Type of Sealant, Tape and do I need both or one or the other?

[Amykins753]

I've been reading tons of DIY resealing roof and corners of RVs/Campers and I'm looking for suggestions. Should I use both Roof Sealant Tape AND the self leveling sealant around the vents, AC, fans, etc OR can I get away with just the Sealant tape? Also, do I really need a self leveling sealant caulk? I was thinking some Marine Sealant might work nice for that water tight seal I need but what are your suggestions? Also should I invest in a corner tape to put under the corner molding or will standard Butyl tape work fine? I've spent days now looking at different sealants and corner tapes and I'm just not sure. Is spending the extra on the DICOR Lap Self Leveling Sealant really worth it or can I get away with something that might be local at Home Depot or Lowes?

 

[donn]

Well, what type of roof do you have? Personally for as long as I can remember I used Dicor self leveling on my fivers roof. On verticle surfaces I tried Proflex once on one seam. After that disasterous experience I went back to Dicor for vertical surfaces. Never had a problem with either. Many people swear by tape with Dicor on the edges. Personal preference, but I never had any seams open up so why add more edges.

 

[TheBar]

7 years ago I put Eternabond tape around all sides, vents, A/C, etc. Over top of any and all roof caulking. It should last 20 years. If it is applied correctly there is no need for any coating on top of the tape or around the edges. Not all tapes are created equal.

There are places on the sides that need vertical caulking. I use clear Geocel ProFlex caulking and it works great. I assume Donn is talking about Proflex being sticky because it is not runny. Like Butyl caulking it is a little harder to apply because it is sticky but it sure as heck ain't ever coming loose.

 

[donn]

Dont ASSUME anything. The Proflex I applied on one seam literally fell off when I washed the trailer a few days after applying the stuff. Use what you want, all Im saying is to me Proflex is junk.

 

[Mark_K5LXP]

I would ASSUME when a sealant "fell off" there was an issue with surface compatibility or contaminants. I've observed how Dicor will give up if applied over silicone, that doesn't make Dicor or the silicone junk, just incompatible. So if I observe a failure like that my first thought isn't the product but the application.

Mark B.
Albuquerque, NM

 

[Gary RV_Wizard]

The right sealing method depends on what you have to deal with. Good old Dicor self-leveling lap sealant (caulk) is still the gold standard for seams and openings. It goes on smoothly, fills gaps, self-levels on most any horizontal surface, and stretches as the surfaces twist and move as you drive or park on uneven ground. Works with EPDM rubber, TPO, fiberglass, aluminum and galvanized roofing materials. Also easy to spread around curves and protrusions such as vents and a/c uits. It's main drawback is that it dries with age and eventually cracks.

A quality roof tape such as Eternabond or Diseal is great for seams on flat surfaces but can be difficult to apply on curves or uneven joints, like a raised bracket or plumbing vent. It's big plus is that it doesn't crack, lasts darn near forever, and usually stays cosmetically nice. If you can get a tight seal with the tape, its usually a one-time job. I have a corrugated metal storage building where I repaired a major tree-limb-caused hole in the roof with tape and it's still holding well 15 years later. I would not try to use tape around plumbing vent pipes, ladder mount brackets, and other odd or sharply curved surfaces.

I can't think of any reason to put tape over sealant or vice versa, but on any roof job there will be places where tape works best and others where lap sealant is the better choice. There may also be cosmetic reasons for choosing one or the other. Thus sealing a roof may involve both types of product.

 

[mrgreen]

You used sealant as a barrier or a means of protection in your RV roof. In this way, you can check what is the best sealant for you to use. You can check the product that I've encounter Semco Liquid Membrane, they have customers that used it in RV roof as well.

 

[IBTripping]

I used Eternabond tape on all my roof seams. I expect it will be strong and vital long after I'm not.

 

[garyb1st]

It's been two years since I put Eternabond tape on my front and rear cap seams and so far no leaks. Of course we're in So Cal and haven't had any rain. Yesterday it was sunny and 90º. I'll be up in the Bay Area next week for about a month so if they have another deluge, I'll find out how good it actually is. If it fails, it will obviously be the fault of the tape.