Lazy Daze Owners' Group

Roof re-sealing questions

July 29, 2010, 07:35:08 pm

Yahoo Message Number: 114879

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I've read a lot of the discussion here and elsewhere about Eternabond tape, and really don't want to start another debate about it. Instead, I just have a few questions for those who have used it.
 My wife and I will become fulltimers in our 1998 30' IB this fall. After inspecting the roof seals, it seems they need some attention before we set off.
 This pic shows the front right corner, which appears to be in the worst shape of all the seams:
 http://farm5.static.flickr.com/4092/4841497361_1c4108c722.jpg

As you can see, there are "pits" in the sealant that have apparently become filled with dirt (possibly bubbles in the original sealant that later burst?). The photo shows where I have scraped away about 3" of the sealant down to bare metal. After discovering how much hard work this is (the old sealant is still stuck REALLY well), I'm pretty much convinced to use Eternabond.

Anyway, my questions:
 -- Do seams in this condition (photo) need resealing? (It is not leaking, so far as I know)
 -- How should I clean seams in this condition before applying the tape?
 -- Should I fill the "pits" with something (Parlastic?) before applying the tape?
 -- Why is everyone using the 4" wide Eternabond tape, when the recommendation is to overlap the original seams by 2"? My seams are easily 2" wide, so the 4" tape obviously would not be adequate. (reference: http://www.bestmaterials.com/RV_roof_repair_info.aspx )

-- Should I go with the 6" wide tape?
 -- I've read that some people lay a bead of some other kind of (liquid) sealant against the edges of the tape. Is this necessary?

Thanks in advance for your feedback!

Re: Roof re-sealing questions

Reply #2 – July 29, 2010, 08:05:35 pm

Yahoo Message Number: 114883

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"Do seams in this condition (photo) need resealing?"
 Visible leaks or not (and not all leaks are obvious), that looks pretty bad to me. I'd definitely reseal it.
 "How should I clean seams in this condition before applying the tape?"
 The thing about Parlastic is that you don't have to worry about how it adheres to the old seam, as long as it seals tightly to the roof on either side. I'd use canned air to blow any loose dirt out of the crevices in that old sealant, but I wouldn't do any more than that. However, I'd clean the adjacent roof areas with acetone. A really clean surface is important for good adhesion.
 "Should I fill the 'pits' with something (Parlastic?) before applying the tape?"
 I don't see any real reason to do that. You'd have to clean them thoroughly, and from the looks of that old, rough sealant, that would be very difficult. Since it's going to be covered with Eternabond anyway, it's probably not worth the trouble.
 "Why is everyone using the 4" wide Eternabond tape, when the recommendation is to overlap the original seams by 2"?"
 Well, I guess we hadn't seen that recommendation. ;-) It certainly can't hurt to overlap by two inches on each side instead of one--it's just going to cost about 50% more. Given that this is a job you don't want to do over again, I suppose using the 6" tape might be worthwhile. I don't know anybody who's done it, though. Is there anybody out there who has firsthand experience with the wider Eternabond tape?
 "I've read that some people lay a bead of some other kind of (liquid) sealant against the edges of the tape. Is this necessary?"
 My personal feeling is that it's needless, but if you want to be really, really, REALLY sure... ;-)

Andy Baird http://www.andybaird.com/travels/