MOULDED 140x100mm 90DANG Internal EMG14/IA90A

Drainage takes waste water from sinks, baths, showers, toilets and appliances, and rainwater from roofs and paved areas, away from a building to the sewer or a soakaway. This department covers above ground soil, waste and rainwater systems, below ground pipe and fittings, cast iron drainage, channel drains and gratings, pan connectors, solvent cement, test plugs, and fire collars and wraps.

Main systems

• Above ground: soil and vent pipe, usually 110mm, waste pipe in 32mm, 40mm and 50mm, traps, and gutters and downpipes.
• Below ground: PVC-U pipe and fittings made to BS EN 1401 in 110mm and 160mm, usually terracotta in colour, with bends, junctions and access fittings.
• Cast iron: soil and drainage systems made to BS EN 877, and rainwater goods, often chosen for heritage buildings.
• Channel drainage: surface channels with gratings, classed under BS EN 1433 by load from A15 for pedestrian areas up to F900 for very heavy traffic. Choose at least the class for the vehicles that will cross it.

Choosing parts

Keep to one system: measure the outside diameter, check the joint type (solvent weld, push-fit or ring seal) and match the colour. Where plastic pipes pass through fire-resisting walls or floors, fire-stopping such as an intumescent collar or wrap seals the opening in a fire.

Regulations

New drainage work should comply with Building Regulations Part H, and Approved Document H gives guidance on pipe sizes, traps and access.

For more detail, see above ground drainage and below ground drainage.