Replacing Deck

[Grotty_Yachty]

I have a Samson C-Breeze built to 14.85 metres, the hull is in good condition, but the deck and superstructure are stuffed. The deck has bad concrete cancer and the superstructure frames are rusting out as the fiberglass work was not done properly. I am going to cut the deck out from the first forward bulkhead to the the last stern one (there is no concrete cancer in the bow or stern). I plan to replace the deck and superstructure with plywood. I am thinking of layering up the deck and superstructure with 4.5 mm hardwood A-Bond ply, and epoxy. Then coating the lot with 2 layers of fiberglass and Epoxy. I also plan to seal all the wood I am going to use with a two pack wood preserver.

I have numerous large scraps 10mm UV/Abrasive resistant polycarbonate sheeting that I plan to use for the windows in the superstructure.

What I do not know is should I use three or four layers of plywood, and how far apart to space the frames.