So here I am on the roof of our 2013 TT. That's because during a recent driving rain we got water on the carpet below a vent. Yep, two years old and the vent covers look like they are at least 10 years old and a small crack has appeared in the plastic near the crank metal support. All three vents covers getting replaced, as they all look and feel like you could stick a finger through them in about any spot.But it was while on the roof checking this out that I ALSO see the factory applied lap sealant looking like it's getting old too. Natural expansion cracks appearing but enough questionable areas that I'm thinking I'll replace it all as well.So here's the question. Would you clean it off and re-apply lap sealant or would you go further and apply Eternabond tape as a replacement for the lap sealant method?

If you have the cash to spare, then eternabond. If not Dicor Lap Seal. My trailer is 10 years old, still no eternabond. Lap seal has proven to be fine for me.

Hi. The proper caulk to use on the roof is "self leveling caulk". Lap sealant is used for vertical surfaces, ie around Windows, along exterior wall trim, etc. On my roof, I installed Eternabond tape along the front and rear seams only. The rest is self leveling caulk. I don't use Eternabond tape around roof fittings such as vents because in the event I ever need to remove or replace the vent fixtures, removal of the tape (once applied) is very difficult. The best thing to do is clean all existing caulk areas on your roof with a hand scrub brush to remove all blackened areas. You can then better assess what caulk needs to be redone. Once the existing caulk is good and clean/dry, you can apply more self leveling caulk right on top of it.

I prefer Eternabond. Clean the roof very well and apply the tape with sufficient pressure and you are done for a LONG time.

Thanks guys.Looks like this same stuff...Dicor Lap Sealantis being called lap sealant or caulk, depending on the seller, but the label calls it lap sealant. I guess it's the right stuff for the roof?I like the idea of cleaning the old, and just reapplying where needed a little here and there. I hate to clean all of the old completely off and re-apply entirely, and I hate to spend the money on a complete Eternabond application. I like the idea of the front and rear seam thing for the tape (in future?) and self-leveling everywhere else.This roof has three skylights, three vents, one antennae, three plumbing vents, one air conditioner and a refrigerator vent so that's a lot of work if just some touch up is perfectly adequate.I'm still open for more thoughts and input.

If you listen to everyone's opinion on this subject, you will end up confused. IMO self-leveling goop came into the picture due to the fact that the RV manufacturers wanted a product that would lend itself to mass production. With self-leveling stuff they can apply it very quickly, and for the least amount of material cost.IMO for private/individual use, self-leveling goop makes no sense. There's other ways, which are more expensive and more work-intensive, which produce superior results.HOWEVER, I'm not so much referring to rubber/membrane type roofs and materials. I only work on metal or semi-fiberglass or all fiberglass roofs. I use 3M 4200 Adhesive/Caulk and Eternabond and Sika non-silicon products.IN other words, some of these things you have to learn on your own. Try whatever you decide to use, and give it a few years.

Lap Sealant vs Eternabond Tape | Good Sam Community

philh
Explorer II
Jun 29, 2015
swamprat 01 wrote:
I use Dicor self leveling for horizontal and Dicor regular for vertical uses, I check my seams regularly and if needed re-caulk, I clean the edges with dawn soap and water and a small brush, I also wipe down the seam with alcohol the apply the caulk.

I called Dicor and talked to a technical specialist. He strongly recommended cleaning with acetone after using any kind of soap product.
Gdlow
Explorer
Jun 29, 2015
I decided my days of climbing up on the roof were going to be numbered, so a year or so ago I applied Eternabond...an am glad I did..:C
mlts22
Explorer
Jun 29, 2015
From what I see, Eternabond is the "permanent" way of fixing the problem, but with a few caveats:

1: As stated above, it needs to be applied to a clean surface. Acetone is a must, and if there is -any- silicon based stuff, it need to be removed.

2: To activate the microsealant, it takes heavy pressure with a metal roller. Don't try with a hand... it won't work, and you will just give yourself scrapes and blisters.

3: It needs done in warm weather. If it is cold, grab a can of EternaPrime which helps with dirty/uncleanable surfaces, and allows work to -20 degrees.

4: I'd caulk the edges of the EternaBond tape just for a better look. The downside of using EB is looks, so doing a neat job is important.

5: Once EB tape is down, it is a PITA to remove, so it is likely there to stay.
philh
Explorer II
Jul 01, 2015
mlts22 wrote:
2: To activate the microsealant, it takes heavy pressure with a metal roller. Don't try with a hand... it won't work, and you will just give yourself scrapes and blisters.

That was the other think they told me, it has to be rolled to activate the adhesive.
JAXFL
Explorer
Jul 01, 2015
Here is the problem I have had with Eternabond tape. I used it a couple of times on the patio roof seems that leaked. After a few years... like 3 years it dries out in the HOT Florida sun and you have to clean it all off and re-do it. Then in about 3 years... again. I have not used the Lap seal so cannot comment on that.

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Lap Sealant vs Eternabond Tape

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