Roof Vent Leak

[Fred G.]

Hi all! This saturday I gently washed my 1978 Trillium 4500, including the roof, and rinsed with a garden hose from ground level. I must have weakend the old caulking. The next day I drove 75 miles through heavy rain with the vent closed tight and found one edge along the vent frame inside was leaking. I tightened the 4 vent frame screws on the ceiling and this seemed to slow the leak down somewhat. It didn't leak anymore while the trailer was stationary even though it rained during the next couple of days. It didn't rain while we drove home today but I'm guessing it will leak again if I hit heavy rain while I'm traveling. Since the initial leak did get the front sofa/lower bunk mattress wet I'd like to make sure it doesn't happen again.

From past posts I've read recommendations to not use anything with silicone, but to use 3/16th inch thick Butyl Putty Tape caulk and then a sealer around that. Is that correct? What other pointers can anyone give me regarding the entire process of recaulking this original metal roof vent? Do I just loosen the 4 screws on the ceiling and then lift the vent up from the roof? Thanks!

[Brian B-P]

Vent details vary, but the four screws on the inside likely just hold the interior trim frame to the main body of the vent. The real installation to the roof uses many (my original had at least 16) screws, rivets, or (for those of us who prefer them) bolts, fastening the flange that sits on top of the roof to the fiberglass shell of the trailer.

The interior trim will likely need to come off first, then the vent comes off upward with the removal of whatever fasteners and sealant were used. Since a sealant is often used which is plastered right over the flange and the heads of the fasteners (mine was), the fastners may not be apparent now.

While vents are quite standard across RVs (even motorhomes), any specific unit could of course have something unusual - my comments are about the common design, which was in my Boler.

[Fred G.]

Thanks for the insight Brian. I'm waiting to get the proper caulking material and dry weather before I start attempting to take the vent off so I hadn't looked at whats above the interior trim frame.

Vent details vary, but the four screws on the inside likely just hold the interior trim frame to the main body of the vent. The real installation to the roof uses many (my original had at least 16) screws, rivets, or (for those of us who prefer them) bolts, fastening the flange that sits on top of the roof to the fiberglass shell of the trailer.

The interior trim will likely need to come off first, then the vent comes off upward with the removal of whatever fasteners and sealant were used. Since a sealant is often used which is plastered right over the flange and the heads of the fasteners (mine was), the fastners may not be apparent now.

While vents are quite standard across RVs (even motorhomes), any specific unit could of course have something unusual - my comments are about the common design, which was in my Boler.

[Pete Dumbleton]

On the factory vent in my 91S13, there is a gasket that slips over the aluminum edge of the vent hole and the lid fits down on that -- If this gasket isn't seated properly on the edge, the lid will leak in hard rain or hosing.