Above Ground Drainage FAQs

Can air admittance valves be used outside?

Polypipe air admittance valves, such as the SPV110, can be used internally or externally. Air admittance valves are also sometimes called ‘Durgo valves’.

Where should air admittance valves be installed

AAVs should be installed at the top of a stack, above the spillover level of the highest appliance connected to it. This is normally a sink or basin. They should be located in a space with some ventilation or outdoors.

Do you make your above ground drainage to RAL colours?

We do not make to RAL colours. The closest RAL colours to the ones that out products are available in are 9003 for white, 9011 for black, 8017 for brown, 8003 for clay brown and 7046 for grey.

Do you produce any high temperature plastics?

No high temperature plastics are available. All have similar resistance, and can withstand 75ºC constantly or 100ºC (boiling) water in bursts of 1-2 minutes. Polypropylene has the highest temperature rating (160ºC), but this is subject to the same limitations as other plastics due to the rubber spacers, washers, etc.

What pipe should be used with the discharge from an unvented cylinder?

The discharge from an unvented cylinder must be drained through a waterless trap (WTV1 for 32mm or WTV2 for 40mm) and polypropylene push-fit waste pipe.

What pressure is soil and waste pipe tested to?

Soil and waste pipe is for gravity draining only, and is so tested to only 0.5 bar.

Can above ground PVCu drainage pipe or fittings be installed underground?

Above ground PVCu drainage pipe and fittings can only be used above ground. They will function if installed underground, but are not manufactured to the correct standards for this application, Building Regulations Part H state that PVCu materials for below ground gravity drainage should be to BS EN 1401 or BS EN 13476. 

Can below ground PVCu drainage pipe or fittings be installed for above ground sanitary pipework?

Below ground PVCu drainage pipe and fittings can only be used underground, they are not manufactured to the correct standards or material formulation for above ground applications, Building Regulations Part H state that PVCu materials for above ground gravity sanitary pipework should be to BS EN 1329.