Fiberglass roofs

Quite a few times I've seen motorhome and trailers (mostly trailers) with rubber roofs and you could see the glue holding it down had given way and the roof material was bubbling up. The driver probably had no idea it was doing that since it was only visible at freeway speeds. My guess it most of those roofs were probably close to failure.

I have a fiberglass roof on my motorhome and never had any issues. I even hit a tree branch once that destroyed my bathroom roof vent and did nothing to the roof. I've heard stories of people tearing holes in the rubber roof with tree branches.