Underground drainage systems are manufactured to the highest possible standards and comply with BS 4660:2000 and BS EN 1401-1:1998 which specifies the requirements for
underground pipes and fittings.
The Europe-wide manufacturing standard BS EN 1401-1:1998 replaced BS 4660 in 2000 and BS 5481 in 1999. The 110mm and 160mm access fittings are not included in the new
standard and conform to BS 4660:2000. Rubber seals conform to BS EN 681:1996.
All systems are capable of meeting the design, layout, construction, testing and maintenance requirements in BS EN 752: Parts 1 to 4:1996 to 1998 Drain and sewer systems outside
buildings and BS EN 1610:1998 Construction and testing of drains and sewers.
Suitable joint lubricant should be used for joining socketed pipe and fittings as recommended by manufacturers and supplied by JDP.
Preformed inspection chambers can be used for invert depths of up to 1.2m. The chamber should be placed on suitable compacted material so that it is evenly supported.
When the base is in position the bungs can be removed and pipes inserted as appropriate. The risers are then placed on the base to reach the desired invert. The use of sealing rings should be used to seal each
joint. The top riser can be trimmed to suit finished ground level. It is recommended that the cover and frame are fitted at this point to stop any foreign matter from entering the chamber. Backfilling may then
take place around the chamber base and the connecting pipes, using suitable granular material. Backfilling continues to within 160mm of ground level. A concrete plinth is then cast, in which the plastic cover and