Forum Discussion

Seminoe_Joe's avatar
Seminoe_Joe
Explorer II
Jan 09, 2021

Do NOT use Flex Seal on your camper roof!

Figured I’d post this since I had a troubling conversation with my repair guy a couple weeks back when I picked up my camper after it was repaired following a minor collision last fall. We were discussing my long battle with a skylight leak in the bathroom and I mentioned that at one point I used flex seal spray as an emergency measure until I could do a proper repair with new butyl tape and Dicor and eternabond. He got all exited and told me that the “flex seal is great stuff! That’s the way to go!” And he used it on his parents’ leaky shed roof and its holding just fine. I nodded and told him it’s great for an emergency but from my firsthand experience, it becomes brittle, cracks, and eventually peels off when it’s been exposed to ultraviolet light for more than a few weeks. He apparently wasn’t aware of that. Ive been thinking about that conversation for a few weeks now and figured I’d post a thread about it to inform others who might be tempted to use flex seal as a permanent solution on camper roofs. DON’T!
Even though the tv commercial shows a guy sealing a skylight,
Even though your repair guy or dealer might tell you it’s great,
Even though a website or blog extols it’s virtues,
It is NOT a permanent solution!!!!! Emergency patch? Sure. But it WILL become brittle, crack, and peel off in a few weeks under UV light (sunlight).
So please, PLEASE, don’t even think about using this stuff I place of lap sealant or eternabond.
This has been a public service announcement.
We now return to your regularly scheduled program.

23 Replies

  • Seminoe Joe wrote:
    Figured I’d post this since I had a troubling conversation with my repair guy a couple weeks back when I picked up my camper after it was repaired following a minor collision last fall. We were discussing my long battle with a skylight leak in the bathroom and I mentioned that at one point I used flex seal spray as an emergency measure until I could do a proper repair with new butyl tape and Dicor and eternabond. He got all exited and told me that the “flex seal is great stuff! That’s the way to go!” And he used it on his parents’ leaky shed roof and its holding just fine. I nodded and told him it’s great for an emergency but from my firsthand experience, it becomes brittle, cracks, and eventually peels off when it’s been exposed to ultraviolet light for more than a few weeks. He apparently wasn’t aware of that. Ive been thinking about that conversation for a few weeks now and figured I’d post a thread about it to inform others who might be tempted to use flex seal as a permanent solution on camper roofs. DON’T!
    Even though the tv commercial shows a guy sealing a skylight,
    Even though your repair guy or dealer might tell you it’s great,
    Even though a website or blog extols it’s virtues,
    It is NOT a permanent solution!!!!! Emergency patch? Sure. But it WILL become brittle, crack, and peel off in a few weeks under UV light (sunlight).
    So please, PLEASE, don’t even think about using this stuff I place of lap sealant or eternabond.
    This has been a public service announcement.
    We now return to your regularly scheduled program.
    • Steve495169's avatar
      Steve495169
      Explorer II

      You maybe did not put the Flex Seal on thick enough and the liquid in the can is way better than the spray.

  • Well I'm on the other side of the equation. I used the Flex seal caulking tubes to seal up a couple of cracks in the roof in the spring. It stayed tacky for about 2 weeks and then became less and less tacky as time went by. Fast forward to fall, after checking a number of times, it didn't crack, peel become brittle or shrink and the trailer rood has full sun exposure for at least 6-7 hours a day.
    • Steve495169's avatar
      Steve495169
      Explorer II

      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!

  • Guess he saw money signs When people call me and say they used it i say good luck i dont want any part of it
  • I carry a quart of Heng’s and roll Eternabond on my travels.
  • It works great but is not UV rated. Use it on the underbelly or in a shady location and it holds up just fine, not in the sunlight tho...