Chronic roof leak resolved

One year after we purchased our 2005 Airstream CCD 25 International we took it to a WBCCI International rally for a couple of weeks (we still were working). Torrential downpours, water on the ground up to our ankles, and we found a drip, drip, drip, from the ceiling onto the floor near our sofa.

Ceiling leaks can be very difficult to track. A roof leak is likely to travel along top or bottom of a joist before gravity overcomes the water. Oh, and the water finds an open passage to below. In our case the water was dripping from the plastic frame of our front fantastic fan.

First break in the rain Jim borrowed a ladder and climbed onto the roof to try to see the water entry point. The caulk around the fantastic fan roof flange seem to have shrunk in places, leaving cracks for water entry. Quick fix — Jim overlaid more caulk.

Before removing caulk

Every six months or so we would again have a drip from within a foot of the fan, and Jim would apply another half-tube of caulk atop the old (and growing) caulk. This went on four years, this slow cycle of caulk and ensuing slow leak within six or eight months. We figure there might be four or five tubes of caulk around the front fan’s flange.

Last year someone asked Jim why he didn’t remove the old caulk and start with a clean surface. Taken aback, Jim responded it just didn’t seem necessary, is more work, takes longer. Let’s see, Jim’s projects usually seem like the longest approach to solutions and always are plenty of work. So why not remove the old caulk to have a clean surface for sealing the fan flange? Just didn’t think of it, that’s all.

Flange is embrittled and water has been hanging out under caulk

A couple of weeks ago Jim climbed up with utility knife, razor blade scraper, and putty knife and started peeling away the old caulk. Sadly and perhaps not surprisingly, much of the old caulk readily peeled off all the way down to the flange. We found evidence of water intrusion through the caulk to the fan’s flange. The flange’s condition ruled out lifting the fan and embedding the flange on fresh butyl tape. The flange is cracked at many screw holes and all the corners are broken.

Surface prepped with scotch-brite pad and denatured alcohol

Jim scrubbed the roof and flange with a scotchbrite pad and denatured alcohol, then applied the new caulk. Looks good but won’t get much testing in Mesa AZ. Funny thing — we have an identical fan at the RVs rear roof and it has NEVER leaked a drop. Who knows, maybe it points to some part of the original caulk prep and application.

The impetus for removing and replacing the old caulk is a bargain find from our Quartzsite trip last month. Debbie found a MaxxAir FanMate to install over the front fan. We had a few years ago installed one over the rear fan and liked a couple of things about it.

FanMate installed over our rear fan has been great

First, the cover allows the fan to remain open all the time regardless of dew or rain. This is important when we are using (and therefore venting) the catalytic heater. Likewise it is really nice when we are sleeping and want a fan open for a little fresh air. The dew would have caused the fan to open, close, open, close, a few cycles before we would tire of it and shut it down in closed position.

Second, the cover’s opaque material shades direct light from hitting the fantastic fan. This is great when we are in a site with security lights overhead or trying to nap during bright sunshine. The opaque fan cover is a nice improvement.

Caulking complete and cured before installing FanMate cover

Jim installed the new FanMate cover on the front fan after recaulking. Hopefully a third benefit of the fan covers is to protect the caulk on the fan flange. The caulk will no longer have direct exposure to sunlight because the FanMate overhangs the caulked flange nicely.

We could take heart that the rear fan hasn’t leaked since we installed the Maxxair FanMate — but then, the rear fan never leaked even once, even before we installed the FanMate cover. We’ll just not worry about that. The front fan is well caulked and we don’t think it will leak again. Fingers crossed.

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2 responses to “Chronic roof leak resolved

  1. akismet-a336d0d6a8fd4282d2603f646b3457fe

    I also have a leaking Fantastic fan. Took off the caulk and found a crack in the plastic housing. Sealed the crack with 3M 5200 and now it’s leaking from the other side of the housing.

    How did the MaxxAir work out? Thinking of picking one up. Is your fan housing (that the maxxair screws into) plastic? Any issues with mounting the maxxair to that housing?

    • The Maxxairs mounted simply and easily. Screws thru two small holes from each of two sides of fan’s plastic curb, and the brackets rest on the roof. Four years later, no more leaks there and no problems.

      Good luck!

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