In considering the purchase of a pre-owned Winnebago Class C with a fiberglass roof should there be a concern with cracking or separation due to twisting of the body over time?
If I had my way (which is fairly expensive), I would go with an anodized aluminum roof, add the usual stuff on top (A/C flange, vents, skylights, satellite dish, solar panel mounts, etc.) then cover it with an elastomer epoxy spray that not just covers the roof and a few inches down the sides, but is used around the tail-light fixtures. That way, if a tree branch gouges a chunk of coating off, the aluminum will still provide decent leak protection.