Planning Portal - Part G - Frequently Asked Questions
The above link provides answers to the question of what to use for the D2 discharge pipe.
Thanks for that link the following section was interesting. They do like to make sure they retain a good swathe of grey area.
Paragraph 3.60 of the Approved Document says that if a discharge pipe is connected to a soil stack the discharge pipe should be either polybutalene or cross linked polyethylene. Does this mean a polypropylene discharge pipe cannot be used?
As stated in its Introduction section, the guidance in the Approved Document is intended to provide advice on how to comply with the requirements set out in the Building Regulations and that “there may well be other ways of achieving compliance with the requirements”.
The Department’s view is that it would be acceptable, subject to also complying with sub-paragraphs a, b and d of 3.60, (better go find sub paragraphs a, b and then) for these pipes to be polypropylene to BS EN 1451-1, as recommended in BRE Information Paper 8/07.
Paragraph 3.60 of the Approved Document allows safety relief discharge pipes to connect to a soil stack if it can safely resist the temperature of the water discharged. Which materials are considered to be suitable?
Metal pipework, such as cast iron, is suitable.
For smaller hot water systems, BRE Information Paper 8/07 indicates that discharges can be made to PVCu stacks, provided that:
relief discharge is from domestic unvented hot water storage systems only – not combi boilers or sealed system boilers.
storage volumes do not exceed about 210 litres.
stacks are fully ventilated (ie. no stack cap or air admittance valve).
pipework complies with BS EN 1329-1:2000 or BS 4514:2001.
