Discharge pipes: Unvented water system (& central heatin

[Breesey]

It has to be either copper or Polypropylene (push fit) no other plastic, it's in the approval doc / regs

No harm in repitition I suppose.

 

[Biggles..]

Depends if what your repeating is correct which yours isn't.

Taken from approved document G


3.57 The discharge pipe (D2) should be
made of:
a. metal; or
b. other material that has been demonstrated
to be capable of safely withstanding
temperatures of the water discharged and is
clearly and permanently marked to identify

Please note item b, where it doesn't say it must be poly, just that it must be suitable of carrying the temperatures of which MuPVC is, as is vulcathene.
Terrain issued us a technical cert saying there solvent pipe is suitable.

A NHBC builders note dated before the latest edition of part g isn't much cop.

 

[Breesey]

Thanks for pointing that out...

I'm aware of what it says in G, but I'm not sure that when it comes to a matter of material properties that interpretation is appropriate!

It's interesting that Terrain were happy to issue that considering that the temp rating for MuPVC pipe is 76 degrees and discharge temps could be 95+ degrees, and that over a period of time potentially.

Not sure that Vulcathene is rated above 90 degrees for more than brief periods

I'll stick to PP as I know this has a 100 degree rating.

 

[Biggles..]

Why I pointed out was that you said the rules say it must be PP, where as they don't and other plastic materials are available that satisfy those same rules.

PP pipe is rated to 90deg long term use and 110 at short term!

 

[Breesey]

Agreed