Re: Rubber roof?
Reply #4 –
It really depends on "cracks". If they are just surface crazing in the gel coat then maybe. I had a few spots to repair not for cracks but because quarter sized spots of gel coat pulled off when I moved my satellite dish. I sanded down into original glass, used polyester resin and a fine glass fabric. One set I sanded it smooth and used the polyurethane paint primer on the spots, then another primer coat on the whole roof and then 3 coats of ceramic bead filled polyurethane paint. I like the result but it is not really a fix for cracks.
If you have real cracks that go down into the OEM glass layers then you need to sand aggressively into but not through the OEM glass layers, 3-4" wide. Fill with polyester resin or epoxy and a glass fabric cloth and maybe a glass mat top layer. Sand it smooth. It probably doesn't need to be flat, just smooth, some extra material won't hurt. This probably needs a wax free gel coat on to to seal it up. And then paint it.
I would very carefully consider a rubber roof coating. It will limit options in the future and might be hard to maintain.
I have seen Dicor lap sealant used on cracks. Seems to seal them up OK, it looks ugly but if it does the job ... it's on the roof. I think you can paint over it.