Surface water sewers should be designed for runoff from roofs and, subject to the agreement of the Undertaker, highways including verges and other paved areas. They should not be designed to take runoff from other areas or land drainage. In these cases, satisfactory and separate arrangements should be agreed with the local Land Drainage Authority and confirmed to the Undertaker. During extremely wet weather, the capacity of the surface water sewers may be inadequate, even though they have been designed in accordance with Clause C3.
Under such conditions, sewers may surcharge and surface water can escape from those manhole covers which lie below the hydraulic gradient. In designing the site sewerage and layout, Developers should also demonstrate flow paths and the potential effects of flooding resulting from extreme rainfall blockages, pumping station failure or surcharging in downstream sewers, by checking the ground levels around the likely points that flow would flood from the system to identify the flood routes.
The Developer is encouraged to have early discussions with the Undertaker to ensure that a sustainable approach to the management of surface water from the site is applied.
The Local Planning Authority can specify restrictions on the route of discharge of surface water from a development. For details of these, refer to the appropriate planning guidance. Flow control devices should be provided with a bypass valve so that the storage can be drained in the event of blockage of the flow control device. The design and location of flow attenuation and flow control devices and chambers are to be agreed with the Undertaker. The design of flow control devices should, wherever practicable, include the following features: a flow controls may be static such as vortex flow controls or fixed orifice plates or variable such as pistons or slide valves ; b static controls should have a minimum opening size of mm chamber, or equivalent; c variable controls may have a smaller opening provided they have a self- cleansing mechanism; d a bypass should be included with a surface operated penstock or valve; and e access should be provided to the upstream and downstream sections of a flow control device to allow maintenance.
Structural design and integrity for surface water sewers and drains should be in accordance with B5. Materials for surface water sewers and drains should be in accordance with Part D of this guide.
Construction of surface water sewers and drains should be in accordance with Part D of this guide. Testing of surface water sewers and drains should be in accordance with Part D of this guide.
Any clauses in this Part which relate to work or materials not required shall be deemed not to apply. Where additional clauses are required, reference should be made to Sewers for Adoption 7th Edition. Where Developers wish to use materials or methods not covered by this specification reference should be made to Sewers for Adoption. One copy of the Drawings shall be kept on the site and shall Works should be pre-scribed, be available for use by the Undertaker.
Precise 2. Details shall be provided of the level and location existing features or to the of the temporary benchmarks and reference points which are Ordnance Survey National proposed to be used. Grid should be shown. The Developer shall be responsible for setting out the Works and for the correctness of the position and dimensions of all parts of the Works. All materials and workmanship shall be subjected, from time to time, to such tests as the Undertaker may direct.
The Undertaker shall be afforded the opportunity to examine any work which is about to be covered up or put out of view, and to examine foundations before permanent work is to be placed thereon. All necessary precautions shall be taken to avoid misconnection to existing public sewers.
Submissions shall be in accordance with the latest published Standard which is current on the date the submission is made.
Materials and components shall be stored in such a manner as to preserve their quality and condition to the standards required by the Specification. Where appropriate, any technical advisory services offered by manufacturers shall be used. Water for use with cement shall be of wholesome quality. Cement shall either: 20 N per mm2 for the use of sulphate-resisting Portland a be factory-produced by the cement manufacturer and comply cement is consistent with with the provisions of the appropriate Standard, as Table D.
Table D. For precast concrete pipes or inspection chambers complying with BS EN , BS EN and BS , a minimum class 3, sulphate-resistant cement shall be used unless the Undertaker can be satisfied that a lower class will resist attack from soils and groundwater.
Mortar shall be mixed only as and when required, in the broadly equivalent see relevant proportions indicated in Table D. The constituent materials shall be use of lime putty or accurately gauged, allowance being made for bulking of sand. Alternative nominal mixes by volume ii The cement:lime:sand mortar is consistent with Cement:sand with Cement:lime:sand Cement:sand Category 1.
All mortar shall be conveyed fresh to the Works as required for use. Mortar which has begun to set or which has been site-mixed for a period of more than one hour shall not be used. Plasticising and set-retarding mortar admixtures shall comply with BS EN and shall be supplied with instructions for use. Constituent materials of precast concrete products shall surface finish should be comply with the relevant requirements of this Specification, shown on the Drawings.
Except where otherwise agreed or specified in a relevant European or British Standard, the surface finish of precast concrete products shall be Rough Finish for surfaces next to earth and Fair Finish elsewhere. Precast concrete slabs and cover frame seating rings shall comply with the relevant provisions of BS EN and BS 3. Vitrified clay pipes and fittings for sewers shall have flexible vitrified clay pipes and mechanical joints.
Pipes for foul sewers and surface water fittings. Extra chemically-resistant pipes and fittings shall comply with chemically-resistant pipes the additional requirements of BS Vitrified clay jacking pipes shall conform to BS EN All pipes and fittings shall have gasket-type joints of spigot and ii Additional protective socket or rebated form.
Pipes shall withstand the jacking loads to which they will be Chemical Environment for subjected during installation, without cracking or spalling. A Concrete class should be certificate shall be supplied, confirming that the pipes are suitable described. Joint lubricants for sliding joints shall have no deleterious effect on either the joint rings or pipes, and shall be unaffected by sewage.
Seals shall be tested in accordance with BS and shall comply with the following: a the average loss in mass Z of the test pieces shall not exceed 3. In the case of composite seals, the requirements apply only to those components exposed to the contents of the pipeline or pipework. Processed granular and "as-dug" bedding, sidefill and guidance on pipe surround surround materials for buried pipelines shall comply with WIS 4- materials.
Recycled materials shall comply with BS Compressible filler for interrupting concrete protection to pipes shall consist of bitumen-impregnated insulating board to BS EN and BS EN The thickness of compressible filler shall be as Table D. Compressible packing for use between pipes and precast concrete setting blocks shall consist of bitumen damp proof sheeting complying with BS Bituminous materials shall not be put into contact with plastics pipes. Units EN and BS which bed into bases shall be manufactured so that imposed should be shown on the vertical loads are transmitted directly via the full wall thickness of Drawings.
The profiles of joints between units and the underside of slabs, shall be capable of withstanding applied loadings from. Inspection chamber covers and frames shall comply with the performance standard only.
They shall be of a non- rocking design which does not rely on the use of cushion inserts. Inspection chamber covers on foul-only sewers shall be of low leakage types in order to prevent excessive surface water ingress. As a minimum, Class D covers shall be used in carriageways of roads including pedestrian streets , hard shoulders and parking areas used by all types of road vehicles. Class B shall be used in footways, pedestrian areas and comparable locations.
All inspection chamber covers shall be the non-ventilating type and shall have closed keyways. Concrete bricks or blocks to be used in inspection chambers been used for precast shall be precast concrete masonry units, manufactured in concrete masonry units. Clay bricks to be used in inspection chambers shall be solid, Class B engineering bricks complying with the relevant provisions of BS EN The shapes and dimensions of special bricks shall comply with the relevant provisions of BS All bricks shall have active soluble salts content designation S2.
Operations shall be carried out in such a manner as to prevent damage to, or deterioration of, the formation of excavations. Excavation in roads and streets shall be carried out in accordance with the relevant Highway Reinstatement Specification. Trenches shall be excavated so that the effective width is maintained within any limit imposed by the design of the pipeline. The sides of excavations shall be adequately supported at all times and, except where permitted, shall not be battered.
Soft spots shall be removed from the bottom of trenches and other excavations, which shall then be refilled to formation level with the same material as the permanent work which is to rest on that formation.
Any void which results from over-excavation below formation level shall be refilled in the same manner. Excavated granular material which can be reused shall be kept separate from excavated cohesive materials.
Water shall not be allowed to accumulate in any part of the be required from the Works. Water arising from, or draining into, the Works shall be Environment Agency.
Any drainage sumps required shall, where practicable, be sited outside the ii Pollution Prevention area excavated for the permanent Works, and shall be refilled Guidance PPG 5 and 6 with either DoT Type 1 granular sub-base material or lean published by the concrete Grade GEN1 C10 to the level of the underside of the Environment Agency should adjacent permanent Works.
All necessary precautions shall be taken to prevent any adjacent ground from being adversely affected by loss of fines through any dewatering process. Discharges to sewers shall not take place without the consent of the Undertaker.
Backfilling shall, wherever practicable, be undertaken may impose requirements for immediately when the specified operations preceding it have backfilling under existing been completed. Backfilling shall not, however, be commenced highways. Backfilling shall be undertaken in such a manner as to avoid uneven loading or damage. Filling material shall be deposited in layers not exceeding mm unconsolidated thickness, and then fully compacted to form a stable backfill.
Where the excavation is within 1 m of the outside of the edge of the carriageway or proposed carriageway , the fill material shall be such as to permit adequate drainage. 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 manner as to minimise the danger of collapse, and all voids formed behind the supports shall be carefully filled and compacted. Filling material to excavations not situated in highways or prospective highways shall be placed and compacted to form a stable backfill.
Hardcore shall consist of clean, hard, durable material uniformly graded from mm to 20 mm, and be free from extraneous matter. Selected fill, whether selected from locally-excavated material or imported, shall consist of uniform, readily-compactible material.
Clay lumps and stones retained on 75 mm and The pipe surround material shall be protected from the foamed concrete by an impermeable layer. Where socketed pipes are required to be laid on a granular or give recommendations on sand bed or directly on a trench bottom, joint holes shall be standards of good practice formed in the bedding material or excavated formation to ensure for the installation of that each pipe is uniformly supported throughout the length of its pipelines on land: barrel and to enable the joint to be made.
Pipes shall be laid on setting blocks only where a concrete bed for the Installation of or cradle is used. Pipes and fittings shall be examined for damage and the joint UK; surfaces and components shall be cleaned immediately before laying. Where pipeline marker tapes are specified, they shall be laid BS 'Workmanship between mm and mm above the pipe. Where a tracer on Building Sites. Code of system is specified, it shall be continuous and adequately Practice for Below Ground secured to valves and fittings.
Bedding for pipes shall be constructed by spreading and guidance on pipe surround compacting granular bedding material over the full width of the materials. After the pipes have been laid, additional granular material shall, if required, be placed and compacted equally on ii Geotextile membranes each side of the pipes and, where practicable, this shall be done may be an acceptable in sequence with the removal of the trench supports.
Where in the opinion of the Undertaker the flow of groundwater is likely to transport fine soil particles, water stops of puddle clay iii Full bed and surround extending up through the bedding and sidefill shall be placed may not be required for rigid, across the trench and immediately downstream of any temporary large diameter pipes. In bad ground conditions, where the migration of the pipe instructions. Pipe surround material shall, where required, be placed and may not be required for rigid, compacted over the full width of the trench in layers not large diameter pipes.
Subsequent backfilling shall then be carried out as specified in Section 3. Pipe jointing surfaces and components shall be kept clean and required to be made in free from extraneous matter until the joints have been made or accordance with the assembled.
Site fusion jointing in polyethylene pressure pipelines shall be settlement or ground undertaken in accordance with the relevant provisions of WIS 4- movement. Where PE pipes are used, a fully-welded system shall be used and the number of joints minimised. Mechanical or electrofusion joints shall not be used.
Where necessary, the cut ends of pipes shall be formed to the tapers and chamfers suitable for the type of joint to be used. Where concrete pipes are cut, any exposed reinforcement shall be sealed with an epoxy-resin mortar.
Pre-stressed concrete pipes shall not be cut on site. Particular safety precautions shall be taken to avoid inhalation of dust when cutting asbestos-cement pipes.
Where junction pipes for future connections are required, they shall be inserted, as necessary, during construction of the sewers, and the ends of connections and pipes not needed for immediate use shall be effectively sealed with a plug. The position of all junctions shall be recorded by measurement from the centre of the manhole cover immediately downstream, and notified to the Undertaker before backfilling is carried out.
Connections shall be made using standard pre-formed junctions, where possible. Pipe saddles for concrete or clay sewers shall be bedded in Class M1 mortar and a mortar fillet formed to give a cover of at least 50 mm to the base of the saddle. No pipe in a sewer or lateral drain shall have a reverse gradient. Precast concrete inspection chamber sections for inspection chambers shall be constructed with steps, ladders and slabs aligned correctly.
Joints shall be made so that the required jointing material fills the joint cavity. Concrete to concrete contact across the joint shall not be permitted. Any surplus jointing material which is extruded inside the manhole, chamber or wet well shall be trimmed off and joints shall be pointed on completion. Concrete surrounds to manholes, chambers and the wet well shall be Grade GEN3 and the height of each concrete pour shall not exceed 2 m.
Each construction joint shall break joint with the precast sections by at least mm. Inverts and benchings in inspection chambers shall have a screeded, ridged finish and shall have a smooth, high-strength concrete topping applied with a steel trowel before the concrete has set. Where rigid pipes are used, a flexible joint shall be provided as close as is feasible to the outside face of any structure into which a pipe is built, within mm for pipe diameters less than mm.
The design of the joints shall be compatible with any subsequent movement. The recommended length of the next pipe rocker pipe away from the structure shall be as shown in Table D. Stub pipes into structures shall be of rigid material. The frame shall be seated on at least two courses of Class B engineering bricks, on precast concrete masonry units or on precast concrete cover frame seating rings to regulate the distance between the top of the cover and the top rung to no greater than mm.
A mortar fillet shall be provided where the corners to an opening in a slab are chamfered and the brickwork is not flush with the edges of the opening. Non-man inspection chambers shall comply with the relevant provisions of BS EN On completion of construction, internal surfaces of sewers, the event of failure to satisfy inspection chambers and other access points shall be thoroughly the tests specified has only cleansed to remove all deleterious matter, without such matter been referred to in general being passed forward into existing public sewers or terms where the text so watercourses.
The sewers and manholes shall be maintained in requires see also Section a clean and serviceable condition until they are vested as public D1. Sewers up to and including mm nominal diameter shall be tested by means of an air or water test.
An air test shall be carried out after the backfilling is complete. The pipelines shall be tested by means of a visual or closed- circuit television CCTV examination, in lengths determined by the course of construction, in accordance with the programme. For flexible pipes, the CCTV examination shall use light rings to measure deformations. U-tube connected to the system.
A tree should not be planted directly over sewers or where excavation onto the sewer would require removal of the tree. Also includes Common tormentil, silverweed and barren strawberry Skimmia japonica; Skimmia Spiraea japonica; Japanese spirea or Japanese meadowsweet Veronica varieties; Speedwell Viburnum davidii; David viburnum Viburnum tinus; Lauristinus When in a highway, the outside of the sewer should be in the vehicle carriageway not footway and be at least 1 m from the kerb line.
The external faces of inspection chambers should be at least 0. Typical layouts are shown in Figures B. Other sewers or lateral drains to be minimum mm diameter Foul sewer Foul lateral drain Unfenced or low fence boundary Foul drain not adoptable High fence boundary Foul manhole Type 3 foul inspection chamber Type 4 foul inspection chambers - not greater than 3 properties Type 4 foul inspection chambers - not greater than 1 property not adoptable Note: Some inspection chambers act as demarcation chambers.
Inspection chambers in footway are sited in zone reserved for street lighting columns 2. Additional inspection chambers give access to sewers in enclosed areas Key: Sewers serving more than 10 dwellings to be minimum mm diameter.
Designation of individual pipes will depend on curtilage. See Clause A1. Designation assumes drain is in private land 3. Designation of pipe assumes road is private Key: Sewers serving more than 10 dwellings to be minimum mm diameter.
Other sewers or lateral drains to be minimum mm diameter Foul sewer Foul lateral drain Foul drain not adoptable Foul manhole Type 3 foul inspection chamber Type 3 foul inspection chamber not adoptable Type 4 foul inspection chambers - not greater than 3 properties Type 4 foul inspection chambers - not greater than 1 property not adoptable Note: Some inspection chambers act as demarcation chambers.
Access points should be located so that they are accessible and apparent to the Undertaker at all times for use. They should avoid rear gardens or enclosed locations. Additional access points may be provided in other locations, as long as access is provided to the system from other access points, in accordance with the recommendations in Clauses B2.
Access points, and any inlets to drains or sewers, should be located so as to minimise the risk of damage to buildings or other critical infrastructure in the event of sewer flooding. Access points and sewers should be sited with due regard to public utility services. An access point should be built: a at every change of alignment, gradient or pipe material; b at the head of all sewers; c at every junction of two or more public sewers; d wherever there is a change in the size of the sewer; e at every junction of a public sewer with another sewer serving three or more properties where the access point is an inspection chamber; f at or within 1 m of the property boundary at the upstream end of each lateral drain preferably inside the property boundary.
Where access to a pipe is provided through an inspection chamber, no part of the pipe should be more than Inspection chambers should be designed to afford reasonable access for equipment to carry out maintenance activities. Inspection chambers should be designed to deter personnel access. The flow diagram in Figure B. Each junction, change of direction or change of status, is described here as a node. No access is required at a node if it connects less than three properties and there already is, or will be, sufficient access to carry out sewer maintenance.
Any pipe, and associated access upstream of the point of demarcation, is a private drain and should be constructed in accordance with the Building Regulations. Figures B. No significant departure from these dimensions should be made without approval by the Undertaker. Where a cover is located in an area of block paving, the bottom of the frame should be mm deep. Covers for inspection chambers should be in accordance with Section D2.
Unless the chamber is designed to withstand the vertical load acting on it, a precast concrete slab or in-situ concrete slab, should be provided, to act as a collar to support the cover and frame. The collar should be separate from the chamber to ensure the loading from the cover and frame is not transferred to the chamber. The first inspection chamber upstream from the connection to the existing public sewer should, when constructed, be fitted with a screen in order to prevent debris entering the public sewer.
The screen should not be removed until immediately prior to the occupation of premises to be served by the sewer. Rocker pipes should be provided at entry to, and exits from, inspection chambers when rigid pipes are used. Their length should be as shown in Table D. Where pipes serving a total of three properties or more connect to a pipe that has a nominal internal diameter less than or equal to mm, the branch connections should be set so that the soffits of all the pipes are at the same level.
In all other cases, branch connections should be set with the soffit levels no lower than that of the main pipe and with the invert level of the branch connection at least 50 mm above the invert of the main pipe. The main channel should extend the whole length of the chamber, comprising a half- round section plus vertical benching from the top edge of the half round section to a height of not less than that of the soffit of the outlet, where it should be rounded off and sloped upwards to meet the wall of the chamber.
Figure B. Maximum Nominal diameter mm effective length m - 0. Benching slope to be to Arch over pipe See Figure B. The minimum size for a gravity foul sewer should be: a mm nominal internal diameter for ten properties or less; or b mm nominal internal diameter for more than ten properties.
The minimum size for a gravity foul lateral drain should be mm. As far as practicable, junctions should be built in for all planned connections when sewers are constructed to avoid damage to the sewer by installing connections at a later date. Where it is necessary to make a post-construction connection to a sewer, B3. The upstream end of any unused connection should be sealed until required. The vertical angle between the connecting pipe and the horizontal should be greater than 0o and not more than 60o see Figure B.
Where the connection is being made to a sewer with a nominal internal diameter of mm or less, connections should be made using 45o angle, or 90o angle, curved square junctions see Figure B. Connections made with junction fittings should be made by cutting the existing pipe, inserting the junction fitting and jointing with flexible repair couplings or slip couplers.
Where the connection is being made to a sewer with a nominal internal diameter greater than mm: a where the diameter of the connecting pipe is greater than half the diameter of the sewer, the connection of an access point should be constructed; or b where the diameter of the connecting pipe is less than or equal to half the diameter of the sewer, then the connection should be made using a preformed saddle fitting. The connecting pipe should not protrude into the sewer. To provide a self-cleansing regime within gravity foul sewers: a a mm nominal internal diameter gravity sewer is laid to a gradient not flatter than where there are at least ten dwelling units connected; or b a sewer or lateral drain with a nominal internal diameter of mm, or a lateral drain serving ten or less properties is laid to a gradient not flatter than , where there is at least one WC connected and if there is no WC connected.
These parameters should not to be taken as a norm when the topography permits steeper gradients. Hydraulic studies indicate that these requirements may not necessarily achieve a self-cleansing regime. When a choice has to be made between gravity sewerage and pumped sewerage, these criteria should not be regarded as inflexible and the Developer should consult the Undertaker.
For developments within the scope of this guide a sewer or lateral drain with a nominal diameter of mm should be adequate unless exceptional flow is expected due to the nature of the commercial property. Where exceptional flows are expected the hydraulic design should be in accordance with Sewers for Adoption 7th Edition. In designing the site sewerage and layout, Developers should also demonstrate flow paths and the potential effects of flooding resulting from blockages, pumping station failure or surcharging in downstream combined sewers, by checking the ground levels around the likely points that flow would flood from the system to identify the flood routes.
The designer should carry out checks to ensure that an adequate level of protection against the flooding of properties is achieved.
Buried pipes should be designed in accordance with BS EN Note: BS gives information and guidance for the use of BS EN Annex A, the UK established method for the structural design of buried pipelines under various conditions of loading.
The procedures are explained and, where general assumptions can be made, loading tables are given. Application details for pipelines laid in various trench conditions and in poor ground are shown. The design of the pipeline should take account of loading from the passage of construction plant as well as normal design loading.
If the depth of cover to the crown of the pipe is less than the values recommended in Clause B2. The structural design of all pipes should take into account the possible incidence of punching shear. The design should ensure that no vertical load is imposed by structures such as shafts onto non-load bearing components such as the pipes. Where there is a risk of tree root intrusion see Clause B2. Materials should comply with the requirements of Part D of this guide.
Construction of the drainage system should comply with the requirements of Part D of this guide. Testing of the drainage system should comply with the requirements of Part D of this guide. The layout of surface water sewers and drains should be in accordance with B2. Surface water sewers and lateral drains should not normally be constructed under any building, or any structure, except that they may cross under a boundary wall not greater than 1 m high see Section C5.
However, for terraced properties it is sometimes necessary to install intermediate rainwater pipes, along the length of the terrace, to take rainwater from more than one property. Where it is not reasonably practicable to route the sewer around the building, surface water sewers with a nominal internal diameter of no more than mm may be laid under a building, provided that the sewer takes the drainage from no more than one rainwater pipe with a nominal internal diameter of no more than DN75, or the equivalent cross-sectional area, provided that the entry point to the rainwater pipe is in the land owned by the building concerned.
Access for surface water sewers and drains should be in accordance with B2. For chambers containing flow control devices, see Section C4. Nodes associated with oversized pipes for storage purposes should be designed as part of the storage. Where the inspection chamber is associated with a surface water attenuation arrangement, the chamber should be designed as part of that structure see Section C4.
Surface water sewers and drains should be in accordance with B2. The minimum size for a gravity surface water sewer should be mm nominal internal diameter, except where a mm nominal internal diameter is permitted, in accordance with C1. The minimum size for a gravity surface water lateral drain should be mm nominal internal diameter. To provide a self-cleansing regime within surface gravity sewers, the minimum flow velocity should be 1 m per second at pipe full flow.
The system should be designed under pipe full conditions to accept the following design storm i. Surface water sewers should be designed for runoff from roofs and, subject to the agreement of the Undertaker, highways including verges and other paved areas. They should not be designed to take runoff from other areas or land drainage.
In these cases, satisfactory and separate arrangements should be agreed with the local Land Drainage Authority and confirmed to the Undertaker. During extremely wet weather, the capacity of the surface water sewers may be inadequate, even though they have been designed in accordance with Clause C3.
Under such conditions, sewers may surcharge and surface water can escape from those manhole covers which lie below the hydraulic gradient. In designing the site sewerage and layout, Developers should also demonstrate flow paths and the potential effects of flooding resulting from extreme rainfall blockages, pumping station failure or surcharging in downstream sewers, by checking the ground levels around the likely points that flow would flood from the system to identify the flood routes.
The Developer is encouraged to have early discussions with the Undertaker to ensure that a sustainable approach to the management of surface water from the site is applied.
The Local Planning Authority can specify restrictions on the route of discharge of surface water from a development. For details of these, refer to the appropriate planning guidance. Flow control devices should be provided with a bypass valve so that the storage can be drained in the event of blockage of the flow control device. The design and location of flow attenuation and flow control devices and chambers are to be agreed with the Undertaker. The design of flow control devices should, wherever practicable, include the following features: a flow controls may be static such as vortex flow controls or fixed orifice plates or variable such as pistons or slide valves ; b static controls should have a minimum opening size of mm chamber, or equivalent; c variable controls may have a smaller opening provided they have a self- cleansing mechanism; d a bypass should be included with a surface operated penstock or valve; and e access should be provided to the upstream and downstream sections of a flow control device to allow maintenance.
Structural design and integrity for surface water sewers and drains should be in accordance with B5. Materials for surface water sewers and drains should be in accordance with Part D of this guide. Construction of surface water sewers and drains should be in accordance with Part D of this guide. Testing of surface water sewers and drains should be in accordance with Part D of this guide.
Any clauses in this Part which relate to work or materials not required shall be deemed not to apply. Where additional clauses are required, reference should be made to Sewers for Adoption 7th Edition. Where Developers wish to use materials or methods not covered by this specification reference should be made to Sewers for Adoption. One copy of the Drawings shall be kept on the site and shall Works should be pre-scribed, be available for use by the Undertaker.
Precise 2. Details shall be provided of the level and location existing features or to the of the temporary benchmarks and reference points which are Ordnance Survey National proposed to be used. Grid should be shown. The Developer shall be responsible for setting out the Works and for the correctness of the position and dimensions of all parts of the Works.
All materials and workmanship shall be subjected, from time to time, to such tests as the Undertaker may direct. The Undertaker shall be afforded the opportunity to examine any work which is about to be covered up or put out of view, and to examine foundations before permanent work is to be placed thereon.
All necessary precautions shall be taken to avoid misconnection to existing public sewers. Submissions shall be in accordance with the latest published Standard which is current on the date the submission is made.
Materials and components shall be stored in such a manner as to preserve their quality and condition to the standards required by the Specification. Where appropriate, any technical advisory services offered by manufacturers shall be used. Water for use with cement shall be of wholesome quality. Cement shall either: 20 N per mm2 for the use of sulphate-resisting Portland a be factory-produced by the cement manufacturer and comply cement is consistent with with the provisions of the appropriate Standard, as Table D.
Table D. For precast concrete pipes or inspection chambers complying with BS EN , BS EN and BS , a minimum class 3, sulphate-resistant cement shall be used unless the Undertaker can be satisfied that a lower class will resist attack from soils and groundwater. Mortar shall be mixed only as and when required, in the broadly equivalent see relevant proportions indicated in Table D. The constituent materials shall be use of lime putty or accurately gauged, allowance being made for bulking of sand.
Alternative nominal mixes by volume ii The cement:lime:sand mortar is consistent with Cement:sand with Cement:lime:sand Cement:sand Category 1.
All mortar shall be conveyed fresh to the Works as required for use. Mortar which has begun to set or which has been site-mixed for a period of more than one hour shall not be used.
Plasticising and set-retarding mortar admixtures shall comply with BS EN and shall be supplied with instructions for use. Constituent materials of precast concrete products shall surface finish should be comply with the relevant requirements of this Specification, shown on the Drawings. Except where otherwise agreed or specified in a relevant European or British Standard, the surface finish of precast concrete products shall be Rough Finish for surfaces next to earth and Fair Finish elsewhere.
Precast concrete slabs and cover frame seating rings shall comply with the relevant provisions of BS EN and BS 3. Vitrified clay pipes and fittings for sewers shall have flexible vitrified clay pipes and mechanical joints. Pipes for foul sewers and surface water fittings. Extra chemically-resistant pipes and fittings shall comply with chemically-resistant pipes the additional requirements of BS Vitrified clay jacking pipes shall conform to BS EN All pipes and fittings shall have gasket-type joints of spigot and ii Additional protective socket or rebated form.
Pipes shall withstand the jacking loads to which they will be Chemical Environment for subjected during installation, without cracking or spalling.
A Concrete class should be certificate shall be supplied, confirming that the pipes are suitable described. Joint lubricants for sliding joints shall have no deleterious effect on either the joint rings or pipes, and shall be unaffected by sewage.
Seals shall be tested in accordance with BS and shall comply with the following: a the average loss in mass Z of the test pieces shall not exceed 3. In the case of composite seals, the requirements apply only to those components exposed to the contents of the pipeline or pipework.
Processed granular and "as-dug" bedding, sidefill and guidance on pipe surround surround materials for buried pipelines shall comply with WIS 4- materials. Recycled materials shall comply with BS Compressible filler for interrupting concrete protection to pipes shall consist of bitumen-impregnated insulating board to BS EN and BS EN
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