Prefabricated Bathroom Unit (PBU)

FOREWORD The Building and Construction Authority’s Authority’s (BCA) Construction Quality Assessment System (CONQUAS) has been widely adopted as the de facto national yardstick for measuring the workmanship quality of building projects. To To meet the rising expectations of homeowners, the Quality Mark (QM) Scheme was launched in 2002 to promote a higher consistency in workmanship standards for private residential developments. To help projects achieve the standards in CONQUAS and QM, BCA has developed a series of publications on Good Industry Practices for different trades. This “Good Industry Practices – Prefabricated Bathroom Unit (PBU)” is part of the CONQUAS Enhancement Series to promote good practices. The PBU has been identied as a technology that can achieve consistent high quality workmanship and productivity, productivity, provided it is done correctly with proper planning, design and execution. PBUs are pre-‐assembled pre-‐assembled off site complete with services and ttings. Much of the labour intensive trade activities are now carried out in a controlled factory type environment shielded from the elements. The PBUs can be produced in parallel with other critical construction site of activities, thus shortening the construction period. Recognising these benets in high quality and productivity, productivity, the use of PBUs will be mandated for all residential government land sales (GLS) sites in later part of 2014. The use of PBUs is also encouraged and recognised under CONQUAS 8th edition. Higher buildable design scores can also be achieved by projects that include PBUs in their designs. This guide shares some of the good practices adopted by practitioners and contractors who consistently deliver high quality work in PBU construction. It provides simple and practical illustrations on how good quality work can be achieved with higher productivity. productivity. Quality checks and critical inspections for PBUs are highlighted. This edition focuses on the Precast Concrete Volumetric Volumetric System PBU, while other types of PBUs will be covered in subsequent publications. This guide is not meant to be a denitive publication on or dictate how PBUs must be designed and installed. As there will always be new materials and construction methods, it will evolve with time and changing technology technology.. To To obtain more comprehensive information and guidance, readers should seek professional advice from designers and suppliers of PBUs. We gratefully acknowledge the contributions of practitioners in the production of this guide and trust that the industry will nd this publication useful. We We welcome any contributions from readers to further improve this and subsequent editions of this guide.

Lam Siew Wah Deputy Chief Executive Ofcer Industry Development Building and Construction Authority

ACKNOWLEDGEMENT This “Good Industry Practices – Prefabricated Bathroom Unit (PBU)” was developed with inputs from Architects, Developers, Builders, Specialist Contractors and members from various industry associations and organisations. A Technical Committee was formed to review the contents and good practices identied. We wish to thank the members of the Technical Committee for their valuable contributions.

Technical Committee: Chairman

Mr Ding Hock Hui

Building and Construction Authority

Dy Chairman

Mr Tan Boon Kee


Working Committee

Mr Rajendran Ramamoorthy


Mr Ng Kam Leong


Mr Gary Chua Chei Seong


Ms Jacelyn Yeo Hui Ping

Building and Construction Construct ion Authority

Mr Stephen Chan Keng Huat


Mr Kelven Yee Weng Cheong

Building and Construction Construct ion Authority

Mr Ng Thiam Min

Housing and Development Board

Mr Richard Lai

Singapore Institute of Architects

Mr Lim Thiam Kooi

Singapore Contractors Association Ltd

Mr Ryan Lim

Singapore Contractors Association Ltd

Mr Keith Ooi

Real Estate Development Association of Singapore

Mr Lim Song King

City Developments Ltd

Mr Kelvin Lo

CapitaLand Ltd

Mr Eddie Lam

Woh Hup (Pte) Ltd

Mr Thierry Brezac

Dragages Singapore Pte ltd

Mr Chiang Kian Hong

Tiong Seng Contractors Pte Ltd

Mr Ichiro Okamoto

Shimizu Corporation (Singapore Ofce)

Mr Yong Chiang Boon

Eastern Pretech Pte Ltd

Mr Tan Bian Tiong

Excel Precast Pte Ltd

Mr Dennis Chew

Excel Precast Pte Ltd

Mr William Ling

Sembcorp EOSM Pte Ltd

Mr Wong Lok Toon

Squire Mech Pte Ltd

Mr Teo Wee Hwee

USGBORAL

Mr Billy Cho

USGBORAL

Members

We would like to thank the following organizations for their valuable feedback in the review of this guide:

Building and Construction Authority Er Rose Nguan Er Tan Chong Lin Deva Lutchia

Construction Productivity Centre (CPC) Building Engineering Engineeri ng (BE) Building Plan & Management (BPM)

Building and Construction Authority Academy Mr Qin Hao

Centre For Construction IT

Agencies and Associations Housing and Development Board (HDB) Singapore Institute of Architects (SIA) Institution of Engineers, Singapore (IES) Real Estate Development Association of Singapore (REDAS) Association of Consulting Consulting Engineers Engineers Singapore Singapore (ACES)

Developers CapitaLand Residential Singapore Pte Ltd City Developments Ltd Keppel Land International Limited Bukit Sembawang Estates Ltd

Architects / Consultants Consultants DP Architects Pte Ltd DCA Architects Pte Ltd

Contractors Dragages Singapore Pte Ltd Straits Construction Singapore Pte Ltd Tiong Seng Contractors Pte Ltd Woh Hup Pte Ltd Shimizu Corporation Hexacon Construction Pte Ltd Lum Chang Building Contractors Pte Ltd

Tan Tian Chong C hong Group Director Technology Development Division Building and Construction Authority

PBU Manufacturers Excel Precast Pte Ltd Eastern Pretech Pte Ltd

Others Hansgrohe Pte Ltd Gerberit South East Asia Pte Ltd

CONTENTS

1. INTRODUCTION

1

2. TYPES OF PB PBU

2

3. PRE PRECAS CAST T CONCR CONCRETE ETE VO VOLUM LUMETR ETRIC IC SYST SYSTEM EM PBU PBU

4

3.1

DESIGN CONSIDERATIONS

5

3.2

BATHROOM PRODUCTION

11

3.3

PROTECTION, TRANSPORTATION AND LIFTING

17

3.4

INSTALLATION

18

3.5

M&E CONNECTIONS AND FINAL FIXINGS

20

3.6

MAINTENANCE, REPLACEMENT AND RENOVATION

28

4. GOOD GOOD PRAC PRACTIC TICES ES IN IN INST INSTALL ALLA ATIO TION, N, ARCHITECTURAL FINISHES, M&E SERVICES AND RENOVATION

34

4.1

INSTALLATION

34

4.2

ARCHITECTURAL FINISHES

37

4.3

M & E SERVICES

39

4.4

RENOVATION RE

42

5. CRI CRITIC TICAL AL INSP INSPECT ECTION IONS S AND QUA QUALIT LITY Y CHEC CHECKS KS

44

5.1

CRITICAL FUNCTIONALITY INSPECTION AND TESTS

44

5.2

QUALITY CHECKS

48

APPENDIX

52

APPENDIX A: SAMPLE OF INSPECTION AND TEST PLAN PRECAST CONCRETE SHELL

52

PRECAST PRECAS T BATHROOM AT MANUFACTURER MANUFACTURER’S ’S FACTORY

56

PRECAST BATHROOM (SITE INSTALLATION)

58

APPENDIX B: REQUEST FOR INSPECTION FORM PRECAST FORMWORK

60

PRECAST CONCRETING

61

ARCHITECTURAL FLOOR / WALL

63

REFERENCES 8

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PREFABRICATED BATHROOM UNIT (PBU)

64

1. INTRODUCTION The bathroom is an indispensable component in all buildings. The conventional method of constructing a bathroom on site involves many labour intensive building trades such as brick or block work, waterproong, nishes, plumbing, sanitary, electrical works and accessories installation. This requires extensive manpower, time and co-ordination among trades within a restricted site environment. environment. A prefabricated bathroom unit (PBU) refers to a bathroom unit preassembled off-site complete with nishes, sanitary wares, concealed pipes, conduits, ceiling and bathroom cabinets before installing into position. A PBU which integrates various trades and constructed in an off-site factory environment can achieve consistent and high quality workmanship and improved site productivity. The introduction of PBU can address the extensive on-site manpower, time, and coordination issues. Off-site fabrication can run parallel to other construction site activities, thereby shortening the the construction construction cycle. The effects effects of inclement inclement weather downtime are also minimized. Other benets of PBU include better control of materials, streamlined factory fabrication and production processes, less co-ordination with multiple trades/parties, less abortive work for construction sites, etc. PBUs have been widely used around the world including Japan, USA, UK, Italy and many other countries. There are many types and variants of PBU in the market. In Singapore, both HDB and private developers have used PBUs in some projects since the mid-90s. This edition focuses on Precast Concrete Volumetric System PBU i.e. PBU with concrete oor and walls, for residential developments. The other types of PBUs PBUs will be covered in subsequent publications.


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1

2. TYPES OF PBU

2.1

There are many types of PBU and it is essential to understand the characteristics of each type before its selection for use. The above pictures show 2 main types viz. PBU formed with concrete base and walls of concrete or other materials e.g. drywall, steel panel, etc. and PBU with bre reinforced walls and oor panels.

Each type has its own characteristics. Developers, consultants and builders should evaluate and select the type that meets their project requirements and this should should be incorpo incorporated rated into their project planning p lanning and design. desi gn.

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Table 2.1 Comparison of Different Types of PBU Precast Concrete Volumetric PBU (Monolithic)

Lightweight Concrete PBU

Steel Wall Panel PBU

Drywall PBU

FRP PBU

~3.4 to 9 tonnes

~3.5 tonnes

~2.5 to 5 tonnes

~2 tonnes (with

< 2 tonnes

(with nishes)

(with nishes)

(with nishes)

nishes)

(with nishes)

No additional temporary stiffening

No additional temporary stiffening

May requires

May requires

May requires

required

required

additional temporary stiffening

additional temporary stiffening

additional temporary stiffening, if preassembled off site

Installation Method

Usually by critical path (top down) method

Critical or non-critical path method

Critical or non-critical path installation

Critical or non-critical path installation

Designed for on-site installation

Hoisting Machinery

Needs hoisting by crane




Needs hoisting by crane crane, if preassembled off-site

Familiar to renovators in maintenance, replacement / renovation works

Similar to conventional bathroom


Cannot use May use conventional conventional method of chisel method of chisel and hammer; and hammer to Heating is remove tiles and cutter to create required to remove tiles openings in installed by glue board to replace piping; Easy to patch opening

Affected panel can be removed; Alternatively, entire PBU can be changed

Provision for Barrier-Free Accessibility Requirements



Need to specify locations of supports in Homeowner User Manual


Weight

Handling and transportation



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3

3. PRECAST CONCRETE VOLUMETRIC SYSTEM PBU

Precast concrete volumetric prefabricated bathroom unit (PBU) is one of the most commonly used PBU systems in Singapore. Its main advantage is its robustness and readiness to accommodate repair and maintenance, which far outweighs the disadvantages posed by its heavier weight and the top down installation method (critical path). This chapter outlines the considerations in design, production, installation and maintenance of precast concrete volumetric PBU including architectural and M&E work sequence, transportation, lifting and protection, installation and

replacement.

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3.1 Design Considerations Design parameters are critical for any construction work. In the case of PBU, design parameters such as structural, architectural, M&E works, installation, and subsequent maintenance challenges must be determined

early to ensure that the PBU system is integrated and can be incorporated in the overall building design. A good PBU design should provide practical solutions to address potential issues arising in different stages of PBU’s life cycle including future renovation. It is also important the design meets the requirements in the Code on

Accessibility in the Built Environment.

3.1. 3. 1.11 Architec Architectural tural Design Consider Considerations ations b. Location of Service Ducts and Access

a. Dimension

for Maintenance Gap between PBU and structural slab above can be covered by drywall board.

It is a good practice to locate services near to the edge of PBU for ease of future maintenance.

Example of vertical soil stack accessible from within dwelling unit

An efcient efcient volumetric volumetric system consideration and conrmation

requires requires of the

careful careful overall

dimensions. The overall dimensions and design should

take into consideration space/oor area taken up by the double wall/oor systems, structural drop slab and

The routing and connection of services should be predetermined and coordinated with the PBU manufacturer during the design stage.

storage heater (if any) to ensure effective use of space. The types of bathrooms should be standardized to achieve economy of scale production while providing sufcient design variation.


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c. Layout The locations of door and window openings and layout of xtures and M&E services should be functional and

practical. The formwork mould for volumetric PBU production is dependent on the locations of these openings. It is recommended that the general layout of the prefabricated bathroom unit be provided in the homeowner user manual.

Door

Sanitary Wares

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Architectural Fixtures xtures

Window

M&E Services

The location of the service shaft is critical to the maintenance of the precast concrete PBU.

Î The service shaft is not accessible once PBU is installed into position.

Drywall Partition



The orientation of this vertical service shaft makes repair and maintenance works more accessible.

It is important to make the vertical service shaft accessible for future repair and maintenance works of the PBU.


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3.1.2 Structural Design Considerations As precast concrete PUB typically weighs up to 9 tons, it is necessary to ensure that the structural strength of different types of receiving platforms are adequately designed. Use of different types of concrete, such as

lightweight concrete or high strength concrete can reduce the overall weight of PBU. The design of the hoisting and lifting devices placed within the precast elements is also crucial to facilitate the installation process. The choice of structural system may have an impact on the buildability score of the project.

a. Double Slab System

Structural design of the secondary slab has to incorporate a gradient to an outlet at the lowest point for drainage.

b. Single Slab System

Perimeter beams for seating PBU

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Corbels for seating PBU

c. Lifting and Hoisting Devices

Different types of lifting and hoisting devices


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3.1.3 M & E Design Considerations The design considerations for M&E services will determine the placement and routing methods of these services.

Embedded services within PBU

Recesses/block-outs Recesses/blo ck-outs provided for services

Shallow floor trap

Conventional S or P trap

Cast-in air-con drain pipe

Air-con drain drain pipe connecting connecting direct to stack stack Different ways of routing the air-con drain pipe

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3.2 Bathroom Production 3.2.11 Precast Unit Producti 3.2. Production on A good design and specication of the formwork mould is crucial for producing high quality precast concrete PBU. The steel plate thickness for the precast concrete mould must be sufciently designed to withstand the concreting pressure. The use of checker plate formwork (for concrete surface receiving nishes) improves bonding between the nished concrete and the adhesive. Proper propping supports should also be provided

during the concreting process.

Use of checker plate formwork

Props to formwork

Î Damage after stripping formwork

Î Demoulding defects


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11

To improve productivity in the manufacturing process, it is advisable to cast the base slab to the required water

gradient (as indicated below) to cut down the screeding process.

If the slab is cast without gradient, it is important to control the thickness of the screed to achieve the required gradient for water ow. Please refer to Appendix Appendix A - Sample Sample of Inspection and Test Test Plan Please refer to Appendix Appendix B - Request Request for Inspection Form

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Install reinforcement bars

Install M&E embedded services

Concreting

Secure block-outs

Use of vibrating system to achieve

Demoulding & curing

concrete uniformity

Please refer to Appendix Appendix A - Sample Sample of Inspection and and Test Test Plan Please refer to Appendix Appendix B - Request Request for Inspection Form Form


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3.2.2

Architectural and M&E Works Sequence

After the completion of of precast concrete concrete shell fabrication, the next construction process process will be the architectural architectural and M&E works. The application of waterproong as well as water-ponding water-ponding test is always an important process towards achieving primary functionality of the PBU. Other key architectural works include xing of door and window frames, followed by tiling works and installation of sanitary wares and components. Adequate allowance for movement joints should be made for PBU and window and door joints openings.

It is recommended the relevant good industry practices for various trades as in the CONQUAS Enhancement Series http://www.bc http://www.bca.gov a.gov.sg/Publications/EnhancementSeries/enhancement_series.htm .sg/Publications/EnhancementSeries/enhancement_series.htmll be followed.

Waterproofing system must be tested before receiving architectural works

Install window frame

Door and window frame installation

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Tiling works installation

Basin and cabinet

Water closet

Shower screen

Mirrors

All fragile xtures xtures can be installed at the last stage of fabrication to minimise possible damage. The The architectural architectural internal nishing works should be properly protected before delivery of the precast concrete PBU to site.


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3.2.3 Manufacturer’s Manufacturer’s Label

The manufacturer’s manufacturer’s label should be incorporated in the completed PBU before delivery. This label must be visible to users and should be used as a reference for any repair, replacement replacement and renovation work. It is recommended that the location of the manufacturer’s manufacturer’s label be provided in the homeowner user manual.

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3.3 Protection, Transpor ransportation tation and Lifting A well-planned transportation, lifting, protection protection and storage system for the PBU is important important to ensure minimal damage to the nished product before and after the PBU is installed at the site.

Sheltered storage facilities eliminate the adverse effects of weather

Delivery of PBU

Protection (to remain) during hoisting

Installation upon delivery

Proper coordination and planning of delivery of PBU can help to resolve the logistical hassle of insufcient

storage space, double handling and control of access to the PBU.


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3.4 Installation The readiness of the construction site to receive the PBU is critical to the successful installation of the PBU. It is also important to understand the different structural systems that are designed to receive the PBU at site, viz: •

Double Slab System

•

Precast Beam System

•

Corbel System

Hoisting of PBU

Positioning PBU (double slab system)

Double slab system

Grouting (double slab system)

The key feature of the double slab system is the xed dimension of the secondary slab to receive the PBU. It is

recommended that the gap between the two slabs be grouted to eliminate any possible water stagnation issues.

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Corbel system

Precast beam system for PBU

For precast beam system, the PBU is directly supported on the perimeter beams and hence the positions and dimensions of these beams must be constructed precisely. precisely.


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3.5 M&E Connections and Final Fixings The installation of M&E services and ttings is probably the most critical work process in the entire PBU fabrication

as it affects the functionality and serviceability of the PBU. Design for the M&E pipes and duct works shall take into consideration their connectivity to power supply, water supply and sanitary drainage.

3.5.11 Provision for M&E Servic 3.5. Services es Generally, there are two methods of laying the M&E services in precast concrete PBU. The M&E pipes and conduits can either be cast together with the precast concrete shell or laid via block-outs or recess, which are provided for on the external or internal surfaces surf aces of the precast concrete volumetric shell. For embedded M&E conduits, their positions must be precise and care should be taken to ensure they are properly bent and securely fastened for long-term durability. durability.

Cast-in M&E services on walls

Embedded M&E services on slab

The selection and installation of the embedded electrical conduits should comply with the relevant Code of Practice (CP5 & CP88).

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Block-outs and recesses should be sufciently provided for in accordance to the layout of M&E services for ease of connection to the M&E ttings.

Recess

Recess for drainage system

Block-outs

Block-outs for M&E services


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3.5.2 Use of Shallow Floor Trap It is common to utilize a shallow oor trap for PBU with double slab system or when there is constraint in oor height. Unlike the conventional oor trap system where pipes are exposed at the slab soft, the shallow oor

trap and its connecting sanitary pipes are fully f ully concealed in the slab and connected to the main discharge stack directly.

Section drawing of shallow floor trap design

Examples of approved shallow floor traps

In Singapore, the use of shallow oor trap is approved by Public Utilities Board (PUB) if the shallow oor trap is

in compliance with EN 1253, which comprises the following 8 tests:

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•

Anti-blockage test

•

Resistance of water seal to pressure

•

Water tightness test

•

Depth of water seal

•

Flow rate test

•

Access for cleaning

•

Odour tightness test

•

Side inlet


3.5.3 Use of Conventional Floor Trap

There is no special maintenance consideration for the use of conventional oor trap in the precast concrete PBU, except for the space required to accommodate the services with the provision of sufcient oor height.


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3.5.4 Connection to M&E Fixtures a. Wash Basin The water and discharge works for the wash basin in the precast concrete PBU should follow the approved method statements and comply with the relevant Code of Practice for plumbing and sanitary works. Accuracy of the penetration joints from the precast concrete PBU to the connecting accessories (i.e. hoses, taps) of the wash

basin is important for its functionality and overall alignment of the wash basin.

Connection and installation of wash basin

Positions and routes of the embedded M&E services should be clearly identied to prevent accidental damage

caused by the drilling of anchors and supports for the wash basin.

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b. WC Pedestal Depending on the type of water closet (WC) pedestal used, the plumbing and sanitary connections of the WC may run horizontally through the wall or vertically to the oor slab of the precast concrete PBU. Accuracy of the penetration joints and sleeves from the precast concrete PBU to the accessories of the WC pedestal is important for its functionality and overall alignment. For better aesthetics, the jointing at any pipe penetration should be

concealed or covered up neatly. neatly.

Horizontal connection to WC pedestal

Vertical connection to WC pedestal


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c. Shower Mixer Tap When there is provision for a shower mixer tap, separate water pipes for hot and cold water should be catered for in the design and fabrication of the precast concrete PBU shell. The routing of the different water pipes could be demarcated by coloured tapes on the nished wall surfaces for clear identication of these pipes.

Connection of shower mixer tap on wall

Demarcation of hot and cold water supply by coloured tapes

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3.5.5 Routing Routing of Air-conditioning Drain Pipes Air-conditioning Air-conditioning drain pipes are normally laid through the wall and oor slab at a gradient to discharge condensate water to the PBU oor trap. The air-conditioning air-conditioning drain pipes could be designed to run embedded in the precast concrete PBU oor slab connecting to the oor trap. An alternative is to run the insulated drain pipes through the

false ceiling (if available) and connect directly to the discharge stack.

Cast in air-con drain pipe



Running insulated air-con drain pipes at ceiling ng and connect connect to a separate stack stack pipe


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3.6 Maintenan Maintenance, ce, Replaceme Replacement nt and Renovation There are differences in the maintenance, replacement and renovation of precast concrete volumetric PBU as compared to conventional toilet. Therefore, it is important for developers and builders to provide a homeowner user manual upon completion of project for instructions and advice on how to maintain, replace and renovate

the PBU.

Use of breaker to hack tiles during renovation

Hammer and chisel method used for replacement and maintenance work

As the wall and oor of precast concrete PBU may not be as thick as conventional toilet, the selection of

appropriate tools and use of recommended methods of work execution can prevent damage to the precast concrete PBU. The types of tools and execution methods must be covered in the homeowner user manual.

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3.6.1 M&E Concealed Services

M&E embedded services (cast-in)

M&E concealed services routing through precast block-out

For M&E services that are cast-in with concrete, both the tiles and concrete need to be hacked during repair works. For M&E services that are laid through through block-outs, removal removal of tiles or surface nishes should sufce. sufce.

Hence, it is essential to provide the M&E concealed services locations through drawings and demarcation of route in the homeowner user manual. This can help homeowners and renovation contractors minimize damage during repair and replacement of M&E concealed services.


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3.6.2 Waterproofing Waterproofing Drawings

Waterproofing detailing

The provision of waterproong detail drawings can help homeowners and renovation contractors identify and prevent damage to the waterproong during renovation, replacement and repair works.

3.6.3 Access Panel on Drywall

Drywall Access Panel Access Panel Location

The location of access to the vertical stack must be made known k nown to the user through the homeowner user manual to facilitate maintenance, repair, repair, and replacement of M&E stack shaft. With the information, the homeowner can also plan their internal unit renovation without obstructing the access panel.

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3.6.4 Ceiling Access Panel Panel

Ceiling Access Panel Location

The ceiling access panel is a common provision for toilets with false ceiling. The function of the access panel within the precast concrete PBU is to access and maintain all M&E works above the false ceiling, similar to that for conventional toilet.

3.6.5 Replacement of Other Items

Re R eplacement of sanitary ware

Replacement of shower screen


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Replacement of bathroom cabinet

Replacement of M&E piping

Replacement of shower mixer tap

Replacement of shower bar

The replacement of sanitary items and components within the PBU is similar to that for conventional toilet. It is recommended that the method of removal and access to the M&E stack shaft be covered in the homeowner user manual. PBU designers should also explore other possible options to access the stack shaft.

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Stack pipe shaft is accessible for maintenance on side of drywall partition

Drywall partion

Example of service duct access to stack pipe shaft

Example of an accessible stack pipe shaft


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4. GOOD PRACTICES IN INST INSTALL ALLA ATION TION,, ARCHITECTURAL FINISHES, M&E SERVICES AND RENOVATION While it is possible to achieve high quality PBU by following closely approved work procedures, adopting good

practices in installation, M & E services and renovation of PBU can often lead to greater productivity and better user experience. This may require the employment of professionals and more skilled workers to achieve higher quality standards. However, However, as every project’s objective may be different, different, it may be necessary to be selective or customize the suggested good practices mentioned herein to suit each project.

4.1 Installation The precast concrete PBU is the sturdiest and heaviest PBU available. Therefore the design of the receiving platform and installation is critical to the success of the PBU installation. As the precast concrete PBU typically weighs up to 9 tons, the slot-in (non- critical path) method may not be suitable and hence, the top down (critical path) installation is often used. For top down approach, coordination is critical and protection of nishes can be challenging.

Top down installation method (critical path)

It is necessary to ensure that the structure of the receiving platform is adequately designed. The selection of single slab or double slab types for receiving platforms is often determined by the oor to oor height and other

considerations e.g. ease of tracing seepage or leakage, etc. 34

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4.1. 4. 1.11 Doub Double le Slab App Approach roach Pros •

Base slab facilitates ease of installation of PBU

Concerns •

A challenge to trace leak

•

Reduces headroom

Edges at gap between slabs should be sealed to prevent water ingress during construction


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4.1.2 Single Slab Approach Pros •

Easier to trace water leakage

Concern •

Need more precise co-ordination during

installation

Beam

PBU resting on precast beam edge

Pros •

Easier to trace water leakage

•

Able to install complete nishes with ttings

Concern •

Need more precise co-ordination during

installation

Corbel

PBU resting on corbel

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4.2 Arch Architectural itectural Finishes It is recommended to cast the oor slab of the precast

concrete PBU with a gradient to reduce some work processes such as screeding works.

Floor slab gradient •

Gradient to fall in both directions

•

For slab without gradient, need to control thickness and quality of the screed

Waterproofing works •

Water proong works to commence after

structural ponding test

Tiling works •

Tiling work is done over render and screed


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Other works •

Other works such as cabinets can follow

Long Bath •

Use metal frame for long bath installation

instead of bricks or blocks

Î

 Manufacturer’s Label •

Incorporate manufactur manufacturer’ er’s s label in the

completed PBU •

Visible to homeowners

•

Reference for repair, replaceme replacement nt and

renovation work.

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4.3 M & E Services The choice of M & E services must take into consideration conduct of tests and future maintenance.

Stack pipe shaft is accessible for maintenance on side of drywall partition

Location of Stack Pipes •

Location of stack pipes and orientation of shaft

within unit is important for future maintenance, repair and renovation •

Locating pipes at or facing external wall will pose

greater challenge for replacement and repair Drywall partion

Concealed Services •

Cast in concealed piping

•

Block-out within PBU make replacement easier


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False Ceiling

Conventional Floor Trap •

Maintenance and repair similar to conventiona conventionall

bathroom •

It is important to have sufcient oor height

False Ceiling

Shallow Floor Trap

40

•

Select brands approved by PUB

•

To comply to BSEN 1253 standard

•

Test certic certicates ates required

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•

Anti-blockage test

•


•

Flow rate test

•


•

Resistance Resista nce of Water Seal to Pressure

•

Depth of Water Seal

•

Access for Cleaning

•

Side inlet


Routing of Pipes Above PBU •

route pipes near the edge of PBU (reachable

from outside) or accessible via ceiling access panel

Air-conditioning drain pipe (Concealed) Pros •

Connect to oor trap and cast in, do not require false ceiling

Concern •

Unable to achieve sufcient gradient within

slab thickness

Air-conditioning drain pipe (through slab) Pros •

Can achieve sufcient gradient Concern

Concern •

Need false ceiling and sufcient headroom


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4.4 Renovation Although precast concrete PBU is similar to conventional bathroom, it is essential to exercise care during renovation to prevent damage to the PBU. A trained renovator renovator should be engaged who should use appropriate tools and follow the instructions in the homeowner user manual.

Renovation •

Renovator should be trained

•

It is important to use appropriate tools for

renovation works •

Exercise care when renovating and replacing

tiles by referring to the homeowner user manual

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4.4.11 Homeowne 4.4. Homeownerr User Manual Besides engaging renovation contractors who are trained, homeowners should have a ready reference of the PBU system used in the unit. It is good practice for developers/builders to provide provide a homeowner user manual manual of the PBU upon completion of the project. project. The homeowner and subsequent subsequent buyers of the unit should obtain

a copy of the homeowner user manual after taking over the unit and follow the recommendations on PBU renovation provided in the manual. The information in the homeowner user manual could include (but not limited to) the following:

(a) General information on PBU (i)

Introduction to the PBU installed

(ii) Safety notices (iii) Instructions for use

(b) Structure of the PBU

(i)

Floor

(ii)

Wall

(iii) Ceiling (iv) Water piping (v) Sanitary discharge pipe/vertical soil stack (vi) Electrical conduits

(c) Layout of the PBU (i)

General layout

(ii)

Waterproong layout

(iii) Locations of concealed services (iv) Location of access panel (v) Location of the manufacturer’s manufacturer’s label

(d) Cleaning and maintenance advice (i)

Internal ttings, tiles and accessories

(ii) Floor trap (iii) Ceiling access panels

(e) Alteration, repair and replacement works (i)

Replacement of accessories/installation of additional ttings

(ii)

Availability and supply of spare parts

(iii)

Instructions for drilling and xing

(iv) Instructions for tile replacement (v) Instructions for grab bars installation


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5. CRITICAL INSPECTIONS AND QUALITY CHECKS 5.1 Critical Functionality Inspection and Tests Every construction process requires inspection or testing to ensure its functionality. The functionality of PBU

is critical and needs to be inspected or tested from fabrication to installation either at the precast yard or construction site.

5.1.1 M&E Provision

M&E cast-in-items

M&E block-outs

It is important to ensure all the M&E cast-in-items/block-outs are provided in the correct position and properly secured during fabrication. M&E services functionality depends on the proper securing of these block-outs during concreting. All works should follow the M&E, sanitary and plumbing approved method statements and construction drawings.

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5.1.2 5. 1.2 Waterproofing Works

Water-ponding tests

Water tightness is one of the primary functionality of PBU. To achieve quality waterproong works, an effective waterproong method should be developed. The BCA’s Good Industry Practices “Waterproong for Internal Wet

Areas” under CONQUAS Enhancement Series is a good reference for f or development of the approved method statement. The waterproong in-process installation, inspection and testing should then be conducted in

accordance to the approved method statement.

5.1.3 5. 1.3 Shallow Floor Flo or Trap Tests

Shallow floor trap

The oor trap is crucial towards the functionality of a bathroom. Manufacturers Manufacturers can choose among the conventional P, S or shallow oor trap. When using shallow oor trap, it is essential to ensure that it has been tested and meet the following requirements: requirements: •

Anti – blockage test

•

Resistance of water seal to pressure

•


•

Depth of water seal

•

Flow rate test

•

Access for cleaning

•


•

Side inlet


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5.1.4 5. 1.4 Pipe Pressure Test

Pipe pressure test

Pipe pressure test will determine the ability of the pipe and its connection to take the stipulated pressure. The test should be conducted in accordance to the approved method statement. All pipes in PBU should be pressure tested.

5.1.5 5. 1.5 Tiling and Tile Pull-Off Pull-Of f Test

Tiling pull-off test

To achieve quality ooring and wall nishing works, it is recommended to conduct in-process tiling installation

inspection and, if applicable, wall tiles pull–off test to an approved method statement as in BCA Good Industry Practices Guides on “Ceramic Tiling” or “Marble and Granite Finishes”.

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5.1.6 Grouting

Grouting to gap between slabs (for double slab system)

It is important to seal up the gaps between slabs for double slab system, by grouting. It is recommended to follow the grouting procedure according to the approved method statement.


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47

5.2 Quality Checks Process checks during every stage of the bathroom unit production are important to ensure a high quality nal

product is achieved.

5.2.11 Structu 5.2. Structural ral Works

Formwork check

Reinforcement check

Concreting defects check

Checks on formwork, reinforcement and concreting defects should be made progressively in accordance to the specied requirements. requirements.

Base slab gradient checks

It is recommended that the PBU base slab is concreted to the desired gradient to receive the tiles. This method is highly productive and it reduces defects by removing the need for thick screed for oor tiling works.

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5.2.2 Architectural Works Upon completing PBU fabrication, it is important to conduct quality checks to approved architectural internal nish standards before delivery.

Floor

Wall

Ceiling

Floor, Floor, wall and ceiling should be checked on nishing, alignment and evenness, crack and damages, roughness, and jointing.


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Door

Component

Window

Floor Trap

Door, window, component and M&E works should be checked on joints and gap, alignment and evenness,

material and damages, functionality fu nctionality,, and accessories defects.

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Protection checks

The nal check before the PBU is delivered to site will be the protection work, internally and externally. It is

important to protect the completed PBU before delivery. The protection of the PBU should not be removed unless necessary until after installation and access to the PBU must be controlled after removing the protection. It is recommended to have another round of checks once the protection is removed to ensure the PBU meets the design and specifed requirements.


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A X I D N E P P A

s d r o c e R

n d i e o v s s o i r p m p b u A S


n d i e o v s s o i r m p b p u A S




s e g a t S

t r a t S k o r o t r W o i r P






r e e n O i g T n R E E E & & M M – – O E T & R M M

t s e t e b u t C l u s & e x r i M l a i r T t n e m d n e m A / y l l a i t i n I

t c e j n o o r i t P a o c t  i m r c o e p f n S o C

t c e j n o o r i t P a : y o c B t  i d m c r e v o e p o f n S r : e o p t a p C A D t n e m d n e m A / y l l a i t i n I

O T R S & C / r e e n i r g e n e E n t i n g e n d E i s S e & R C – – O S T & E C R

x d i e M v o n r g p i p e A D

d l e i a v r o e r t p a p A M

w e i v e R

w e i v e R

t n s t c o - t g c e e c n j C i n j n g e j e o o o R o i o r & w r i t r P r a P a o t a n P o i o c t c o D t t   & t n i r i m a m c i m c n c o r r o i e f o e t  o o p p i t f c c f n a S n e r u n S o l o p t o C u s C C S t t t n n n e e e m m m d d d n n n e e e m m m A A A / / / y y y l l l l l l a a a i i i t t t i i i n n n I I I p o h s d t n d S g e d e e n o v v g n d i m h o o e w r t e r i s v a p e t p e a o r r D p M t p D A S A p p A

a i r e t i r C e c n a t p e c c A

y c n e u q e r F

n a l P t l l s e e h T S d e t n e a r c n n o o C i t t c s e a c p e r s P : n k I f r o o W e f l : o p t c e e p j m a o r o c S P S

52

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t n e e c m n e e r r i e u f q e e R R n o d i t o c h e t p e s M n I e g r a h C – n I – e l p o e P

y t i v i t c A

o N / S

) t n e m e t a t S d o h t e M / g n i w a r D p o h S ( n o i s s i m b u S 1

w e i v e R

w e i v e R

w e i v e R

S & C / H E & C M R / A / R B

E & M / S & C / R B

E & M / S & C / R B

s g n i w a r D p o h S 1 . 1

S & C / R B

, d ) l n i l d d s o p a n e n o t i r p a i a h n t c l u a a ) l t a v a t e l e l c r r r e m u r e u e u M e l c e b t v i t s t t a e a h c E c E t a r c c u u e r t r & t r & S C h A ( S M S M E P ( w 2 . 1


3 . 1

4 . 1

t n e m d n e m A / y l l a i t i n I

E & M / H C R A / R B t n l u g i s s e e D R t s e e t e T r c & n x o i C M 5 . 1

d e n o e l i v p s o s r m i p a m p S b A u S e l p m w a e i S : v e e E t & a R M D E & M / H C R A / R B d l a n n i o a r e i l t s a s r a i u M m t c E b u & u r t S : S M y B d e r a 6 . p 1 e r P

O T R l a r u t t c c e t e t i i h h c r c r A A – – H O C T R R A A

. p e R r e d l i u B – R B : e t a D

d n e g e L

. y l n o e d i u g a s a s e v r e s m r o f s i h T

A X I D N E P P A


s d r o c e R

s t l u s e R t s e T





s e g a t S

g n i t s a c g n i r u D






t c e j n o o r i P t o a c t  i m c r o e p f n S o C

t s e T & e t t a r c o p  i e t r r e C l l i M

t t s c e e T j o & r P n t o r o i t t o p e m a c r r i o  f n c o e p C S

t t s c e e T j o & r P n t o r o i t t o p e m a c r r i o  f n c o e p C S

y c n e u q e r F

y r e v i l e D h c a E

e g a n n o t T s e n t o / d e s a B

h c t a d B r e n e v o i l d e e D s a B



t n e e c m n e e r r i e u f q e e R R

d e d i e x v o M r n p i p g s A e D





/ g l n a i u t s s e i V T



O T R A / R B

O T R M / R B

n o d i t o c h e t p e s M n I e g r a h C – n I – e l p o e P

y t i v i t c A

o N / S

- / g - / g  i s i s n  n n i n i c o c o t t e i e i s s p t e p t e a T T S a S c c

n o i t c e p s n I g n i m o c n I 2


t t s c e e T j o & r P n t r : y o o i t t o B p e d m a c r r e  i v o f c o : n e r e o p p t p a C S A D

E R / R B

E R / R B

O T R M / R B

e t e r c n o C

d e d l e h s W e / r M a b e R

d e d d e b m E E & M

l a r s u l t a i c r e t e t i h a c M r A

d n s a i e s r o m s e s t e I E c c & A M

1 . 2

2 . 2

3 . 2

4 . 2

5 . 2

n o i s s i m b u S e l p m a S : e E t & a M D

: y B d e r a p e r P




d n e g e L



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53

A X I D N E P P A


54

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n d i e o v s s o r i p m p b u A S k o r o t r W o r i r t a P t S t n s c o g e j n C i o r & w P n r a o o D t i t n m a o r c i o  i t f c n c r u o e t p C S s

s d r o c e R s e g a t S a i r e t i r C e c n a t p e c c A

n o i t s c r m e o p s F n I




k o r o t r W o r i r t a P t S

e o t t e k r r r c o o i n r o W P C

e o t t e k r r r c o o i n r o W P C

e t t s e k a r r c c o e n W r o P C


- t g c e e n o R j o i t r o t P a c &  i m r n c o i o e f p n t a S o l C u

t s e t e b u t C l u s & e x r i M l a i r T


y c n e u q e r F

n o i t a c o L h c a E

n o i t a c o L h c a E

U B P h c a E

U B P h c a E

U B P h c a E


n d i e o v s s o r i p m p b u A S




n o p i u t c t e e i S r e W e n S i

n o d i t o c h e t p e s M n I

s n o / i l t a a u c s  i i V c e p S

t n / e l m e a r u u s i s V a e M



l a u s i V

R P

R P

O T E R / R B / R P

O T E R / R B / R P

k r o o t w n o m i r t d a r o a f t y r f o t o p s n s a o n c i t r a e a T r p c i r d b n a a F

E s & k M o , o r a h b g e i n R f t f i o l n & s o i t e c a l l i v a r t e s s n I

o k t r r o o i r w p r m n f o o i t g c i n e s p o s l n c I

d n a e r u s b o l c m u l k r P o w m r o F

1 . 3

2 . 3

3 . 3

4 . 3

– n e I – r e g l p a o h e C P

y t i v i t c A

o N / S

) e p y T t s a c e r P ( n o i t a c i r b a F s s e c o r P n I 3


O T E R / R B / R P t i n U m o o r h t a B f o g n i t s a C 5 . 3


: y B d e v o r p p A

: e t a D






d n e g e L


A X I D N E P P A


s d r o c e R

n o s i t c r m e o p F s n I




s e g a t S






n o i t a c  i c e p S o t m r o f n o C




y c n e u q e r F

U B P h c a E

U B P h c a E

U B P h c a E

U B P h c a E







– n e I – r e g l p a o h e C P

y t i v i t c A

o N / S

d e u n i t n o C – ) e p y T t s a c e r P ( n o i t a c i r b a F s s e c o r P n I 3

l a u s i V

l a u s i V

l a u s i V

g n i t s e T / l a u s i V

O T E R / R B / R P k r o w m r o f f o g n i d l u o m e D

O T E R / R B / R P

O T E R / R B / R P

O T E R / R B / R P

s k r o w n o i t a c  i t c e R

t s e T g n i d n o P e r u t c u r t S

6 . 3

7 . 3

8 . 3

9 . 3

g n i r u C



: e t a D






d n e g e L



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55

A X I D N E P P A

s d r o c e R


n d n d n n n d i o o d o d o i i i i e o e e e e v s v s v s v s v s s s s s o s i o i o i o i o i r r r r r p m p m p m p m p m b p b p b p b p b u A u u u p u A S S A S A S A S

s e g a t S




y r o t c a F s ’ r e r u t c a n f a u l P n a t M s t e a T d m o n o r a h n t a B o i t t c s e a c p e r s P : n k I f r o o W e f l : o p t c e e p j m a o r o c S P S 56

|

y c n e u q e r F

t n e e c m n e e r r i e u f q e e R R n o d i t o c h e t p e s M n I e g r a h C – n I – e l p o e P

y t i v i t c A

o N / S







t t t c c c w e e e a j & r j n j n o o o n o o r o D r i r i t t P i t n s P a P a o a i o c t o c o t t c t g   i i n  i m c i c m m u r c r r e r c o e t o p f o e p f f s p n n S n S n S o o o o C C C C t t t n n n e e e m m m d d d n n n e e e m m m A A A / / / y y y l l l l l l a a a i i i t t t i i i n n n I I I s g n d i d d t n d e w e e n v a v o e v i g m h o o o r r D r t t r s e p p e a p e p p p t p D A o A M S A h S





t c e j n o o r i t P a : y o c B t  i d m c r e v o e p o f n S r : e o p t a p C A D t n e m d n e m A / y l l a i t i n I


x d l d d i e e M e i a e l v v r v p o n o t o e r r r g p i p a p m a p e p M p S A D A A

w e i v e R

w e i v e R

w e i v e R

w e i v e R

w e i v e R

w e i v e R

E & M / H C R A / R B

E & M / H C R A / R B

H C R A / R B

H C R A / R B

E & M / R B

E & M / R B

s d n ) s g a n l e i c a i w r v a t r u r e c D e s t E p i o h & c h r S A M (

- n d a o l l n d a n a o t M i a n i s r r i l h n l i s o i u l e s t e o a t e r a t s r m e p c s a i s u u b e i m t t e c u i t m m M m c M t a b E b e E t e S h S a i t t i c l u & u & r h S h i a A S c M c r M S r r e A A t

1 . 1


2 . 1

3 . 1

4 . 1

5 . 1

: y B d e  i r e V

e n l p i o m s s a i S m E b & u M S : y B d e r a 6 . p 1 e r P

: e t a D



d n e g e L


A X I D N E P P A

y r o t c a F s ’ r e r u t c a n f a l u P n a t M s t e a T d m o n o r a h n t a o B i t t c s e a c p e r s P : n k I f r o o W e f l : t p c o e e j m p a o r o c S P S

s d r o c e R







s e g a t S

l a r u s t c k e r t o i h W c r A

l a r u s t c k e r t o i h W c r A

l a r u s t c k e r o t i h W c r A





d e v o r p s p g A i n o w t a r m D r o f n o C


y c n e u q e r F

U B P h c a E

U B P h c a E

U B P h c a E

U B P h c a E

d e a c h d o n c d o a e L i t E b e p m i E P

U B P h c a E









/ s n o g i t i n a t c s  e i T c e p S





s n o i t a c  i c e p S

s n o i t a c  i c e p S

O T R A / R B

O T R A / R B

O T R A / R B

O T R A / R B

O T R M / R B

O T R M / R B

R B

s d e n a m r r a o F o D w l l o a d t n s i n I W

s k r o W g n i l i T

e r u s s t e s r e P T e p i P

y r a r t i e s n h e a t r u S O t l x l d i a n F t a s n I

n o i t c e t o r P

3 . 2

4 . 2

5 . 2

6 . 2

7 . 2

e g r a h C – n I – e l p o e P

y t i v i t c A

o N / S


d g r e g n e n i  ) e o s d n d n o k o r e c r r P a f p o r r n r u e w t e O t s ( a a t s W W e T 1 . 2

2 . 2

d t d t e c e c v e v e o j o n r o n r j o o o p r p r i i p P t p P t a A & a c A & c o o   t s i t s i g c g c e n n e m m i r i p r p w w o o f a S f a S n r n r o D o D C C

d t e c v e o n r j o o p r i p P t A & a c o s  i t g c n e m i r p w o f a S n r o D C


l a r u s t c k e r o : t i y h W B c r d A e v o r p p d t A t e c c v e e o j j n n r o o r o o p r i i p P t P t A & a o a c t c o   i t s i g c r m c n e o e m i r p f p o w S n S f a o n r o D C : e C t a D U B P h c a E n d i : e o y v s s o i B r p m d e p b u  i A S r e V

: e t a D

r e e n O i g T n R E E E & & M M – – O E T & R M M O T R S & C / r e e n i r g e n e E n t i n g e n d E i s S e & R C – – O S T & E C R


. p e R r e d l i u B – R B

7 . 2

: e t a D

d n e g e L



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57

A X I D N E P P A

) n o i t a l l n a t a l s n P I e t i t s S e ( T m d o n o r a h n t a B o i t t c s e a c p e r s P : n k I f r o o W e f l : o p t c e e p j m a o r o c S P S

58

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n d i e o v s s o i r p m p b u A S k o r o t r W o r i r t a P t S





n o & i o t n t o m i t a r c a  o i f l n u c e o g e p C R S

n o i o t t m a r c o  i f n c o e p C S



y c n e u q e r F






d e n v i g o r s p e p D A

d d t n e v o e o h t m r e p e t a p M t A S



s d r o c e R s e g a t S

n o d i t o c h e t p e s M n I – n e I – r e g l p a o h e C P

y t i v i t c A

o N / S

) t n e m e t a t S d o h t e M / g n i w a r D p o h S ( n o i s s i m b u S 1 . 1

w e i v e R

w e i v e R

w e i v e R

w e i v e R

/ S & E C & / M R B

/ E h & c M r A / / S R & B C

/ E h & c M r A / / S R & B C

) y t e f a S ( R B

g n i t s i o ) t H ( n n e o m i t i p a u l u q c E l a C E P

e t a t S d o h t t n e e M m n o i t a l l a t s n I

d o h t e M t n n o e i t m c e e t a n t n S o C E & M

n a l P g n i t f i L

2 . 1

3 . 1

4 . 1

5 . 1




: e t a D






d n e g e L


A X I D N E P P A

s d r o c e R s e g a t S a i r e t i r C e c n a t p e c c A

y c n e u q e r F

) t n e e n m c n o e e r i r t i u f e a e q e l l R R n a t a l s n n i o I t d P o c h e t e t i t p e s S s n M e ( I T m d o – n o n e I r – g a h l e r a p h n t a o e C B o P i t t c s e a c p e r s P : i y n k t I v i t f r c n o o A i o W t a e l f l l : a o t s p t c e n I e p j m a o o r o c N / S P S S 2

n n n n d i d i o d o o d i i e o e e e v s v s v s v s s o s o s o s i i i o r r r r i m p m p m p m p b p b p b p u p b u u A u A A S A S S S n n n n o o i o o i i i t t t t a a a a l l l l l l l l a a a a t t t t s s s s n n n n I I I I

n d i e o v s s o r i p m p b u A S n o i t a l l a t s n I

n n o n o n o n o i o o o t o o o t i t t i t t i t t t i t a a a a m c r m a m c r m c r m c r r c     o o o o o  i f i f i f i f i f n c n c n c n c n c o e o e o e o e o e p p p p p C S C S C S C S C S

n d i e o v s s o r i p m p b u A S n o i t a l l a t s n I

n n d i o e o i t s v s s c r m i o r e p m p o s F p b u I n A S n o i t a l l a t s n I

n o i t a l l a t s n I

n o i t s c r m e o p s F n I n o i t a l l a t s n I

n n o n o n o i o o o t o o t i t t i t t t i t : a a a y m c r m c r m c r m a r c B     o o o o f i f i f i f i n c n c n c n c d e e e e o p o p o p o e v p o C S C S C S C S r : e p t p a A D

U B P h c a E

U B P h c a E

U B P h c a E

U B P h c a E

U B P h c a E

U B P h c a E

n o i t c e n n o C h c a E

n o i t c e n n o C h c a E

U B P h c a E

3 n o i t c e S

3 n o i t c e S

3 n o i t c e S

3 n o i t c e S

3 n o i t c e S

3 n o i t c e S

3 n o i t c e S

3 n o i t c e S

3 n o i t c e S

p p p p p o o o o o t t h s h s h s h s d s n d n h S g S g S g S g S g e d e e d e o o v v n n n n n d i d i d i d i o h m o h m d i e w e w e w e w r t e r t e e w v a v a v a v a p e t p e t v a a p M t a r o r o r o r r o r r o r p M t r r p D p D p D p D A S A S p D p p p p p A A A A A



/ / O O T O T O R T R T A E A E / R / R R R B B

O T R M / R B

O T R M / R B

/ O T O R T A E / R R B

n o i t c e n n o c e p i P E & M

t u O g n i t t e S

1 . 2

2 . 2


O T R M / R B



n o i t a l l a t s n I

i t r e V t a t n f a o h i t S a l l l a a t s c n I e p i P

n o i t i s o P n I U B P g n i r u c e S

g n i t u o r G

e r u t x i F l a n i F

3 . 2

4 . 2

5 . 2

6 . 2

7 . 2

O T R A / R B

: y B d e  i r e V

t s e r u T S g d n e i i d l n T ) o d e p e c r a f e t h s i a n i W F l a n n O : i y F ( B d e r a 8 9 . . p 2 2 e r P


O T R l a r u t : c t c e e t t t e a i i h D c h c r r A A – – H O C T R R A A

. p e R r e d l i u B – R B d n : e e g t a e D L



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59

APPENDIX B

Request for Inspection Form (Precast Formwork) Project Title: XY Condominium Condominium

Supplier:

Work Trade:

Main Contractor:

Precast Formwork

AB Contractor Pte Ltd

Type of PBU Mould: Type A-1 Supplier Rep.:

Inspection No: XY/123/ABC/4474/01 ITP Reference No:

123 Formwork Pte Ltd

Builder Rep.:

3 (In-Process Fabrication)

...................................................... ................................................ Drawing No: Name Name XY/123/ABC/A-1/001 XY/123/ABC/A-1/001 Note: Use Approved Approved drawing of the unit to be inspected. inspected. Mark defect defect on the formwork. formwork. S/N

Inspection Criteria

Acceptance Criteria

Accepted

Yes 1

Thickness of Mould

As Per Approved Submission

2

Welding


3

Supports / Props


4

Dimension (L x B x H)


5

Plumb

+/- 3mm/m

6

Alignment

+/- 3mm per 1.2m

7

Evenness

Even, Not Wavy

8

Squareness

+/- 4mm along 300mm square

Appearance

Smooth / Checker (As Approved), no crack, no dent, no bulging, no holes & visible gap

9

No

Remarks / Comments

at joints, no weld spatter

12

Door / Window Openings As Per Approved Submission (Size) Door / Window Openings As Per Approved Submission (Position) Door / Window Openings No Tolerance

13

Finishing

10 11

(Alignment & Squareness)

Opaque and Clear Painting

Others 14 ...........................(Specify) Note: Use Approved Approved Drawings Drawings of the unit to be inspected. inspected. Mark defects on the floor floor & wall.

S/N

Date of Inspection

Signature (Supplier Rep.)

1 2 3 60

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Signature (Builder Rep.)

Remarks / Comments

APPENDIX B

Request for Inspection Form (Precast Concreting) Project Title: XY Condominium

Work Trade:

Supplier:

Main Contractor:

Precast PBU Concreting

123 Interior Pte Ltd

AB Contractor Pte Pte Ltd

Type of PBU:

Inspection No. for Same PBU:

Type B-2

40

Supplier Rep.:

Builder Rep.:

................................. Name

.................................. Name

S/N

Inspection Record No: XY/123/ABC/4483/202 XY/123/ABC/4483/202

ITP Reference No:

RE / RTO:

3 (In-Process Fabrication)

Inspection Criteria

.................................. Name

Drawing No: XY/123/ABC/B-2/002 XY/123/ABC/B-2/002 Remarks / Accepted Comments Yes Yes No

Acceptance Criteria

Note: Note: Use Use App Approv roved ed drawi drawing ng of the unit unit to be insp inspec ected ted.. Mark Mark defec defectt on on the the Formwo Formwork rk or Finish Finished ed Conc Concret rete. e.

Stage 1 – Preparation for Concreting 1

Reinforcement Bars

Rebar size & spacing as per Appr Approv oved ed Draw Drawin ings gs.. Reba Rebarr Con Condi diti tion on..

2

Formwork

Evenness, Cleanliness, Any Damage.

3

Internal Dimension

As Per Approved Drawing.

4

Door / Window Openings

Size, Position, Alignment.

5

Cover

As Per Approved Drawings.

6

M&E Embedded0

Numbers, Position, Properly Secured, No Damage.

7

Lifting Anchors

Position, Properly Secured, No Damage.

17

Others (Specify): ..............................

Note: Use Approved Approved Drawings of the unit to be ins inspected. pected. Mark defects defects on the floor & wall.

Inspection No

Date & Time of Inspection



Signature

Remarks / Comments

Signature

Remarks / Comments

1 2 Stage 2 – After Formwork Closing 8

External Dimension


9

Thickness of Wall


10

Verticality

+/- 1mm

Inspection No 1 2





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61

Stage 3 – After Stripping Formwork 11

Verticality

+/- 1mm

12

Alignment / Evenness

+/- 3mm per 1.2m

13

Size of Openings

As per Approved Drawings

14

Dimension

As per Approved Drawings.

15

Square-ness

+/- 4mm along 300mm square.

16

Fall


17

Fini Finish shed ed Conc Concre rete te Surf Surfac ace e

No Damage, No Honeycomb, No Lost of Grout.

18

M&E Provision

No Damage, No Blockage

Inspection No




Signature

Remarks / Comments

1 2 S/N

Inspection Criteria

Acceptance Criteria

Accepted Yes Yes

No

Remarks / Comments

Stage 4 – Defect Rectication

1

Cracks

As Approved Method Statement.

2

Honeycomb / Loss of Grout


3

Damaged M&E


Inspection No




Signature

Remarks / Comments

Signature

Remarks / Comments

1 2 Stage 5 – Structural Ponding Test 4

Structural Ponding Test

Inspection No


As Per Approved Drawings. Signature (Supplier Rep.)

1 2

62

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APPENDIX B

Request for Inspection Form (Architectural Floor / Wall) Work Trade:

Project Title: XY Condominium

Tiling/Marble/Stone Tiling/Marble/Stone Laying

Supplier:

Main Contractor:

123 Interior Pte Ltd

AB Contractor Contractor Pte Ltd

Type of PBU:

PBU No:

Type C-3

45

Inspection Record No: XY/123/ABC/Floor/303 XY/123/ABC/Floor/303

ITP Reference No:

Drawing No:

2 (In-Process Inspection)

XY/123/ABC/C-3/003 XY/123/ABC/C-3/003

S/N

Inspection Criteria

Acceptance Criteria

Accepted Yes Yes

1 2 3 4

n n e o m i i s D g n i h s i n i F

5 6 7

t n e m n g i l A

8 9 10 11

e g a m a D w o l l o H

Layout and Orientation


Size of tile / marble / stone


Dry Lay (Tonality)

Within approved range and colour evenly matched

Stains/Marks

No Stains or Marks

Surface Evenness

< 3mm per 1.2m

Lippage

No Tolerance

Squareness

< 4mm per 300mm square

Fall to Floor Trap

Test result

Chip / Dent Dent / Crack Crack / Scratch Scratch No chip, chip, dent, crack crack or scratch scratch Sealing of Stone Porosity (only for Stone)

As Per Approved Method Statement

Hollowness

No hollowness Properly grouted joints with

g n i t n i o J

Grouting of Joints Pointing

Neat & Consistent

E & M

Sani Sanita tary ry Ware are Ins Insta tallllat atio ion n

As Per Per Met Metho hod d Sta State teme ment nt

Grouting Around Floor Trap

Neatly Finished

16

Protection

As Per Approved Method Statement

17

Others (Specify): ..............................

12 13 14 15

No

Remarks / Comments

consistent thickness (<2mm)

Note: Use Approved Approved Drawings of the unit to be ins inspected. pected. Mark defects defects on the floor & wall.

S/N S/N

Date ate of Insp Inspe ectio ction n

Nam Name & Sig Signatu naturre (Supplier Rep.)

Name & Signature (Builder Rep.)

Name & Signature (RA / RTO)

Remarks / Comments

1 2 3 PREFABRICATED BATHROOM UNIT (PBU)

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63

REFERENCES i.

SS CP5: 1998 Code of Practice for Electrical Installations

ii.

SS CP88: 2001 Part 1 – Construction and Building Sites Code of Practice for Temporary Electrical Installations

iii.

SS 492 : 2001 Specication for Performance Requirements for Strength and Robustness (including methods of test) for

Partition Walls iv. iv.

BS EN 1253-2: 2003 Gullies for buildings. Test methods.

v.

Public Utilities Board Code of Practice on Sewerage and Sanitary Works (1st Edition)

vi.

BCA Code on Accessibility in the Built Environment 2013

vii.

BCA Code of Practice on Buildability 2013 Edition

viii. BCA Buildability Series What you need to know about Prefabricated Bathroom Unit (PBU). ix.

BCA CONQUAS Enhancement Series Good Industry Practices – Precast Concrete Elements

x.

BCA CONQUAS Enhancement Series Good Industry Practices – Waterproong Waterproong for Internal Wet Areas (2nd Edition)

64

xi.

BCA CONQUAS Enhancement Series Good Industry Practices – Ceramic Tiling (2nd Edition)

xii.

BCA CONQUAS Enhancement Series Good Industry Practices – Marble and Granite Finishes (2nd Edition)

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Prefabricated Bathroom Unit (PBU)

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