Roof leak around air conditioner

The only way to do it right is to remove the A/C unit, and if you're going to do that you may as well replace the $20 gasket. If you try to caulk around it you'll just make a mess (BTDT).

But if you insist, I'd use an interior/exterior type door & window caulk. I've used it before and it peels off easily - at least off of my old-school aluminum roof.

Maybe just tighten the bolts up a little.

Do not caulk it, take the time and effort to remove the old and put on the new. The po of one of the used units I bought caulked and it still leaked and caused a real mess. Have you tried just tightening the mounting bolts and compressing the current gasket more?

as stated earlier, tighten the bolts on the AC unit. It is a crush type gasket, and may need just a bit more tension to seal. Most likely that will do the trick.

Dicor self-leveling lap sealant or Eternabond tape. Neither is easily removed completely, but if something more extensive is required at a later date, they can be removed enough to effect a further repair.

Don't do it! It will take less time to replace the gasket that to try and caulk it.

I have had my four long screws get vibrated loose especially going down bumpy concrete separation every 8-feet or so.

You can pull the bottom cover on the interior ceiling side and see the gasket in question. It should be depressed about a 1/4-inch all the way around it...

Easy job to re-tighten the four long screws depressing the 14" x 14" gasket.

The only other times I have got water coming through the A/C ceiling vent is when it would ice-up during very humid days/nights... Could be doing this on you as well...

On those very humid nights in our OFF-ROAD POPUP trailer running one of those 11-inch O-2 COOL portable fan's inside the area really helped alot...

Roy Ken

wildtoad wrote:
Do not caulk it, take the time and effort to remove the old and put on the new. The po of one of the used units I bought caulked and it still leaked and caused a real mess. Have you tried just tightening the mounting bolts and compressing the current gasket more?

Agree. Tighten up the bolts and if that fails go through the effort of getting a new gasket.

My last trailer the air conditioner also leaked, turned out it was not properly fastened to the roof and could have lost it while traveling. I agree with the others, don't caulk it - get it checked out first.

Just got through checking my bolts after a vibration I had from the fan.Three were loose.

Did you find your problem?