Iccording to Ihe length of the joint) so .. to present I c1C1n bright .urflce whIch i. Hscntial for the thorouih .dhtllon of the solder. The Ippelnn<:e of the finished joint is improved If prior to .h.ving, I ring is carefully chllk-mlrked round Ind .t the proper dlltance from the end of the pipe. A, solder will not Idhere to soil (hence the rClson for" soiling ") ;t fo11o ...... thlt if the ring II carefully marked, the edge of the solder (sec I.ter) will be shlrp Ind uniform. The Inside of the lower opened end should liso be shlved. Immediately.fter.mlving, Iile bright ends Ire smeared with grease or 1.110.... to pre"enl them re.tlrrushing Ind 10 ICI II I flux (10 .SSIIl fUSion between the solder and lead). The pipes Ire now reldy for soldering either by pou~,"g or splnhing it on from Ihe ladle (M, F,g. 79) or by uSing the blowllmp (A', F'I. 79) Ind I strip of solder (ace p. 14J). The former method is only adopted In certain districts for jomts made on the bench Ind the litter for joml$ m.de on the job. When Ihe .. Ildl~" method i, Idopted, the IOlder IS melted in the pot (u, Fig. 79) to Ihe required tcmpeTiture (denoted when the IOlder ignlles I piece of paper), and .f,eT the p;pn have been accuTitely adjusted the .older is poured from the ladle on to the the prepared ends until the tcmpeTifUre of Ihe pIpes ., th~ end. II approxImately thlt of the solder; the latter II thcn WIped round Ihe Jomt wilh • wlpmg doth (z, Fig. 79). the lurflce of" hich has been tfreased to prevenl the solder adhenng 10 II: additionll solder is spluhed on Ind quickly worked wllh !h~ doth untol the desired ,hlpe is obtained. "hen Ihe jomt " left undl5!ur~ Ind allowed to cool. When the" blowlamp .. method is Idopted, the prepared ~ndl of the pipes Ire filled together Ind heated by the flame of the limp: solder is applied by meltini one end of I Strip, and i. graduilly brought 10 the required shipe by the u~ of the cloth; the joml II then lefl to cool. The thicknts.5 of the sotder al the ....·idest part of the jOint need not exc«d one and I hl]f urnes the pIpe IIl1cJr"tJl.
Toft or Coppu·bit Joint (see B', Fig. 77).-This is used where the pipes are not required to withstand much pressure, as for~verflow and gas pipes. The preparation of the end. of the pipn is SImIlar to that for wlped.jomll, ncrpt Ihlt the lower pIpe is opened wider, Ihe amoum of ,hl""'JI II reduced and the soil II often omitted. A lillie powdered resin " apploed to the scraped surfaces afler the ends are filled together. and Ihis ICts IS I Au): for the" ord,,,ary" solder (conliu",g of equal parts of lead .nd lin) "hich is in the fonn of I thm narrow strip. The solder II melted by the heated copper-bit (1'1'. F,g. 79) UnUIIUfficlt:m i, run to fill the splice b~t"ecn the two pipes . . . .hown. Alternatl"ely, the solder may be melted by tho!: Iype of blowlamp .JIUSlrlled at A'. Fig. 79. Copper Tube.-This has been mentioned above. The two most common joints are the (;3pillary and the compression types. Cop,liQry joint (see A, Fig. 78).-The application shown here is at a bend where a brass alloy elbow is used; tees, reducing pieces and straight couplings, etc., are also obtainable and they are all made on the same principle. The fitllngs incorporate recessed rings conllm;nl thc correct amount of solder for mlklnllthe joint After the end. of the copper lUbe h.ve been cut sqUire, they Ind
PLUMBING
·sfj
the . . . . 01 th. 6ttinp an; deIncd IDd broqht toldhn. A blowllmp is then applied to the au" to melt the.oldu whteh fiJI. die -.mWar ~ between the,.m beinc' joined. Tb. joint is tbu. CMily nude raultin. in • nal, comPKl fittinl. C,.".mor. joiltt.-Onc type o( this is the ff11f1-1fUlIIipvllJtitJt fitting. It cor.Qu of an cxtemaIlythrndedb..Mllloy rouplina with internal ahoulden ctaat.nc:c.~ to the eopper Nbe. A nut lInd,n umeakd b~ c:omp~ are iNidi 0'Ia' the end of the Nbe which i, then plKM ineid~ the eouplin, to fit ...... d,e.houkkr. 'The rin, _b .pintt the mouth of the couplin,. and by tichtaUttc the n\lt, the riD• • JDIId,e to triP the tube and to provide I w.tntilhtjoint.
Ktiftt _
rin,
DOMESTIC
WATER.
SERVICES
roof apace or just below the fim Roor ceiling. E" N1fII~, a 1 S mm dia. bnnch is taken off it to IUPply the kitchen aink. The remaining IS mm dia. cold pipet ue fed from the ciatem, i.~., those to the bath, wuh baain and w.e. 1 which ia auitable for mo.t The hot water circuit abawn is the direct hou.ea where hardne. depoeiu do not develop in the pipet. The cylinder it wanned by water from the back boiler which is placed behind the kitchen fire. A 22 or 28 mm dia. flow pipe from the top of the boiler deliven hot water to near to the top of the cylinder. A return pipe of the pme aize supplies water from the bue of the cylinder to the bue of the boiler. Theat two pipes are the main circulation pipes for hot water and are known u the primary Rowand return. Hot water to the varioua .pplian~ ia fed from a branch off the expan~ aion pipe which riaea from the top of the cylinder; thia pipe: acts .. a vent to eliminate air locka in the aystem and tenninates over the cold water cistern.
""u.
TOOLS
---COLD WAH"
--HOT V
",AU AllO)'
• SlO' VALVE WAS~
fl,OW
"-+-tf;+
'A liN
Fall lUeE
Drtun-, BflJI" or.Sa, (A).-Uted ror dreuinl Rat POrUont or lead. &mi. Stil:/t (a).-Uted principally ror .... orkinlle.d ruund rolla, etc.
SOlDt" otl HCi
CA"LLAkY
FIT T , N
The following ia. brief dCKription of lOme of the tools uaed by the plumber, lOme of which have been referred to, and are iIIuatrated in Fig. 79. Stui,.,i" Stlclr (J).-U.ed ror ronning uprurm of ftuhtng, worlUng lead inlO ,nglel
"
(j ~T
CO"I"
lOUtoio",,,y WAlL
WAUot
,
I
(YLtNOU.
JOINTS
I I~~ IS
B
2101128
21011.28
,,,r
HOW
.. nu"..
"
t
.0ILU.
v
DIt.AIN COC
...," .1--
WAH ..
or rolla, etc. &ui,., MaJid (o).-Used for liriking lhe,hove 100J'lnd ror workil1llnd Into comen direct. eMu Wid" ( K).-Of varlou, IhI~ .nd IIzn; 11.0 ailed drifts; employed Cor working .nllea of roll., drija, etc. on gutten where 'PIIOt il mtricted; driven by Ihe ~~ MIlIUI. I "mllir 100110 tM boninR millet. Drip Platt (L).-h inserled belween two lheeu of lead to prevent movemml of the lower Iheet where the lOp .h«:1 i. bemg worked; eumplet, ovcrdOllb of roll. and drips. B.mdi". Stulr (c).-UItd for bendil1l plpel. Bo6bfll,.-S,:tet Crom 15 to 115 mm; used in conjunclion With the melll 1«;'101 or /olf_ for bendin, pipet. l.Dty nv",,,,,. (v), /taNl tIw....y (It) and Ioul dUIIIIII,. (p) Ire used Cor bendmg pIpes. Ta"IJi" IN (.).-SIU1l £rom:l5 to 115 nun dismeter st the held; used for openmg tnd, of PIpes (lee p. lIs). MaJtdnl (T).-Used fOf' 'Imi Ir purpose .. bobb,n. for removmg bu1rc- in long pipet.. SJrm.~ Hoolu or Scrapcn (e Ind ").-Used 10 -.have the end. of pipes prior to .oldcrmg. Rtup (limilar 10 th.1 thawn '14), Fil. 67).-Used for filing end. of pipes to be .oldered. Bfofdalllp (A').-Thl' i. one of mlny deaign. in which either petrol , panffin or benzohne .. used; capaclly for genenl l i l t YlIrin from 0 ' ) to I' a htm; used for healing wider. etc .
nu..,. ..
( _ p. 155)·
FIGURE
,8
Cold and Hot Water Dittribution (8« Fig. 78).-For the average houle • t S mm o.d. lupply pipe is adequate and this is connected to the water main and brought into the house at a depth where it .....ill be unaffected by frost (460 to 610 mm). It muat be. fitted with a atop valve just outside the boundary of the pumisea and another one at ground floor level inside the houae. The aupply pipe riaeI preferably on an inaide wall to the cold Wlter ciatem aitualed in the
So/dm", tw Plullltn", /rOil (Q).-Used for heat;n; wider (e5pccially when ;omllng Ilrge pIpes); lar~ly repl.~ by the blowllntp. Cop/Hr BII (N).-Ueed for fonning wldertd joml' (see p. ISS) . Devdopmetu. of this bit are the g •• heaud .nd electric wldering iron •. Holelod BII {v).-Uled for I .imil.r purpose .. the copper b,t, .nd for I.pped jom!" Md,.", or Soldtr p,t (u).-Sozea .... ry from 100 to lOO mm diameter; used 10 mtlt wider. LDdf, (M).-UItd to apply Ihe ""der obtained from the meltmg pot (~ p .• SS). WI/JI,. Clotlt (1).-11 pad ofsevcnl folded I.yten of moletlr.m In YlInOU.IIZellnd used Cor wlpmg ;Otntl (.ee p. ISS). c_Un", TooI(I).-Uteci for aullr..nglnd and .. mldeoC CIIlat«1 (ltCpp 14l.nd ISS ). I 5« Chip X, Vol. IV for the Indlrecl Iynan.
l
TOOLS
o
'57
L
s
F1MUU
:--::::::::==::4 S TIC
~
c
»0
D
o s
NOS.
S I NG
A l
K
l
"A •
C HAS
Wf D G E
H
m
o
I • •l •
•
E L A HD
0
A T
U M M 'I
o
~
I L
u 700
B LOW l
• 0 FICUR!' 79
Dol Mould {JI').-Used for fonmng I~ad dOli (~p. ,sat Drmn1l1 Knift {w).-UMd for cUlung Iheel-lead; I chl/1pmg Inu/t, hiving" Ilron,!!!!r lind paralltl blade, II usrd ror cumng IC1Id .. II ,. 51 ..... k .... llh Ihe hammu . Bolt (x).-UKd fOf OpeniOR holrs .n the IIdrs of P'p<'~ 10 rt:«"'C bn"ch plpt'l.
Other equipment includes: Hammer•• pliers. screwdrivera. screw-wrench (for turning nUIS, etc.). spanners, soil pot (conlainjog soil required for wiped juints), ullt:-Illctrc rule, ~uarc, scribing platt: (for des<:ribing ordea on pipes, CIC.), copper tube benders and a complete outfit fnr lead-burning.
T
CHAPTER. SEVEN
MilD STEEL SECT ION S, BOl TS AND RIVETS ' \Iu.o ~teel (complylllK with B.S ..B60) is a very important building material used c:xtensi,ely 111 structural engim:er1l1g. \\cldable ~Iructural sted te H.S. 4360 IS used te a lesser e~tcnl for the same purpose. It is manufactured from iron ore (mined or quarried in certain parts of this country. S.... \·dcn, Spain. etc.) which is subjected to a ~'er~ high tempcratur~ in the blast furnace to produce pig iron, this is con"eTted into ~ted in the smelting furnace, re-heated and finally rolled to the required sectiom ~uch as plate!", anjfles, tees, channel,;, ~ams, etc. (see Chap. II, \'01. IY). Structural steds arc dl' ided i1110 11\0 ll1;lin ~roups accord in!: to the manufacturin~ process. ,i/. ( I) hot rolbl sections Jnd (2) those obta1l1«1 by cold rolling. The former comprise the heavier sedilln". St(.'Ci components are used in fi\c "dYS :-(a) as hearn!> cs. (e) as ties \\here the stre!>SCI are u:nsik. (d) in roof tnllSCS and lattio.:e girders "here the forces arc: compressi"e and tcn!oile. ,lIId (t) for the reinforct:ment in ~inforced conuell:. Characteristics ofSteei. It is ebstic, ductile (capable of bein.t! dra"n into "ire). malleable (em be beaten OUI). welJ:lhle ,lIld can he t('mpered 10 Jilr~renl degrees of hardne~s. The ma"\imurn carhon conl('nl of mild stttl is 0'z5 per cellt .. and its breakin~ ~trength in compres'Iion and tcm~ion i~ i]O to 510:\ mOll. S"mc of tht' nf;ous st:lml.lfll seclion:; inlo which mild steel are rollt·J arc IlIlIstrated m Figs. go and 1\1
HOT R.OLLED SECTIONS Flo/ Hms (A, Fig. Ro). OOl,linable in si;l.cs \"arying from J mm by 12 mm to 2 m hy Z5 mm or more, Ihe 'Iider sections being known as plat" (see E.', Fig. 81); purposes for which flals.are uS('d han: hceo indicated in prel·jous chapters (such :b bars supporting linlds. floor joists. "traps. etc.). and they are still used (but not!iO c\lensl\d) u formerl,·) for tenslOll members in Sled roof Irusses. Plates .Ire used for conoec1ions in sud roof'S. hase plates and caps of steel f'illars. dC. 'Th.s " somellm~1 Included In M hn"~~;lr cOur..., ''1 iJu,ldlnlf CunslruulUn I" f'lnl,h~Tlzt· stud.,ntl '''Ih the princIpal mcmbe ... u...,d In .trucUlr~1 dcl.llh "h.ch un, 'ncluded m ,ubK'IUttli yur, of ,he cuur.., Sleellind re,nforced ronerelt: IIfl,1<;lUrU >Ire dl'SCrlbcd In \'01. IV
,,8
Squart Bars (8, Fig. 8o).-Sixes vary from 5 to 305 mm length of side; not much used for buildin.e: purposes. RQund or Circlliar Barr or Rods (c, Fig. 8o).-Diameter5 vary from 6 mm to 300 mm; the smaller ones arc used in Ihe construction of reinforced concrete Roor5, pill;us. foundatIOns, lin!eis, etc., and the larger (x, Fig. 81) for columns. A1Ig/~s (D and E, Fig. 80 and ... to c, Fig. 81). Those WIth equal arms, arc callt:d rqual (m.r:/tf, and thc others arc known as u1If'qllal a1lglts. The~ are "f'CCi. fied according 10 Ihe overall dimt'nsions, thickncss and weight per m~ re; thus in Fig. 80, 0 is a 50 mm by So mm by 6 mm b)" 4 ·.. 7 kgim British Standard Equal Angle (abbrevialed to .. B S.E.A."), and h is a 75 mill by 50 mm by 6 mm by S·65 kgm British Standard l'ncqual Angle (abbreviated to .. B.S.U.A"); the sizes of the equal angles var)" from 20 mm by 20 mm by ] mm by 0·88 kg/m to zoo mm by 200 mm by 24 mm by 71 I kg m and unequal angles from 30 mm byzomm by] mm by I 12 kg mto 200mm by Isomm by 18mm bYi7'1 kJ!,m. Angles art' wlddy used in structural ('ngincenng, Including all member5 of J stccl roof truss. Tee Bars or Tus. These consist of a tJ:tb and aflunxt and are of four kinds: tees cut frum till' ers.;.11 lle.lIll~ and l niH:rsal Culumns (SI:e hchl\\). rulkd ICC baN with short MCd 11\ ~Ittl roof trusses. 1'ttS nlllrom ("itYnallklilns. In Iht:St; Ihe \leb is parallel and the flan,,: m ... y be parallel or ha\e a:2 5z·laper. They range in Sll.t: from 102 mm \lcep hy IJJ mm \lido:: by 1.1 kg III W iS9 10m hy lOS 10m hy l a6 k~. 1't'tst:ul/ro/ft ('"i'una/ (olu",tu ha\"e outh web :lIld flan~e parallel. They vary in size from 76 mm deep by I Sl mm \\idt: hy IZ k~.:1ll to 191 mm by ]9S mm ny IIR kg. Rul/"d slut Ir,. bars mIlt l/lllrl sta/lts have Range and .... en 'I jlh a ~ tarer. They range in Sl;l.e from ]8'1 mm hy 3R'1 mm hy i kg 10 152'i mm hy 152'" mm hy 36 kg. (:\n e"\ample of one is gi"en at ~. Fig. Ro.) Rol/td I1ttl 1ft burs fdth lo,,/( slullts ha\"e a parallel .... en "ith a ~D 13pt'red flange. The~' \ar)" from 7ft'2 mm deep hy Z5'" mm widc hv ]'''5 kg to z54mm by 127 mm hy ]5'4z k~. ChQlm,,1J (G, Fig. 80 and E. Fig. 81). The Ranges are thicker than thc web; the sixes "ary fmm 76 mm by J8 mm by 6'69 kg to 432 mm by 102 mm by
MILD STEEL SECTIONS 65'-+8 kg B.S.C. (British Standard Chann~I); the weh is of uniform Ihickne~s and the flanges are tapered from the root to the toe. They may be used as girders, pillars, roof purl in!!, etc. Th<;se can be built up for hea\'ier loads as at K, Fig. ~ I. ll"Q,"'. There are six main kinds of heam British St::mdard lln;vcrsal Beams (B.S.U.J1's), rolled steel Joists (R.S.J.'s) known also as British Standard Beams (B.S.8.'1), beams with £Ian!,!:!! plates, castellattd beams, plate girders and lauice girders. The Brll;th Standard l -1fI't~rsQI Beam is the most widely \lsed type of beam. It is 3nilahk In many !liles from 203 mm deep by 133 mm wide by 2S kg /m to 920 mm hy 420 mm by 387 kg. An example of the former is dr:awn at II, Fig. 80; sec also I, Fig. 81. The .... eb is of uniform thickness and the flanges may be parallel or have a 2 ~ 52' taper as shown at H, Fig. So. The web joins the flan~e'! wilh a small radius curve at the roots;1 the toes of the flanges are square to facilitate welding. These beams arc extensi\'ely used in the cnnstruction of I ~lany nudcnll II Cumlnatlons shu" earelenly drlwn k"CIIOnl of Mlm •. common crro.~ MInI! "ebs Itl1cker Ih'n flam~es and Ihe lau"r ellh". laperlnl! 10 ~ POint or pmvtd«l "'Ilh bulbous Ion.
S TEE L
SQUA~l
FLAT.
AF'°::3i ~
L
~
T
•
~OUND
{.
TEE
BA"i
ANCilES.
BEAMS,
• QUA L
50.50" -4'41'"
"
8
TO' fL ... ,.,Gf
EO
E
•••
CHANNELS.
ANGLE
~ ~ T
,,~
SQU~~E
'59
jloors, lintels, etc. and have largely rt:placed the next type of beam mentioned which was once the m~t popular type. Roll~d SUtl JOIst, six sizes of this are made from 76 mm deep by 51 mm wide h~ 6'7 kg/m 10 203 mm by 102 mm by 25'3 kg. The web is of uniform thickness ;11,,1 tnl' Rangl''! n:lVt a S· tapt'r; tnfO wen join' the flanges with a small radiUI> curve and the extremities of tht: flanges have a small radius a[ the toe. An example is shown at II, Fig. 81. Plotu ~Q1fIS are made by riveting or welding flange plates to the flanges of the above two types of beam, see L, Fig. 81. They may also be made by similarly aUOIching flange plates to channels as at K, Fig. 8,. Plated beams are used for heavy loads or where thick walls have to be supported. Costellottd ~oms (see 0, Fig. 81) are formed by cutting .I steel beam in a zig.zag line along the web and welding the two parts together to i:\creue the depth. This is used for long lightly loaded beams where the stres~ are greater in the Ranges than in tnt web. Hcnce the web area is reduced and the resistance to deAection is increased. Platt Girdtrs are u$ed to carry loads beyond the capacity of Universal Beams. They are of two kinds. Th~ one at 1', Fig. 81 has AanJi:e plates riveted to a
•
"
10 Tt-M.EAOS
U'" 2$
,-:~_r-b·"-jl ~
H
WE
"" "'l1.:1+:.-,t+---f-
...
t"~
....
F ~OUNO
• ~"
.-
• ~ '" U's_u,'",,,,
T E f
a,,~
i
HEX .... fLA-NGlS tAA"Y IE ,M,l,UU ..... Vl A Z" SZ' TAI'f."
O~
I"ITISK
STAH"A~O
"
aOOT
lOTTO" HMtGf.
U'IVl~lAl
20S'" '" I l I _ . lS ".
FICURE 80
IEAM
BOLTS
G
"IVETSI
p
T Y
C A L
s
T
s
E E L
E C T
o
N S
D
I o x
v
D
o
fLI'tTS
t
~OD~
s
TU&U L A"
x
u
y
w
0
Z
J'
~
'----.
L..J'
0
II
,6,
MILD STEEL SECTIONS \\eb pL.nc hy iI"Rles; this is nOl om\ !;(I cnffimun as thl' nne .11 I' II hert; the plates .m: "tided lo~tthcr 10 form J mOTl' !';cunowic.11 ~(;Iioll. Ollt; 'lPC of this bc;trll is the Autufab h(,(1111 pruJU(l:J 111 sl.lIld.lnl SII.C~ up tn :z III Jeep
by 560
Irln
v.idc and
2i III
lonJ.:.
Thi~ IS
.11,1ilahlc
III
Illild sted
or
hiJ.:h )'icld
$tress Sled .md is fOlmed by JUlumJI.L 111.'ll,;,,," \\ddil1).: wJ.:cthcr of the thn:e
plates. LIltliu Glrdrrs,
Dcuil!! at Q. It and ~, Fil-:. ill, .In: of differenl types (If Jauice J.:irdcr. the".,; .Ire used I,here pLitt: girllcl"lt \\ouIJ l'H;:comc c\ccssilcly heavy ol-er !ar.'!c "p.ln\<. They are oflen "los.xi,lleu "ilh :\orth-liJ.:ht mof trusses for cOI-cring rdrJ.:c RooT drcas (~C Fig. 15. \"01. I\) The c'Jmplc at Q requires gus;;et plates ,It the cl)llnt:clinns, bm these can he "mined when welding is adoptcd. The J.:irdl.:r .It It \\()Uld ht.- suitahle for light loads. The welded tubular one at s m;lkC! a neat pleasing design: thc tube is J sound, economical load carrying member, for II has ).:ood stiffness in relation to the small amount of metal. Prior to the U!:IC of weldin).;,1 tht: juinting~ of luhes was a clumsy husiness; the practice of welding and Ihe emplu)lllent of IUhes is increasi~. ColumlU. The most Wldcl} used columns Jrc the l'ni\'ersal Columns which range from I S2 mm hy 152 mOl by 2] kJ.: III .. i5 mm by ,,24 mm by 634 kg. They ha\e parollrl flanJ.:es. The he3m memhers at it to I .• Fi,.;. 81, can also be used as columns, as un the sections at the hOllom left-hand side of the same Fi~ure. The one:1l I I .. a ho\-seUmn m."I .. nf Iwo ch:lnnell welded to!-:'ethcr, angles can be similarly used. That OIl II is.1 n.:ctanJ.:ular hollow section (R.H.S.), this is obtainable III ~i~es from 5o-R hy .l5'i hy 2·6... mm thick by 2·8 kg to 3°4.8 by 203'2 mm by 12'5 mm thick by I .l·S kg 'rhe R,II.S. has a greater resistance to bending than the tuhe olcr whieh it al:«) has the adl'antage of hal'ing flat sides to simplify .... elding Slluare hollow st.'ellon" (:U 1.5.) arc also made in a similar range. When stanchion si/t's h:l\e to he kept IlI.1 minimum, the solid rouod section at x can be used. Beams art' connQ.:le"-' to IhlS by " cap plate which is shrunk or wclded on. The U::K' of lubes at , h;u alre;Idy lleen mentioned, they can be adopted for columns. or ~irden (':', Fi\.':. gil Jnd I'ary illli2e from 26'9 mm o\erJU dia. by 3'2 mm thick 10 86J'6 mm n.d. by II mm thick. The other columns at z to I"~ arc built up ffom the sections gi\'en to form stiif columns. The one at A has four angh.'S 10 which internal ring battens are welded, the a0Ftle size depends, of CIIUrse. on the load. For example, four 5°.8 mm by 50'8 mm by 6'4 mm an,gles made into a 1 S2 mm square will c;lrry single-storey domcstlc lipan roof loadings. The ones at B' and t.:' will carry heavy loads, the tormer sho\\s slllg1c loIClllR but double lacing in a criss-cross pattern is also used . Bolts, NMts and lI'arnns 0. Fig. 80).-Theac are used for sewring members , !Xc Chap II. Vol IV 1 The "",Ihods of JOlOllng lubular "orlr. are Ihrtt 10 number In lhe ~umple aha... n. lhe lUI)., mel, Ire m...:h,ned to fit 10gflher and tMll ... elded. Secondly, Ihe lUI)., end. ar~ fbllened, CUI 10 aIllpoe and ... dded Where the Or more tuba are connected al one potnt. lhey Ire C:1Ot and welded 10 a sleel ball or nne 10 'III h>c:h • di.phra.", plale II 'III'ekl«l
comprisinJ: wood and steel roof truSK"S ami similar framed structures, built-up wood lintels, steel heams, CIC. When the bolts ;lre used 10 fasten wood members (as in trusses-see I, I-ig. 39). washers must he introduced between Ihe timber .11Il1111t: heaJs and nulS to prcventlhe lalter frum hein~ forced into the timber as till' nUIS arc hein,!!; tightened by a spanner. A bolt consists of d shank and htad. alld, .IS shown. the proportions of the head and nut ;ample II isappro,>;imately t'6 mm. nolts nlry in size from 6 mm to 150 mm diameter, but rarely is 38 mm exceeded in buildin,g construction. Jnd 20 mm bolts arc of len employed for fixin~ steel· work; the length (which is that of the shank) Jlso \·aries. The thicknees and diameter of a washer depend upon the si~e of the Lolt; that shown at J is 3'2 mm thick and the external diamett'r i$ either 4"3 or 70 mm. Uolts. nuts and washers arc made of mild steel. I\TOught irflll and brass, the former heing used for steel· ""ork. The head and nUl shown at J arc hexagonal on pldn, and this is the type in general asc; S<.juJre-he3Jed holts (see T, Fig. 33) and nuts are oIlso made but tht'SC arc 1lU\\ rarely usc:J in building and structuntl e:tginecring_ Rn'rls Jrc made of alcel llnJ u" used at the connee[tons of llcel beams, pillars, roof memhers, cte.; the 20 mm dia. size is the most common. The Srtop-It~ad~d rtt-tl sholln at I. is the usual type employed; it is also known JS a ClI.p-htodtd " ·Vtl. :"iOle the proportion of the hcad in relation to the shank; the sh3nks (which Jrc sli).:htly tJpered) I';lry in diameter from 9 mm to H mm. The shank before fi\lllJ.: (" rivctillfi: ") e\lends to the icn).:th indicated by broken Jines and this length depends upon the diameter of the rilet, the method of riH:ting (machine or hand) and the amount of K"P (the O\eran thickness of the plates, angles, etc. "'hich are connected t~clher). The second head is formed durin~ ri\'ctin~. the heated end of the shank hetnK forced into a cup shape. Court/nS/mk Riedl (M) afC employed when the bottom head is required to finish Rusb with the underside of the lower member being ril'eted, e.g., at the connection between the foot of a principal rafter of a steel roof tfUSS and the plate \\ hich is supgorted by the wall and which should ha\'e a le\'e! hearing. Note that rivets are seldom used now in steel building framn having been replaced by welding-see Vol. 4, COLD ROLLED SECTIONS
These ha\-e been increasingly used since the 1939 war; because of their lighter .....eight. the load carrying capacity is not to great 2. the hot rolled sectiolll. Even so. they are a useful adjunct to the builder'. range of material. and have successfully been adopted for IChool and house con.truction. They Ife ideally
,62
MILD STEEL SECTIONS
suiled for prefabricated structures where the light weight leads to rapid sile erection. The thickness of metal varies accordinR to requirements. a common thickness being of mm. The shapes into which the metal can be pressed or rolled are almost unlimited and the sections haye a wide range of uses from beams and columns 10 skirtings, door frames, gutlc~, etc. Joinlin~ is best done by shop welding, bolts being needed for site connections. Cold rolled sections should be well protected from corrosion by galvanizin~ or similar effective process. Some typical sections are shown in Fig. 81, Btaml.-Dctails f, G and Mare self-explanalOry and the range of sizes is given, the stronger type of channel is provided with lips, this is known as the lipptd or box channel. Thl:rc is also the outward lipped channel (or top-hat, see F') made in sizes from 38 mm by 38 mm hy 1'2 mm to 100 mm hy 100 mm by -fmm. The buill-up beam at T is of two sections spot-welded together, it is used in lieu of and at the same' centres as timber floor joists. The hollow flanges allow for the insertion of wood fillets for nailing the floor boards. The one at T' is
used for the same purpose, it comprises a l-seclion and 1\\0 Jngles, The kinks in the web trap thc nails used for fastening down the bnarding- and so timber fillets are not needed. The lattice girder al u has a top boom of 1\\'0 lipped channels i5 mm aparl and a bottom boom of two angles. The intermediate memhers are lipped channels welded into the spaces. A similar example to this is shown in Fig. 17, \'01. IV. Columns.-These are shown at F' and G', the former being made of 1\\'0 plain and two outward lipped channels welded togelher, diaphragm plates may be welded inside the cavity at intervals. The one al G' is made witr. two cold rolled and one hot rolled channels welded together. Stanchions of this sort at 2'5 m centres have been used'to carry floor beams 6 m long which support a precast beam floor and a similar roof load above. The box channels e.\tend two storevs to the roof and the B.S.C. is stopped off beneath the first-floor beam. • Cold rolled sections can be formed into practically any shape for special purposes, some exampl~s are gi\'en at J' where' there is a skining, " panelling trim, a mullion CO\'er pressing, etc.
HOMEWORK
PROGRAMME
THE nalure and amount of homework in Building Construction let each week arc influenced by • number of con.iderations. such u the character of the course, length of each c1us period, number of periods per leHion. type and special requirements of students, treatment of subject in class, etc. The following homework schedule i, based upon the author', experience in teaching the subj«t to architectural students preparing for degrees in Building. R.UtA. examinations and those attending National Diploma and Certificate courses, and whilst it is clur that the programme cannol have general application, it is hoped that it will .uve as a useful guide. It is assumed that each sheet will be commenced in dau and completed as homework. Whilst it may be considered Ihal the programme unduly emphasizes the seclion de\'oted 10 Brickwork, il should be pointed out that there is now a general tendency to concentrate upon bonding, etc., in thc first year in order that subsequent years of a course may be free for the greater development of other seaions including those concerned with new materials and forms of construction. The programme may with advantage be modified. especially for architectural students. 10 include less brid: bonding and more details of the units of construction. It is likely that the drawing sheets will be of Az s~ze. Care should be taken to ensure a well-balanced set of drawinK', and a suggested lay-out of a sheet is gi\'en in Fig. 58. As indicated. each sheet should be given a suitable title, Ihe printing of which by the studenl afforda practice in plain lettering. The details should be drawn to a large scale, and whnn,;tr possible thue should be to full SI:U; Ihisapplies particularly to joinery details. As the length of session varies in different colleges, the I1omework programme provides (or the maximum number of sheets, numbering from twenty· four 10 twenty-eight. which mW)' be produced per session.
T Shnt Sumb.:.
Subj"Cl or Dr..... lnll
3,
3
3
3
• , • , 5
5
5
Draw, to a scale of I ; 10. alternate plans of stopped ends II, J, Ii. and L, and part elev.uions at G, Fig. 3. Draw, 10 a ~cale of I [0, alternate plans of stopped ends E, F, G and J, and part ele\'ation 0, Fig. 4. Draw, to a scale of I : 10, altern:lle plans of rightangled Junctions, A, B, t', D and ~, Fig. S. Draw, to a scale of 1 10, alternate plans of rightangled quoins A, B. D and E, and sketch G, Fig. 6. Draw (a) to a scale of I 10, eleution and plan of 'Aindo'A A, Fi.e;, ss; and (b) full size details G. J and Ii. of ca\it} walling and Joinery.
6 7
6
7
7
8
Draw, to a scale of I . 10- {O) plans and elevations of piers ~, L, 0 and Q, Fig. 7, and (b) alternlle plans of rebated Jambs E, H, Land 0, Fig. 8. I>',.'A, to a scale of I 10, complete details of piers in Fig. 7 Dra'A, to a scille of I: 10, complete details of rebat~J Jambs In Fig. 8. (.) J)ra'A. 10 a scale of I 10, &Celions through foundations A to D, Fig. 10, and sections through oundat ions s.imilar 10 A sUita.ble for 215 mm and +p mm walls; (b) sketch, approximately to I : 20 scal~, umbenng 10 Irenches 10 Fig. 40.
jJ
1 "J
HOMEWORK PROGRAMME
16.j Sh«t
Num~r
Number of Leclurn pcr Snsion
·s
••
'7
7
8
8
9
8
•
• '0
..
10
9
10
10
'.
'5
,6
'7
Onw, to I : 10 scale, Ihe arches in Fig. 15; thiek!leSS of joints between voussoirs need not be
'5
,6
'7
,8
,6
'7
,8
'7
,8
,8
'9
A,
corbels
L, M
shown. (Leave space for sections c and K, Fig. 41); I « Sheet No. 16 (or 17 or 18 or 19). Dl"llw. to I : 20 scale, portions of rubble work Ii and B, Fig. 20, and F, C and II, Fig. 22. Include quoins, Jambs, part plan A8 and section <.:0, Fig. 22; the mullions and tr .. nsome need not be shown. Draw: (1I) I : 20 devauon of arch N "lth panion of
II
" 12
13
"
12
"
13
I)
1.4
Ii
'5
16
If
I
••
and cap 0, R, Band c, Fig. 12; (e)
Sketch: (D) offset
Fig. II; (6) lintels A, threshold 0, Fi~. 16; (d) copings a, J and plinths N, R, Fig. 17.
"
'J
SubJecl of 01"11" inl
Subjro.-I of Dr..... '"Ill
walling and section at ~ includmg cornice, parapet and coping. Fig. 2 .. ; (6) I ' 5 S(;aic sections o£ cornice A, Fig. 26, Siring course n, FiR. 26, "indo\\ Sill I, FiJI:. 25. and copmgs A IInu t·, FiJI:. 27. Draw. 10 I : 20 scale. ptan. sccllons .mu part de:\ation of fapdc sho"n in hg. 24· Dn." 10 1 5 Sl.:ale. s«tions lhrou~h cornice" and string course 0, Fif(. 26, \\inJow sill .... MI plinths Q and li, Fij(. 25. wpmgs " ,IOd t·, Fig. 27 anu cornice 0, Fig. 7~t Dr"" (0) I 20 scale h... lf of pl.m" "m.l St:Cllons B .mu (. of floor, I·I~. 32, (Il) I 10 M:ale s«lion:; J and ,t, Fig. 32, \\ith aitcrnati\e skt"pt:r wall detail at c, FiJ!:. 10; (r) sketch,,:; of JOints (;, ,. and p. Fig. )2, (d) full-size sccllon tmough JOint R,
'.
'.
'0
"
'0
" "
'J
n
'J
••
'1
••
'5
'5
,6
Fig'34'
J)raw; (0) I 20 scale part P\;'IOS of Roors P, Fig. )), and A, Fig. 3.. , shuwlII~ trimming of hearths; (6) I 10 SCAle seCllon •. Fig. 34. int:luding adjacent hrillgin,::: joist \\itn cle\·"t;"n of slrlllling and SCCllullslmihir to ""; (r)tluartcr full-sizc dct .• il! of lusk Icnon I and huusedJoints M ;lnd N, Fig. 34. Draw (0) I . 20 scale t:le:ulions of R.II roof A. leanto roof II and do>-(': couple roof I, Fig. )6; (Il) I . 10 sdlle delJil" Q. M. S, G, I', X Jnd z. Omit l'>latinp: dewl,..
t .. cnly-t:ight
'1
-
-
lectures p"r _jun. ;rl<.:luJ" ".ther (u) shl'l'1
IIpon
'.
'.
Draw: (a). 20 scale e1evalion of collar roof E, Fig. 37, omilling hip', angle ties and jack rafters; (h) I : 10 scale eaves de:tails Y, Fig. 36, and L, Fig. 37, showing boarding in lieu of batte:ns. Draw I : 20 scale: put elention E and plan F of builtup truss, Fig. )9, and I : 20 scale isome:tric eavc:s del ail. To I : 10 scale, add centering for arche:s A, I, F. G, J and K, Fig. 41, to Sheet No.8 (or 9 or Io--sc:e adjacc:nt), and sketch M and N, Fig. "I. Ora": (a) I: 10 scale A, I, C and 0 of framed, ledged, braced and batte:ne:d door, Fig. H; (h) one-fifth fuU-sLte details L, 10'1 (e1c:nlion and section), N (elevation) and 0 (elevation and plan). Ora.... : (a} I : 10 scale ", II and c of two-panelled door, Fig. So; (h) full-size details H, J and K, Fig. so--architra\'e and panel mouldings 10 be: selected from Figs .•6, 48, 50, 52 and 63. Or:.w: (0) I 10 scale ". B and c (or 0, E and F) of steel windo ..... Fig. 62; (h) full-size delails G, H, K, I.. and 0, Q and N. Ora.... : (a) I : 10 scale A, 8 and c of cased frame: window, Fig. 58; (h) half full-size details K, I., fool and 1'1. Draw I . 5 scale: ....ood and slating ea\'e:s and ridge: details A and eaves details F and G, Fig. 71. Cast-iron guller to be: shown \0 e:ach case; incorporate a swan-ne:ck bend F. Fig. 77. Alternatively, dra" one-fifth full-size plain tilin~ details, Fig. 72, and interlock,".': tile details, Fi~.
39.
Ora"' (a) flill-size: de:tails J, R, " and s, [·il(. 74, (h) one-fifth full-size details" and o. FiJ!'. 7). Dra.... (a) I : 5 scalc :!>tclions f, F and G. Fig. i (h) sketch, appro"\lmalely to I . 10 scale, ". L. \1 and :\"i (I") dra" 1 10 sl:Jle de1J.ils II. I' and Q. Fig. 75. Dra\\ full-size stc:el sections I), F, G and H. hC". ~c , sketches () Jnd A', Fig. 81.
-
Iinmestic w,Ih:r services, Fig. 78, or (h) one: on stairs, Fig. 65.
is
-
,
INDEX A
Abutment,
1;
Air bm:h, 00-6. Albumum, H Anldt buds, '07, 1112 lInfn, 39 Cle. 7J
An)(lel. stttl, '!II, 107. ISK. '5<,1, ,60 Annual ron~, SS, ~Ii, ~IJ, .~'" Apc.oJl JIO"", 52 Au.de.211 Arch". '"eu bncJc, 1:4 cl ...,hcaln>n,1;2 construction, J'1-2.4. Ho.I:I:. Rat, :12-2.4, -I9.1k1-111, 'B. lOS. ,,(, JlIUj(N, 2)-24
i.,k.
24
p"rpok-mlLl" bnck, 2:1, 24 rough rellt\'lnl(. 24 5ellfTlent.I,
'J.
IJaIl , ... 10,12, 1;(, Ulltlena, ~6, hy, 114-116,
21
A~rCIC'lc.,
lJillh atune, H, )11
"f. 49
Kflllcircul.r, "4, 49 soldier, 20 stone, )9...6-49 term_, 2.1-:1'1 Arch,II'1IH:I,120
Arri., I, J. S K«ne', c:rmenl, j:l. 107. I:t.J ArtlficI.1 RllOnlnl(, ~_~'s6 Ashlar, 40, .U-S2 Alphah, '7. 69. 70, 1~2 Auached plt'rI, 12-1]. III Auger, 118
Axe, 1:18 And-brick an::h«, 24
• Band. and IfUdgoeon hooks, 90 Banker muon, ]6 Ba~facrd Itnon, 90 Bllfk, 55 s.rs, atl!C'l, "21, I ~R Bue~. 3S. J6 Bastard luck POLnllnl, 3'
Bond-conld
lI.ulks, 55 Ik.urd joint, JI Ik.us, mm", III , 112, 11.~-117 \lul.'r, liS lle.mlillm ll.77. ql Ikanll, 11.'..1, 51'!. r.W-Ih2 Uearn1l. l/:ulIl'r, 70. 7b, 14H Iku. J. JH, l'J lmnlS, 3. 22, ::Z]. 2,. • .10, 11 ..1'1. ,.0, m"ulus. ;4 lkuumJ,(, 17,21.411,60, M4, '04
srtlppcd cnus, 7 stretch"'lI, 4. 7 Bonue .... , 40 BonumI/:. l-I.~. "o-H
Boss"'g, 1,,2 m.lIcl. ISh 5trC~, 142. 156
He. dlru b,lt". 4. I J clOI':rs, 4 hllUn.cheu JOlm. 65. H houS('u Joint, 65 rdr"l'djurnt, 112 IIr.ch. W HlruAllourhj
sUlre.kl, UJ. 124 therm.1 insulat,on, ], 58, q.I lOo,ndoWI.IOJ
sa";
ButtT"S$e•• I] CIPP'n~. 1'1
Bnck"ork,I_]1
'J.',
lOS, 11('
c
f')oI,nt!'. IS. Ifr. '7 Irntcll. 20_:U phnthl,211 5,Ib, 24-::z6. 104 rhresh"lus. 2fr Bnc~11\ n', crJfI, J IIndd.yers' lools, 211 IIncks. 60-61
Cllclum sulph •• ., pluters. J2-]1. 67-68 C.lllpers. 125 l'Ymbcr, 22-2) C.mh,um,55 C~p,IIIr,' gTOOU'S. 107. '+4 C.rpo:ntr,-. H-b dl"fimllOn, S8. II] C....m.,m r~3'''''':'~, 'U7, IIOJ
"r.
811Uffil'n,17 Black onon ... 47 Bloc~-rn-cou •.., munnr,', 42
.""J, '££,
24
haU.4, '0. 12, 'l. 2(> hollnns..·, 4, 12. 2t>
Bloc~rnR coorst', ~2
Slo"l.mp. '''), IH, 156 Slul' StUloro.blll.r bnc~ I) p_c. III Doardlnl/:, roor. 114. I J7 ilouds Roo.. 57, 5'1,61-67 Boulrr, J8 Hobbrns, 1~8 . 1504. 156 ilolrction moulu, 'I). <)6 8olstrt. ::z8 8ohs. blTnl. 86, 88. I 'Q Rush. 87, <)6 llfO.ugh! 'fOn. 20, 7J. 77, 161 Bond. drfinrlmn, )
Sll~.
closers, 4-1._ coprn". 26-211 Udl~lI,
.~.,I.,ton. OJ7.
1_2
1001.
racing,
I,
Cemrnt,2
purpose-midI'. 4. rubht·rs. ::z::z. '24 und_facrd. l'
hudm¥".4
san<.l-hme. I
JUnCll0nS, 9. 10 Pll"rI. 12-IJ quo",., 4. 10, II
spo:ei.I.4
'I~CS,
spIn, 4
Il"rml, J-4
\\clltht.2
,0,
~I,
fill.,IS, 152 HO.[lOg coat, J I. "4 If.oul. 2, 20. 45, 47. 5J monar,::Z, 12. 17. 18,26, ]1. 45. 47, SJ \\'ll"rproorrrJ, )T, IJS
n, l4
) 21.
_lr .. -COlt, I
~o
Cillty ".11. J, 4, IJ. 106. 1.111 e.,lhn", JOIS[I. 72 CI",lrn"", 67-bII. 74 e.,II •• B
pllOth,211 pU'ned, I. )0
II, 12, I J f l . r::z
156
ell CliO moulu. 48,
.10
jOlnt'n" IInu porntrn". )0. ] 1 mOlnufll(:tuR'. 1.2 p,ers.ll·'l
Q,
911
elul~IOIf,~. 14], ISS
UOI(I.,",4 I. J han<.l_maUI".
'07
Cl$l"menlS. l0 4- 10<,I el'IO~. f ..med. QII pll,n. 'no y.II. """,, 101
ch.raeten",cl,I-2
dOli"
R'bAl~ j.mt-. I], 14 Imlt1c FInnish, 7. 8 IlIIIIli, Ill. 1]4
.111" concrcte. ,II
I1oI\lnl/:. ~II 126 Brace ~n,J bill, 1211 "rael"ll. S2, SII. 90 H..d .... I, I::ZS Btlck archei, 2'_2". Ho-II::z, con~trucllon, 24 C<)P"'I(I.26-21'!
lJo"
~7
l~'·nurnj.( 1c~u P'PI"I. 146, 148 .II"~. '4!1,IS6 Iklrl. 2H, '2~
tooth, 40 doublr Arml.h, 7, 8, EnRlrsh. 4. 6. 7, K, Q,
Brrulh Columbian PlOe, SQ, 64 SUlldinl( Rl"gulltion.bAlustrade, 124 Hoor jt>iSl., 60. 6S rnundlttonl, J /I hnnhl, 61, tiS. 67
IIQUUC I~mhs. I)
lit!. ~o. 1H, 1)5
n.
~J, 2 ..
•
nelt erment. n plul(. SJ Cl"nt.,rrnlj:. 24. 8o-b Cha,n, dOIfS. 54 I......
,s. 54
Chaml. ush. 109. IIJ
IN DEX
166 Ctumn~I •• 11«1, IS8, '59. 16~
ChIpped gram, ,58 ChIsel drafted marillnl, 39 Chisels, 0118, )8, 39. 126
C,rcular uw, 10), 1:18-129 carborundum, )6 diamond, J6 Circumferential .hrinklt!C'. s8 Clamp, 10118
C""r.
I
Clay-holn, 39 Cln.I, ,8
Close couple roof, 72 Close-pIcked ..... Ihng, 4:1 CloSord mon,ce and I~on jomt, 8)
Closers, "'1) Coa.::h KrewI,
u.s
eoan.!: rrlm, 57
Cold chiHI. 128 Collar roof., 7011-, .. ColumbIan pme, ~9 Comp.u"I, 12 5 Comp.,. saw, 1:16 Compo. a Compound "'alb, 47 Compresaion Itre", 19. 6~ Concrete, a, IS-I7, 61, 6.. , 67. 68 IR/E,ell'"es, :I blocks, H
Hoo",,6 .. foundaltOnl, IS-I, hurt/ •• , 61, 62, 66, 6, hntel" 19, Z I, 24. 48, ,6, 106, I IS
matnx, 1 rmx,"s. :a no-fine., 3J proportiOning, 18 reinforced, 19. :11, 24 ... 8, ,6, ,06, 11,5. lal.
124
',Ie, 18,6, ContinUous vertIcil jo;nlll, ] • .t. 7. 10, U
Convenlon. tImber, ,56 Copinga, 26-28, 51, 52 apex-$tone, ~2 briclr.-on-edgc, 26, 28 brick-on-end, 18 bulinOK', 26 fnther-edlr', 5:1 knHier,5:1 parallel, 51 rakinlf, 51 saddle-back, :18, 5:1 segmtntal, ~:I aemicircu.lar,26 sprinlr'r "one, 5:1 Copper dunp proof course, 18 tuba,ISS-15 6 Corbel" 18.19.61, 67 bracket•• 61
-
Cord. n .. h. 109, 113. liS Corn'CH. )6. )9, 50-5:1, IB prot«tlon of. 15:1 Corona, 5' Corrulfattd saw edge £astenel"l, 125 Counter.banen•• 1]6, 1)7,1)8 Couple roofs. 72-74 COUrlel, ),4
Cover t1tshmgt, 14)-146, 148. 150-152 ('radlin!!' illC'«. 67 Cnmped ;oml, 53 Cnmpln,ll doo,., 101, 10) floor boards. fI).(q C.,.mps. 52, 6]-64. 102. 1211 Crt1Ismll:, Ille, :18 Creosol", S6, 60 CroA-Cut sa,,'. us Cro"n,21 Cuban mahotrany. 59 Cuppmg, s8 Cup .hakes. 57 Cup., 106, 124-125 Cunmlf Iron, 126 l...u, '0) Cyma rt'CU mould, 50, S I re,'ena mould, 50, S I CJ11lal!um, 50, 5' D lJamp proof courtet, 16-18,28 ..phalt, 17 blue Staffordshire brick, ,8 copper, ,8 fibrous asphalt felt, '7 lead, 18 plallic, 18 slates, 18 Uead",ood,57 Driecu In It......" 39 clay-holes, 39 mottle, 39 sarw,t_holes, 39 shakes, 39 ahclly t.J'$, 39 IInailcrttp, 19 Defe.:It in timber, 57-58, 60, 61, bo¥nnll. 58 dupped grain, 58 arcumferenual ahnnka ..., 58 coarse gnln" 57 cup thakes. 57 cupping, 58 deadwood, 57 doatmest, 57 druxmn8, 57 dry rot, 57-58, 60. 61, 77 foxineu, 57 hurt . hu.es, 57
Defecu on umber--contd knots, ,57, 59 thnnkong. 58, 84-86, 91,120 .welhng, 58, 98 tWitted gnlln, 57 upseta'i' wane,S w"p, 58, 59 wet tot, 58 Derbythire Itone, 35, 36 intached plen, 12, 13, 17 Olmmi,hlnR couraed work, 131, 134, 13!,
'J9
57 Dop. Door chain, 91, 96 locks and IUchn, 86-90, 96, tOO atop, 100 Doon, 83-103 da"Ifiatlon. 8.. flu.h,9 1 framed, ledaed and bauened, 90 ledlltd, braced and battened, 90-91 hangmll, 116, 90, 91. 96.100 ledp:ed and battened, 8.-88 braced and battened, 88-90 manufacture, 86, 90, 100-10] panelled,9 1 -103 prepanllon, 86, 90 proportion, 8" ai:tel, II" Dot mould, 157 Double, boarded floors, 6. elves course, 135, 1.0 Flenush bond, 7, 10, 12, I) roar., 72-77 tenons, 8 .. , 90 Douglal fir, 59 Dovelail saw, 126 Dovetailed h.h'ed joint, 7:1 houted joint. 65, 74 tenon jrunt, I 12 Dowelled joinfl, 5:, 53, 83, 84 Dowel., 49. 5:1, 53. 83. Down-Plf>Ko 154-155 Drqon beam, 69. 74 Orap, 38-39 Draught be,d, III Draw pinned .101 mortice and unon joint, DOIiIiI"lCSS,
n.
a..
n
8, Orcsacr, 142-143. 156 Onll., ponable electric, U9 Drip plate, 156 Onps, lead, 14a, 143, 146, l..,s Orwrineu, ~7 Dry TOt, 57-58, 00, 61, 77 Dummy, h.nd, 148, 156 heel. 148, 156 10nR', 148, 156 Ouramen, 55
E
Ea,,", defuution, 61) doted, 69, 74-n, 138 courx. alatina:. 135 Jilin«. 140 Hu.h, 60} gulten., lSI joll'U, 159 open,. 61), 74, 138, 139 ,proc:keted, 69, 74-76, 137-139 Electnc power toola, 1:18'1]0 Elm, 59 Endose"" 55 EacutWcn, 88
Ex.O(lt:ftS, 55 Expanded metal, 6'] fuc:tenaion hin.,es, 107, ExtradOl, :II, 49
101}
F
race, 3, ]8 Face-bedded .cone, 39 Fa$CII board, 61), 70, 74, 77 Fatteners, corrupted 1111«11 uw edre, us Fender wall., 18, 6, F.brou. asphalt fdt, 17. 68, 61), 135. 137 FII"re,s6 Finlltr pbte. 100 Fireplace hHrth., 61, 65. 66 F.rmer clute!, 1:16 Fi.rrinp, 70 room&, 73 Fi:.ed ..~, 107·'01} Flaahinp, 'pl"OD., 143, ISO horizontal COVeT, 143, 1+8 raking cover, 143, 151 atepped covtr, 143. ISO-IS' Flat root's, 10, l..,s Flint w.llinll:, +4'4~ Floor, oo.rd •• 57, 58, 61-64 JOOl". 58, 60, 61, 603.67 FlooTl, double, 58, 6.4 e!eaning off, 64 concrete, 6.4, 68 protcc:tion, 64 .ingle, 58·6'] tnmminll, 61, 65, 67 tnple, 58 wood-coven-d concrete, 64 Folding wedges, 6], 80-82 Forked tenon joint, II a Foundationt, 15-17, 40, 45 brick foottnp, 16-17 conc:Tete, IS-I, and rootings, 16 1I0ne, 40, 4' Frame IIW, 36, 126
.,6,
INDEX Framf'd, k-d!<:t:d and rn.ucncd door, 90 It:dged, braced and battcned door, 90-9' Frames, door, 8J beddln~, 13,8 .. ,107 ",mdo\\, 10J-IIS. 119 ,:.to Frankrd jolnl, 104 Frenchm.n, "II Fne~e, 51 Froll, 3, JO
G Gable wan, 4" Galleted joints, ,,0 Gauge-stick. 131, 133 Gauge, Cllttlng, uS marklll~, uS mortlKe, '02., 125 p.nel, 102., 125 roo, 2.B, JO slick. 11' Gcn"nl jmner, .03 Gimlet, 12.8 Glass, 106 pane., proportion, 106 plpering, 102, u8 Gla~ing blrs, 104~I06, IU, 119 beads, 104, .06 Glue, 83,84, 102, 112 Gluing, 102, 112 Goug~, }8, 39, 126 Gnmte,35 Grindstone, '28 Ground floor, 58-64 Grounds 98, no Grout. 2, 20, 45, 47, 53 Gud~on hooks, 90 Gutters, 70, 77-78,142, '46-148, 152-154 Gypsum plaste... , 32-33
H Half-bata, 4, 5 Hslf-llpped joint., 60, 62 HII .. t'd joints, 108 HanuneT'!l, ::t8, 38-39, 128. 129 Hind board, 28 Hand-dreued II
Ha",k,28 HeadH, 3, 7, '0, ,1I~19 , 40 Headin" bond, 4 joint, 63 H ..ad-nall .. d &lIl1n", 76, 13 •• 137-l.1ii H ..arl shakcs, 57 HUllng,45 Hearlhs,67 Heartwood, 55 Herrinl/-bone Sirutun!l:, 67,7° Hinges, bun, 90, 96, 100, 107 eXlensiOn, 107 sk.. w butt, 100 llrap.90 T, 86, 88, 90 Hips, 69, 73-7", '36-137 511llinll, 135 tibng, '36 Holderbats, ISol Holdful, 128 Hollow bed jOlnl, 53 Hom .. w"rk prognmm .. , ,6], 164 shecl, 101} Hori~ontll .lidmg Juhes, 119 HornB, 65, 113-84, '04, 112 Hou.d jOints, 60, 65, I I I , '23
19m,ow: rocks, 35 Imposl,22 Inhands, ·n, 115 Indenls,4 Inner linings, 10I}-112, II) Inlers..Cl10n, brick, 10 IntradO$, ::tl, 49 lronm()flgery. See" Hard .... ar.. "
J jllck arches, 24 raftera, 69, 73, 74 jambs, rebated, brick, 13 square bnck, 7, I) Joggkjoint, 20, 47, 5'-52 joggled arches, 49 Joiners' tools, laS-I)o jOinery, 8)-1)0 tit'finilion, 83 Jointer, 211, 30, J I Jointing, )0-3', 36, 94 joint.; briCInooTJ/. a"d maJmrry---bed,), 22, a3, 24, JO, )1, 39, 41, 47 bun, 10, 52 continuoul vertical, 3. 4, 7. 10, 12 crampt'
joints iJrulro.'f}rJ/. and "'aJonTl~nld jogglt:, 20, 51, 52 k..}'ed, JI mlUOnry, 52-53 mason's m.t"" .. 9 plugged, 5J projt'Cling, 30, 3 I rebaled,5 2 rt'Ccs.ed, 30 rusl,cal..,J, 5" saddl.. , 5' .truck, 30 o\'erhand, )0 tongued and grooved, 52 vee, 31, 52 Jo.nlll· mrJ>i'nlr.l' andjoirury--barcfact'd lenon, QO be\el rebaled, II ~ bt'\'elled haunched, 65, 7 .. houscd, b5 ImdsmoUlh, 72, 73 butt, 6, doled m<)TlIC" and lenon, 8J cogKed, 60, 62, 73 double lenon, 8.. , 90 dOH'ta,led, hah"d, 7:.t housed, 65, 7J tenon, 112 dm.'dled, 84, 90, 94, 100 draw_pinned slot mortic .. and tenon, 84 fishing, 73 forked tenon, 112 franked, 104 hIIlf-llpped, 60, 73 halv ..d, 104, 112, " .. haunched mon,c .. Ind tenon, 8), 90, 98, 104,112 h...ding,63 houled, 60, 65, III, 123 mitred, 64, 93, 120 mitred and rebtil ..d, 122 mOrlicc-d Ind lenont'd, 8}, 90. 94, 102 nOlched, 60, 65, 72, 74 oblique lenon, 73 pinn.. d, 74, 8J ploughed and longued, 63, III rehlued, 61, 63 rebtited, longued Ind grooved, 6J scarfing, 73 scribed, 9),104,112,122 splayed, rebatt'd, tongued and grooved,
.]
aqulre, butt, pllin Or .hot, 6,,63 hauled,65 .tub tenon, 91, 102 tongued and grooved, tl3, 66, 86, 122 grooved and belded, 116 grooved and V-jointed, 74, 86 IU.1t tenon, 6$ twin If'flon, 100
Joinu. pll.lmiJingcaflilluv, 1~~-1~6 compreSSion, 156 copper bl!, '4J, 156 down_pipe, .• 54-I 55 drip., '+4eave. gUller, I p laps, '4-4 rolls, 14-4 welts, 1+4--146 wiped, ISS joins, floor, 58, 60, 61, 63, 65-67 .;zes, 5B, 60 lrimming, 65 jumt)CB,41 K
Keen..'. c .. ment arri., )2, '07, I2J Kenl;sh rag, 42 Key brick Or stone, 21 Keyedjoinl, )1 Kiln, ' Knlpped flcmg, 4.~ Kneder, 52 KnOll, 57, 59
L Lac..d. vllIey, I 40
Llcing courses, +4 Ladle, 'SS, 156 Laggings, 82 Lak .. Oislrici masonry, IB, 40. 45 Lancashire Silles, '3', '32 Lap, 4, '34, '37, '38, '39, '40 Larrying,45 Latch~, 86-90, 96 Llths, 67,1)4 uld Ipron, '4), 'So burning, '4], '52 chlractenstics, 142 covered corniCH, 51, 15::t damp proof COUBf', 18 dowels, 104, 152 drips, 1+1Rashings, 142, I,,), 150-151 Ran, 70, , ..8 gUHn., 77,146-148, '52-154. ISS hips, 136, ISO manufacture, '43 pipes, 14J, 146, 148, ISS pltch,69 plug, 5) ridga, 1)6, 15::t rollB, ...... uddle_piect', '5a
.48.
r 168
IN DE X
LucI-contd. MUcn, 1)6, IJ7. '4l1, 143. ISO-IS'
ta.,
I,U. ISO
vallcy*. 137, ISO 'A'eciga. I,U. 151
"'''elihu, '42 'Atlll,I+4-146
"fIool, 155
LHn-to roof, 70-71
I...edau. 84-90
Leiter pl.te, 96
Levellen, 41-42 Lewi_.H Lier botItd, '50
Liflina 'pplianeet, 54 Lime, a
h)'dnted,
)1.
hydnuiic, J I lTLIif\ul.n, JI mann, 2, lI), JI, 47, '15
black,47 w.terproo(ed, J I putty, 23. JI, Ja, 53 LimutoM., 35. )6, 42
B.th. lS, )8 Kendll,45 Ponland, 35-36, 39. 49, 53 Line and P"UI, 28, ]0 LinUlI', door, 96-98. 101 ....'ndow, 109-11:1 Lmte.l., brick, 19-;u, 107
concr-ete:, 19. :II, 115 'Ione, 20, %1 wood, 19-20,99
Lodr, monioe, 88-1}O. 1}6.
100
rim, 86, 18--90. 96. 100 de.
M MKhlne-drea&ed .tone, )6-)8 M~na, brick, I cin:ular Ilw, 36, 10), 1:18-1:19 Cllrborundwn, )6
diamond,36 fJWne laW, 36 Itnem joiner, 103 morh,,",. 10) panel planer, 10J planin( and matchilll. 61 and mouldlna:. J6 pDewnltic draain, and carvin, plant, )8 rubbi", bed, 36 lind paperina. 103, 128 .I.te boline, 133 IPlndle moulder. 103 au.rf..ee planer, 10) tlU~, 10)
Mahopny, 59, 1)6 M.Uet, u8 Mandril,156 M.ple, 59, 64 Mlrxua, chIsel drarted, 39 M.riu", ....1, 125 Masonry, 35-54 MIIIOftI' milre, 49 tools, 28, )8, 39, 119 Mutlc, 04, 84,109. '48. 154 Match boardmg, 86 M.nix, 2 Medulla, 55 Medullary ray •• 55-51), 59 Meetll'\i ra,l •• 111-112 Me1tina pot. 156 Metamorphic rockl, 15 Mica. 39 Mild .Ieel.nlles, 21, 158 beaml, 58, 158 bolli, 73. 78, 161 chlnnel., 158, 16, chlracterillic., 158 cold rolled, 158, 161 columnl,161-11)2 flat ban, 21, 61,158 manuracture, 158 nutl,161 nvell, 161 round bt.n, 21, 68,1511 sqUire bin, 158 .tnps, 73 lee bt.n, 158 W1IUlen, 161 Mitre blocll:, 10). 128 box, 128 joint, 49. 64, 74, 9l, 120 ~ut.re, 125 templet, 128 Mitred closer, 4 and rebated joint, 122 Moisture conknt, 56, 59 Mortlr, See "Cement Mortlr" and " Lime Mortlr " fillets, 1,2 jointina and pointiDIJ, 30-)1, 47, 52-54 Mortite chitel, 10l, 126 , lock, 88-90, 1)6, 100 Mullet, 102 Mullions, 4), 49, 104, no Muntin., 91, 100, loa-103
N Nail punch, 64, 118 Nailm, 800r board., 63, 64 d..- and open, '41
Nidi, 124, '3), 1)4, ')s, 1)7, 140, 143 alummium alloy, 133 chrome-iron, 133 cornpollilon, I]] copper, 133, 14) cut clasp. 124 Roor bradl. 124 plVUlitcd ... Muahl '"'"' 13] jomers' brads, 124 lead, 13] needle pomll, 124 panel pins, 93, 124 Ipikes, 124 wi~, 64, 114 wrought, u-4 :tmc, 13] Nuural ~d, ]9 seasoning, 55 Night latch, 96,101 Norrolk la,,,h, 85, M, ~, Notched joint, 60, 6S, 71, '4
o Oak, S9, 61, 64, 8).1)6, 104, IU Oblique tenon housed joiJ\l', 7), 84 Offsets, 16, 18,61 Ogee mould, 51, 93, '09 Oil can, u8 Itone, 128 Open slalmg, 135 valley rutten, 1So Outbandl, 49 Outer linings, 109, f II Overhead struck joint , )o Oversalling CO!,Ir.$, 19 Ovolo mould, 51, 1)6,104
p Pld,ltone, 12,73,78 Pld """,126 Padlock, 86, 87 PllIeu, 14, 96 Pinel mouldin.., 9)-94 bolection, 9), 1,16, 101 pllnted,93 solid or IIUck, ~I, 9], 99 St.jUlre,93 lunk,93 planing and thickne..inIJ machine, 10] ..w, 101, las Panellet4 doors, 91-105 flush,9' four, 91, 1OD-102 manufacture 0(, 100-103 linale, 93-91 two, 9:1, 911-,00
Pinel., "It, 91, 93, 101 "Ised and chamfered, 93 and fial, 9] lunk and fielded, 9], 96 lunk and moulded, 93 lunk,9] Plnliles, 68, 69 Plrapet., 51, sa, 77, .46-148 fUllen, 52, 77,141)-148, 154 Pltina chisel, 126 Plnma bettdl, 109-111 IlIp', 109-111 Pebble-dl,h, 34 Peii'es, 131, 1)4 Pencil-rounded, 93 Ptnnubility, 17 Perpends, 4, 30, 133 PIC1U~ "ill, 120, U2 Plen, 12-13, 18,44 fn"ndlt;onK, 16, 17 Piluten, 12 Pincer" I Pinned, jomu, 14, 83 P,lCh, 69. Ill, 139, 141, 161 pine, 59, 64, 104, 112 P,tc:hinll tool, ]8 Pllh, S5 Pit lind, I PIVoted ...hes, I'S-119 Pllin 1t!II'\i, 68, 69. 70,139-141 Planes, l16-u8 bead, 126 block, 116 bullnose, 121)-11, comJHI", 126 holfG,", and round, 116 Jack, 10:1, la6, 127, 129 meell IITIOOlh, 126 plough, 102, 126, 127 panable eleetric, 129 rebtlte, 126, I a7 router, 116 .r.oulder, 118 trnOOthil'\i, 101, 116, 127 .pokeshave, 116, 127 toothina, 126 tonauinl' and grooving, 126 tryinK, 102, 116, 117 Pllnks,55 Pllnted mouldl, 93 Pluterina, 31-34, 67-68 Plutic: wood, 12:1 Plate lock, 88 Plinth b1oeb, I aD Plinths, brick, II, 18 "one, 36, 49-51 Pl~na, 70, 14, 91, III chllel, 126 Plumb-bob, 1:18 Plwnben'tooJ.., 1,6-.S?
as
s..
l 16<)
INDEX Ribe.82 Ridre'COU.IW.
Plumbin,. r..,a-I57 teI!Da, 142-146
III
Pointina:
I).
IB, )0, JI,
buurd bid, 3 I rule, 28
135
~ft tlwi. . . 56
Plywood, 91 Pocket c:hitel, 126
Poekeu,
tl.atinc,
tiline,I35-1)6 ~ 61), 71. 1]5-136, 140. 141
Plumblna-up, 30 Plumb-Nit, :a8, 30, S4
a.., 140. '43
tuclr., ]1 Pole plate, ,8 Patina boarda, 79. 80 PoUed facina, 45 Polygonal _lling, 42 Poroaity, Portable power tool., 128-U9
I,
Portland cement, :& .tone, lS, 36, 39. 47. 49. Sl Priming. 8. Principal nflen, 77 Pulley Itiles, 10I}-1I9
Pull~, 101}, III, II]
Purl;"" 60). 7], 77
no, IS .. lime, 2). ]1, ]2, 53
Putty, 106,
Q QUfonies, 35. 36 OUf.rry-dreued atone, 38, 40, 44-47 Quarrying Iione, 35. )6 Quarry "p,)8 tiles, 25 QuanerinlJl. 56 Queen dONn, 4-IJ Quirked bead, 1%3, 116 Quoiru, 4. 7. 10, "0, 'U. 47
R Racking blCk, 4 Raften, common, 68-77 hip, 6<}. 73-7<4jack, 68, 6Q, 75 prlncipal,77 vIlley, 60}, 73. '49 R,il., 90-112 Rain-wlter good_, '52-IS': Random rubble, )8, 40, 4., 45 ,111H, 1)1, Ill. 1)6, 139
R.I.p', uS, 156 Receu, 11 Redwood , SQ. 60, 61, I~, In Reinforced brick lintel, ;10-;11 concrete, 4,1;1,19, ;II, 70, 106, 110 hntd., 19, ;II, 106. 110 Rendering, 33-34 Re-poinling. ) I Revni., I)
Rim. dft,d lock, 88 latch, 88 Iodr;. 86. 88-90, 96, 100 nisht latch, 96, 101 Rirll. arch, 21 Ripper, I ] ) Rip tlW, Ip2, 125 Rite. 21, 69,12) Riten, 41,123 Rivera, 161 RoKh bed, 3S, )6 Rod., Ktting out, 101 Iteel, 21. 67. 68, Is8 RolIl,lnd, 144-148 ROOD, clauificalion, 69 close couple, 71 collar, 71 couple, 72 coverinR, 68, 70, 111-148 double, 71-77 lean-to, 71 fbt, 70, 142-148 lean_to, 70-71 lingle, 69-71, 73 lema, 68-69 tnpie,77 Itus.;.,d t~fl~r, bo), 77 trUISC'S, 69, 77 Rough picked wallmg, 41-"" reliel'mg archu, 14 Rougha..t, 3] Rouler piane, 126, 117 Rubben, 11, 14 Rubbll'lg bed, ]6 Rubble work, ]8, 40-47 Rulet, 18, uS, 157 Runnen, 71, 74 Rustu:aled joinll, 51
s Saddle-joint, 51 Saddle-piece, lead, 15;1 Sand, l, ] 1, JJ, 47 Sand-hole., 39 Sand_papering, 10) , 118, 119 machine, 103 ponable electric tander, Il9 Sindsionell, ]5, 36, 47 Bradford, ]5 Huddenfidd,35 Lanclllhire, )5 Stancliffe, 3S, )6 Woollon, 33, 47 York.hire, ]]
St.~td_
Sap, 38, 55 Sapwood, 55. S9
SathasJepu.l.l~,I09,
111,
II]
balance. 109, 115 catches, 117 cluina, '09, 113 dati. 117 cord, t09, "3, 115 eydeu,123 £utener, 111-113 handle, 113 lif1, 113 pivOtl,115- 116 weight., log, 113, 115 Sashes, lo)-no Saws, 18, 36, 10l, 103, U5-n6, Il8-119 5cabbling hammer, )8 Scantlinp, 56, 106, III Scontion., 47 Scllper, 101, u8, 156 Screed,64 Screwdriven, 1l8, 1l9, 157 Screw" 106, Ill, 114-115 Screw-wrench, 157 Scribing, 7., 9), 94, 104, 111 pllte, 157 Scutch, l8 Seasoning umber, 55-56 Secrel nliltnR, 6), 6. Sedimentary roch, 3S Self-faced Iione, 38, .S Selling-in IIICk, I S6 Selling 01,11 doon, 101 Shlkes, 39, 57 Shale, I Sha\'e hooks, 155, 156 Shell.tretl, 19, 11, 65 Shettlng, 79 Shett lead, 141 Shetudizing, 107 Shmgl«, 6g Shrinkage, ss-s8, 93, 110 Sills, z4-16, 49, I~ , 106, log-III, 118 Silver, 54 Silv~r grain, 56 Sizeuick,I3 1 Sizes, finished, 61, 94 nomll'lll,61 Skewback,ll Skinmgs, 110, 111 Sllb tawing, S6 Slaking lime, 1, )1 Sllte damp proof coune, 18 holing mlchine, 1)1 , 13) Slalen' lools, 131 , 131 SIIIe., 18, 35, 1)1-141 chinclerilllCl, I) I, 1]1 C(lnvenion, 131 formation, III pilCh, 69, 1))-1)4
prepqwobon, 133. 137 quanym,.I]I, ,\\Aeen, 131 1UCI,13 1 - 131 uUy, t3. terma, 11J-134 weiaht,70 SLatirll, 131-141 Sleeper Will., 18, 60.61 Slip, 1 atone, u8 Slurry, • Snap betden, 7 Snecka, 4. Snow boards, 146 Soaken, 1)6, 1)7. 14', 14J, 150-151 Soffit, 69 heI~n, 69, 76 boardl, 69, 74, 76 lining, log Softwoods, 55, 58 Solder, 14], ISS, IS6 pot, 15S, 156 Soldering iron, I S6 Soldier IIches, 10 Solid mould., 91-9]. 99 Itrulling, 67 Spills, 40, 4S Span, 21, 68-69 Spandril, 11 Spin, 68, 70-77 Spindle moulding machine, 103 Spirit levd, ;18, Ill!" Splay bricks, 4 Split brick coune, ;10 Spring wooe, 55 Springer 1I0ne, 11, 51 Springers, II Sprockell, 69, 74-77, 1)7-139 Spruce, 59,61,81 Squared rubble, )8, 40, 41-41 Squares, 18, 38, 101, u5, 157 SlIff held, 109 SlIin, 11)-124 SlIncliffe stone, 35, 16 Siaple,86 Steel. See" Mild Steel" Slept, brick, 16 concrete, ;16 Slone, 16, 49,11) timber, 11) Stiles, 1jIO-119 Siock lock, 88 Slone IIchel, )9, 46-.9
.1.
COPIl'lP, Sl
cornices, ]9, 46, 5", SI-Sl fOOlmgs,4° frine, 46, 50, S I lintdl, 19, ll, 49
INDEX
'70 St~rche~,
SIO~ntd.
mulhont, 41, 4J. 49 pads, 12,73 JHll"SpeU, 5:1 plinth., )6, 49-51, 5:1 qunry, 35, )6 riOl", IH. 1]& ~tep-. :a6, 49. 12)
'!lInt courses, 46, S I thrnhold., 26 t .... ntomH, 4',49 "'indow ,il1l, 45. 49, 105 Ston". tlu.,nc.lion, J7
Stmchln. bond, 6, 7 Strilune: plate. 96 Strine: couran,]9. 46, 50. 51.15:1 Structu~. wood. 55
1OUn:es, S9
Stru1S.77
uses. S9
l',cpa.a"on, 33-39 ",If·faced, )8,-45 snapping, )8
.phnmg. ]8 ,\HfKe finolh". ]6-)8 b.t~, )8 boaued, J8 dralll!N, )8 furrowed, )1 hlmmu-drt5Kd, )8, 39. 4' picked. )8 p1am work, )8 punched, ]8 qu.try-d~. )8, "O-H rel,culatC'd,39 f'OCk-rlc~. ]8 rub~, J6 Kibbled, J8 ttra'llht-cut, J8, 4', .. :a H~rmll:ul.ted. ]9
Slone .... Ilmg .•~hllr, 39. 40, ,n-H block·m-coune, 42 cI.n.fiCllt;on,40 miscellaneous, Ami, 4:1-",6 Lake Di.w~1 mU<)nry. 18, 40, 45-.7 pol)'l(Onll. 4a-·u undom rubble, )8, 40 built·IO-COUT'$eS, 40, H uncouned, )8, 40, .p tulol>l" ... ork, l6, )8, 4o-i'I
tquartod rubble, ]8, ,*0, 41, 4:1
bUIll_to_courses,
electrie,
",0, ",:I
~uhu
ooui'H'd, 40, 42 unoournd, 40. 4'
Stone ",orll,nl machines. 3b Stool •. '" mdo ..... abo .9 Stop~ ends ••• 7, 8 Su~",y-rod. 28. ]0
Stra.!fht edge. <14. 28, JO, ]8, uS
liB-II.
mlsons', 28. 3 . J9. tl9 I'la~.~ren. 1.1
plumbcn.', 'S6-'S7 slaten', ']1-133 Toolhlng,4 Torchina. I J§ Tnmmel, laS
T
39
formlnl( truo: flce, )8 ""ural ~, )9
.-peafialuon, S9 stacking, 55 Ilnlet"re, SS wetght, 59 ..... indo ..... IOJ-I'9 ToolI, bnclliayen', 28 carpenten' and jomcn·. IIS-IJO canridge .",!IIed, 130
5to..lllng. floor. 67 Stub tenon, loa Stuck moulding. 9'. 9J. 99 Suffolk lalC:h. 86, 88 Summer ..... ood. 55 S .... ept valley, 1]7. '40
defect., 39
rlee·~ded.
w
Timber--c:ontd,
]. 7. 10, 19
Tangential ...... Ing. 56 Tanpln .• -t8. ISS. '5" Teak. 59, 64,10"" Ila Tee-ban. 158
rod, 24, 82
Template, la Templet, a4 Temporary IImbenn". 79-82. ~tenng, 8o-Sa trenches, 79-80 Tenonln' machine, 10] Tenon U"', 10:1, laS, 12.7 Tenon.. S« Jorn .. "Carpentry and
JOinery .. Tens"," IHeM. 19. II, 6S Thllich. 68, 70, 1]1
Thermal m,ul~lIon. 1. H. 58, 'l~, 141 1'h,~Io.rn."""nl( machm", 10) ThR'Vwld •• a6, 49.
Throannlt, 26, 49 Throughs. 40. 42,
roofs. 74
Tnple Roan. S8 roofs, bc). 77 Trough lfUue". '54 Truss. bUlh-up. 77 Tru,..cd nl ... r n .. ,t. "'1.77 Tuck I"'mlmll, 3' Turnmll p,eces. 24, 80-8:1 T""st~ lI ... m. S7
u
4~ }It,.
Thumb latch. 85, 17 Tile c~.. mfl, 28 Tiles, as. 26. 68. hoi, 70. 107. 1)9-141 Tlhng. '35, 14°_141 Til''"fl MlclI, 134. 1]6-1J8
T,mber, dUsltic"uon.
Transomes. "3, 49, 104 T.-.nsverse sepu. 55 Tnverse, '3' Trem:h IImberin«. 79-10 Trimminll Roan, 6" 65
~8.
t:pper Roors. 65-67 t.:p&ets. S7
L5C1I, Itmber. S9
59
COnVCrIlOn, ~S-57 dcfects, 57-S", 84-86, 98 IIro .... lh.
\'alleys, {,q. 74, '35, 1]7, 140, 150 V.,., iomt. 31, p.
S~
hanJ""",b, ~~, J'''''<, ~II, (>0 pn-,,,cr'lllhn, roofl,611·81
v
6,.
doorl,8]-loJ fdhnll". ~s
~II, ~9
~6
_sonlnll, B-S6 lIal"l. finl~hed or d~ or "", or ..... rouj[hT. 61, Q4, 105, IQQ. I I I n"mlnal or Iluff. 6,. 8]. 114. 106. I I ' !'Of.woods, B. s8. w
WalUlp. 79.80 Wall piece, 70 pl.tel, 60-6:1, 6oJ. ", 13B, ')9 WaU., bnck. )-)1 cav,ty, ., 7. IJ-'5
compound. 47 toNlruction, JO, 54 110m, 40-54
Wine, sB W'rping, S6. 58 W.te-T bar or we-the. bit l6 • • 9. ¢, 101W.ler services. IS5-156 Watcrproofed monaro ]1 W.tenhol.4S-47 Weathcr bo.rd. C}6 Weathermg. 25, 49 Wedges ..... ood. 65, 67. 113. 102, III, '4] lead, '4). 145, 151 \Veigh,-, Clst .ron. '09-1". 112., I']-I'S W('ldlnl, 143. 'So, 'Sa. 156 ",'('Ish 11'ln, IJI. IJ2.. 13~ \Vcllt,lead. 1#-1.6, 149 Western red ced.r, 59 Wct rOl, S8 Whi·i>td,3S Wh.,e9000d, 59. 61 Wmdfilling,77 Winding stn]H. 102 Wmdo ..... boards, 106, 10'] frames. IOJ- •• 6, 119-UO nshl"l. 10J-1:I0 si\1 •. brick, 24-a6. 104. 105 1I0ne, 49, 104. 105, 110 ..... ood. '04, ,0S. 106. II', 11:1-1'9 W,ndo ....s.IOJ-laO cased (... me and sliding $Uhes, 109-115
eucmenu, '04-109 fi:lcd, lOS. 107-109 metIIl. IIl}-120 pivoted, "5-1'9 Yorkahlfe light, 119 W,pedjomt. ISS Wipinll" cloth. 155, I S6 Woollon 1I0ne, 35, 47
Veneers, 91 Venillatmit folrate, 60, 6:1 \'entilallon, 800n, 60, (12, 77 Vents. J9 VerJ(e, 52. (''I
1111lnlt, '35 •• ]6, 1)7 IIhnl!:, 143 \·"rt;r.al shdiTlI( sa~hes, '09-117 VouSlOi~. 11-24, ",9
y
York 1I0ne, 33, II) Yorkshire hll:h, 119
z
