Caulking your Roof

[garym053]

Hi All! Camping season starts in 30 days!! At least here in VT!
I would like your opinion on caulking around the seams on the PU Roof. I have a Jayco which has an aluminum roof with a center seam and edge pieces that have butyl tape under the moulding that covers the joints. I have had them caulked before and they just ran a bead of caulk beside the edge of the moulding and the edge of the butyl tape underneath. The caulking is hard and cracking and I'd like to replace it.
Would you remove the moulding and replace the butyl at the same time, or just scrape as much of the old caulking off as you can and recaulk?
Thanks!

[brainpause]

I'm not sure I know what you are talking about with the butyl tape and moulding, but...

as for the caulking, I highly recommend using what my local PU dealer recommended for caulking our leaky seams and such. I cannot remember its exact name, but I think it was construction caulk, and it WASN'T water soluble. He said to use kerosene or something like that if I needed to, but I didn't. That stuff filled well, hardened, and doesn't leak.

HTH.

Larry

[Tim5055]

Would you remove the moulding and replace the butyl at the same time, or just scrape as much of the old caulking off as you can and recaulk?
Thanks!

I would suggest just scraping off as much as you can and re-caulking.  When scraping, go light and use a soft tool (wood, like maybe a paint stir stick).  Scrapers and screwdrivers will easily punch a hole in the thin roof covering.

Larry has a good idea to ask for a recomendation from your dealer, but as a minimum use and exterior grade caulk, possibly silicone based.

Removal of the moulding and butyl sealant is just going to open a new can of worms - I don't suggest it.

[HersheyGirl]

When the dealer re caulked my roof, he just scraped off the old caulk and added new.  I would not take off the seal either, I had to do that to replace the electrical plug hole thing, I don't know what it is called, but that was such a mess to deal with.

[garym053]

Thanks! I already bought the caulking from an RV dealer, but being a part of a company that deals in Building Materials, I can get Butyl Tape pretty cheaply and easily, so wondered if I should go for it. I don't think I will!  I do agree that it could open up a new can of worms!!!

See that's why I love this board, you save me work!!!

[mike4947]

Gary, the butyl caulk is a favorite of RV dealers for a couple of reasons: It's easy to work with as the strips handle easily and like you said it's real cheap.

What we've found over having to deal with it on RV for about 30 years.
It will Ooze out or harden and crack over time,turn black, or all the above.
Again dealers and manufacturers use it because it's cheap, easy to work with and usually lasts long enough to get them through the warranty period.
 
IMHO even RTV silicon bets butyl caulk, but there are even better choices in Uranthane and polysulfide caulks, that don't shrink, slay flexible, don't collect dirt, discolor and will in most case outlive the trailer, not just the warranty.

[topcat7736]

Our dealer said to always use a polycryllic caulking & never a silicone based one (for whatever reason). I noticed that the caulking on the aluminum roof of our Taos, which uses the stuff, is still pliable after 4 years of sitting in a spot where the sun constantly shines on it.

[garym053]

I had the Jayco Roof Seams caulked by a RV Dealer two years ago and whatever they used is dried up very hard and cracked all over. I'm going to try to gently scrape it away from the Butyl that is underneath the corner moulding and the roof center strip and apply a caulking I got from a different dealer.
The caulking this dealer sold me is by Dicor and it's called Lap Sealant. It doesn't say any more than that other than saying it's stays flexible!

[kmh1596]

The caulking this dealer sold me is by Dicor and it's called Lap Sealant. It doesn't say any more than that other than saying it's stays flexible!

I went to an RV place near me this afternoon, and they sold me the Dicor Lap Sealant also.. I hope this is good stuff?
 Kevin

[haroldPE]

:sombraro: wow!! - where do you live ??:sombraro::sombraro::sombraro::sombraro:    

sitting in a spot where the sun constantly shines on it.

:sombraro:

[skamper75]

I forget what the dealer sold me but I dont like it. It was a red and silver tube at just under $7 each. The seams had started to crack before a year. I did use it to fill a small hole punchered by a fallen tree limb, it did work for that but its pretty thick.

[flyfisherman]

I forget what the dealer sold me but I dont like it. It was a red and silver tube at just under $7 each. The seams had started to crack before a year. I did use it to fill a small hole punchered by a fallen tree limb, it did work for that but its pretty thick.

Most of the silicone sealants available today are really made by two, maybe three manufacturers ~ these sealants are then labeled for different brands. Most Home Depots or Lowe's Bldg Supply places have a cross reference chart where you can look up one particular brand and it will show it's equivalent under a different name ... and who knows, maybe made by the same manufacturer!

For my Starcraft Venture roof seams, the recommended product recommended in the owner's amnual is Dow Siicone Sealant #999A. I've re-caulked my roof once with this product and then later helped a friend re-do his Jayco PU, but we could not find the Dow product I had used. Called Starcraft and they put me on to this cross-over chart and that's what we did ... went to Lowe's, used the chart and got the product that said it was the Dow equivalent and it has worked out just fine.


Fly