I have a 14" heavy duty john boat. The boat came with foam under a thin
metal deck. The foam was saturated with water and disintegrated. I don't
think I can get the exact same foam thickness to reinstall the metal deck
and I don't care for the look of the metal sheeting. I realize that
marine plywood would be best, but it is hard to find and is expensive. I
would need two sheets. Is treated 1/2" plywood acceptable?