Last year I installed some decking in the garden using the Jouplast decking risers and it has been pretty solid and keeps it away from water.
IMG_20170430_153002 by MarkStephen posted 15 Feb 2018 at 11:02 AMIMG_20170507_172858 by MarkStephen posted 15 Feb 2018 at 11:02 AM
I'm thinking of...