Code of Practice on Sanitary Plumbing and Drainage System

CODE OF PRACTICEON

SANITARY PLUMBING AND DRAINAGE SYSTEM

CONTENTS

APPENDUM NO 1 (Sep 97)

INTRODUCTION

PART I : SANITARY DRAINAGE SYSTEM

PART II : SANITARY PLUMBING SYSTEM

PART III : SANITARY APPLIANCE/FITTING

PART IV : SANITARY APPLIANCE AND MATERIAL

PART V : PROCEDURE FOR APPLICATION TO CARRY OUT SANITARY PLUMBING AND DRAINAGE WORKS

PART VI : APPENDICES

a. STANDARD DRAWINGS ON SANITARY PLUMBING AND DRAINAGE SYSTEM

b. STANDARD FORMS FOR SANITARY PLUMBING AND DRAINAGE WORKS

c. LIST OF STANDARD METRIC DRAWING AVALIABLE FOR SALE

CODE OF PRACTICE

ON


(3rd Edition -Feb 90 and 4th Reprint - May 97)

ADDENDUM NO. 1

(Sep 1997)

This addendum shall be read in conjunction with the Code of Practice on Sanitary Plumbing and DrainageSystem (3rd Edition- Feb 90 and 4th Reprint - May 97) and shall form part of the Code of Practice.

*S/No. Part /Page No Clause /

Appendix

DrawingNo

Amendments /corrections

1 Part I /page 1Clause1.2

Insert new Clause 1.2 after Clause 1.1

-Sanitary drainage system shall be designed to convey onlysewage. Rain-water is to be channelled to surface storm-water drain.

2 Part I/ page 4Clause6.3

Replace the existing Clauses 6.3 with the following :

-Every floor/gully trap intended to receive sullage watershall be located within covered areas and designed such thatit will not allow ingress of rain-water into the sanitarydrainage system. The floor/gully trap shall be fixed with aframe and a grating at least 5 mm below the paved floor.The floor surrounding such gully trap shall be slopedtowards the trap.

3 Part I/page 4Clause6.9

Replace the existing Clause 6.9 with the following:

- In accordance with the Vector Control & ResearchDepartment's requirement for prevention of mosquitobreeding, every floor/ gully trap fixed with perforated covershall be provided with an approved anti-mosquito device soas to prevent mosquitoes from gaining access to breed in thewater seal in the floor/ gully through the holes at theperforated cover.

4 Part I /page 7Clause11.2


- Every wash area shall be constructed in concrete not lessthan 75mm thick with a curb 75mm by 75mm all round.Rain-water from the surrounding shall not discharge into it.

S/No. Part /PageNo

Clause /Appendix

DrawingNo


5 Part I/ page8 Clause

13.1


(a)-All sullage water from covered wash areas, refuse chutes,bin centres, markets, basement car parks and other likeplaces of any building shall be discharged into the seweragesystem. Floor/gully trap shall be provided in such areas andconnected to an inspection chamber. For basement car parks,the area shall be laid in falls to floor/gully trap so that therun is not more than 5 metres to each floor/gully trap. Whereadditional drainage outlets are required, floor wastes may beprovided. In such cases, the floor wastes shall be connected tofloor traps before connection to the sanitary plumbing anddrainage system. At the entrance to the areas as mentionedabove, a ramp shall be provided to prevent ingress of rain-water from the surrounding floor into the sewerage system.

(b)-The drainage system serving common corridors, commonverandahs, covered play areas/ void decks (except washareas), multi-storey car parks (except car washing areas),open car park ramp, pump islands at petrol stations, openshower points in public and private swimming pools, openareas in back-yards/courtyards/airwells and other uncoveredpaved areas within premises where rain-water flows areexpected shall be connected to surface storm-water drains.

6 Part II /

page 10

Clause1.3

Replace " fourteen storeys" with "twenty five storeys"

7 Part II /

page 11

Clause2.3.1

Replace " fourteen storeys" with "twenty five storeys"

8 Part II/

page 11

Clause2.3.5

Insert " fifteenth, eighteenth and twenty-first " after "twelfth"

9 Part II/

page 13 Clause3.2.13

Insert new Clause 3.2.13 after Clause 3.2.13

- Every discharge pipe shall also not be located in placeswhere it can give rise to nuisance conditions duringmaintenance. In particular, for buildings under the LandTitles (Strata) Act, discharge pipes shall not run abovebedrooms, living room, dining room or kitchen areas of thestrata unit below. Where such routing cannot be avoided,suitably designed service duct to allow access formaintenance shall be provided.

10 Part II/

page 13 ClauseInsert new Clause 3.3.5 after Clause 3.3.4

-In the case of multi-storey buildings of 7 storeys or higher,

3.3.5 an additional cross venting pipe shall be provided betweenthe main and secondary discharge stack at a position of atleast 300mm above the finished first storey floor level.

S/No. Part /Page No Clause /Appendix

DrawingNo


11 Part II /

page 14

Clause3.5.3

Insert " of 7-storey or higher " after "multi-storey buildings"

12 Part III/

page 17 Clause3.1.1

Replace the existing Clause 3.1.1 with the following:

-Every water closet pan shall be of a design suitable for usewith low capacity WC flushing cisterns of up to 4.5 litresmaximum capacity and shall conform to the functionalrequirements and tests in the relevant Singapore Standards.

13 Part III /

page 18 Clause3.4.2


-Every wall hung water closet pans for use in public toiletsshall be of a design suitable for use with 6-litre flush valvesand shall conform to the functional requirements and tests inthe relevant Singapore Standards.

14 Part III /

page 19

Clause4.1.7

Amend "750 mm" to "600 mm"

15 Part III /

page 19

Clause4.1.8


-Every individual urinal shall be operated by flush valvewhich must be adjusted to give a flush of not less than 1.5litres and not more than 2.5 litres.

16 Part III /

page 19

Clause4.1.12


-Individual urinal shall be more than 300 mm wide and thecollection area shall project from the wall by at least 300mm.

17 Part III/

page 20

Clause5.1.1


-Every flushing cistern serving a water closet pan shall be ofthe low capacity type capable of delivering an effective flushof volume not more than 4.5 litres and shall conform to thespecifications, tests and installation requirements in therelevant Singapore Standards.

18 Part III /

page 20

Clause5.1.3

Insert " except when it is of a self supporting close-coupledwater closet suite" after "Every flushing cistern"

19 Part III /

page 20

Clause5.3.1

Delete Clause 5.3.1

20 Part III/

page 21

Clause6.2.3


-Every flush valve must be so adjusted to give a flush of notless than 1.5 litres and not more than 2.5 litres of water forindividual urinal and not more than 6 litres of water forwater closet pan. The flush volume for each water closet pan

shall be adjusted to the minimum required for effectivecleansing of the pan.

S/No.

Part /Page No Clause /Appendix

DrawingNo


21 Part III/

page 22 Clause6.2.11

Insert the following new clauses after Clause 6.2.10

- All automatic flushing devices shall be activated by sensors.Automatic flushing devices that can be used are either :

a) Sensor devices/mechanisms that can activate an approvedmanual flush valve; or

b) A fully integral sensor-operated flush valve.

Clause6.2.12

Clause6.2.13

Clause6.2.14

- Each sensor unit shall only operate one flushing device for asanitary appliance. The sensor unit when installed shall notbe affected by the operation of adjacent sensor unit.

-The sensor unit shall be firmly installed on the wall frontingthe appliance. It should not be supported by the water pipe.

-The recommended height of sensor unit shall be at 750 mmabove the rim level for oriental water closet pan and at 500mm above the rim level for other types of water closet panand it shall not be affected by the WC seat and cover whenthey are at raised position.

22 Part III /

page25

Clause10.12

Insert new Clause 10.12 after Clause 10.11:

- In accordance with the Vector Control & ResearchDepartment's requirement for prevention of mosquitobreeding, every floor/ gully trap fixed with perforated covershall be provided with an approved anti-mosquito device so asto prevent mosquitoes from gaining access to breed in thewater seal in the floor/ gully through the holes at theperforated cover.

23 Part III /

page 25

Clause11.2


- The minimum internal diameter of the floor waste shall be50 mm. However, where the floor waste also serve a wastesanitary appliance, the minimum internal diameter shall be75 mm.

THE SANITARY PLUMBING AND DRAINAGE SYSTEM

REGULATIONS, 1976

CODE OF PRACTICE

ON


INTRODUCTION

The Code of Practice on Sanitary Plumbing and Drainage System, issued under regulation 3 of TheSanitary Plumbing and Drainage System Regulations, 1976 shall be complied with by ProfessionalEngineers, Registered Architects and Registered Plumbers for the design, installation and execution of allsanitary plumbing and drainage works.

The requirements under this Code are supplemental to The Sanitary Plumbing and Drainage SystemRegulations, 1976. They do not exhaustively cover all aspects of the design and construction of sanitaryplumbing and drainage works but only set out the minimum requirements.

This edition incorporates changes in design and construction based on recent experiences and practices.

This Code of Practice may be amended and revised from time to time.

Sewerage Department

Ministry of the Environment

Singapore

CODE OF PRACTICE

ON


PART I : SANITARY DRAINAGE SYSTEM

1. Design and Layout of Sanitary Drainage System (1)

1.1 The design and layout of the sanitary drainage system shall be as simple and direct aspracticable for the proper conveyance of sewage within the premises for discharge to thesewerage system

2. Branch drain-line (1),(2)&(3)

2.1 Every branch drain-line shall have a minimum diameter of 100 mm.2.2 The depth of every branch drain-line connected directly into an inspection chamber

shall not exceed 1.5 metres where practicable. Where the depth exceeds 1.5 metres, anadditional inspection chamber may be required. Alternatively a tumbling bay orbackdrop may be made provided the size of the branch drain-line is at least 150 mmdiameter.

2.3 The distance from the inlet of the branch drain-line to the inspection chamber shall notexceed 10 metres where practicable. If the distance is required to be extended, themaximum distance shall not exceed 20 metres provided the size of the branch drain-lineis at least 150 mm diameter.

2.4 Every branch drain-line shall be connected obliquely in the same direction of flow as themain drain-line within the inspection chamber by means of curved vitrified clay channelbedded in concrete and finished with a benching sloping 1 in 6 to 1 in 10 upwards tomeet the wall of the inspection chamber.

2.5 Every branch drain-line shall be laid in a straight run with a constant gradient and shallbe water-tight.

2.6 Every branch drain-line shall have flexible pipe joint.2.7 Every branch drain-line shall be laid using the same material throughout its entire

length.2.8. The invert of the branch drain-line entering the inspection chamber shall be connected

above the horizontal diameter of the main channel.2.9 The gradient of branch drain-lines shall be as follows except where otherwise required.

Diameter of branch Maximum Gradient Allowable Gradient

drain line Upstream of Backdrop/

Tumbling Bay

in other Cases

100mm - 1 in 2o to

1 in 60

150mm 1 in 70 1 in 30 to

1 in 90

225mm 1 in 90 1 in 40 to

1 in 150

3. Main Drain-line (1)&(4)

3.1 Every main drain-line shall have a minimum diameter of 150 mm3.2 The maximum distance of main drain-line between inspection chambers shall not

exceed 50 metres3.3 Every main drain-line shall be laid in a straight run with constant gradient between

inspection of the main drain-line.3.4 An inspection chamber shall be provided for every change in direction and every

change in gradient.3.5 Where there is any significant difference in invert levels between inspection chambers,

a backdrop or tumbling bay connection shall be made between the inspectionchambers. The backdrop or tumbling bay shall be constructed in accordance with theSewerage Department's Standard Drawing. An in-drop connection shall only be usedwith the prior approval of the Director.

3.6 Every main drain-line shall have flexible pipe joints.3.7 Every main drain-line between inspection chambers shall be of the same diameter and

laid using the same material throughout its entire length3.8 The gradient of main drain-lines shall be as follows except where otherwise required.3.9 No main drain-line shall be sited within road reserve, public road, service road,

backlane or drainage reserve

Diameter of branch

drain line

Maximum Gradient

Upstream of Backdrop/

Tumbling Bay

Allowable Gradient

in other Cases

150mm 1 in 70 1 in 30 to

1 in 90

225mm 1 in 90 1 in 40 to

1 in 150

4. Drain-line under Building (5)

4.1 No drain-line shall pass under any building except where an alternative route is

impracticable.4.2 Where a drain-line passes under a building, it shall be laid in a straight run for the

whole distance and shall be surrounded in concrete at least 100 mm thickness4.3 Where a drain-line is to be encased within the basement floor slab, it shall be of heavy

duty cast iron pipe or ductile4.4 Where a drain-line passes through the basement wall, it shall be of heavy duty cast iron

pipe or ductile iron pipe. The joint through the wall shall be designed to ensure watertightness and accommodate any differential movement.

5. Drain-line under Driver-way and Car-park(5)

5.1 Every drain-line under drive-way or car-park shall be laid in heavy duty cast iron pipeor ductile iron pipe and shall be bedded and encased in concrete of at least 100 mmthickness

5.2 Where the depth from the top of the drain-line to the ground level exceeds 1.4 metresother pipes except uPVC pipe may be used and shall be completely embedded inconcrete to a thickness of at least 100 mm all round.

6. Inlet to Drain-line(6)

6.1 Every inlet to the drain-line shall be properly trapped and capable of maintaining awater seal of not less than 50 mm

6.2 Proper means of access shall be provided for the purpose of maintenance.6.3 Every gully trap and inspection chamber shall be located outside the building proper

but under cover wherever practicable.6.4 Every gully trap shall be embedded in concrete to a thickness of at least 100 mm all

round.6.5 Every gully trap shall be fixed as near the floor level as practicable and the depth

from the floor level to the bottom of the trap, including the depth of any riser ifrequired, shall not exceed 600 mm. Where the depth exceeds 600 mm, it shall behoused within a sump of at least 900 mm x 700 mm. The gully sump shall be coveredwith removable precast concrete slabs or chequered plates. However, the maximumdepth of gully trap from the bottom of sump shall be maintained at 600 mm.

6.6 Every waste discharge pipe shall be connected to a gully trap at the riser below thegrating and above the water seal of the trap

6.7 Where a riser is provided to a gully trap, it, shall be made of uPVC or other approvedpiping material to provide a smooth and even finish.

6.8 Where a gully trap is sited in a location where it is likely to receive rain-water or onunpaved ground, it shall be fixed with a gully frame and an unperforated cover flap atleast 20 mm above the ground or floor level to prevent ingress of rain-water. The floorsurrounding the raised gully trap shall be sloped away from the trap.

6.9 Where the gully trap is intended to receive sullage water, it shall be fixed with a gullyframe and grating at least 5mm below the paved floor. The floor surrounding suchgully trap shall be sloped towards the trap.

7. Excavation

7.1 Every trench excavation shall be properly timbered to support the walls thereof fromcollapsing and shall comply with the provisions in The Building Operations andWorks of Engineering Construction Regulations.

7.2 Where the trench excavation is contiguous to a public tboroughfare or where it wouldconstitute a danger or hazard to the safety of the public or to any adjoining property,every precaution shall be taken against accidents occurring.

7.3 Adequate appropriate warning signs shall be displayed conspicuously.7.4 Adequate flashing warning lights shall be displayed at night.7.5 Where pipejacking is required, details of such work shall be submitted by a

Professional Engineer prior to commencement of work.

8. Bedding, Haunching and Backfilling to Drain-line (5)&(7)

8.1 Where the cover depth is between 0.6 metres and 2.0 metres and on firm ground, everydrainline of cast iron or ductile iron pipe shall be laid on granular bedding (Type '1'bedding). However, every drain-line of uPVC, vitrified clay or reinforced concrete pipeshall be bedded in concrete at least 100 mm thick and properly haunched in concrete toat least 100 mm on either side of the pipe (Type '2' bedding).

8.2 Where the cover depth is less than 0.6 metres or more than 2.0 metres and on firmground, every drain-line of uPVC, vitrified clay or reinforced concrete pipe shall beencased in concrete of minimum thickness 100 mm (Type '3' bedding). However, everydrain-line of cast iron or ductile iron pipe shall be bedded in concrete at least 100 mmthick and properly haunched in concrete to at least 100 mm on either side of the pipe(Type '2' bedding).

8.3 On soft or yielding ground, every drain-line shall be provided with the same beddingas for firm ground except bat the bedding shall be founded on 'bakau' piles.

8.4 Granular material for bedding of flexible jointed pipes shall be of such size rangingfrom 3 mm to 12 mm or a free running coarse sand.

8.5 Selected fill material, free from lumps exceeding 75 mm in size and from stones, shallbe placed over the pipes and compacted in layers not exceeding 150 mm in depth to aheight of 300 mm above the top of the pipes. The rest of the trench shall then bebackfilled to the surrounding level with ordinary fill material properly compacted.

8.6 Break joint for concrete bedding and haunching shall be provided along every drain-line at intervals not exceeding 6 metres.

9. Inspection Chamber and Ventilation (8)

9.1 Every inspection chamber of the sanitary drainage system shall have a minimumdepth of 750 mm from surface level wherever practicable

9.2 The first inspection chamber shall be provided with a ventilating stack or not lessthan 100 mm in diameter. The ventilating stack shall have an untrapped opening inthe inspection chamber and no bend or angle, except where unavoidable, shall beformed in any such stack. However, ventilating stack for the first inspection chamberneed not be provided for guard house and bin centre.

9.3 A discharge stack at the first inspection chamber shall constitute a suf6cient opening

for such ventilation.9.4 On firm ground, the inspection chamber shall be constructed on a base of concrete at

least 150 mm thick and such base shall extend at least 150 mm beyond the externalwalls of the inspection chamber.

9.5 On soft or yielding ground, the inspection chamber shall be constructed on a piledfoundation and a base of reinforced concrete.

9.6 Every inspection chamber shall have minimum internal dimensions of 900 mm inlength and 700 mm in width. The length and width shall be increased accordinglydepending on the number of branch drain-line connected or to be connected to theinspection chamber and the depth of such inspection chamber.

9.7 The internal dimensions of every inspection chamber shall not exceed 1350 mm inlength and 1350 mm in width. Where the dimensions exceed 1350 mm, anadditional inspection chamber shall be provided

9.8 Brickwork for the inspection chamber shall be laid in English bond in level coursesand set in cement mortar. The internal and external walls shall be rendered withcement mortar.

9.9 The inspection chamber shall be roofed with a reinforced concrete slab of not lessthan 150 mm thick in all areas and provided with an opening which shall be 6ttedwith an air-tight frame and cover. Heavy duty cast iron frame and cover shall beused in every drive-way and car-park.

9.10 Where the inspection chamber is more than 2.5 metres deep but not exceeding 6.0metres, it shall be constructed in precast concrete sections with 150 mm thickconcrete surround and in accordance with the Sewerage Department's StandardDrawings for minor sewer.

9.11 Where the inspection chamber exceeds 6.0 metres deep, details of such chambershall be submitted by a Professional Engineer for approval prior to commencementof work.

9.12 Every branch/main channel shall be of half-round channel in vitrified clay9.13 The depth of the channel shall not be less than the diameter of the drain-line. Branch

drain-line shall be connected to the main drain-line at a level of not less than halfthe diameter of the main drain-line.

9.14 No inspection chamber shall be sited within the areas where food is prepared,cooked, stored or served; or other areas where they are likely to give rise to nuisanceconditions.

9.15 The last inspection chamber shall be located within 2.5 metres of the lot boundary.9.16 No inspection chamber shall be sited within 2.5 metres of the top or bottom of an

embankment.

10. Testing

10.1 Every drain-line laid shall be water - tight and subjected to a water test under a statichead of not less than 1 metre of water at the upstream end of the line.

10.2 The said water test shall be applied after laying and before placing concrete forhaunching or encasing. Any leakage in the drain-line shall be rectified

10.3 Every inspection chamber shall be water-tight and subjected to a water test.

11. Wash Area(9)

11.1 Every wash area where provided shall be roofed over. Rain-water run-off from the

surrounds of the wash area shall not be discharged into it.11.2 Every wash area shall be constructed in concrete not less than 75 mm thick with a

curb 75 mm by 75 mm all round and rendered smooth with cement mortar or otherimpervious material. Alternatively, instead of a curb, the wash area may be recessedThe recess shall not be less than 75; mm below the surface of the surrounding oradjacent floor.

11.3 Every wash area shall be provided with either a floor trap connecting to gully trap ora gully trap connecting directly to an inspection chamber.

12. Provision of Grease Trap for Eating Establishments (10)

12.1 Every eating establishment, food centre and other like places shall be provided withgrease trap.

12.2 Every grease trap shall not be sited within areas where food is prepared, cookedstored or served

12.3 On the first storey level, sufficient cast iron floor traps shall be provided andconnected to a screen chamber and a grease trap before connection to the inspectionchamber (see Appendix 10).

12.4 On the upper storey level, a separate cast iron discharge pipe and stack of at least100 mm diameter shall be provided. Sufficient cast iron floor traps shall be providedand connected to the cast iron discharge pipe and stack. The discharge stack shall beextended to serve as ventilating stack but may be reduced to 75 mm diameter andeither extended to the roof or connected into nearby ventilating stack. The dischargestack shall be connected to a screen chamber and grease trap prior to connection tothe inspection chamber.

13. Provision for Sullage Water Discharge (11)&(12)

13.1 Common corridors, common verandahs, covered play areas, covered car parks,refuse chutes, bin centres, markets and other like places of any building wheresullage water flows, shall be recessed below the surrounding or adjacent floors orcurbed up. Such areas shall be laid in falls to floor trap/gully trap so that the run isnot more than 5 metres to each floor trap/gully trap. Where additional drainageoutlets are required, floor waste may be provided. In such case, the floor waste shallbe connected to a floor trap before connection to the sanitary plumbing and drainagesystem

13.2 On the first storey level, sufficient floor traps and a cast iron gully trap with analuminum alloy strainer bucket (Standard Drawing ENV/SEW/76/113 & 83) housedwithin a sump shall be provided before connection to an inspection chamber (SeeAppendix 12).

13.3 On the upper storey level, the floor traps shall be connected to a separate sullagewater discharge stack of at least 100 mm diameter. The sullage water discharge stackshall be connected to a cast iron gully trap with an aluminum alloy strainer buckethoused within a sump at first storey level before connection to an inspectionchamber. Similarly where there are several sullage water discharge stacks, sumps areto be provided at every change in direction to collect and direct the sullage water to

an inspection chamber. However, the last sump prior to connection to the inspectionchamber shall be provided with a gully trap with strainer as stipulated above (SeeAppendix 11).

14. Sump for Sullage Water Drainage (6)&(11)

14.1 Every sump for sullage water drainage system shall have a minimum depth of 450mm from surface level to invert level where practicable

14.2 Every sump shall have a minimum internal dimensions of 600 mm in length and600 mm in width. However, where a sump is required to accommodate a gully trap,it shall be at least 900 mm x 700 mm. Sump shall be provided with main channel tocollect and convey sullage water from branch waste pipes. The sump shall beprovided with a slope of not less than 1 in 6 towards the main channel

14.3 Every sump of 600 mm x 600 mm shall be provided with cast iron frame and cover.However, removable precast concrete slabs or chequered plates shall be provided forsump of 900 mm x 700 mm to facilitate maintenance.

15. Provision of Silt Trap for Shower/Bathroom Compartment at Beach Site/Construction Site (13)

15.1 Waste water from shower/bathroom compartment/wash area shall be discharged intoa silt trap before connection to an inspection chamber.

16. Sewer Connection

16.1 No uPVC pipe shall be used for sewer connection between the last inspection chamberand the sewer/manhole.

16.2 Every sewer connection shall be construed in accordance with the SewerageDepartment's Standard Drawing ENV/SEW/76/11

17. Material and Component

17.1 General

17.1.1

Subject to the foregoing and the requirements in Part IV, the followingmaterials are acceptable for use in sanitary drainage system viz

a) uPVCb) Heavy duty cast ironc) Ductile irond) Vitrified claye) Reinforced concrete

17.1. A list of approved materials and components for use in sanitary drainage

2 system is available on application to the Sanitary Unit of the SewerageDepartment.

17.2 Pipe Joints

17.2.1 Every joint in a sanitary drainage system shall be made air-tight and water-tight and shall remain so during use.

17.2.2 No jointing material shall protrude inside the bore of the pipe.17.2.3 Pipes for sanitary drainage system shall be flexibly jointed by means of

rubber rings suitably designed to accommodate rubber ring seals such thatwhen the spigot is introduced the joint ring will be compressed to renderthe joint air-tight and water-tight. Alternatively a coupling with rubberrings suitably designed to ensure air and water tightness may be used.

**** Note : Numerals in parenthesis refer to the corresponding Appendices in Part VI ***

CODE OF PRACTICE

ON


PART II: SANITARY PLUMBING SYSTEM

1 Design of Sanitary Plumbing System (14)(15)(16)&(17)

1.1 The Sanitary plumbing system for any premises shall be designed to carry away sewageand waste water from the building quickly so as not to create any nuisance or risk ofinjury to health.

1.2 No sanitary plumbing system shall be used to convey rain-water.1.3 The one pipe "fully ventilated system is recommended in the design of the sanitary

plumbing system. However, in the case or residential buildings where the sanitaryappliances are closely grouped around a discharge stack, the "single stack system" maybe adopted for buildings up to six storeys high and the "ventilated stack system" forbuildings up to twenty five storeys high.

2. Description of Sanitary Plumbing System

2.1 Fully Ventilated System (14)&(15)

2.1.1 The fully ventilated system is used where there are large number of sanitaryappliances in range or where they have to be widely dispersed

2.1.2 Every discharge stack shall have a uniform diameter of not less than 100mmthroughout its entire length.

2.1.3 Where more than one trap is connected to a discharge stack, each trap shallbe provided with a branch ventilating pipe of not less than 50mm in diameter.

2.1.4 Every ventilating pipe shall be constructed upwards individually and beconnected to a main ventilating stack. Such connection shall be above thespill over level of the soil sanitary appliance or floor trap served by suchventilating pipe.

2.1.5 The top end of every main ventilating pipe or main ventilating stack shalleither terminate as high as the discharge stack or connect into the dischargestack at a point not less than 150mm above the spill over level of the topmostsoil sanitary appliance or floor trap

2.1.6 For multi-storey buildings of seven-storey or higher, the discharge pipeserving the second storey shall be connected to a separate discharge stack ofdiameter not less than 100mm. This stack shall be extended to serve asventilating stack but may be reduced to 75mm diameter.

2.1.7 Cross venting between the ventilating stack and the discharge stack shall beprovided at every ten storeys.

2.2 Single Stack System (16)

2.2.1 The single stack system may be adopted where there are single appliancesconnected to a discharge stack or where the sanitary appliances/fittings areclosely grouped round a discharge stack which is large enough to limitpressure fluctuations without the need for a ventilating stack.

2.2.2 The single stack system may be adopted for residential buildings up to sixstoreys high.

2.2.3 The main discharge stack shall have a uniform diameter of not less than150mm without offset throughout its entire length.

2.2.4 The length of the discharge pipe connecting to the discharge stack shall notbe more than 2.5m and there shall be not more than two numbers ofconnections made to the discharge pipe.

2.3 Ventilated Stack System (17)&(20)

2.3.1 The ventilated stack system may be adopted in situations where there areclose grouping of sanitary appliances around the discharge stack in residentialbuildings up to fourteen storeys high.

2.3.2 The main discharge stack shall have a uniform diameter of not less than150mm throughout its entire length.

2.3.3 The length of a discharge pipe connecting to the discharge stack shall not bemore than 2.5m and there shall be not more than two numbers of connectionsmade to the discharge pipe.

2.3.4 A separate discharge stack of diameter not less than 100mm shall be providedto serve the second and third storeys. This secondary discharge stack shall beextended to serve as ventilating stack but may be reduced to 75mm diameter.The ventilating stack shall either terminate as high as the discharge stack orconnect into the main discharge stack at a point not less than 150mm abovethe spill over level of the topmost soil sanitary appliance or floor trap.

2.3.5 Cross venting between the ventilating stack and the discharge stack shall beprovided at third, ninth and twelfth storeys.

3. General

3.1 Trap

3.1.1 Every inlet to the discharged stack shall be properly trapped to prevent the

entry of foul air from the drainage system into the building.3.1.2 Every trap for soil sanitary appliance and floor trap shall have a water seal of

not less than 50mm.3.1.3 Every trap with an outlet of less than 75 mm in diameter shall have a water

seal of not less than 75 mm.3.1.4 Every trap shall be provided with access cover so as to facilitate cleaning.

3.2 Discharge Pipe and Discharge Stack (14)(15)(16)(17)(18)&(20)

3.2.1 Every discharge stack shall have a uniform diameter and be made of thesame material throughout its entire length.

3.2.2 Every discharge pipe conveying soil shall have a diameter of not less than100 mm.

3.2.3 Every discharge pipe shall not be reduced in diameter in the direction offlow.

3.2.4 Every discharge stack shall be extended through the roof to the atmosphere.3.2.5 Every discharge pipe and discharge stack shall be fined with access covers,

bends, branches, junctions and other fittings for connections from thesanitary appliances and floor traps.

3.2.6 In the case of the "fully ventilated system" and "ventilated stack system",the discharge stack shall, as far as practicable, not form any offsetthroughout its entire length. Where offset is to be made, large radius bendsof at least 200 mm radius shall be used and cross venting between theventilating stack and the discharge stack is required above and below theoffset.

3.2.7 Swept branch connections from discharge pipe to discharge stack arerecommended. Opposed discharge pipes without swept entries shall be atleast 200 mm apart so that the discharge from one branch into the other isavoided

3.2.8 In the case of 'P' floor trap and water closet pan connected in series to thesame discharge pipe, a double 45° bend shall be incorporated between the~' floor trap and the water closet pan to prevent backflow. Alternatively, a'S' floor trap may be used without the double 45° bend.

3.2.9 Every access cover Shall be so fixed in a manner for easy access to facilitatemaintenance and also away from hidden comers. Access cover on the invertof pipe shall be avoided. Access for rodding and testing shall be provided alor near the foot of the discharge stack.

3.2.10 Every discharge pipe and discharge stack shall be securely supported orfixed to the wall of a building. The pipe supports or fixing shall be properlyaligned and the distance between them shall not exceed 2.0 metresvertically and 1.5 metres horizontally.

3.2.11 Where discharge pipe or stack passes through wall or floor, the jointthrough the wall or floor shall be water-tight.

3.2.12 Every discharge pipe shall not be located above any potable water storagetank and electrical transformer/switchgear.

3.3 Ventilating Pipe, Ventilating Stack and Cross Venting (20)

3.3.1 Every ventilating pipe shall be fixed as close to the crown of the trap aspracticable.

3.3.2 Every ventilating pipe shall be constructed upwards individually or beconnected to a main ventilating stack. Such connection shall be above thespill over level of the soil sanitary appliance or floor trap served by suchventilating pipe.

3.3.3 Where cross venting is to be provided, the cross connection shall be slopedupwards from the discharge slack to prevent the entry of discharge water intothe ventilation system. This connection shall be of the same diameter as theventilating stack.

3.3.4 The lowest cross venting between the ventilating stack and the dischargestack shall be fixed at a point not less than 225 mm below the lowestdischarge pipe connection.

3.4 Termination of Discharge Stack and Ventilating Stack (14)(15)(16)&(17)

3.4.1 The top end of every discharge stack shall be provided with a guard (i.e. wireball for cast iron ventilating stack and uPVC cowl for uPVC ventilating stack)and extended not less than IS0 mm above the highest sloping roof or IS0 mmabove a flat roof without parapet, or in the case of a flat roof with a parapet tothe height of the parapet above the roof.

3.4.2 If a flat roof is used for any purpose other than as a covering to the building,the discharge stack or the ventilating stack shall be extended at least 2.5metres above roof level.

3.4.3 The top end of the discharge stack or ventilating stack above the roof shall beat least 3 metres away from any window or opening of an adjoining buildingin the horizontal direction so as to give efficient ventilation and prevent anylikelihood of contamination or nuisance to an adjoining building.

3.4.4 Where a stack passes through a roof the area surrounding the stack shall bewater-tight.

3.5 Connection of Discharge Stack to Branch Drain-line (19)

3.5.1 Every discharge stack shall be connected directly to the inspection chamber.Where individual connections of discharge stacks are impracticable, acommon discharge pipe to serve the discharge stacks may be provided to suitconnection to a branch drain-line.

3.5.2 The bend at the base of a discharge stack (including secondary stack) shall beof large radius, at least 200 mm radius to the centre line, but preferably two45º large radius bends shall be used.

3.5.3 In the case of multi-storey buildings where both discharge and ventilatingstacks are to be connected to inspection chamber, the invert of the dischargeend of the ventilating stack shall be at least one diameter above that of thedischarge stack.

4. Sewage Divertor, Sewage Ejector or Other Pumping Appliance

4.1 For wastes collected from canteen, cooked food centre and restaurant located belowsurrounding ground level, sewage divertor shall be provided.

4.2 For domestic wastes collected below surrounding ground level, sewage ejector shall beprovided.

4.3 For waste water from covered car park below ground level, sewage ejector or any otherapproved system of pumping shall be provided.

4.4 Where a sewage divertor or sewage ejector is required a room of minimum size 3.0metres be 3.0 metres shall be provided.

4.5 The tank for the sewage divertor or sewage ejector shall be constructed from non-corrodible material.

5. Access to Pipework Enclosure

5.1 No pipe other than the ventilating pipe or ventilating stack and waste pipe shall beencased in columns, beams, walls or floor slabs. Where the pipework is required to beconcealed, it shall be accommodated in an enclosure.

5.2 Pipework enclosures such as ducts or casings shall be of a suitable size and providedwith ready access for maintenance, painting, testing and cleaning.

6. Testing

6.1 The sanitary plumbing system shall be tested either by means of an air test, smoke testor water test for soundness of the installation.

7. Painting

7.1 After testing, the pipework of the sanitary plumbing system may be painted to anysuitable colour.

8. Material and Component

8.1 General

8.1.1 Subject to the foregoing and the requirements in Part IV, the followingmaterials are acceptable for use in a sanitary plumbing system viz

a) uPVCb) Cast ironc) Ductile iron

8.1.2 A list of approved materials and components for use in sanitary plumbingsystem is available on application to the Sanitary Unit of the SewerageDepartment.

8.2 Pipe Joint

8.2.1 Every joint in the sanitary plumbing system shall be made air-tight and water-tight and shall remain so during use.

8.2.2 No jointing material shall protrude inside the bore of the pipe.8.2.3 Joint for cast iron pipe shall be made as follows:

a) spigot and socket cast iron pipe joint shall be packed firmly with spunyarn and then tightly caulked to not less than two-thirds of the depth ofthe socket with molten lead or fibrous lead yarn.

b) rubber ring joint.c) rubber sleeve joint

8.2.4 Joint for uPVC pipe shall be made as follows:-

a) solvent cement jointb) rubber ring joint

8.2.5 Joint for ductile iron pipe shall be made as follows:

a) rubber ring jointb) rubber sleeve joint

CODE OF PRACTICEON


PART III : SANITARY APPLIANCE FITTING

1 Sanitary Appliance

1.1 Every sanitary appliance installed in any premises shall be connected to the sanitaryplumbing and drainage system.

1.2 No direct connection from any water service pipe shall be made to any part of a soilsanitary appliance other than a connection through the flushing cistern or flush valve asdetailed under Clause 6 of this Part.

2. Connection of Soil Sanitary Appliance

2.1 The discharge from a soil sanitary appliance shall pass through at least one trap havinga water seal of not less than 50 mm before connecting to a branch drain-line on firststorey level or to a discharge pipe on upper storey level.

3. Water Closet Pan (21)&(22)

3.1 General

3.1.1 Every water closet pan shall conform to the functional requirements and testsin Singapore Standard 205.

3.1.2 Every water closet pan shall connect directly to an individual branch drain-line to an inspection chamber on first storey level or to a discharge pipe onupper storey level.

3.1.3 Every water closet pan shall be firmly bedded in cement mortar or by other

approved method of fixing.3.1.4 The jointing of the outlet of the water closet pan to the branch drain-line or

discharge pipe shall be done either with a purpose made flexible connector(pan collar or floor flange) or other method of jointing approved by theDirector.

3.1.5 Where a water closet pan has a horizontal outlet but is intended forconnection to the branch drain-line or discharge pipe through the floor slab, apurpose made bend connector is to be provided.

3.2 Oriental Water Closet Plan (Squatting type)

3.2.1 Every oriental water closet pan installed in a combined bath and water closetcompartment shall be fixed at least 75 mm above floor level.

3.2.2 Every oriental water closet pan shall be installed within a specially designed recessedreinforced concrete floor slab such that no part of the pan shall protrude into the floorslab or the floor below. The pan shall then be bedded in sand and concreted over toprovide an impervious surround. The floor surrounding the pan shall also be graded todrain off any water into the pan.

3.3 Pedestal Water Closet Pan

3.3.1 Every pedestal water closet pan shall be secured to the floor using stainlesssteel or non-ferrous fixing screws. Provision shall be made in the floor toreceive the fixing screws

3.4 Wall Hung Water Closet Pan

3.4.1 Wall hung water closet pan shall be fixed with stainless steel bolts and nutsor other approve means to an independent support frame such that no strainis transmitted to the water closet pan connector or any other part of theplumbing system. The support frame, depending on the design, shall beeither fully or partially fixed within the structure of the building.

4. Urinal (23)

4.1 General

4.1.1 Urinal shall be of the individual wall hung type.4.1.2 Every urinal shall be firmly fixed to the wall by either stainless steel bolts

and nuts or other approved means.4.1.3 Every urinal shall be provided with a fitting trap of at least 40 mm in

diameter. The connection by means of an urinal trap of at least 75 mm indiameter shall be made directly to an individual branch drain-line to aninspection chamber on first storey level or to a discharge pipe on upperstorey level.

4.1.4 A group of urinals connected in series may be discharged to a common

urinal waste pipe of at least 50 mm in diameter for connection as in sub-clause 4.1.3

4.1.5 An urinal trap shall be provided to serve a maximum of 10 numbers ofurinals. For more than 10 numbers of urinals, more than one trap shall beprovided.

4.1.6 Where a group of urinals are connected in series, loop venting is requiredThe loop venting requirement and the minimum diameter of commonurinal waste pipe for urinals connected in .series shall be as follows :-

Number of

Urinals Connected

is Series

Minimum Internal

Diameter of Common

Urinal Waste Pipe in mm

Diameter of Loop

Venting Pipe

in mm

not more than 2 50 Loop venting not required3 to 5 50 256 to 10 75 25

4.1.7 Every urinal shall be spaced at least 750 mm apart from centre to centre.Where urinals are provided, the maximum height of urinals shall be asfollows:-

For adults - 550mmFor Children - 380mm

4.1.8 Every urinal shall be operated by flush valve which must be adjusted to givea flush of not less than 2.5 litres and not more than 4.5 Litres. The flushvalve shall preferably be concealed Heavy duty type flushing cistern may beallowed only where the use of flush concealed Heavy duty type flushingcistern may be allowed only where the use of flush valve is not technicallyfeasible. At least one 9-litre flushing cistern shall be fixed for every 4urinals in series.

4.1.9 For flush valve operated urinals, the minimum internal diameter of the flushpipe shall be 13mm.

4.1.10 Every flush pipe for flush valve shall be made of either stainless steel orchrome-plated copper alloy and shall preferably be concealed.

4.1.11 For urinals coupled with flushing cistern, the minimum internal diameter ofthe flush pipe shall be 25mm.

5. Flushing Cistern

5.1 General

5.1.1 Every flushing cistern shall conform to the specifications, tests andinstallation requirements in Singapore Standard 68.

5.1.2 Every flushing cistern shall be firmly fixed to the wall by either stainless steelbolts and nuts, stainless steel brackets (or support pads) or other approved

means.5.1.3 Every flushing cistern shall be installed abutting the wall.5.1.4 Where brackets or other approved means are used, they shall not protrude

beyond the bottom width of the cistern and shall not have any sharp edges.5.1.5 The connection of the flush pipe of the flushing cistern to the water closet pan

and the urinal shall be made using a purpose made connector or bush toensure a robust and water-tight joint.

5.2 High Level Flushing Cistern

5.2.1 The high level flushing cistern shall be fixed to an oriental water closet panwith a flush pipe of height not less than 1.5 metres between the bottom of thecistem and the top of the water closet pan.

5.2.2 The flush pipe connecting a flushing cistem to the water closet pan shall befixed as straight as possible and shall not be less than 32 mm in diameter.

5.2.3 Every flush pipe from the cistern shall be securely filched to the wall.

5.3 Low Level Flushing Cistern

5.3.1 The low level flushing cistern shall be Fixed to a pedestal water closet panwith a pipe of vertical arm not less than 3SO mm from the base of the cisternshell to the centre line of the flush inlet socket of the water closet pan. Theinstallation shall be of such a configuration that an assembly of the flushingcistern with a pedestal water closet pan shall enable a seat and cover toremain in the raised position.

5.3.2 The minimum internal diameter of the flush pipe shall be 35mm.

5.4 Flushing Cistern For Close-Coupled Water Closet Suite

5.4.1 The flushing cistern for close-coupled water closet suite is designed for useonly as a complete unit with a particular water closet pan. The suite shall beinstalled in accordance with recommended practice.

6. Flush Valve (22)

6.1 General

6.1.1 Every flush valve shall conform to the installation requirements in theSingapore Standard CP 48 - Code of Practice for Water Services.

6.1.2 Every flush valve shall preferably be concealed with only the activatingknow/lever exposed to the user.

6.1.3 Every flush valve shall be corrosion resistant. All exposed surfaces shall bebright chrome-plated or in stainless steel.

6.1.4 Only water closets and urinals may be fitted with flush valves.

6.2 Installation

6.2.1 Every flush valve for water closet pan shall incorporate approved checkvalve and vacuum breaker. 241tematively, flush valve for water closet panshall derive water from a separate storage tank which is not connected inany way with all other fittings supplying basin, sink, heater, etc in thebuilding.

6.2.2 Every flush valve shall be controlled by an approved stop-valve.6.2.3 Every flush valve must be so adjusted to give a flush of not less than 2.5

Litres and not more than 4.5 litres of water for each urinal or not less than 8litres and more than 9.5 litres of water for each water closet pan.

6.2.4 Vacuum breaker of the flush valve shall be installed at least I metre abovethe rim for oriental water closet pan and at least 300 mm above the rim levelfor other types of water closet pan.

6.2.5 Every flush valve shall be Fixed to a urinal with a flush pipe of height notless than 150mm.

6.2.6 Every flush pipe shall be made of either stainless steel or chrome-platedcopper alloy and preferably be concealed.

6.2.7 The connection of the flush pipe of the flush valve to the water closet panand urinal shall be made using a purpose made connector to ensure a robustand water-tight joint.

6.2.8 The minimum internal diameter of the flush pipe for water closet pan shallbe 25 mm

6.2.9 The minimum internal diameter of the flush pipe for urinal shall be 13 mm6.2.10 For auto-sensing/electronic sensor flush valve, the installation of the

sensor/electronic sensor unit shall be carried out by a PUB licensedelectrician who shall ensure compliance with the relevant regulations andCode of Practice.

7 Bidet

7.1 General

7.1.1 Every bidet shall be provided with a spray nozzle fixed above the spill overlevel of the bidet pan

7.1.2 Every bidet shall be provided with a fitting trap of at least 40 mm indiameter. The connection by means of a bidet trap of at least 75 mm indiameter shall be made directly to an individual branch drain-line to aninspection chamber on first storey level or to a discharge pipe on upperstorey level.

7.1.3 Water for the flushing of the bidet shall not be supplied directly f from thewater main unless through an approved vacuum breaker and check valve orother approved means for reverting backflow or back siphonage andcontrolled by an approved stop-valve.

7.2 Installation

7.2.1 The bidet pan shall be installed in accordance with the pedestal water closet pan or the

wall hung water closet pan as specified in clauses 3.3.1 or 3.4.1 of this Partrespectively.

8. Special Soil Sanitary Appliance for Hospital

8.1 Approval of the Director shall be obtained for the use of any special soil sanitaryappliance not covered under this Part.

9. Waste Sanitary Appliance

9.1 Fixing of Waste Sanitary Appliance

9.1.1 Every waste sanitary appliance which is suspended shall be fixed to thewall by means of brackets which are built or screwed into the wall

9.1.2 Every floor mounted waste sanitary appliance shall be provided withpedestal, fool and leg.

9.1.3 Any sink and wash basin may be mounted on a cabinet.9.1.4 All fixing screws shall be corrosion resistant.9.1.5 All joints between any waste sanitary appliance and the abutting wall shall

be water-tight.

9.2 Connection of Waste Sanitary Appliance (24)

9.2.1 Every waste sanitary appliance shall be provided with a waste fitting trapfor connection to the waste pipe.

9.2.2 The waste pipe shall connect to the floor trap above the water seal of thetrap.

9.2.3 The waste pipe for waste sanitary appliance fixed on firs storey leveloutside the building may connect directly to a gully trap above the waterseal of the trap.

9.2.4 Where a group of 3 or more wash basins are connected in series, loopventing is required. However, the loop venting shall be terminatedseparately to the atmosphere. The minimum diameter of loop venting pipeshall be 25 mm. The minimum internal diameter of waste pipe for eachtype of waste sanitary appliance and the maximum number of wastesanitary appliances allowed on common waste pipe for waste sanitaryappliances connected in series shall be as follows:-

a) Minimum Internal Diameter of Waste Pipe for Each Type of WasteSanitary Appliance.

b) Maximum Number of Waste Sanitary Appliance Allowed on EachDiameter of Common Waste Pipe for Waste Sanitary Appliances

Connected in Series.

Minimum Internal Diameter

of Waste Pipe in mm

Type of ApplianceWash basin 32Sink (Single or double bowl) 40Laboratory sink 40Longbath/Shower tray 40Foot bath 40Wash tub 50Wash trough/Custom-made sink 50Drinking fountain 32

Type of Waste Sanitary

Maximum Number of Waste

Sanitary Appliances Allowed

on Common Waste Pipe

Appliances Connected in

Series

Minimum Internal Diameter

of Common Waste Pipe in mm

50 75Wash Basin 3 10Sink

(Single or double bowl)

2 6

Laboratory sink 2 6Drinking fountain 12 40Wash trough/Custom-made sink 2 6Wash tub 2 6

10. Floor Trap

10.1 Every floor trap at First storey level shall be connected to a gully trap above thewater seal of the trap and the length of the waste pipe bet between the floor trapand gully trap shall be as short as practicable.

10.2 Every floor trap at upper storey level shall be connected to a discharge pipe.10.3 Every floor trap shall be located inside the building wherever practicable10.4 The minimum internal diameter of the outlet of the floor trap shall be 75 mm.10.5 The riser to every floor trap shall be of the same diameter as the opening of the

trap.10.6 The height of a riser to every floor trap shall not be more than 600 mm from the

top of the grating to the bottom of the trap.10.7 Where a riser is provided to a floor trap, it shall be made of uPVC or other

approved piping material to provide a smooth and even finish.10.8 Every waste pipe connection shall be flushed with the internal surface of the riser.

10.9 Every floor trap frame and grating shall be fixed at least 5 mm below the lowestpoint of a graded floor where it is intended to receive sullage water.

10.10 Floor trap shall be provided for bathroom or shower compartment. The floor shallbe graded towards a floor trap to receive sullage water.

10.11 For group showers, a floor trap shall be provided to serve a maximum of 5showers. A channel not less than 100 mm in width and 50 mm in depth at a gradeof 1 in 100 shall be provided.

11. Floor Waste

11.1 Floor waste where provided Shall be connected to a floor trap above the water sealof the trap and the length of the waste pipe between the floor waste and floor trapshall be as short as possible.

11.2 The minimum internal diameter of the floor waste shall be 75 mm. ,Only onesanitary waste appliance may be connected to the floor waste.

11.3 The floor waste shall be covered with a grating.

12. Grating and Cover for Gully Trap, Floor Trap and Floor Waste

12.1 The grating and cover shall be constructed of durable plastic, stainless steel orother suitable approved material.

12.2 The grating and cover shall be of an approved design so as to enable them to bebolted down to the frame or otherwise secured to deter the unwarranted opening ofthe grating or cover and hence the discharge of garbage or other solid waste intothe sewerage system.

12.3 Subject to the sub-clauses 6.8 & 6.9 of Part I the grating or cover shall be installedand located such that they blend in with the surrounding ground levels and do notpose a hazard in causing trip, etc

13 Sanitary Appliance and Material

13.1 A list of approved sanitary appliances, fittings and their material of construction isavailable on application to the Sanitary Unit of the Sewerage Department.

13.2 Part IV stipulates the procedure to be followed to obtain the approval of theDirector for the use of a sanitary appliance.

CODE OF PRACTICE

ON


PART IV : SANITARY APPLIANCE AND MATERIAL

1. Sanitary Appliance and Material

1.1 The term "sanitary appliance and material" shall refer to sanitary appliance/fitting, pipeand fitting, and manhole/inspection chamber frame and cover.

1.2 Every sanitary appliance and material used in the construction of a sanitary plumbingand drainage system described in this Code shall be of a type, size, brand, quality andworkmanship approved by the Director.

1.3 Every sanitary appliance and material shall be clearly embossed or permanently markedwith be brand name/trade mask and the country of origin at a conspicuous position suchthat they can be clearly identified after installation.

2. Procedure for the Approval of Sanitary Appliance and Material

2.1 Every application for approval for sanitary appliance and material shall be made bythe applicant to the Director in writing.

2.2 The applicant shall deliver to the Director such samples of the sanitary appliance andmaterial and give such other information in connection therewith as the Director mayrequire

2.3 If so required by the Director, the applicant shall deliver one or more samples of thesanitary appliance and material to the Singapore Institute of Standards and Industrial

Research (SISIR) for examination and testing. The applicant shall pay such fees asSISIR may determine for such examination and testing or any other fees associatedwith the application for approval.

2.4 The applicant will be notified in writing of the approval/disapproval based on the testreport/s received directly from the SISIR.

2.5 The Director may require the applicant to dispose of all unapproved sanitaryappliances and materials and to submit proof of such disposal.

2.6 Notwithstanding the approval given for the use of the sanitary appliance and material,further samples may be required and selected at any time for periodical testing.

2.7 The approval given by the Director for the use of any sanitary appliance and materialmay be rescinded at any time if

(a) the sanitary appliance and material is found to be unsafe or unsuitable for use; (b) the design, material or construction of the sanitary appliance and material is

changed or modified without the approval of the Director; and (c) the applicant has contravened or failed to comply with any of the requirements

as may be stipulated by the Director

CODE OF PRACTICEON


Part V : PROCEDURE FOR APPLICATION TO CARRY OUT SANITARY PLUMBING ANDDRAINAGE WORKS

1. General

1.1 A11 sanitary works shown on the approved Sketch Plan/Building Plan Shall be carriedout in accordance with The Sanitary Plumbing and Drainage System Regulations, 1976and The Code of Practice on Sanitary Plumbing and Drainage System.

1.2 Application for sanitary permit is required before the commencement of any sanitarywork

2. Sanitary Permit Under Sketch Plan

2.1 Application

2.1.1 The Registered Sanitary Plumber Shall ensure that the following accompanythe application:

(a) Application Form A in duplicate (See Appendix 25) duly completedand signed by the Occupier, Owner/Developer and Land Owner orManagement Corporation, where appropriate, and the RegisteredSanitary Plumber.

(b) Pour (4) copies of location/site plans; plans and sections. (c) Plans and sections shall show the following:

(i) scale to which the plans and sections are drawn; (ii) details of any sanitary plumbing and drainage system

which shall be coloured in blue, red and yellow forexisting, proposed and to be abandoned itemsrespectively;

(iii) position of any existing sewer, pumping main andindustrial water main;

(iv) every sanitary appliance to be installed, repaired orreplaced;

(v) every compartment which is to have or has any sanitaryappliance and which is to be constructed or repaired; and

(vi) signatures of the Owner/Developer or the Occupier andLand Owner, and the Registered Sanitary Plumber shallbe endorsed on the plans. In the case of properties underLand Titles (Strata) Act, endorsement by theManagement Corporation is also required.

*(d) Payment of Sanitary Plan Fee of +$25.00 per application. (Asprescribed under The Sanitary Plumbing and Drainage System(Amendment) Regulations, 1989.)

*(e) Payment of cost for each Y-junction/box-out/advance sewerconnection (as determined by the Director).

*(f) In the case of temporary toilet facilities for construction site, letter ofundertaking by Registered Sanitary Plumber to demolish temporarytoilet/temporary septic tank and seal off temporary connection aftercompletion of the project (See Appendices 26 & 27).

2.2 Commencement of Work

2.2.1 Upon approval of the Sanitary Application, the Registered Sanitary Plumbershall notify Sewerage department by submitting Form B in duplicate (SeeAppendix 28) OD the following:

(a) intention to commence work (b) witnessing sewer connection to sewer/manhole

2.2.2 A representative from the Sewerage Department is required to be present onsite to witness the sewer connection to an existing sewer or manhole(including replacement of pipe junction the sewer connection to an existingsewer or manhole (including replacement of pipe junction. fitting andbreaching of manhole).

2.2.3 The owner, occupier or developer of any premises in which the sanitary worksare to be carried out shall ensure that the Registered Sanitary Plumber:

(a) has given all notices and obtained all consents that may be required byany law to be obtained from all relevant authority or persons in respectof the sanitary works; and

(b) has taken appropriate insurance coverage against any damage orinjury which may be caused to persons or property or against any other

liability which may be incurred under written law by reason of theexecution of the sanitary works and sewer connection. Such insurancecoverage should be kept in force for the entire duration of the works.

2.2.4 Where the trench to be excavated exceeds 4 metres in depth, it shall beconstructed in accordance with design and drawings of a ProfessionalEngineer, a copy of which shall be submitted to the Sewerage Department forrecord prior to commencement of work.

2.3 Supervision

2.3.1 The Registered Sanitary Plumber whose name appears on the approvedSketch Plan shall be fully responsible for the supervision and construction ofthe sanitary plumbing and drainage system in accordance with The SanitaryPlumbing and Drainage System Regulations, 1976, and the Code of Practiceon Sanitary Plumbing and Drainage System based on the approved SketchPlan.

2.3.2 The Registered Sanitary Plumber shall notify the Sewerage Department ofany proposed deviation of work from the approved plan and obtain approvalfor the deviations before proceeding with the work.

2.4 Certificate of Supervision

2.4.1 Upon satisfactory completion of the work, the Registered Sanitary Plumbershall submit Form C-'Certificate of Supervision' (See Appendix 29) induplicate and arrange with the Sewerage Department for an inspection of thecompleted work.

2.5 Inspection of Completed Work

2.5.1 The Registered Sanitary Plumber shall ensure that Form B (See Appendix28), Form C -'Certificate of Supervision' (See Appendix 29) and Form E (SeeAppendix 31) in duplicate are duly completed and submitted beforearrangement for an inspection of the completed work can be made.

3. Sanitary Permit Under Building Plan

3.1 Application

3.1.1 The Registered Sanitary Plumber Shall ensure that the following accompanythe application:

(a) Application Form A in duplicate (See Appendix 25) duly completedand signed by the Owner/Developer, Management Corporation,where appropriate, the Architect/ Professional engineer and theRegistered Sanitary Plumber.

(b) Letter from the Architect/Professional Engineer to notify theSewerage Department of the appointment of a Registered SanitaryPlumber for the work under approved Building Plan and to confirmthat a certified true set of plan which is identical to the approvedBuilding Plan has been given to the Registered Sanitary Plumber forthe work.

3.2 Commencement of Work

3.2.1 Upon approval of the Sanitary Application, the Registered Sanitary Plumbershall notify Sewerage Department by submitting Form B in duplicate (SeeAppendix 28) on the following:

(a) intention to commence work.(b) witnessing sewer connection to sewer/manhole

3.2.2 A representative from Sewerage Department is required to be present on siteto witness the sewer connection to an existing sewer or manhole (includingreplacement of pipe junction fitting and breaching of manhole).

3.2.3 The owner, occupier or developer of any premises/buildings in which thesanitary works are to be carried out and the Architect or ProfessionalEngineer who prepared the plan or specification of the sanitary works orwho is to supervise those works shall ensure that the Registered SanitaryPlumber: The owner, occupier or developer of any premises/buildings inwhich the sanitary works are to be carried out and the Architect orProfessional Engineer who prepared the plan or specification of the sanitaryworks or who is to supervise those works shall ensure that the RegisteredSanitary Plumber:-

(a) has given all notices and obtained all consents that may be requiredby any law to be obtained from all relevant authority or persons inrespect of the sanitary works; and

(b) has taken appropriate insurance coverage against any damage orinjury which may be caused to has given all notices and obtained allconsents that may be required by any law to be obtained persons orproperty or against any other liability which may be incurred underwritten law by reason of the execution of the sanitary works andsewer connection. Such insurance coverage should be kept in forcefor the entire duration of the works

3.3 Supervision

3.3.1 The Architect/Professional Engineer whose name appears on the approvedBuilding Plan shall be fully responsible for the supervision and constructionof the sanitary plumbing and drainage system in accordance with TheSanitary Plumbing and Drainage System Regulations, 1976, and the Code ofPractice on Sanitary Plumbing and Drainage System Regulations, 1976, andthe Code of Practice on Sanitary Plumbing and Drainage System based onthe approved Building Plan

3.3.2 The Architect/Professional Engineer shall notify the Sewerage Departmentof any proposed deviation of work from the approved plan and obtainapproval for the deviations before deviation of work from the approved planand obtain approval for the deviations before proceeding with the workproceeding with the work.

3.4 Certificate of Supervision

3.4.1 Upon satisfactory completion of the work, the Architect/ProfessionalEngineer shall complete Form C-'Certificate of Supervision' (See Appendix29) in duplicate to enable the Registered Sanitary Plumber to arrange for aninspection of the completed work.

3.5 Inspection of Completion Work

3.5.1 The Registered Sanitary Plumber shall ensure that Form B (See Appendix28) and Form E (See Appendix 31) duly completed and Form C-'Certificateof Supervision' by the 1Architect/Professional Engineer are submitted induplicate before arrangement for an inspection of the completed work can bemade.

4. Inspection of Completion Work

4.1 In cases of withdrawal of sanitary application/permit, the Registered Sanitary Plumberis required to submit Form D-(See Appendix 30) in duplicate.

* To comply with where applicable

+ Subject to revision without notice

CODE OF PRACTICEON


PART VI : APPENDICES(A) STANDARD DRAWINGS ON SANITARY PLUMBIGN AND DRAINAGE SYSTEM

Appendix 1 : ENV/SEW/SAN/1 Layout of Sanitary Drainage SystemAppendix 2 : ENV/SEW/SAN/2 Branch Drain-line Connection on First Storey LevelAppendix 3 : ENV/SEW/SAN/3 Branch Drain-line Connection with Backdrop or Tumbling Bay to

Inspection ChamberAppendix 4 : ENV/SEW/SAN/4 Backdrop and Tumbling Bay DetailsAppendix 5 : ENV/SEW/SAN/5 Type Bedding for Drain-lineAppendix 6 : ENV/SEW/SAN/6 Sump with Gully TrapAppendix 7 : ENV/SEW/SAN/7 Break Joints to Concrete BeddingAppendix 8 : ENV/SEW/SAN/8 Inspection ChamberAppendix 9 : ENV/SEW/SAN/9 Wash AreaAppendix 10 : ENV/SEW/SAN/10 Layout of Sanitary Drainage System for Eating Establishment and

Food CentreAppendix 11 : ENV/SEW/SAN/11 Sump for Sullage Water DrainageAppendix 12 : ENV/SEW/SAN/12 Layout of Sanitary Drainage System for Market, Bin Centre and

Refuse ChuteAppendix 13 : ENV/SEW/SAN/13 Silt Sump for Shower/Bathroom Compartment at Beach

Site/Construction SiteAppendix 14 : ENV/SEW/SAN/14 Fully Ventilated System with Ventilating Arrangement for Six-

Storey or Lower Multi-Storey BuildingsAppendix 15 : ENV/SEW/SAN/15 Fully Ventilated System with Ventilating Arrangement for Seven-

Storey or Higher Multi-Storey BuildingsAppendix 16 : ENV/SEW/SAN/16 Single Stack System for Residential Buildings up to Six StoreysAppendix 17 : ENV/SEW/SAN/17 Ventilated Stack System for Residential Buildings up to Fourteen

Storeys

Appendix 18 : ENV/SEW/SAN/18 Piping Arrangement for Floor Trap (P-Type) and Water Closet PanConnected in Series

Appendix 19 : ENV/SEW/SAN/19 Below Ground Details (Connection Between Discharge Stacks andInspection Chamber)

Appendix 20 : ENV/SEW/SAN/20 Offset and Cross VentingAppendix 21 : ENV/SEW/SAN/21 Jointing of Outlet of Pedestal Water Closet Pan to Branch Drain-

line or Discharge PipeAppendix 22 : ENV/SEW/SAN/22 Flush Valve Installation for Water Closet Pan and Wall Hung

UrinalAppendix 23 : ENV/SEW/SAN/23 Loop Venting Requirement for Wall Hung Urinals Connected in

SeriesAppendix 24 : ENV/SEW/SAN/24 Loop Venting Requirements for Wash Basins Connected in Series

CODE OF PRACTICE

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PART IV: APPENDICES

(B) STANDARD FORMS FOR SANITARY PLUMBING AND DRAINAGE WORKS

Appendix 25 : ENV/SEW/SAN/25 Application for a Permit to carry out Sanitary Plumbing and Drainage Works under The SanitaryPlumbing and Drainage System Regulations, 1976 -Form A

Appendix 26 : ENV/SEW/SAN/26 Undertaking by Registered Plumber to Demolish *Temporary Toilet/Temporary Septic Tank and Sealoff Temporary Sewer Connection after Completion ofProject.

Appendix 27 : ENV/SEW/SAN/27 Transfer of Obligation under Undertaking given byRegistered Plumber to Demolish *TemporaryToilet/Temporary Septic Tank and Seal off TemporarySewer Connection.

Appendix 28 : ENV/SEW/SAN/28 Notice of Intention to Commence/ Inspect SanitaryPlumbing and Drainage Works - Form B

Appendix 29 : ENV/SEW/SAN/29 Certificate of Supervision for Construction of SewerageWork/ Sanitary Plumbing and Drainage Works -Form C

Appendix 30 : ENV/SEW/SAN/30 Application for Withdrawal of Sanitary Application/Permit - Form D

Appendix 31 : ENV/SEW/SAN/31 Declaration by Registered Plumber for Type/Quantityof Sanitary Appliances and Material used in project -Form E

CODE OF PRACTICE

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PART VI : APPENDICES

( C ) LIST OF STANDARD METRIC DRAWINGS AVAILABLE FOR SALE

SerialNo.

Drawing Number Description

1. ENV/SEW/76/2B Standard Details of Main Sewers and Manholes2. ENV/SEW/76/3B Standard Details of Minor Sewers and Manholes3. ENV/SEW/76/4D Standard Precast Concrete Manhole Parts4. ENV/SEW/76/11 Standard Details of Sewer Connection5. ENV/SEW/76/91A Standard Heavy Duty Manhole Frame and Cover6. ENV/SEW/76/92A Standard Medium Duty Manhole Frame and Cover7. ENV/SEW/76/93 Standard Light Duty Inspection Chamber Frame and Cover8. ENV/SEW/76/39 Standard Temporary Septic Tank for Work Site9. ENV/SEW/76/80B Standard Grease, Petrol and Silt Interceptor - Three

Compartments10. ENV/SEW/76/113 Cast Iron Gully Trap for Bin Centre / Refuse Centre11. ENV/SEW/76/83 Cast Iron Grease Interceptor for Motor Workshops12. ENV/SEW/76/82-4 Standard Circular Grease Trap for Small Eating Stall ( 1

metre)13. ENV/SEW/76/114 Standard Circular Grease Trap for Canteen and Restaurants (

2 metres )14. ENV/SEW/76/97 Standard Details of Deep Precast Concrete Manhole with One

Intermediate Platform

Code of Practice on Sanitary Plumbing and Drainage System

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