Re: 1971 Starcraft Restoration
No i did not waterproof it i did use CCA, in my exsperiences it works just as well as marine plywood.
Kiln dried CCA plywood is the best plywood you can put in a boat, and it will never rot... but unfortunately it will absorb water and swell and check (split/crack). I found this out the hard way.
My Tracker came from the factory with CCA decking, and the first time I recarpeted it I didn't seal the decking (I didn't know any better) before carpeting it. The carpet only lasted about 5 or 6 yrs. and when I pulled it up I found that my CCA had checked considerably. Sooo, I had fun fairing and filling the checking with an epoxy resin fairing compound and then sealed it with 4 coats of epoxy resin.
You should be ok if you keep your boat covered and "dry" clean the carpet with a foam shampoo instead of hosing it down and scrubbing it like I used to do mine.:facepalm:
Please note, I'm in no way trying to insult your build or "bad mouth" your boat. You're doing some really nice work and your boat looks great.
I only bring these matters up because I've either dealt with them myself or have seen others have problems with them and I'm just trying to help you not have these same problems.