Sealing Roof Vent

[fireman24]

Hi everyone. I am installing a new roof vent this week. Its a standard 14x14 vent. My question is what the recommended sealant would be, and If I needed to remove it at a later date something that wouldnt tear up the roof or never come off. There are so many to choose from, is there a certian one that is really good for this application.

-Dan

[austinado16]

Maybe that grey sticky "tape" that comes on the roll would be best as a bed for it, and then once screwed down (I like stainless screws) put a bead of that self leveling caulk from a caulk gun around the edge.

[fireman24]

I was looking at something like that. I dont know how it will hold up over time though. I did buy the stainless hardware, that is the reason why the old one is coming off, all the old screws are almost rusted down to nothing. It looks like there is some type of silcone on there now but its old and has some mildew stains. I guess I would try and find something resistant to the mold or mildew.

[austinado16]

What did the RV place you got the vent from recommend? Or if you bought online, give your local RV place(s) a call.

My whole camper is put together with that grey caulking tape.  Seems to do okay, and in the places I've taken apart, it released without doing damage.

I don't think I'd use silicone in your application.  

Another neat product is 3M Strip Caulk.  I get it at NAPA.  It's a black butyl based caulk that comes in about a 3/16" diameter rope shape, either on a roll, like a cinnamon roll, or in a box in strips.  Bulletproof, and will smash out into whatever flat shape it needs as you tighten down your stainless fasteners.  You could even put a tiny bit around the head of each screw, so the screw sealed off as it tightened down.  Then do the edge of the vent flashing in the self-leveling stuff and call it done.

[wavery]

I was going to recommend the 3M strip caulk also (it's sorta like play-dough). It doesn't get hard and it doesn't adhere permanently to either surface. It just sorta sticks and molds itself to fill gaps as you screw down your vent. I wouldn't use anything else. Like you said, you probably will be faced with removing that thing in the future, for any number of reasons.

[fireman24]

3M strip sealer. I will try and find some today. Sounds like a good product.

[austinado16]

3M strip sealer. I will try and find some today. Sounds like a good product.

It's called "3M Strip Caulk."

[fshnfool76]

I just got a Fantastic vent to replace my a/c with. According to the instructions,
make sure surfaces are clean,

you put the fan on top of the 'closed-cell' gasket that comes with it,

tighten the scews all around the edge,

then put a bead of silicone around the the lip, also on each screw thread before the last 1/4" of tightening.
 
I believe you can get similar closed-cell material from places like Home Depot. It looks like the same thickness as the stuff used when building a house, layed on top of the concrete foundation before the wood sill plate and walls go on. It's usually pink and comes in rolls.

It's supposed to rain all weekend so I won't be doing my install til next week. Good luck with yours. Take pics if you can!

[austinado16]

Mmm.......didn't even think about our old friend "closed cell foam."

[fireman24]

I am having a hell of a time finding the 3M Strip Caulk. I found a couple of places online but they were only selling it in bulk. Lowes, Depo, Pepboys, Advance Auto, hit them all today and no luck. This is starting to be a real project. I called camping world where I got the fan and they told me just to load it up with silicone. I really dont want to do that. Besides this 3M product sounds to good to pass up. I will keep looking.

[wavery]

I am having a hell of a time finding the 3M Strip Caulk. I found a couple of places online but they were only selling it in bulk. Lowes, Depo, Pepboys, Advance Auto, hit them all today and no luck. This is starting to be a real project. I called camping world where I got the fan and they told me just to load it up with silicone. I really dont want to do that. Besides this 3M product sounds to good to pass up. I will keep looking.

Check automotive paint supply stores. All auto body shops stock that stuff. It's used to bed tail lights and other parts in body repair.

When you finish fastening the vent, You will find some of the caulking bulging out of the sides. Just take a dull knife and trim it off. No need to put any other sealer like silicone or anything.

It's 3M pt# 8578
http://autobodystore.net/Merchant2/merchant.mvc?Screen=PROD&Product_Code=3M8578&Category_Code=JASS

[fireman24]

FOUND IT. I was even on 3M's website and they didnt have it. So I jumped on Ebay. Got two boxes of the stuff $11.99 a pop. Should be here sometime next week.

[austinado16]

FOUND IT. I was even on 3M's website and they didnt have it. So I jumped on Ebay. Got two boxes of the stuff $11.99 a pop. Should be here sometime next week.

I'm not surprised the schlock auto parts stores didn't carry it.  I get it locally from our NAPA auto parts store, as well as the local bodyshop supply stores.  I always have a box on hand because it can do so much....like bedding lights, and it's great for squeaking interior panels and dashes in cars and trucks.

[ptbrauch]

When I replaced our vent, I bought some rubber sheets from the local hardware store and essentially made my own gasket to go between the vent and the roof of the camper.

[paulski617]

I think the earlier posts suggested NAPA Auto Parts stores in order to get it.  May want to check there.  I know that they carry a lot of items that other auto parts stores don't.