All ActivityMost RecentMost LikesSolutionsRe: Do NOT use Flex Seal on your camper roof! We used it on our RV 36ft fifth wheel roof over 6 yrs ago and it is doing just fine in the HOT Arizona sun. The key is whatever a person coats be sure to clean it well first. We have used it many times on various things---this stuff works great! Re: Do NOT use Flex Seal on your camper roof! You maybe did not put the Flex Seal on thick enough and the liquid in the can is way better than the spray. Re: Do NOT use Flex Seal on your camper roof! You probably did not put it on thick enough. Use the liquid not the spray. Re: Do NOT use Flex Seal on your camper roof! My husband covered our RV roof (540 sq ft) with white Flex Seal used about 4 gallons. It has held up great in the HOT Arizona sun for over 6 years and is still fine. You need to divide the roof into 4 sections, mark them off and use 1 gallon per section. With our roof it is 9 linear feet per section. This stuff is wonderful...but be sure what you are coating is clean. With an RV take a hose to clean the roof off the day before so it dries well overnight.