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KATHIE 02-11-2009 06:34 PM

Why Does my Flat Roof Leak?
I built a new Spanish style house with a flat roof. It has framing made of the newfangled insulation panels, both in the exterior walls and above the ceiling. The insulating qualities work great! However, it had a poorly done roof, and it leaked...So I got an entirely new foam roof put on. It still leaks. We thought since the AC unit is on the roof, it may be coming thru the AC unit, but we screwed a cover onto it...then waited for the rain...and it still leaks! Many of the leaks have come thru the ceiling fans in various rooms...So is it an electrical problem, or just coincidence? I know very little about building. But I cant understand how a brand new foam roof can leak. Any suggestions? Should I get one of those thermal infrared imaging inspections from the leak detection companies? Help!!!

Scuba_Dave 02-11-2009 07:39 PM

Where are you located?
Any snow loads?
What type of flat roof was installed?

KATHIE 02-11-2009 07:49 PM

Joshua Tree California. Snow is not an issue. Not sure what you mean by type of flat roof. original roof was tar and squares..cant recall the technical name but the new roof is foam.

7echo 02-11-2009 09:11 PM

Do you have conduit or MC cable for wiring, or is it exposed romex?

We had a situation where when it rained we had leaks out of 4" electrical boxes-water running out, not just dripping. They are tied in with seal tite and connect to hvac gear. The hvac fan would pull rain water into the seal tite and it would flow into the boxes.

Maybe use a hose when it isn't raining to isolate the leak.

KATHIE 02-11-2009 11:22 PM

I'll have to check that out and get back to you tomorrow.

KATHIE 02-12-2009 09:26 PM

WE HAVE ROMEX. My roofer who did the foam roof thinks the leak source may be the cracks in Parapet walls or underneath the AC unit which is located on the roof.

Maintenance 6 02-13-2009 07:43 AM

Make sure the condensate drain for the AC unit isn't clogged.

Michael Thomas 02-13-2009 09:17 AM

Was the air-conditioning unit installed before after the flat roof? A frequent source of leaks on such roofs are roof penetrations for AC power and refrigerant lines; A/C contractors are not roofers, and sometimes attempt to seal penetrations at foam roofs using traditional techniques that do not provide a durable water seal.

AaronB 02-17-2009 09:30 PM

My first question is.... Did the roofer lift the AC unit in order to roof underneath it? Was this foam roof applied by a licensed roofer or was it a general foam company, i.e. an insulator?

KATHIE 02-17-2009 09:52 PM

I don't think the original roofer (and defintely not the subsequent foam roofer) did lift the AC unit. The foam roof was done by a licensed roofer. Everyone who looks at it seems to agree that the leak source must be under the AC unit. Since we likely have to lift the AC unit, I am planning at this point to remove it from the roof and have the roofer add foam to that area and relocate the AC unit to the ground. My contractor says it won't be a great deal of work...and I've never been thrilled with the AC unit on the roof to begin with. I can't imagine that this won't fix the leak...but we will see.

KATHIE 02-17-2009 09:59 PM

With these leaks that have dripped thru to the ceiling, am I likely to have mold or mildew above the drywall? There is no crawlspace, just SIPS (structural insulated panels ) under the roof. Thanks for your help!

AaronB 02-19-2009 09:54 AM

If there is organic matter for the mold to feed on, then yes, you may have mold.

I don't get why, if the roofer can lift the air conditioner now, why it wasn't done to begin with. This is still part of the roof that should have been addressed when he installed the new roof. If he is a licensed roofer, he knows this. If you paid for a new roof, I would certainly consider calling him out on his warranty. I do not think you should have to pay for this service IF you paid for a complete roof.

AaronB 02-19-2009 09:55 AM

Air conditioners on the roof are not the problem. Incompetence is.

KATHIE 02-19-2009 10:51 AM

when you say "organic matter" will create mold, would the styrofoam insulation panels be considered organic matter? I have a great fear of getting mold since I know it is costly to remove, etc.

Are you saying the 2nd roofer who installed the polyurethane foam roofing should have raised the AC unit when that foam roof was installed, not just gone around it? I still owe him some money since part of the cost was deferred, so I can probably negotiate to reduce that now that I have to spend more money to move the AC unit. Thanks!!

KATHIE 02-19-2009 10:53 AM

when the AC unit is relocated and the interior work is done, I assume they can look behind the drywall to see if there is any mold???

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