Roof Vent Caulk ???

[GPW]

Guys , we're getting to the point of installing the roof vent ... got one like everyone else... 14"x14" ... What kind of caulk /sealer should I use to make it leakproof .....saw some rope caulk at the Auto store , another friend recommends scotch 5200...??? You guys have any favorites .... wet climate here ...

[Boodro]

I used the butyl tape on mine. Its like a flat roll of putty tape. It works well , I set my vent in place marked & drilled the holes , then moved the vent , layed ther tape down so there was enough to cover the holes& hang over the sides of the vent when placed back in place. I ran the screws thru the tape & trimmed the outside putty with a sharp knife after tightning all the screws. As a bonus I used a self leveling caulk around the edge of the vent & put a dab on all the screw heads. Has not leaked yet in very hard rains.
Just my 2 sense worth.

[madjack]

G, the way Boo desrcibes is one of the best ways to do it...we used auto windshield adhesive/sealant because we wanted as flush a finish was we could get...
madjack
p.s. the Scotch 5200 is good stuff...as are SikaFlex 221, 252, 552

[len19070]

Boodro's method is the same method I used. Only I didn't use the sealant around the edges.

A few reasons, #1 on a teardrop you see everything and don't have the luxury to goo the daylights out of a joint.

#2 they don't make green sealant.

#3 as long as the putty tape squeezes out when screwed in, and I mean a lot, then trimmed. It won't leak. (25 years as an RV Tech)

The only problem is the screws rusting. If nobody can see them anything will do. But I used a spray can of Clear coat on the screw heads. Its doing fine.

Happy Trails

Len

[cracker39]

I used a liberal aplication of poly sealant, one heavy bead at the inside close the cutout, another closer the edge so that it would squeeze out when tightened down, and around each screw hole (on the underside). When I pressed it into place, the sealant did squeeze out around all the edges, and came out the screw holes. After putting in the screws, I dabbed it on the screw heads. Before installing, I emailed Scott at Fantastic Vents about the gasket and after reading his email, I threw mine away. This is what he said:

"The gasket goes against the roof. Alot of mfg of RV's don't use the gasket, they throw them away. I like polyurethane sealant. Fantastic Vent Corp suggests silicone. I hate silicone. All Airstream owners swear by Vulkeum. Whatever you do just make sure you seal around the vent flange to the roof and dab the screw heads."

Most of the caulking on my trailer is with the poly sealant. When I pulled the window out to reshim it, after it had been in the side for nearly a week, the poly sealant on the inside was still soft and pliable. On outside areas, it cures more, but still stays elastic.

[rainjer]

#2 they don't make green sealant. Len

FYI, most stores that sell Formica can get you custom mixed calk that matches the formica samples. It is made by Kampel ColorFlex. It will run about $10-15 a tube.

http://www.kampelent.com/colorflex.htm

[GPW]

Gentlemen , once again , I'm indebted to you for your responses ... Many Thanks !!!!

[sunny16]

So, I shouldn't use the LOVELY gasket that comes with the Fantastci Vent. It doesn't look like it would be too good anyway. The vent itself looks great and I can't wait to uinstall it. Thanks for this thread.

Sunny16

[cracker39]

You can use the gasket if you want to, I think most people do. But, if I had used it, I'd have put sealant on both sides of it anyway. One of the reasons I didn't use it was that the fan thickness was already a bit less than the thickness of my roof (1 5/8" for the fan, 1 7/8" for the roof total thickness). If I had used the gasket, the inside of the fan would have been over 1/4" into the ceiling. The garnish would have still worked though.

[cracker39]

PS...I'm using the fan while I work on the interior to help move the air through it. I also have a box fan plugged in to blow on me when it's hot, and it was well over 90 yesterday.

[Witch]

I work at an RV plant, and for the roof fans, we use a product that is basically a liquid caulk. It's made by Schnee-Moorehead. Sorry I can't give you more info on it, but this stuff seals great.

Careful though, it's stickier than h3ll, and hard to get off your skin.

Later