We have a 3-year-old utility building with vertical walls made of Stimpson
Plywood Siding (Dura Temp). It looks exactly like pine or cedar siding. In
fact, we thought it was wood until today when we started to put up a
trellis. The siding is made up on several wood plys with an outside ply of
masonite with a grain pattern stamped into it. Is there anything you can
seal this stuff with to make sure it doesn't take water?