cuprinol :number 10..it'll out last us all- under a deck on plywood....lumberyard or hardware store.........it's made for wood thats under water..or wet area's....
roll some deck enamel on the underside before you screw it down.
glue and paint,, all in one can
I was thinking 6oz cloth nothing heavy I am afraid of checking if I don't I do have some 2 part epoxy paint laying around I could use. Also not ready to glass the floor down I need to get a tank for under there and make a box for that, am getting things all lined up for some serious glass work before we get real cold weather