Leak Around Roof Vent of 78 Trillium 4500

[susan s.]

I wonder if someone could help me with this. We just bought this trailer and rain is leaking in through the roof vent. My husband removed the base from the inside, and you can see that on one side of the square opening it has probably been leaking for years-- the pop rivets had got loose with time, causing the leak. Anyway, although we'd love to install a new vent/fan, for now we are putting the old one back. I read that silicone does not stick to fiberglass, and something about butyl tape . . . My husband intends to put screws through from the roof (fiberglass). He says it's ok because there were already many holes. I know this is all horribly vague, sorry. What product should he use for caulking--and what should he NOT use? He's been looking at a product called Eternabond: http://www.eternabond.com/articles.asp?id=148
Also any general help re re-installing the vent is welcome.

[Raya]

Butyl tape is user-friendly and lasts for decades, so it's a good choice. Other products may work also.

The main thing is to get the vent off, clean and prep the mating surfaces (roof and vent flange), and then put whichever sealant you choose under the flange. In other words, if you are using butyl tape, you would apply it to the solvent-washed underside of the vent flange, and then re-insert the vent into the camper roof. Then you can either re-rivet or use other fasteners to affix the vent to the roof.

There's no need to apply sealant to the outside or top of the flange (although going by many of the campers I looked at, it must be very tempting*).

You are right on to stay away from Silicone. It's the gift that keeps on taking.

Raya

* I suspect that the layers and beads of sealant on the outside and on top of many vent flanges and around the edges of windows are probably attempts to fix leaks the "easy" way. Unfortunately, the leaks usually persist (or come back) until the item is re-sealed properly (removed and re-sealed from under the flange).

[MyronL]

THIS is what silicone really becomes!! You can find butyl tape on ebay under "butyl tape".

My roll cost just over $9 - plus $10 shipping. Clean, neat, foolproof, absolutely worth it.

[susan s.]

Thanks, Myron and Raya. What do you think of my husband's intention to use screws?

[MyronL]

Thanks, Myron and Raya. What do you think of my husband's intention to use screws?

Screws will work fine, -- that just makes it a 2-person job. Use Stainless steel screws with a pan head for a lower profile outside, if you can find 'em --and lock washers.

[Roy in TO]

What do you think of my husband's intention to use screws?

The question I might ask is what is your husband going to screw into? That is what are the threads of the screw going to grasp if it was originally held in place with a rivet?

[MyronL]

You use nuts, Roy. That's why its a 2 person job with screws. Probably no longer than 1/2 inch long screws, depending on measured thickness of roof and if you do it inside the rat fur - insullation - whatever. Certainly wouldn't want to see those nuts going through the interior trim framing. Somebody's got to be standing inside with a nut driver or wee wrench thing. Then you cap it all with the trim frame.

[Roy in TO]

Gotcha Myron,
So we are talking about bolts, not screws then?

[MyronL]

Yes, machine screws, either size 6-32 or 8-32, probably, (that refers to the screw thread/thickness), depending on what comes closest to filling the existing pre-drilled holes in the outside flange of the fan.

[K Slade]

I wonder if someone could help me with this. We just bought this trailer and rain is leaking in through the roof vent. My husband removed the base from the inside, and you can see that on one side of the square opening it has probably been leaking for years-- the pop rivets had got loose with time, causing the leak. Anyway, although we'd love to install a new vent/fan, for now we are putting the old one back. I read that silicone does not stick to fiberglass, and something about butyl tape . . . My husband intends to put screws through from the roof (fiberglass). He says it's ok because there were already many holes. I know this is all horribly vague, sorry. What product should he use for caulking--and what should he NOT use? He's been looking at a product called Eternabond: http://www.eternabond.com/articles.asp?id=148
Also any general help re re-installing the vent is welcome.

Hi Susan
You should be able to find butyl tape at your local Canadian Tire store usually in the section for RV roof vents. Good luck with your project.
Ken

[MyronL]

Here's my hatch rehab using stainless steel 1/2 inch screws with lock nuts, and butyl tape. All old silicone caulk residue removed, and instead of replacing the plastic cover I fiberglass repaired and painted the cover. All repainting was Krylon. Wasn't going to spend $40+ for a new hatch cover.

[Larry C Hanson]

Hi, Here is an old thread discussing Trillium vents:

http://www.fiberglassrv.com/board/index.ph...ent+replacement

Larry H

[susan s.]

Here's my hatch rehab using stainless steel 1/2 inch screws with lock nuts, and [b]butyl tape. All old silicone caulk residue removed, and instead of replacing the plastic cover I fiberglass repaired and painted the cover. All repainting was Krylon. Wasn't going to spend $40+ for a new hatch cover.

Thanks so much for posting these Myron. Very helpful!

[Scott S.]

this s right on. butyl tape all the way. and never try to do a quick fix on a roof vent that is leaking. take it of, clean all surfaces and do it right. I made a wood frame for the inside of mine so the screws had lots to bite into.