roof leak through a/c in heavy rains

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shatterproof

Member
Joined
Dec 17, 2007
Posts
7
hey guys.  im up in the cazadero hills, and its rainy season.  ive never had leaks before but  the heavy rains im getting a drip through my roof a/c unit.  could it be the winds?  or could i bondo around the unit?  or is it more likely to be a leak internal to the unit that needs to be looked at?

thanks for any thoughts,
xo shatterproof
 
It could very well be a leak in the area where the AC attaches to the roof.  You may be able to correct the condition by giving the mounting bolts a turn.  Do not try to tight them all the way down just a turn on each one.  The mounting bolts can be accessed from the inside by taking the AC grill off.
 
Re the mounting bolts that Ron referred to:  There are four of them, one in each corner.  You can see the nuts.  To start with only do one turn of the nut on each bolt.  Do it slowly so you can get a feel as to how hard each nut turns.  Real pros torque them to about 10-12 inch pounds.  You may not want to tighten all four if, let's say, one turns quite hard which may mean it's already torqued down down to far. 

What you're doing is compressing a 5/8 to 3/4 inch thick foam rubber gasket to about half it's original thickness and for that reason bondo or caulking will not work.  Up on the roof the gasket should be compressed evenly all the way around.  It's tough to see it.  You've got to lay down with your temple flat on the roof in order for one of your eyes to to see it well.

OTOH, ultimately you may have to have new rooftop A/C gaskets installed.

If you haven't already check to see if your A/C rooftop cover is cracked or broken.

JerryF
 
Water dripping from the AC air intake doesn't necessarily mean the leak is in the AC mount - ANY water that gets under the roof generally flows along the inner surface until it comes out through the gaping AC hole or runs down the insides of the side walls. Do not assume it is the AC - check the entire roof for leaks, e.g. around roof and plumbing vents, antennas, marker lights, satellite dish, ladder mounts, etc.

Yes, the wind may be piling up water where it does not usually rest, but it is still a roof leak.
 
Yesterday I added another comment right after Jerry's, but guess it got lost along the way.  So I'll try again.

Two years ago we had what appeared to be an A/C leak that turned out to be dried caulking around the crank-up through-the-air TV antenna.  It took quite a while to pinpoint the problem.  You need to go up on the roof after things dry out a bit and check all your rooftop caulking at every opening.  Water seeks easy entry which might be a minute crack in the caulking and then, as Gary said, it finds its way to the easiest exit which often is an A/C vent.  The entry and exit points can be many feet from each other so don't assume anything.  Also, if you live in a hot and dry area, make a rooftop caulk check part of your annual maintenance.

ArdraF
 
Thanks!  I'll check out the bolts as soon as I have some tools and a minute away from the class I'm taking up here.  Reading the rest of your suggestions, I'm worried the leak could result from a large paint chip on the back of the van that I meant to Bondo and never got to...  I tapped a low level bridge getting out of an awkward parking situation and took off a good chunk of "paint".... seems to run deeper than paint, there is exposed (fiberglass?)....

definately a newbie, ill let you know if the bolt adjustment helps. 

Thanks Again,
Shatterproof
 
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