Do NOT use Flex Seal on your camper roof!

[Seminoe_Joe]

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.

[QCMan]

Another old post resurrected out of desperation from looking for new threads.

[MBS2004]

How about the Flex Seal tape? I carry some but haven't used it yet.

[ChillMark]

I tried Flex seal tape a few months after I had already used "Henry Tropicool Silicon roof sealant" throughout the entire roof. Busted a seam on a previous bad repair during a trip. Cleaned the area thoroughly but the tape did not want to adhere. 

JUST NOW...(5:30pm 4Aug2024)...I tried it again on a very hot roof. smoothed it out, let it sit for an hour THEN applied a good smather of Henry Topicool silicon sealant over the tape. Waited an hour to let that cure then liberally applied more Henry over that. With that said, we will see how it holds up on the next stretch of road. 

[ChillMark]

Replying to myself for ALL...

So far so good.  Drove through tropical storm Debby for 2 hours of heavy rain on I-40. Next day of sunshine took a 3 hour tour on mountain roads. While at RV site the roof AC condensate collected in that area as usual. Currently only 550 miles...might be close to 800 miles by the time I get home.

Obviously where I DID NOT clean and dripped the silicon...came off with a good fingernail. Where I did thoroughly clean with alcohol it appears to have a good bond. I picked at the good areas a little bit with my fingernail but did not want to force it off. This is still a new patch so this short trip may not be a good benchmark. 

[PNWtruckCamper]

Nothing will stick to silicone, not even fresh silicone. That's why it's not recommended for sealing any areas on a camper.

[ChillMark]

Well, bummer! There I go again believing what I read on the internet. Thanks for that info. 

Let's see if this new patch lasts for a little while. I guess now I'm obligated to keep checking in here with updates. LOL.

[d1h]

[Steve495169]

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.

[Seminoe_Joe]

Yeah. As others have stated, it’s fine in areas not exposed to UV. But it’s just rubber and degrades rapidly in UV. Even the non-spray version will break down. Not as fast, because it has more volume to surface area, but it will eventually. Best to keep an eye on it!!

[narcodog]

Sometime ago I used Flexseal both the tape and spray on my woodstove chimney and found it last just a short time. It became very brittle. I say that because I was considering using it on the roof of my TC, glad I didn't.

[Fisherman]

deltabravo wrote:
This is what I did when I wss bored last summer after I found an old tube of Dicor

Well, at least it's insight how much to use and adding a little fudge factor for temperature.

[Deb_and_Ed_M]

I agree about Flex Seal being a VERY temporary fix. I used it on a leaky sunroom roof (on our Snowbird condo) - it worked for a month, then the Florida sun just seemed to vaporize it. When we returned the following fall, the roof leaked just as badly and when I climbed up to look at it - there was NO sign that I had ever tried to seal the leaks 😞 Fortunately, I hadn't left any furniture in the sunroom because it would have been a moldy mess....

There was one patch that I had made previously, using Eternabond tape - and that was still holding very well.

[Steve495169]

You probably did not put it on thick enough.  Use the liquid not the spray.

[Kayteg1]

I bought my Fleetwood with roof damage, where the seller bothered the repair with eterna bond tape.
Was fighting the leaks for 3 years as no caulk would hold for long time.
I tried expensive marine caulks, RV caulks and top-grade construction caulks and none of them would stick permanently to my rubber roof.
Finally the Henry Tropi-cool roof sealer come on the market and after trying it on my house roof, I put it on my camper.
That coat sealed everything solid, regardless if the caulk under was holding better and worse.
It is self-leveling coat, so nice finish and the only problem was avoiding running on tilted camper nose.