Weather proofing fiberglass roof and body

[Rickf1985]

Time moves on, products go obsolete and other products emerge as research moves ahead. Don't get me wrong, Butyl has it's place, just not everywhere and especially not where water will be laying. And I have seen more than enough cracked and dried self leveling.

[DRMousseau]

I wanna know more about relaminating roof/ceiling assemblies! And I mean a SOLID relamination!!!

AND ENDCAP SEAM SOLUTIONS!!!! DANG,... I hate those!!! Especially when they are more on top than on the side. I have much less problems with the side seams.

I too prefer the butyl and lap sealant for most up top,... and will admit that I've never yet used Eternabond. I suppose it seems to me to be a "last resort" at a repair that I should better be considering replacement. Butyl and sealant DO need to be watched and inspected occasionally,... while I consider replacement. LoL!

My roof is aluminum,... and ACTUALLY pretty good, with some poor "fixes" that have been attempted by the PO. One being a "coating" over the rear bedroom area. Biggest issues are those damn end-cap seams and trim, and corrosion "pin holes" in the thin skin here and there. No real problems with vents, AC, ladder, or anything else up top. I'm STRONGLY considering a one-piece sheet roof of either TPO or EPDM,... can't do much about the front cap seam, but to do it right. The rear seam I'll lower over the back a bit and do it better. Thought about a roof coating,... but I don't wanna a fix to jus get by with. The rubber roofing is IMO the best solution.

First, I have to relaminate the rear portion over the bedroom. UGH! And in the meantime,... MAYBE I'll pick-up some Eternabond for those endcap seams. I sometime reflect on marine solutions, certainly watertight! In the meantime, I try to maintain a "starboard list" to keep water runnin' over the side when it rains.

"Got some silicone??" SURE,... never use it much, if at all, but others always seem to need some, and I got it if they ask and really wanna use it. Not really sure why I always seem to have some layin around, I never buy the stuff!

[bluebird]

My 80 Itasca had a one piece aluminum roof with pin holes. I used a product called Kool Seal. They make a thicker product made for patching holes that is used with some nylon screen looking stuff, then I coated the whole roof with the roll on Kool Seal. It is pretty good coating, I never had another leak after that. I did brush some of the thicker material on the seams where the the caps were installed the year after coating. Held up real good.   

[DRMousseau]

I've strongly considered elastomeric coatings like Kool Seal. The problem I have with such "repairs",... is usually a matter of economy. Seems we never can afford the costs or the time to do such things right, but we can always find the time and money to do it again!!!

Ya really gotta admit, such treatments and repairs really only prolong the replacement of that which has reached the end of it's intended useful life. Now I really like the aluminum, but since it's an original laminate construction, it's really jus not practical to replace. With every thump I hear overhead, I wonder if the thin aluminum has been punctured by a falling object. With every step I take up there, I wonder if I've loosened another pinhole underfoot. Such damage leads to delamination, such as now occurred in the bedroom portion.

While the thin aluminum has lasted 30yrs, I much prefer the maintenance free seamless covering of membrane roofing over the available options. Even with a shorter life expectancy, it's much quieter than aluminum, resilient and weatherproof, with a very good useful life that offers full protection of the existing roof, with good sealing options around fittings.

It IS a major expense,... but the roof is of major importance, deserving of far more than a cheap repair.

[bluebird]

I sure wasn't going to consider on installing a rubber roof on a 2 thousand dollar coach, that's what I paid for it. I ended up with about 4 grand in it and sold it for 4 grand when I bought my Challenger. Had the Itasca for 3 years and the Challenger for 7 years. The coating was the way for me and it held up for the 3 years I owned it and looked as good as when I put it on.

[Oz]

Two, good points were brought out about Eternabond tape.

1.  It seals really well and it lasts.  If forms over irregularities and is clean to work with.
2.  It can be a PITA to get off if needed.  Especially the double-sided tape.  It's denser and thicker than the single sided, aluminum backed type.  But, it's no worse than removing layers of whatever that black stuff was I had to clean off my first Winnie roof!  I swear, it was tar!

I used the double sided on my roof vents, between the vents and the roof, and then the single sided tape over the edges and screws.  A REALLY good point was brought up about that which I really didn't think about at the time... those may need to be replaced sometime because the plastic becomes brittle and breaks, or may be damaged by tree limbs or airborne items such as semi truck tire tread coming apart.  OMG!  What a job it would be for me to have to undo all the Eternal - bonding!  All I was thinking about was, "this won't leak as long as I live!"  So, the advice NOT to cover the screws and edges may be a very wise thing to consider.

I did the same with the roof seam edges and corner moldings.  This, however, might not be a bad thing to do since those are not areas which should have to be removed for a very long time. 

[legomybago]

Well written Oz. I wonder if the owner of your old Bago with the double eternabond roof vent seal has ever cussed? hahahaha

[Rickf1985]

You obviously did not see the pictures of Oz's Bago that turned up recently. Damn shame.

[legomybago]

Oh no....I seen it, and made my so sad comments too. A lot of people out there think RV's don't leak or something. Like they came with a 30 year roof? It's a shame.

[Aaarrghh]

There's no denying that the correct approach is to remove all that dried PO goop that's probably cracked and leaking. But what you could do first to stop the leaks simply and quickly is to get from a hardware store some elastomeric roof coating and paint it on over the goop with a brush. Worked for me! It will fill the tiniest cracks, ones you wouldn't think leak but they do.

[rajoford]

This sure looks familiar. Included is the repair of the seams between the roof and side panels and over the drivers’ compartment on the 1980 Winnie Wagon. The roof panel is aluminum, and a steel Dodge cab. So with this construction there are fibreglass to aluminum, to steel and to fiberglass joints.

The basic components are all big box store items. Elastomeric white acrylic roof coating, drywall, 2” wide fiberglass mesh for the seams and assortment of putty knives.
The tedious part is scraping off all the original sealant as much as possible.  My son & I spent hours doing this. First peeling away all the loose stuff then scraping down to the metal/plastic as much as possible. Buckets of dead goo when done. Once clean a uniform layer of the acrylic. I used the blade to mark a line along the seam. Start the mesh at the corner and all the way along making sure it is centred on the line. Our goal was to minimize any joints in the mesh. If a joint is required then overlap approximately 6-8”. Once dry or almost dry a second coat as per manufacturer’s instructions. You will get the flexibility of the rubber reinforced with the mesh. From the photos some of the mesh is still visible. then I applied the 2nd coat the mesh wasn’t visible but after drying it shrunk thus exposing the mesh. This shouldn’t affect anything or if fussy a third coat can be applied.
One 20/20 hindsight suggestion is to create a nicer outside edge putting down some masking tape say ~1 ¼” either side of the seam then feathering to it. Peel up when done.  This would also help aiming the mesh centered on the seam.

Included in the photos is a sample of blue EIFS fiberglass mesh used for the more modern two layer acrylic stucco (verses the old three layer portland cement which uses a wire mesh). This usually comes in 3’ wide rolls. This with one or two 5 gallon acrylic roof sealant could be used to cover the whole RV roof.

[87Itasca]

ARRGH! THAT^^^ is the stuff that someone slathered all over the roof on my Elandan. Such a pain to remove to replace. You're literally chiseling it away, half a millimeter at a time. So not cool!