ice dams

john_bry

If I get an ice dam sooner than most people, what does that mean?
Could there be heat leaking into the atic with a combination of a poorly ventilated attic?

I figure an attick thats too hot could cause the snow to melt.
I have a gable roof.

joecaption

That's right.
Not enough insulation.
http://www.energystar.gov/index.cfm?...sulation_table

Not air sealing the attic, blocked soffit vents, no ridge vent can also be factors.
That attic area needs to be about the same tempature as the outside air.

yuri

Also the perfect storm scenario. If you get a Chinook or unusually fast quick melting of the snow in one day and very cold weather that night the snow on the edges by the gutters does not do it's usual slow progressive thaw and the water from above cannot get thru it and backs up under the shingles and can leak into the house. Next time I get shingles done I am going to pay extra for that membrane under the shingles at the edges and valleys.

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Dave Sal

Whenever it snows, I tend to look at people's home and see which ones still have snow on the roof the next day. The majority are mostly melted but there are a few that remain covered in snow. These are the ones that are obviously well insulated. Mine is not quite up to speed but it is much better than it was since I've added extra R30 insulation on top of my existing R19 blown in. I also added an R30 attic hatch which I think helped a lot. I still need to add a second R30 attic hatch on the upper level, as I have a tri-level home. That will be taken care of this spring. I also replaced all of the small soffit vents this past summer with the large versions and doubled the number of them so I know the attic is well vented.
This image may help you understand about ice dams.

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joecaption

Please go back and add your location to your profile, yes it's very important.
http://www.energystar.gov/index.cfm?...sulation_table

GBrackins

typically when you see icycles hanging from the eaves you have issues with either your insulation (amount) or air leaks into the attic.

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Gary

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