On 2006-12-06, Staffbull wrote:

If you want it to last a long tiime buy a Butyl pond liner and use that
as a roofing membrane, it'll go for 30 years or more !! I have two
sheds/utillity room done like this with ply underneath, works a treat
!!
got mine from www.pondlinersdirect.co.uk

I'll look into that; thanks.