Roof membrane , different replacement!

Hammer - I think once you get in there you'll discover that the wood around the AC penetrations have been wicking up water and rotted. This is the most likely reason for the sag around the unit. Cut back to good wood and patch before you recoat. We had a bus in the shop last week with the same problem. And you're right; left unfixed and you'll end up with the A/C inside the trailer. It may be on the next bump.

Rubber roof replaced with fiberglass then painted. As done by the Famous Tioga George (he is still rv'ing it ) He had it done on his rig in Mexico by a small boat building outfit in . It came out great from my point of view. Rubber roofs on RV's are the thickness of a bicycle tube. It might have a chance of lasting if it was a comercial grade PVC/rubber roof but they're not. In my opinion fiberglass is the best material for RV roofs. If you remove your roof, I bet you will find the aluminum edge trim puncturing it in several places. Meaning it was leaking there from day 1 installation at the factory.

Thanks everyone, I'm going to check out the spray on stuff but will probably lay some glass. Unfortunately. Lol. I'll take some pictures no matter what way I go.

Just as a point of interest, the newer Open Range use PVC on the roofs. Pros? Cons?