Here's the dry glass cloth laid over the 6.5 ft. section i cut out, gutted, and filled with spray foam. there's two layers of 6oz. glass...so it should be damn strong....i hope. there's a shitload'a bubbles in it so it's not ideal....but to get rid of them would've required a whole 'nother method (this stuff called pourfoam) which would basically be like starting from square 1 again. no.