anybody know where I can get hold of an offcut of 9" underground plastic gas pipe? (or any 9" polyethylene pipe with decent wall thickness.

Kicking myself as transco were operating roadworks out of the yard at work for months and had heaps of offcuts when I didn't need them!!

[Edited on 12/5/13 by NS Dev]

Find the Transco depot a lot of the stuff seems to go back to skips there we went to local spot and blagged 4' to make a santa's post box for school kids they actually chopped a bit off a new length!
Good luck
Mike

cheers, will try and find where the closest depot is!

I think they only do 8" or 10" near the size you are looking at.

10 would probably do the trick

how long is an offcut ?

good point! A metre would be great