Several years ago on our first camper we had much of the same problem the roof leaked by the vent in the back and ran down the wall behind the shower wall. ruined the shower wall. To repair I was able to pull the wall down and glued boards on where it was rotted put FRP on the shower walls and patched the roof. only did what was needed to make it work. So ya I have that camper along time.and the camper is still rolling down the road today still going since 1981. SO I say just fix it and use it if it was not 14 years old already I would say fix it right. just enjoy it! they have gallon buckets of elasto something its white and is awesome stuff will stick to firestone roofing and everything else. We used it on our layton with a tin roof on all the seams works wonders tape off where you dont want it though