Drainage Works for Buildings

7/29/2019 Drainage Works for Buildings

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Qatar General Organization for Standards and Metrology

QCS 2007, 3rd

Edition

Qatar Construction Standard 2007

Section 20 DRAINAGE WORKS FORBUILDINGS

Part 1 GeneralPart 2 Internal Drainage WorksPart 3 External Drainage Works

Part 4 Drainage Pipes in TrenchesPart 5 Structures Related to Drainage WorkPart 6 Surface Water Drainage

Part 7 Commissioning of Systems


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QCS 2007 Section 20 Part 1 General Page 1


QCS 2007, 3rd

Edition

1. GENERAL......................................................................................................21.1 INTRODUCTION............................................................................................2 1.1.1 Scope 21.1.2

References 2

1.2 REGULATIONS AND STANDARDS..............................................................21.2.1 Public Works Authority 21.3 CONTRACTORS RESPONSIBILITY ............................................................21.3.1 General 21.3.2 Existing Services 21.3.3 Maintenance Period Requirements 21.4 CRAFTSMEN.................................................................................................21.4.1 Workmanship 21.4.2 Qualifications 31.5 MATERIALS...................................................................................................31.5.1 General 31.6 DRAWINGS ...................................................................................................31.6.1 Shop Drawings 31.6.2 Co-ordination Drawings 31.6.3 As-Built Record Drawings and Survey Drawings 31.7 SITE WORKS ................................................................................................31.7.1 Co-operation with other Trades 3


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1. GENERAL

1.1 INTRODUCTION

1.1.1 Scope

1 This Section specifies the requirements for the construction and installation of drainageworks for buildings. It does not include highway drainage.

2 Related Sections are as follows:

Section 1 General

1.1.2 References

1 The following standards are referred to in this Part:

BS 8000 Workmanship on building sites

1.2 REGULATIONS AND STANDARDS

1.2.1 Public Works Authority

1 The Contractor shall carry out his work in accordance with the relevant requirements of thePublic Works Authority.

1.3 CONTRACTORS RESPONSIBILITY

1.3.1 General

1 The Contractor is responsible for obtaining all necessary approvals and permits required to

complete the parts of the Works included in this Section.

1.3.2 Existing Services

1 The Contractor is responsible for locating and identifying all existing services that may affect,or be affected by, the construction of the parts of the Works included in this Section.

1.3.3 Maintenance Period Requirements

1 The Contractor is responsible for all the maintenance period requirements for all parts andcomponents of the Works included in this Section.

1.4 CRAFTSMEN

1.4.1 Workmanship

1 Workmanship shall comply with the relevant provisions of BS 8000.

2 Construction of each part of the Works covered in this Section shall be undertaken byexperienced craftsmen capable of performing the tasks allocated to them in a professionaland competent manner.

3 If required by the Engineer, the Contractor shall instruct craftsmen to demonstrate their abilityto perform tasks allocated to him.


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1.4.2 Qualifications

1 Where the Project Documentation specifies that specialist craftsmen are required toundertake a specific work task, the Contractor shall furnish the Engineer with copies ofqualifications pertinent to performing such work tasks for those craftsmen who will beundertaking the work.

1.5 MATERIALS

1.5.1 General

1 All materials, components and products shall comply with the relevant provisions of Section1, General.

2 All materials, components and products shall be supplied by experienced manufacturers asdesignated in the Project Documentation or to the written approval of the Engineer.

1.6 DRAWINGS

1.6.1 Shop Drawings

1 The Contractor shall prepare shop drawings for all parts of the Works to be installed orconstructed under this Section and submit them to the Engineer in accordance with therelevant provisions of Section 1, General. The shop drawings shall include diagrams,illustrations, schedules, general arrangements of equipment and appurtenances in relation tobuildings and structures, method statements and details of specialised installation andconstruction work.

1.6.2 Co-ordination Drawings

1 These shall be prepared by the Contractor to show how interdisciplinary work will be co-

ordinated. The location, size and details of fixings, box-outs, ducts, holes, pipe chases andplinths shall be shown on the detailed layout drawings which shall be fully co-ordinated withall other work disciplines.

1.6.3 As-Built Record Drawings and Survey Drawings

1 The Contractor shall prepare Record Drawings of all works constructed or installed under thisSection in accordance with the relevant provisions of Section 1, General. These shall beprepared as work proceeds. They shall provide a record of any modification to materials andequipment, and to the layout, arrangement and installation of the Works.

1.7 SITE WORKS

1.7.1 Co-operation with other Trades

1 The Contractor shall so organise work progress to harmonise with the work of all trades sothat work may proceed as expeditiously as possible. The Contractor shall be responsible forthe correct placing of the Works and the connection thereof to the work of all related trades.

END OF PART


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QCS 2007 Section 20 Part 2 Internal Drainage Works Page 1


QCS 2007, 3rd

Edition

2. INTERNAL DRAINAGE WORKS ...................................................................2

2.1 GENERAL......................................................................................................2

2.1.1 Scope 2

2.1.2

Reference 2

2.1.3 Contractors Responsibility 22.1.4 System Description 22.1.5 Site Work 32.1.6 Fixing 32.1.7 Sealants 32.1.8 Inspection 3

2.2 INTERNAL DRAINAGE PIPEWORK .............................................................3

2.2.1 General 32.2.2 Materials 3

2.3 LABORATORY DRAINAGE SYSTEMS.........................................................4

2.3.1 General 4

2.4 GULLIES........................................................................................................4

2.4.1 Floor Gullies 4

2.5 ACCESS TO DRAINS....................................................................................5

2.5.1 General 5

2.6 ROOF TERMINATION...................................................................................5

2.6.1 Ventilating Pipes and Stack Vents 5

2.7 PUMPING FACILITIES ..................................................................................5

2.7.1 Sump Pumps 5

2.8 SANITARYWARE INSTALLATIONS .............................................................5

2.8.1 General 52.8.2 Pedestal WC Pans 52.8.3 Squat Type Toilet 52.8.4 Flushing Cisterns for Toilets 62.8.5 Slab Urinals 62.8.6 Bowl Urinals 62.8.7 Wash-basins 72.8.8 Sinks 72.8.9 Showers 72.8.10 Taps 72.8.11 Traps 8


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2. INTERNAL DRAINAGE WORKS

2.1 GENERAL

2.1.1 Scope

1 This Part specifies the requirements for internal drainage pipework, internal drainagesystems and sanitary appliances.

2 Related Sections and Parts are as follows:

This SectionPart 1 GeneralPart 7 Commissioning of Systems

Section 1 GeneralSection 8 SewerageSection 9 Mechanical and Electrical

2.1.2 Reference


BS 416 Discharge and ventilating pipes and fittings, sand-cast or spun in cast ironBS 437 Specification for cast iron spigot and socket drain pipes and fittingsBS 539 Dimensions of fittings for use with clay drains and sewer pipesBS 1010 Specification for draw-off taps and stopvalves for water services (screw-

down patterns)BS 1125 WC flushing cisternsBS 1184 Specification copper and copper alloy trapsBS 1188 Ceramic wash basins and pedestalsBS 1206 Fireclay sinks. Dimensions and workmanship

BS 1212 Float operated valvesBS 1244 Metal sinks for domestic purposesBS 1254 Specification for WC seats (plastics)BS 1255 WC seats (plastics)BS 2456 Specification for floats (plastics) for ballvalves for hot and cold waterBS 3402 Quality of vitreous china sanitary appliancesBS 4514 Unplasticized PVC soil and ventilation pipes, fittings and accessoriesBS 5254 Polypropylene waste pipe and fittings (external diameter 34.6 mm, 41.0 mm

and 54.1 mm)BS 5255 Thermoplastics waste pipe and fittingsBS 5503 Specification for vitreous china washdown WC pans with horizontal outletBS 5572 Sanitary PipeworkBS 5889 One-part gun grade silicone-based sealants

BS 8313 Code of Practice for accommodation of building services in ducts

2.1.3 Contractors Responsibility

1 The Contractor is responsible for checking the dimensions of all internal drainage works to beinstalled against the availability of space at their intended installation location.

2.1.4 System Description

1 Internal drainage systems shall generally conform to the relevant provisions of BS 5572.

2 Internal drainage systems shall comprise the minimum pipework necessary to carry away thedischarges from sanitary appliances in buildings quickly and quietly.


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3 Drainage pipework installations shall be such that there is no leakage of contaminated wateror foul air into the building.

4 Drainage systems, including materials, joints, supports and fixings shall be durable under theexpected operating conditions.

5 Pipework and fittings in drainage systems shall be installed so that defective parts can bereplaced without undue diff iculty.

2.1.5 Site Work

1 A check should be made to ensure that all holes, chases and ducts required for pipeworkhave been properly provided in accordance with the relevant provisions of BS 8313.

2 Where several pipes pass through floors in close proximity, the Contractor may provide asingle framed opening in lieu of individual sleeves. Framed openings shall be to the approvalof the Engineer and shall be provided with 100 mm high curbs, on all sides.

2.1.6 Fixing

1 Water supply and discharge pipes should be installed before sanitary appliances are fixed.Before fixing an appliance into position, the Contractor shall ensure that the discharge pipe isclear of obstruction. Joints between appliances and traps and/or pipes should be of the unionor detachable type.

2 Sinks and baths should be installed so that they drain to the outlet by gravity.

3 Cistern overflow pipes should be arranged to give a visible warning of discharge.

2.1.7 Sealants

1 Sealants shall comply with the relevant provisions of BS 5889, type B (high modulus sealant)

with a fungicide incorporated. The sealant should be applied using a purpose made gun ordevise.

2.1.8 Inspection

1 Upon completion of the work, all appliances, materials and workmanship should be carefullyexamined for defects and for faults in installation. Any defects or faults shall be correctedbefore the appliances are handed over for use.

2.2 INTERNAL DRAINAGE PIPEWORK

2.2.1 General

1 Pipes and fittings used shall be suitable for their purpose.

2 If pipes, pipe joints and pipe fittings are of dissimilar metals, measures shall betaken to prevent electrolytic corrosion.

3 The Contractor shall comply with all the recommendations of manufacturers when jointingpipes of different materials.

2.2.2 Materials

1 Soil, waste and ventilating pipes, fittings and accessories for above ground drainage systemsshall comply with the relevant provisions of the appropriate standard, as set out in Table 2.1.


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Table 2.1

Standards for pipes, fittings and accessories for above ground drainage systems

Material Standard

Cast Iron BS 416, Parts 1 and 2

PVC-U (soil and ventilating) BS 4514

Polypropylene (waste) BS 5254

Plastic (waste) BS 5255

2 Internal drainage pipes and fittings for below ground applications shall comply with therelevant provisions of Section 8, Sewerage.

2.3 LABORATORY DRAINAGE SYSTEMS2.3.1 General

1 The chemical resistance properties of pipes, fittings, jointing systems and any other drainageaccessory shall be suitable for conveying all solutions expected to be discharged to thedrainage system. Where possible, technical advisory services provided by manufacturersshall be used to ascertain the suitability of products to be used in the drainage system. A fulllist of the solutions expected to be discharged to the drainage system is given in the ProjectDocumentation.

2 Drainage systems for the collection of solutions which are not permitted to be discharged toexisting drainage facilities shall be kept totally separate form other drainage systems.

3 Drainage systems to which grit, gravel, sand or other granular material shall be dischargedshall have sufficient abrasion resistance properties and be fitted with suitable traps and catchbasins.

2.4 GULLIES

2.4.1 Floor Gullies

1 Floor gullies shall comply with the requirements of the following paragraphs unless otherwisedetailed in the Project Documentation.

2 Floor gullies shall be coated cast iron and comply with the relevant provisions of BS 539.

They shall have a 90 mm diameter trapped outlet and be fitted with a galvanised flat gratingof an approved type.

3 Floor drains shall be selected with sufficient grate free area to pass the anticipated flow. Thegrate free area is defined as the total area of the drainage openings in the grate and shall benot less than 1.5 times greater than the pipe to which the grate is draining.

4 With the exception of those located in toilets, all floor drains fitted with traps shall incorporatea removable bucket.

5 The gully should be installed on a firm base and located relative to the floor finish. Themethod of fixing shall be as detailed in the Project Documentation.


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2.5 ACCESS TO DRAINS

2.5.1 General

1 Sufficient and suitable access should be provided to enable all pipework to be tested andmaintained effectively. Access covers, plugs or caps should be sited so as to facilitate the

insertion of testing apparatus and the use of equipment for cleaning and/or for the removal ofblockages. The use of apparatus or equipment should not be impeded by the structure orother services.

2 Access points should not be located where their use may give rise to nuisance or danger ifspillage occurs.

2.6 ROOF TERMINATION

2.6.1 Ventilating Pipes and Stack Vents

1 Ventilating pipes and stack vents shall terminate with a domical cage or other cover that doesnot restrict air flow. They shall be positioned so that foul air does not cause a nuisance orhealth hazard.

2.7 PUMPING FACILITIES

2.7.1 Sump Pumps

1 Sump pumps shall comply with the relevant provisions of Section 9, Mechanical andElectrical Equipment.

2.8 SANITARYWARE INSTALLATIONS

2.8.1 General

1 Sanitary fittings shall, unless otherwise stated in the Project Documentation, be as describedin the following Clauses.

2 Where screws are used to fix sanitary appliances to concrete, blockwork or brickwork theyshall be rust-proofed steel and plugged.

2.8.2 Pedestal WC Pans

1 Pedestal WC pans shall be of white glazed fireclay and shall comply with the relevantprovisions of BS 5503. They shall have P, Q or S traps as required. WC seats shall be blackplastic and shall comply with the relevant provisions of BS 1254. The traps shall be provided

with antisyphonage outlets, where required

2 Where pans are fixed to timber floors they shall be jointed to the drain pipe with hemp gaskinand red lead putty. Where pans are fixed to concrete floors, they shall be jointed to the drainpipe with cement/sand mortar mixed in a 1:2 ratio. The pans shall be screwed to the floor.

2.8.3 Squat Type Toilet

1 Squat type toilets shall comprise a closet of white vitreous china complying with the relevantprovisions of BS 3402 for sinking into the floors and integral or separate tread plates in amatching material. They shall have P, Q or S trap as required. The traps shall be providedwith antisyphonage outlets, where required.

2 The closets and tread plates shall be set into a concrete bed with the top surface level withthe floor finish.


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2.8.4 Flushing Cisterns for Toilets

1 Flushing cisterns shall be black plastic or white vitreous china complying with the relevantprovisions of BS 1125 and shall be the single flushing type. They shall be fitted with a nylonor brass ball valve complying with the relevant provisions of BS 1212 with a plastic floatcomplying with the relevant provisions of BS 2456. They shall have connections for 12 mm

diameter supply and 20 mm diameter overflow pipes. Flush pipes complying with the relevantprovisions of BS 1125 shall be provided and shall be of galvanised mild steel.

2 Flush pipes shall be jointed to the bottom of the cisterns by means of watertight unions whichallow for easy removal and shall be jointed to WC pans by means of approved rubber coneconnectors. The cisterns shall be fixed to walls with screws.

3 High level cisterns shall be provided with chromium plated chains with rubber pull handles.They shall be fixed a height of 1500 mm from finished floor level to the underside of thecistern. Flush pipes shall be 30 mm diameter and shall be fixed with pipe clips which shall bescrewed to walls.

4 Low level cisterns shall be provided with chromium plated lever flushing handles. They shall

be fixed at a height of 600 mm from finished floor level to the underside of the cistern. Flushpipes shall be 35 mm diameter.

2.8.5 Slab Urinals

1 Urinal slabs shall be white glazed fireclay and shall have end screens. All urinals shall have awhite glazed fireclay floor channel and white glazed fireclay fluted treads set flush with thefloor finish. The channel shall have a 40 mm diameter chromium plated brass outlet withhinged grating.

2 The urinal slabs, channel and floor treads shall be bedded in cement mortar and jointed andpainted with white cement. The flushing cistern shall be a white glazed fireclay automaticflushing cistern, complete with cover, and shall be fixed on white porcelain enamelled cast

iron brackets which shall be screwed to the wall.

3 Flush pipes and spreaders shall be chromium plated and shall be fixed to walls withchromium plated holderbats. A 40 mm diameter trap with 40 mm or 75 mm deep seal asnecessary shall be provided.

2.8.6 Bowl Urinals

1 Urinals bowls shall be white glazed fireclay with lipped basin and flushing rim. Urinal bowlsshall be screwed to the wall. Flushing cisterns, flushing pipes and spreaders shall be asdescribed for slab urinals. The bowl urinals shall be complete with chromium plated brassoutlet and trap.


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2.8.7 Wash-basins

1 Wash-basins shall be white glazed fireclay size 625 mm x 450 mm overall and shall complywith the relevant provisions of BS 1188. Each basin shall be provided with a 30 mm diameterchromium plated waste outlet and rubber plug with a chromium plated chain and stay.

2 A 30 mm diameter trap shall be fixed to each basin having a 40 mm deep seal and one ortwo 12 mm pillar taps shall be fixed as required. Where only one tap only is required, thebasin shall be provided with a tap hole stopper to match the basin. Unless otherwisespecified, each wash-basin shall be fixed on two cast iron brackets complying with therelevant provisions of BS 1255 which shall be screwed to the wall. If required the pedestalWC pan shall match the basin.

2.8.8 Sinks

1 Ceramic sinks shall be white glazed fireclay size 600 mm x 450 mm x 250 mm deep andshall comply with the relevant provisions of BS 1206.

2 Metal sinks shall be stainless steel or aluminium to the sizes stated in the Project

Documentation and shall comply with the relevant provisions of BS 1244.

3 Each sink shall be provided with a 40 mm chromium plated brass waste outlet, outlet grating,overflow and rubber plug with chromium plated chain and stay. A 40 mm diameter trap shallbe fixed to each sink having a 40 mm or 75 mm deep seal as necessary. Each sink shallhave one or two 12 mm diameter pillar or bib taps, as required. Where only one tap isrequired, a tap hole stopper to match the sink shall be provided. Pillar taps shall have 150mm raising pieces and bib taps shall have extension pieces of adequate length.

4 Sinks shall be supported and fixed on brackets or legs unless otherwise specified in theProject Documentation. Two cast iron brackets shall be used for sinks supported and fixedon brackets. The brackets shall comply with the relevant provisions of BS 1255 and shall bescrewed to the wall. Legs for supporting sinks shall be of cast iron or galvanised steel with a

painted finish. Sinks shall be fixed at a height of 550 mm from the outlet grating to finishedfloor level.

2.8.9 Showers

1 Shower fittings shall comprise a 100 mm diameter adjustable chromium plated brass inclinedshower head with rose and 12 mm diameter supply pipe(s) with 12 mm diameter stopvalve(s) to control the water supply.

2 The shower head shall be fixed a height of 1800 mm above the finished floor level. Allexposed pipework and fittings serving the showers within the shower area shall be chromiumplated and fixed with chromium plated holderbats.

2.8.10 Taps

1 All taps shall comply with the relevant provisions of BS 1010. Taps shall be of the followingtype as appropriate and, where necessary, shall be provided with extension pieces.

(a) pillar taps shall be 12 mm diameter chromium plated brass with cross heads.(b) bib taps, unless otherwise stated, shall be 12 mm diameter chromium plated brass

with cross heads, complete with backplate elbow or wall flange. Bib taps to standpipes shall be 12 mm diameter unplated brass, and shall have an extended nozzlesuitable for hose connections.


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2.8.11 Traps

1 Traps shall be of the following types:-

(a) traps for sinks, lavatory basins and baths shall be copper, brass, or aluminiumcomplying with the relevant provisions of BS 1184, complete with cleaning eye.Traps to sinks, baths shall have an overflow connection.

(b) traps for urinals with suspended drains shall be 75 mm diameter cast iron complyingwith the relevant provisions of BS 416, Table 14. They shall be fitted with cast ironconnectors and threaded to receive the outlet from the urinal.

(c) traps for urinals with buried drainage shall be 75 mm diameter cast iron complyingwith the relevant provisions of BS 437. They shall be fitted with cast iron connectorsand threaded to receive the outlet from the urinal.

END OF PART


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QCS 2007 Section 20 Part 3 External Drainage Works Page 1

Qatar General Organization for Standards and MetrologyQCS 2007, 3

rdEdition

3. EXTERNAL DRAINAGE WORKS..................................................................2

3.1 GENERAL......................................................................................................2

3.1.1 Scope 2

3.1.2

References 2

3.1.3 System Description 2

3.2 PIPEWORK....................................................................................................2

3.2.1 General 23.2.2 Vitrified Clay Pipework 33.2.3 Unplasticized Polyvinyl Chloride (PVC-U) Pipework 33.2.4 Testing of Pipework 3

3.3 ACCESSORIES .............................................................................................3

3.3.1 Gullies and Gully Gratings 3

3.4 CONNECTION TO EXISTING PIPELINES....................................................3

3.4.1 Connections to Existing Government Mains 3


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3. EXTERNAL DRAINAGE WORKS

3.1 GENERAL

3.1.1 Scope

1 This Part specifies the requirements for pipework and accessories for external drainageworks in building areas. External drainage works includes foul water sewerage and surfacewater sewerage.



Section 1 GeneralSection 5 Concrete

Section 6 RoadworksSection 8 Sewerage

3.1.2 References


BS 2494 Elastomeric seals for joints in pipework and pipelineBS 4346 Joints and fittings for use with unplasticized PVC pressure pipes.BS 4660 unplasticized polyvinyl chloride (PVC-U) pipes and plastic fittings of nominal

sizes 110 and 160 for below ground drainage and sewageBS 5481 Unplasticized PVC pipe and fittings for gravity sewersBS 6209 Solvent cement for non-pressure thermoplastic pipe systemsBS EN 295 Vitrified clay pipes and fittings and pipe joints for drains and sewers

ISO 4633 Rubber Seals -Joints rings for supply, drainage3.1.3 System Description

1 Pipes and fittings to be used for foul sewerage shall be suitable for carrying sewage at

temperatures of up to 45C with hydrogen sulphide concentrations up to 400 mg/l.

2 Pipes shall be suitable for immersion in corrosive groundwater conditions typically exhibitingthe following characteristics unless otherwise specified:

SO3 Content : 1.7 g/lCI Content : 1.07 g/lpH : 8.6

Conductivity : 4000 s/cm

3 The Contractor shall be responsible for providing a jointing system as recommended by thepipe manufacturer that enables the installation and use of the designated pipeline systems.

3.2 PIPEWORK

3.2.1 General

1 Pipes shall have adequate strength to meet the loading requirements, be sufficiently robustto withstand site handling and be sufficiently durable to remain watertight for the anticipatedlife of the system.

2 Pipes and joints should remain sufficiently water tight to prevent the ingress of ground water

and the ingress of effluent when subject to ground movement and settlement.


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3.2.2 Vitrified Clay Pipework

1 Vitrified clay pipes and fittings for drains and sewers shall comply with the relevantprovisions of BS EN 295.

2 Pipes shall have spigot and socket joints complying with the relevant provisions of BS EN

295. Joints shall have elastomeric joint seals. Complying with the relevant provision of ISO4633 or, BS 2494 (Type D) and shall be obtained from the pipe manufacturer. For pipes upto 150 mm diameter, push-fit (sleeve type) polypropylene flexible couplings may be used inplace of spigot and socket joints.

3 All other requirements related to the manufacture, inspection and testing of vitrified claypipes shall be in accordance with the relevant provision of Section 8, Sewerage.

3.2.3 Unplasticized Polyvinyl Chloride (PVC-U) Pipework

1 PVC-U pipe joints and fittings for gravity drains and sewers shall comply with the relevantprovisions of BS 4660 or 5481.

2 Joints shall have elastomeric joint seals complying with the relevant provisions of ISO 4633or BS 2949 (Type D) and shall be obtained from the pipe manufacturer.

3 Solvent cements for jointing PVC-U pipes shall comply with BS 4346. For pipes and fittingscomplying with BS 4660, solvent cement may alternatively comply with BS 6209.

4 All other requirements related to the manufacture, inspection and testing of PVC-U pipesshall be in accordance with the relevant provisions of Section 8, Sewerage.

3.2.4 Testing of Pipework

1 Internal and external pressure tests shall be carried out on external drainage pipes. Testprocedures are detailed in Part 6 of this Section.

3.3 ACCESSORIES

3.3.1 Gullies and Gully Gratings

1 Gullies and gully gratings shall comply with the relevant provisions of Section 6, Roadworks.

3.4 CONNECTION TO EXISTING PIPELINES

3.4.1 Connections to Existing Government Mains

1 Connections to existing Government mains shall comply with the relevant provisions of

Section 8, Sewerage, and the following clauses.

2 Where possible and practicable, connections shall be made to future connection ports inexisting Government manholes. The caps on future connection ports to which connectionsare made shall be cleaned and delivered to the government stores in accordance with herelevant provisions of Section 1, General.

3 Where it is not possible of practicable to utilise future connection ports in existing manholes,connections shall be made by either breaking into existing manholes or constructing newmanholes on existing mains.

4 If it is necessary to break into an existing manhole, the Contractor shall break into themanhole wall, insert pipework, break out the existing benching, construct benching to suit

new connection and make good. If necessary, the Contractor shall relocate the accessladder and the cover slab to suit the new benching layout.


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5 Manholes built on an existing Government mains shall be constructed in accordance withClause 6 of this Part. On completion, such manholes shall become the property of thegovernment.

6 The Contractor shall be responsible for all over-pumping operations associated with makingconnections to Government mains.

END OF PART


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QCS 2007 Section 20 Part 4 Drainage Pipes in Trenches Page 1


QCS 2007, 3rd

Edition

4. DRAINAGE PIPES IN TRENCHES................................................................2

4.1 GENERAL......................................................................................................2

4.1.1 Scope 2

4.1.2

References 2

4.2 LAYING OF DRAINAGE PIPES IN TRENCHES............................................2

4.2.1 System Description 24.2.2 General 24.2.3 Bedding 34.2.4 Protective Coatings 34.2.5 Concrete Protection to Pipes 34.2.6 Completion of Pipe Surround 44.2.7 Backfilling 44.2.8 Protective Coatings 4

4.2.9 Pipes under Buildings 44.3 ACCESS TO DRAINAGE PIPES IN TRENCHES..........................................5

4.3.1 General 54.3.2 Rodding Eyes 54.3.3 Provision of Access to Drains 5

4.4 TESTING........................................................................................................5

4.4.1 Testing of Pipework 5


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4. DRAINAGE PIPES IN TRENCHES

4.1 GENERAL

4.1.1 Scope

1 This Part specifies the requirements for trenches and bedding for drainage pipes constructedinternally and externally.


This SectionPart 1 GeneralPart 2 Internal Drainage WorksPart 3 External Drainage WorksPart 6 Commissioning of Systems

Section 1 General

Section 5 ConcreteSection 8 Sewerage

4.1.2 References


BS 743 Materials for damp-proof courses.BS 882 Aggregates from natural sources for concreteBS 1142 Fibre building boardsBS 2494 Specification for elastomeric joint rings for pipework and pipelineBS 6076 Tubular polythene film for use as a protective sleeving for buried iron pipes

and fittings

4.2 LAYING OF DRAINAGE PIPES IN TRENCHES


1 The laying of drainage pipes in trenches shall generally be in accordance with the relevantprovisions of Section 8, Sewerage.

4.2.2 General

1 Where socketed pipes are required to be laid on a granular or sand bed, or directly on atrench bottom, joint holes shall be formed in the bedding material or final excavated surface toensure that each pipe is uniformly supported throughout the length of its barrel and to enable

the joint to made.

2 Pipes shall be laid on setting blocks only where a concrete bed or cradle is used.

3 Where pipes are required to be bedded directly on the trench bottom, the final excavatedsurface shall be trimmed and levelled to provide even bedding for the pipeline and shall befree from all extraneous matter that may damage the pipe, pipe coating, or sleeving. Whererock is encountered, the trench shall be cut at least 150 mm deeper than other ground andmade up with well compacted selected fill material.

4 No protective cap, disc or other appliance on the end of a pipe or fitting shall be removedpermanently until the pipe or fitting which it protects is about to be jointed. Pipes and fittings,including any lining or sheathing, shall be examined for damage and the joint surfaces and

components shall be cleaned immediately before laying.


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5 Suitable measures shall be taken to prevent soil or other material from entering pipes, and toanchor each pipe to prevent flotation or other movement before the Works are complete.

6 Where pipeline marker tape is specified, it shall be laid between 100 mm and 300 mm abovethe pipe.

4.2.3 Bedding

1 Bedding for pipes shall be constructed by spreading and compacting granular beddingmaterial over the whole width of the pipe trench. After the pipes have been laid, additionalmaterial shall, if required, be placed and compacted equally on each side of the pipe, andwhere practicable, this shall be done in sequence with the removal of the trench supports.

2 Bedding material shall be in accordance with Table 4.1 unless otherwise specified in theProject Documentation.

3 Nominal single sized aggregate and graded aggregate shall comply with Table No. 4 of BS882.

4 Sand for bedding material shall comply with the relevant provisions of BS 882.

5 Bedding systems other than those specified in this Clause may be allowed upon approval ofthe Engineer or as recommended by the pipe manufacturer.

Table 4.1

Bedding Material

Pipe Diameter Bedding

up to 65 mm Sand

65 - 100 mm 10 mm single sized aggregate

100 - 200 mm 10 or 14 mm single sized or 14-15 mmgraded aggregate

Over 200 mm 10,14 or 20 mm single sized or 15-5 or 20-5mm graded aggregate.

4.2.4 Protective Coatings

1 Coatings, sheathings or wrappings shall be examined for damage, repaired where necessary,and made continuos before trench excavations are backfilled.

4.2.5 Concrete Protection to Pipes

1 Pipes to be bedded on or cradled with concrete shall be supported on precast concrete settingblocks. The top face of each block shall be covered with two layers of compressible packingcomplying with BS 743.

2 Concrete provided as a protection to pipes shall be Grade C20, placed to the required depthin one operation.

3 Where pipes with flexible joints are used, the concrete protection shall be interrupted over itsfull cross-section at each pipe joint by a shaped compressible filler of bitumen impregnatedinsulating board to BS 1142 or equally compressible material. The thickness of thecompressible filler shall be in accordance with Table 4.2.


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Table 4.2

Thickness of Compressible Filler

Nominal Bore of Pipe (mm) Thickness of Compressible Filler (mm)

Up to 300

Over 300 and up to 600

Over 600 and up to 1200

13

25

38

4 Rapid hardening cement shall not be used in concrete for the protection of plastics pipe.

5 Plastics pipes shall be wrapped with a layer of plastic sheeting complying with a composition inaccordance with Clause 3 of BS 6076 and a nominal thickness of 125 microns before beingsurrounded by concrete.

6 Concrete work shall comply with the relevant provisions of Section 5, Concrete.

4.2.6 Completion of Pipe Surround

1 Fill material shall, where required, be placed and compacted over the full width of the trench inlayers not exceeding 150 mm before compaction, to a finished thickness of 250 mm abovethe crown of the pipes.

4.2.7 Backfilling

1 Backfilling shall, wherever practicable, be undertaken immediately the specified operationspreceding it have been completed. Backfilling shall not, however, be commenced until theparts of the Works to be covered have achieved a strength sufficient to withstand all loadingimposed thereon.

2 Backfilling around existing structures shall be undertaken in such manner as to avoid unevenloading or damage.

3 Filling material to excavations shall be deposited in layers not exceeding 250 mmunconsolidated thickness and compacted to 95% modified proctor.

4 Where the excavations have been supported and the supports are to be removed, these,where practicable, shall be withdrawn progressively as backfilling proceeds in such a manneras to minimise the danger of collapse. All voids formed behind the supports shall be carefullyfilled and compacted

4.2.8 Protective Coatings

1 Coatings, sheathings or wrappings shall be examined for damage, repaired where necessary,and made continuos before trench excavations are backfilled.

4.2.9 Pipes under Buildings

1 Where a pipe has less than 300 mm of cover under a load bearing slab, it should besurrounded with concrete as an integral part of the slab. Where possible, the concretesurround shall be poured at the same time as the slab. The surround shall be tied to the slabwith nominal steel reinforcement placed vertically with turned over ends.

2 No provision for pipe flexibility along the concrete surround shall be made, unless anexpansion joint is included in the slab. A construction joint should be included in the surroundat that point which must also coincide with a pipe joint.


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3 In normal, stable ground conditions, and with 300 mm or more of cover to the pipelinebeneath the slab, a total granular surround can be used as a pipe bedding. Refer to Clause4.2.3 of this Part for the bedding specification.

4 Flexibility shall be incorporated into the pipeline as it leaves any concrete surround.

5 Where plastic pipes are to be surrounded in concrete, Clause 4.2.5 of this Part shall apply.

4.3 ACCESS TO DRAINAGE PIPES IN TRENCHES

4.3.1 General

1 Access is required to drainage installations for testing, inspection, maintenance and removalof debris.

4.3.2 Rodding Eyes

1 Rodding eyes shall be constructed in pipework of the same diameter as the drains it serves

and should connect to the drain at an angle not steeper than 45 from the horizontal.

4.3.3 Provision of Access to Drains

1 Every drain length should be accessible for maintenance and rodding without the need toenter buildings. Access should be provided at the head of each run of a drain and at changesin direction, gradient or pipe diameter.

2 Table 4.3 indicates the recommended maximum distance between rodding eyes, inspectionchambers and manholes.

3 Where a branch drain joins another drain without the provision of an inspection chamber ormanhole at the junction, access should be provided on the branch drains within 12 m of the

junction.

Table 4.3

Maximum Spacings of Access Points

Distance to from Junction orBranch

from InspectionChamber

from Manhole

start of external drain - 22 m 45 m

rodding eye 22 m 45 m 45 m

inspection chamber 22 m 45 m 45 m

manhole 45 m 45 m 90 m

4.4 TESTING


1 Pressure tests shall be carried out on below ground plumbing pipes. Test procedures aredetailed in Part 6 of this Section.

END OF PART


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QCS 2007 Section 20 Part 5 Structures Related to Drainage Work Page 1


rdEdition

5. STRUCTURES RELATED TO DRAINAGE WORK........................................2

5.1 GENERAL......................................................................................................2

5.1.1 Scope 2

5.1.2

References 2

5.1.3 Concrete Work 25.1.4 Pipes built into structures 2

5.2 CONSTRUCTION OF MANHOLES, CHAMBERS AND SOAKAWAYS.........2

5.2.1 General 25.2.2 Soakaways 2

5.3 PRECAST CONCRETE MANHOLES ............................................................2

5.3.1 General 25.3.2 Jointing of Precast Manholes 3

5.4 TESTING OF STRUCTURES RELATED TO DRAINAGE WORK.................3

5.4.1 General 3


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5. STRUCTURES RELATED TO DRAINAGE WORK

5.1 GENERAL

5.1.1 Scope

1 This Part specifies the requirements for the construction of manholes, chambers andsoakaways for drainage works.

2 Related Section and Parts are as follows:

This Section Part 1 GeneralPart 3 External Drainage WorksPart 6 Commissioning of Systems

Section 5 ConcreteSection 6 RoadworksSection 8 Sewerage

5.1.2 References


PWA Developers Drainage Guide

5.1.3 Concrete Work

1 Concrete for manholes, chambers and soakaways shall comply with the relevant provisionsof Section 5, Concrete.

5.1.4 Pipes built into structures

1 Where pipes are built into concrete, they shall be rigidly secured in position to preventmovement and shall be free from external coatings which might adversely affect the bond.

5.2 CONSTRUCTION OF MANHOLES, CHAMBERS AND SOAKAWAYS

5.2.1 General

1 The construction of manholes and chambers for drainage works for foul sewage and surfacewater sewage shall comply with the relevant provisions of the following:

(a) Section 8 of this Specification, Sewerage(b) PWA - Developers Drainage Guide

5.2.2 Soakaways

1 Soakaways for surface water sewage shall comply with the relevant provisions of Section 6,Roadworks, except as amended in this Part.

2 Soakaways shall not be constructed closer than 5 m from a building or in a position wherethe ground below foundations is likely to be affected.

3 Precast concrete soakaways shall be dry jointed.

5.3 PRECAST CONCRETE MANHOLES

5.3.1 General

1 Precast concrete manholes shall comply with the relevant provisions of the PWA, except asamended in this Part.


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5.3.2 Jointing of Precast Manholes

1 The jointing material for precast manholes shall be mortar or a proprietary bitumen or resinmastic sealant, with the concrete surfaces primed with an appropriate sealant. The jointingmaterial which is extruded inside the manhole shall be trimmed off and joints pointed oncompletion.

2 Units which bed onto bases shall be manufactured so that imposed vertical loads aretransmitted directly via the full wall thickness of the unit.

3 For joints between units and the underside of slabs, joint profiles shall be capable ofwithstanding applied loadings from such slabs. Spigot ended sections shall only be usedwhere the soffit of the slab is recessed to receive them.

5.4 TESTING OF STRUCTURES RELATED TO DRAINAGE WORK

5.4.1 General

1 Testing of structures related to drainage work shall be done in accordance with the relevant

provisions of Part 6 of this Section.

END OF PART


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QCS 2007 Section 20 Part 6 Surface Water Drainage Page 1


QCS 2007, 3rd

Edition

6. SURFACE WATER DRAINAGE ....................................................................2

6.1 GENERAL......................................................................................................2

6.1.1 Scope 2

6.1.2

References 2

6.1.3 Submittals 26.1.4 Pipe Marking 36.1.5 Handling and Storage 36.1.6 Quality Assurance 3

6.2 PIPEWORK....................................................................................................3

6.2.1 General 36.2.2 Vitrified Clay Pipework 36.2.3 Unplasticized Polyvinyl Chloride (PVC-U) Pipework 46.2.4 Reinforced Concrete Pipes 4

6.2.5 Testing of Pipework 46.3 PIPE LAYING.................................................................................................4

6.3.1 General 46.3.2 Pipe Bedding 56.3.3 Concrete Protection to Pipes 56.3.4 Completion of Pipe Surround 56.3.5 Backfilling 5

6.4 GULLIES AND DRAINAGE CHANNELS .......................................................6

6.4.1 Gullies 6

6.4.2

Pre-formed Gullies 6

6.4.3 Drainage Channels 6

6.5 SOAKAWAYS................................................................................................7

6.5.1 General Requirements 7

6.6 MANHOLES AND CATCH PITS ....................................................................7


6.7 CONNECTION TO GOVERNMENT MAIN.....................................................7



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6. SURFACE WATER DRAINAGE

6.1 GENERAL

6.1.1 Scope

1 This Part specifies the requirement for pipework, gullies, manholes, catch pits, soakawaysand other items related to surface water drainage.



Section 5 Concrete

6.1.2 References


BS 65 Vitrified clay pipes, fittings and ducts, also flexible mechanical joints for usesolely with surface water pipes and fittings

BS 497 Manhole covers, road gully grating and frames for drainage purposesBS 743 Materials for damp-proof coursesBS 1142 Fibre building boardsBS 1247 Manhole stepsBS 2494 Elastomeric seals for joints in pipework and pipelinesBS 4660 unplasticized polyvinyl chloride (PVC-U) pipes and plastic fittings of nominal

sizes 110 and 160 for below ground gravity drainage and sewerageBS 6076 Tubular polythene film for use as protective sleeving for buried iron

pipes and fittingsBS 5481 unplasticized PVC pipe and fittings for gravity sewersBS 5911 Precast concrete pipes, fittings and ancillary products

BS EN 124 Gully tops and manhole tops for vehicular and pedestrian areasBS EN 295 Vitrified clay pipes and fittings and pipe joints for drains and sewers.

6.1.3 Submittals

1 The Contractor shall order materials to suit the construction programme and obtain theEngineers approval of submittals before placing orders. The Contractor shall submit twocopies of the following documents for the approval of the Engineer.

(a) Product Data

(i) originals of catalogues and engineering data sheets for manufactured items;each item and option to be provided shall be clearly marked and each item notto be provided shall be deleted

(ii) literature to show that products provided meet the requirements for material,construction, operation, and testing

(iii) information on the following items as a minimum: pipes; pipe jointing systems,manhole covers and frames and gully covers, gratings and frames.

(iv) manufacturers installation instructions for all items(v) certified reports for all tests and inspections designated herein, signed and

sealed, showing full compliance with referenced standards(vi) maintenance requirements and procedures

(vii) period of guarantee for products.


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(b) Shop Drawings showing the following:

(i) profiles of each pipe system including chainage, ground levels, invert levels,critical clearances and position of pipework structures.

(ii) material, class, grade, joint type, pressure rating, dimension, location andidentification number of each pipe and pipe fitting to be furnished and

installed.(iii) procedures for building pipes into concrete structures.(iv) procedures for encasing pipes in concrete.(v) class, dimensions, location and identification of each manhole cover and frame

to be furnished and installed.(vi) procedures for placing and fixing manhole covers and frames.(vii) class, dimensions, location and identification of each gully cover, grating and

frame to be furnished and installed.(viii) procedures for placing and fixing gully covers, gratings and frames.(ix) details for handling and storage of pipes, manhole covers and frames and gully

covers, gratings and frames.(x) all other miscellaneous details required for complete installation.

6.1.4 Pipe Marking

1 Each pipe and pipe fitting shall be marked with the following:

(a) serial number(b) class of pipe(c) nominal diameter(d) name or trademark for manufacturer(e) date of manufacture.

6.1.5 Handling and Storage

1 Each item to be provided under this Part shall be stored and handled in accordance with therecommendations of the manufacturer of the item.

2 Products susceptible to ultra violet degradation shall be stored under cover and out of directsunlight.

3 Pipes and fittings shall be subject to visual inspections after off-loading at the site and beforeinstallation.

6.1.6 Quality Assurance

1 Pipes, pipe fittings, manhole covers and frames and gully covers, gratings and frames shallbe supplied by approved manufacturers as designated in the Project Specification.Production facilities shall be quality assessed in accordance with ISO 9000 or equivalent.

6.2 PIPEWORK

6.2.1 General

1 Pipes shall have adequate strength to meet the loading requirements, be sufficiently robust towithstand site handling and be sufficiently durable to remain watertight for the anticipated lifeof the system. Pipes and joints should remain sufficiently water tight to prevent the ingress ofground water.

6.2.2 Vitrified Clay Pipework

1 Vitrified clay pipes and fittings for surface water drainage shall comply with the relevant

provisions of BS EN 295.


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2 Pipes and pipe fittings shall be extra strength class.

3 All pipes and pipe fittings shall have flexible mechanical joints. Pipes with diameters largerthan 150 mm shall have spigot and socket joints complying with the relevant provisions of BSEN 295. Spigot and socket joints shall have elastomeric joint seals, Type D, complying withthe relevant provisions of BS 2494, and shall be obtained from the pipe manufacturer. Push-

fit (sleeve type) polypropylene flexible couplings may be used in place of spigot and socketjoints for pipes up to 150 mm diameter.

6.2.3 Unplasticized Polyvinyl Chloride (PVC-U) Pipework

1 PVC-U pipes and fittings for surface water drainage shall comply with the relevant provisionsof BS 4660 and BS 5481.

2 All pipes and pipe fittings shall have spigot and socket joints complying with the relevantprovisions of BS 4660 and BS 5481. Spigot and socket joints shall incorporate Type Delastomeric joint seals complying with the relevant provisions for BS 2494 and shall beobtained from the pipe manufacturer.

6.2.4 Reinforced Concrete Pipes

1 Reinforced concrete pipes and fittings and flexible or ogee joints shall comply with therelevant provisions of BS 5911: Parts 100 and 110 respectively.

2 All pipes and fittings shall have gasket type joints of spigot and socket or rebated form,unless otherwise described in the Project Specification or shown on the Project Drawings.


1 Pressure tests shall be carried out on surface water drainage pipes. Test procedures aredetailed in Part 6 of this Section.

6.3 PIPE LAYING

6.3.1 General

1 Where socketed pipes are required to be laid on a granular or sand bed, or directly on atrench bottom, joint holes shall be formed in the bedding material or final excavated surfaceto ensure that each pipe is uniformly supported throughout the length of its barrel and toenable the joint to made.

2 Pipes shall be laid on setting blocks only where a concrete bed or cradle is used.

3 Where pipes are required to be bedded directly on the trench bottom, the final excavated

surface shall be trimmed and levelled to provide even bedding of the pipeline and shall befree from all extraneous matter that may damage the pipe, pipe coating, or sleeving.

4 No protective cap, disc or other appliance on the end of a pipe or fitting shall be removedpermanently until the pipe or fitting which it protects is about to be jointed. Pipes and fittings,including any lining or sheathing, shall be examined for damage and the joint surfaces andcomponents shall be cleaned immediately before laying.

5 Suitable measures shall be taken to prevent soil or other material from entering pipes, and toanchor each pipe to prevent flotation or other movement before the Works are complete.

6 Where pipeline marker tape is specified, it shall be laid between 100 mm and 300 mm abovethe pipe.


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6.3.2 Pipe Bedding

1 Bedding for pipes shall be constructed by spreading and compacting granular beddingmaterial over the full width of the pipe trench. After the pipes have been laid, additionalmaterial shall, if required, be placed and compacted equally on each side of the pipes, andwhere practicable, this shall be done in sequence with the removal of the trench supports.

6.3.3 Concrete Protection to Pipes

1 Pipes to be bedded on or cradled with concrete shall be supported on precast concretesetting blocks. The top face of each block shall be covered with two layers of compressiblepacking complying with BS 743.

2 Concrete provided as a protection to pipes shall be Grade C20, placed to the required depthin one operation.

3 Where pipes with flexible joints are used, concrete protection shall be interrupted over its fullcross-section at each pipe joint by a shaped compressible filler of bitumen impregnatedinsulating board to BS 1142 or equally compressible material. The thickness of thecompressible filler shall be in accordance with Table 6.1.

Table 6.1

Thickness of Compressible Filler

Nominal bore of pipe (mm) Thickness of compressible filler (mm)

Less than 450

450 to 1200

Exceeding 1200

18

36

54

4 Rapid hardening cement shall not be used in concrete for the protection of plastics pipe.

5 Plastics pipes shall be wrapped with a layer of plastic sheeting complying with a compositionin accordance with Clause 3 of BS 6076 and a nominal thickness of 125 microns beforebeing surrounded by concrete.

6.3.4 Completion of Pipe Surround

1 Fill material shall, where required, be placed and compacted over the full width of the trenchin layers not exceeding 150 mm before compaction, to a finished thickness of 250 mm abovethe crown of the pipes.

6.3.5 Backfilling

1 Backfilling shall, wherever practicable, be undertaken immediately the specified operationspreceding it have been completed. Backfilling shall not, however, be commenced until theworks to be covered have achieved a strength sufficient to withstand all loading imposedthereon.

2 Backfilling around existing structures shall be undertaken in such manner as to avoid unevenloading or damage.

3 Filling material to excavations shall be deposited in layers not exceeding 250mmunconsolidated thickness and compacted to 95% modified proctor.


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4 Where the excavations have been supported and the supports are to be removed, these,where practicable, shall be withdrawn progressively as backfilling proceeds in such a manneras to minimise the danger of collapse. All voids formed behind the supports shall be carefullyfilled and compacted

6.4 GULLIES AND DRAINAGE CHANNELS

6.4.1 Gullies

1 Gullies shall incorporate rodding eyes. Rodding eyes shall be fitted with rubber stoppersduring normal operation.

2 All gullies shall be trapped to prevent unwanted odours escaping from the drain.

3 All gullies shall incorporate aluminium silt buckets.

4 The Contractor shall ensure that the gully outlet and the outlet pipework are compatible.

5 Gully covers, gratings and frames shall comply with the relevant provisions of BS 497: Part 1

or BS EN 124.

6 The class of gullies covers, gratings and frames shall be as described in the ProjectSpecification or as shown on the Project Drawings.

6.4.2 Pre-formed Gullies

1 Precast concrete gullies shall comply with the relevant provisions of BS 5911: Part 2 andSection 5 - Concrete.

2 Vitrified clay gullies shall comply with the relevant provisions at BS EN 295: Part 1 or BS 65.

3

Polypropylene gullies shall be of a type detailed in the Project Specification or shown on theProject Drawings and shall be obtained from a reputable manufacturer as approved by theEngineer.

4 Cast iron gullies shall be of a type detailed in the Project Specification or shown on theProject Drawings and shall be obtained from a reputable manufacturer as approved by theEngineer.

5 Pre-formed gullies shall be bedded and surrounded with Grade C20 concrete to thethickness described in the Contract Documentation.

6 Frames shall be bedded in mortar on two courses of Class B engineering brickwork orprecast concrete gully cover slabs. Precast concrete gully cover slabs shall comply with the

relevant provisions of BS 5911: Part 2 and Section.

6.4.3 Drainage Channels

1 Precast concrete drainage channels shall comply with the relevant provisions of BS 5911:Part 2 and Section 5 - Concrete.

2 Drainage channel gratings and frames shall comply with the relevant provisions of BS EN124.


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6.5 SOAKAWAYS

6.5.1 General Requirements

1 Soakaways shall not be constructed closer than 10 m from a building or in a position wherethe ground below foundations is likely to be adversely affected.

2 Excavation round the soakaway shall be backfilled with a band of 40mm nominal single sizestone to provide a permeable surround to the soakaway. The permeable surround shall befully wrapped in a geotextile fabric. The dimensions of the band shall be as shown on theProject Drawings.

6.6 MANHOLES AND CATCH PITS


1 Bases and walls to manholes and catch pits shall be cast in situ using Grade C30 concrete.

2

Cover slabs to manholes shall be precast using Grade C40 concrete and shall incorporate anintegral GRP liner with a minimum thickness of 3.5mm. The vertical sides of the openings ofcover slabs shall be formed of filament would GRP pipe and soffits shall be formed of GRPsheet.

3 The Contractor shall provide the Engineer with a seven year unconditional guarantee againstfailure of all GRP linings whether caused by defective materials or workmanship. Theguarantee shall be valid from the date of completion of the installation and must be handedover to the Engineer before the issue of the Final Completion Certificate.

4 Unless otherwise stated in the Project Specification or shown on the Project Drawings,manhole inverts and benching shall be formed in Grade C20 concrete. Where there is nochange of diameter, the invert of the benching shall follow the same gradient as the outgoing

pipe.

5 Where a high strength concrete topping (granolithic finish) is required, the invert andbenching shall be formed in Grade C20 concrete, and the topping shall be applied as soon aspracticable thereafter.

6 All concrete works, including benching, shall comply with the relevant provisions of Section 5- Concrete.

7 Step irons shall comply with the relevant provisions of BS 1247:Parts 1, 2 and 3.

8 Covers and frames shall comply with the relevant provisions of BS 497:Part 1 and have aminimum clear opening of 600 mm diameter if circular or 600 x 750 mm if rectangular. All

covers shall have closed keyways.

9 The Contractor shall prepare a standard record sheet for every manhole and catch pit to theapproval of the Engineer.

10 Testing of manholes and catch pit chambers shall be as detailed in Part 6 of this Section.

6.7 CONNECTION TO GOVERNMENT MAIN


1 Connection to government mains shall be done at manholes. Pipe saddles and obliquejunctions will not be permitted.


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2 Where possible and practicable, connections shall be made to future connection ports inexisting Government manholes. The caps on future connection ports to which connectionsare made shall be cleaned and delivered to the government stores on completion of thework.

3 Where it is not possible or practicable to utilise future connection ports in existing manholes,

connections shall be made by either breaking into existing manholes or constructing newmanholes on existing mains.

4 If it is necessary to break into an existing manhole, the Contractor shall break into themanhole wall, insert pipework, break out the existing benching, construct benching to suitnew connection and make good. If necessary, the Contractor shall relocate the access ladderand the cover slab to suit the new benching layout.

5 Manholes built on an existing Government mains shall be constructed in accordance withClause 6 of this Part. On completion, such manholes shall become the property of thegovernment.

6 The Contractor shall be responsible for all over-pumping operations associated with making

connections to Government mains:

7 When a connection is made to an existing manhole in an area with high groundwater levels,the Contractor shall undertake the following if instructed to by the Engineer.

(a) undertake a CCTV survey and deflection test between the manhole immediatelyupstream and the manhole immediately downstream of the manhole to which theconnection is to be made before commencing dewatering operations.

(b) construct two mass concrete stanks round the base of the manhole to preventgroundwater from flowing into the excavation. The stanks shall be positioned eachside of the proposed connection and shall extend across the full width of theexcavation. The stanks shall be in place before any dewatering takes place.

(c) undertake a CCTV survey and deflection test between the manhole immediatelyupstream and the manhole downstream of the manhole to which the connection hasbeen made when work is complete and groundwater levels have returned to theirnatural levels.

(d) the Contractor shall submit all CCTV survey data and deflection test data to theEngineer. Such data shall be used to determine whether any damage has beencaused to the existing main by the Contractor while carrying out his work.

(e) the Contractor shall be responsible for rectifying any damage caused as a result ofhis work.

(f) the Contractor shall submit his proposals for carrying out remedial works to theEngineer for approval prior to starting such work, should it be necessary.

END OF PART


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rdEdition

7. COMMISSIONING OF SYSTEMS .................................................................2

7.1 GENERAL......................................................................................................2

7.1.1 Scope 2

7.1.2

System Description 2

7.1.3 Submittals 27.1.4 Connection to Existing Mains 2

7.2 CLEANSING OF PIPES, MANHOLES AND CHAMBERS .............................2

7.2.1 General 2

7.3 TESTING........................................................................................................3

7.3.1 General 3

7.4 TESTING AND INSPECTION EXTERNAL DRAINAGE PIPELINES .............3

7.4.1 General 37.4.2 Inspection 37.4.3 Water Test 47.4.4 Air Test 47.4.5 CCTV Inspection 47.4.6 Infiltration 4

7.5 TESTING AND INSPECTION INTERNAL DRAINAGE PIPELINES...............5

7.5.1 Air Test 57.5.2 Leak Location 57.5.3 Water test 5

7.6 TESTING OF SANITARY APPLIANCES .......................................................5

7.6.1 General 57.6.2 Self-Siphonage and Induced Siphonage in Branch Discharge Pipes 67.6.3 Induced Siphonage and Back Pressure in Discharge Stacks 6

7.7 TESTING OF DRAINAGE STRUCTURES.....................................................6

7.7.1 Manholes and Chambers 6


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7. COMMISSIONING OF SYSTEMS

7.1 GENERAL

7.1.1 Scope

1 This Part specifies the requirements for the testing and cleaning of drainage installations.

2 Related Sections and parts are as follows:

This SectionPart 1 GeneralPart 2 Internal Drainage WorksPart 3 External Drainage WorksPart 4 Trenches for Drainage PipeworkPart 6 Surface Water drainage

Section 1 General


1 Inspections and tests should be made during the installation of the discharge system as thework proceeds, to ensure that the pipework is properly secured and clear of obstructingdebris and superfluous matter and that all work which is to be concealed is free from defectsbefore it is finally enclosed.

2 Prefabricated units should be tested at the works or place of fabrication, and inspected ondelivery at the Site.

7.1.3 Submittals

1 The Contractor shall prepare a detailed testing and inspection programme and submit it tothe Engineer for approval. This programme shall identify each item to be tested, the type oftest to be performed and the date and time of the test.

2 The Contractor shall prepare test and inspection record sheets for all tests and inspectionsundertaken. The format of the test record sheets shall be to the approval of the Engineer.On successful completion of a test/inspection, the test record sheet shall be signed andstamped by all the Contractor and the Engineer. The Engineer shall retain the original testrecord sheet.

7.1.4 Connection to Existing Mains

1 Connection to existing mains shall not take place until all tests and inspections have been

successfully completed and the system has been cleaned.

7.2 CLEANSING OF PIPES, MANHOLES AND CHAMBERS

7.2.1 General

1 On completion, the discharge system should be meticulously inspected to ensure that therequirements of the Contract Documentation have been observed.

2 The Contractor shall ensure that no cement droppings, rubble or other objects are left in oron the pipes and that no jointing material projects into the pipe bore.

3 Manholes and chambers shall be thoroughly cleansed to remove all deleterious matter,

without such matter being passed forward to existing mains.


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4 Sanitary appliances shall be thoroughly cleansed. Any chromium plated or other metallicsurfaces forming part sanitary appliances that exposed to view shall be polished.

5 All parts of the Works included in this Section shall be maintained in a clean and serviceablecondition by the Contractor until completion of the Contract.

7.3 TESTING

7.3.1 General

1 The Contractor shall notify the Engineer at least two clear working days prior to his intentionto test a section of pipeline.

2 Items failing any test shall be corrected immediately and re-tested before further workproceeds.

3 Unless otherwise stated in the Project Documentation, the Contractor is responsible forproviding materials and apparatus required for testing purposes and for their removal andproper disposal on completion at testing.

7.4 TESTING AND INSPECTION EXTERNAL DRAINAGE PIPELINES

7.4.1 General

1 Unless otherwise agreed by the Engineer, both interim and final test shall be undertaken oneach section of the Works. The Contractor shall note that the satisfactory completion of aninterim test does not constitute a final test.

2 Non-pressure pipelines laid in trenches shall be tested after they are jointed and before anyconcreting or backfilling is commenced, other than such as may be necessary for structuralstability whilst under test.

3 The pipelines shall be tested by means of an air or water test or by a visual or closed circuittelevision (CCTV) examination, in lengths determined by the course of construction.

4 A further test shall be carried out after the backfilling is complete.

7.4.2 Inspection

1 Visual inspection shall be carried out before backfilling in order to detect faults inconstruction or material not shown up under test but which could lead to premature failure.

A careful record shall be kept of such inspections.

2 On external pipelines, the following shall be visually inspected:

(a) pipe bed(b) pipe line and level(c) joints(d) pipe protective coating(e) any pipeline appurtenance.

3 Trenches shall be inspected to ensure that the excavation is to the correct depth to guardagainst mechanical damage due to traffic loading.

4 No part of the pipe trench shall be backfilled until the above are performed to the satisfactionof the Engineer.


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7.4.3 Water Test

1 The test pressure for external drainage pipelines up to and including 750 mm nominal boreshall be not less than 1.2m head of water above the pipe soffit or groundwater level,whichever is the higher at the highest point, and not greater than 6m head at the lowest pointof the section. Steeply graded pipelines shall be tested in stages in cases where the

maximum head, as stated above, would be exceeded if the whole section where tested inone length.

The pipeline shall be filled with water and a minimum period of 2 hours shall be allowed forabsorption after which water shall be added from a measuring vessel at intervals of 5minutes and the quantity required to maintain the original water level noted. Unlessotherwise specified, the length of pipeline shall be accepted if the quantity of water addedover a 30 minute period is less than 0.5 litre per linear metre per metre of nominal bore. Thisrelationship in equation format, with water added measured in litres, can be written asfollows:

Maximum volume of water added over a 30 minute period = 0.5 x L x D

Where: L = pipe diameter (m)D = Length of test section (m)

7.4.4 Air Test

1 Non-pressure pipelines to be air tested shall have air pumped in by suitable means until apressure of 100 mm head of water is indicated in a U-tube connected to the system. Thepipeline shall be accepted if the air pressure remains above 75 mm head of water after aperiod of 5 minutes without further pumping following a period for stabilisation. Failure topass the test shall not preclude acceptance of the pipeline if a successful water test, orderedby the Engineer, can subsequently be carried out in accordance with Clause 7.3.3.

7.4.5 CCTV Inspection

1 Where internal inspection of pipelines by CCTV is required, the Contractor shall provide allnecessary equipment, including suitable covered accommodation for viewing the monitorscreen, together with personnel experienced in the operation of the equipment andinterpretation of results.

2 The intensity of illumination within the pipe and the rate of draw of the camera shall be suchas to allow a proper examination of the inside of the pipe. Provision shall be made for themovement of the camera to be stopped and its position recorded and for permanentphotographs to be taken at any point requested by the Engineer.

7.4.6 Infiltration

1 External drainage pipelines shall be tested for infiltration after backfilling. All inlets to thesystem shall be effectively closed, and any residual flow shall be deemed to be infiltration.

2 The pipeline shall be accepted as satisfactory if the infiltration, including infiltration intomanholes, in 30 minutes does not exceed 0.5 litre per linear metre per metre of nominalbore. This relationship in equation format, with water infiltration measured in litres, can bewritten as follows:

Maximum volume of infiltration over a 30 minute period = 0.5 x L x D

Where: L = pipe diameter (m)D = Length of test section (m)


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3 Notwithstanding the satisfactory completion of the above test, if there is any discernible flowof water entering the pipeline at a point which can be located either by visual or CCTVinspection, the Contractor shall take such measures as are necessary to stop suchinfiltration.

7.5 TESTING AND INSPECTION INTERNAL DRAINAGE PIPELINES

7.5.1 Air Test

1 The water seals of all sanitary appliances should be fully charged and test plugs or bagsinserted into the open ends of the pipework to be tested.

2 To ensure that there is a satisfactory air seal at the base of the stack, or at the lowest plug orbag in the stack if only a section of the pipework is to be tested, a small quantity of watersufficient to cover the plug or bag can be allowed to enter the system.

3 One of the remaining test plugs should be fitted with a tee piece, with a cock on eachbranch, one branch being connected by means of a flexible tube to a manometer.

Alternatively, a flexible tube from a tee piece fitted with cocks on its other tow branches can

be passed through the water seal of a sanitary appliance. Any water trapped in this tubeshould be removed and then a manometer can be connected to one of the branches asdescribed above.

4 Air shall be pumped into the system through the other branch of the tee piece until apressure equal to 38 mm water gauge is obtained. The air inlet cock is then closed andpressure in the system should remain constant for a period of not less than 3 min.

7.5.2 Leak Location

1 The use of smoke to detect leaks shall only be permitted if approved in writing by theEngineer. A smoke producing machine may be used which will introduce smoke underpressure into the defective pipework. Leakage may be observed as the smoke escapes.Smoke cartridges containing special chemicals should be used with caution, taking care thatthe ignited cartridge is not in direct contact with the pipework and that the products ofcombustion do not have a harmful effect upon the materials used for the drainage system.Smoke testing of plastics pipework or systems with rubber jointing components is notpermitted.

2 With the pipework subjected to an internal pressure using the smoke machine or air testmethod, a soap solution can be applied to the pipes and joints. Leakage can be detected bythe formation of bubbles.

7.5.3 Water test

1 There is not justification for a water test to be applied to the whole of the plumbing system.The part of the system mainly at risk is that below the lowest sanitary appliance and this may

be tested by inserting a test plug in the lower end of the pipe and filling the pipe with waterup to the flood level of the lowest sanitary appliance, provided that the static head does notexceed 6 m.

7.6 TESTING OF SANITARY APPLIANCES

7.6.1 General

1 To ensure that adequate water seals are retained during peak working conditions the testsdescribed below should be carried out. After each test a minimum of 25 mm of water sealshould be retained in every trap.


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2 Each test should be repeated at least three times, the trap or traps being recharged beforeeach test. The maximum loss of seal in any one test, measured by a dip stick or smalldiameter transparent tube, should be taken as the significant result.

7.6.2 Self-Siphonage and Induced Siphonage in Branch Discharge Pipes

1 To test for the effect of self-siphonage the appliance should be filled to overflowing level anddischarged by removing the plug; WC pans should be flushed. The seal remaining in the trapshould be measured when the discharge has finished.

2 Ranges of appliances, connected to a common discharge pipe, should also be tested forinduced siphonage in a similar way. The number of appliances which should be dischargedtogether is given in Table 6.1. The seal remaining in all the traps should be measured at theend of the discharge. Only those appliances included in Table 6.1 shall be tested undersimultaneous discharge conditions.

Table 6.1

Number of Sanitary Appliances to be Discharged for Performance Testing

Number of appliances of eachkind on the stack

Number of appliances to be discharged simultaneously

WC Wash Basin

1 to 9 1 1

10 to 18 1 2

19 to 26 2 2

27 to 52 2 3

53 to 78 3 4

79 to 100 3 5

7.6.3 Induced Siphonage and Back Pressure in Discharge Stacks

1 A selection of appliances connected to the stack should be discharged simultaneously andthe trap and seal losses due to positive or negative pressures in the stack should be noted.These selected appliances should normally be close to the top of the stack and on adjacentfloors, as this gives the worst pressure conditions. Table 6.1 shows the number ofappliances which should be discharged simultaneously. Only those appliances included inTable 6.1 shall be tested under simultaneous discharge conditions.

7.7 TESTING OF DRAINAGE STRUCTURES

7.7.1 Manholes and Chambers

1 Manholes and chambers shall be tested for infiltration after backfilling. Where appropriate,they shall be inspected for water tightness before placing cover slabs.

2 Manholes and chambers shall be substantially water tight, with no identifiable flow of waterpenetrating the structure. Manholes and chambers which are not substantially water tightshall be corrected immediately.

END OF PART

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Drainage Works for Buildings