Inside: Leak. Outside: Water (ice) coming from under eaves. What to do?

January 28, 2012 1:54 PM

HOME REPAIR: My over-the-range microwave had water in it! I uninstalled it and found a slow drip coming from the vent duct. Then I went outside and saw a bunch of ice coming out from under the eaves. I don't know much about home construction or repair. What should I do?

OK, here's the other info I can provide, if it is helpful.

1. I live in Anchorage. It's been very cold here -- in the -15F to +10F range.

2. The house has an attic -- by which I mean, a space up there of some kind. I've never been up there. After I finish writing this I'm going to go up there and see what I can see.

3. There is about a foot or so of snow on the roof -- certainly nothing I would consider unusual.

4. My neighbor says I need more insulation up in the attic. So in the absence of any other plan, I am going to try that.

5. If you look at the linked photos, there is kind of one primary leak coming out from under the eaves, and then another secondary one, off to the right.

So the bottom line is, I really have no idea what is causing this. I would be grateful for whatever guidance more knowledgeable folks could provide.

posted by Alaska Jack to home & garden (12 answers total)

Oh, and, to clarify -- the primary leak outside is just about exactly in the location that the microwave was at inside.
posted by Alaska Jack at 1:55 PM on January 28, 2012

If it's coming from the vent duct, I'd bet that the hole in your roof through which the vent goes is no longer sealed properly. this can likely be fixed with some gobs of roofing tar, but you'll be able to tella lot more once you see what's going on in the attic.
posted by cmoj at 2:10 PM on January 28, 2012

Could the vent to the range hood be blocked, possibly by snow or ice? Im assuming its venting out the roof: can you get up there and check. More insulation isnt going to help. Either the vent is blocked or warm moist air from the kitchen is getting sucked into the attic and then condensing causing the frozen waterfall i.e. you need to airseal...
posted by ennui.bz at 2:24 PM on January 28, 2012

ugh, I just got down from the attic. I can't even really GET to the spot in there. The main part of the house has kind of a cathedral ceiling. But the roof doesn't go up accordingly. So the extra space comes out of the attic. That part of the attic would be very, very difficult to get into. Maybe this is a job for a professional :^(
posted by Alaska Jack at 2:45 PM on January 28, 2012

Are you familiar with the concept of ice dams? Because this sounds like that sort of thing.
posted by Kid Charlemagne at 3:00 PM on January 28, 2012

ugh, I just got down from the attic. I can't even really GET to the spot in there.

Can you get up to the roof where the vent comes out? I'm going to double down on my bet that if you do you will discover the vent outlet is blocked by a thick chunk of ice.
posted by ennui.bz at 3:34 PM on January 28, 2012

Yeah, and insulation is not going to help. All additional insulation will do is get wet and damaged. You may need insulation for other reasons (although it can affect the way snow melts), but it won't fix a leak.
posted by zvs at 3:50 PM on January 28, 2012

OK, one of my neighbors has a really long ladder. I'm off to borrow it, so I can inspect the roof.
posted by Alaska Jack at 4:19 PM on January 28, 2012

Seconding ice dams as the probably cause of all your woes. Once water gets into the roof it can find its way almost anywhere. Kid Charlemange's link looks pretty helpful.
posted by grog at 4:48 PM on January 28, 2012

That ice coming down from the soffit is unfortunately coming from somewhere inside the roof/attic structure. I suspect this will be a job for a professional, and will involve both repairing damage inside the roof and at the very least repairing flashing at penetrations in the roof surface itself. At the worst it is ice dams combined with a roof that has totally lost integrity and is just letting in water between the tiles. While you are in there it is a good idea to insulate well, but this doesn't look like it is just melting due to poor insulation.
posted by meinvt at 5:10 PM on January 28, 2012

Could be you have a localized problem with the vent itself but you have ice dams forcing water under your shingles for sure. you can see in the last picture of the set you posted that water is also leaking from under your roof in other places. Specifically the second rafter over from the right has an icicle forming behind the facia and it looks like water has been wetting the wall underneath that rafter.

The vent is probably exasperating the problem because the heat loss is melting the snow allowing more of it to form icicles. Plus there often is a reduced shingle coverage at roof penetrations.

Also judging by the condition of your soffit boards this has been a problem for a while.

Long term dams are usually caused by insuffiecent ventilation and poor insulation. Short term you can treat the symptom effectively with heat tracing. Though designed for permanent installation you can lay it over the existing dam and it'll melt it's way through to the roof surface.
posted by Mitheral at 5:10 PM on January 28, 2012

Short term you can treat the symptom effectively with heat tracing.

In the even shorter term you can throw a few pantyhose filled with calcium chloride up there to cut some channels through an ice dam.
posted by ROU_Xenophobe at 5:54 PM on January 28, 2012 [1 favorite]