On 15/10/2010 19:39, Andrew Gabriel wrote:

I don't think brown pipework is UV proof, so you'd need to paint it
anyway, [...]

AIUI, polypropylene (PP) pipe is not UV stable and must be painted.

OTOH, uPVC and ABS wastes have good UV resistance and don't have to be
painted, although they usually look better if they are. ABS
solvent-weld seems to be the most commonly used type of waste now.

--
Andy