On Thu, 3 Nov 2011 08:11:36 -0000, DIYer wrote:

Also, Screwfix stock a plastic pipe system by FloPlast (Flo-Fit) at a
good price.

Check the temperature and pressure ratings. The pressure rating drops
dramatically as the temperature rises. Plastic also needs to be well
supported if you aren't going to get excessive sagging, over time,
between supports.

--
Cheers
Dave.