i used wbp exterior grade plywood from wickes to build a long box for timber offcuts. the box has a hinged lid treated with preservative and is kept outside my garden shed. after a few weeks and some rain the plywood lid's top veneers started to curl up and splinter. isn't wbp exterior grade ply supposed to be waterproof? or is only one surface of the ply waterproof? if so how does one tell which surface should be exposed to the elements? TIA.
- posted
17 years ago