Ice dams aren't a roofing problem — they start with a warm attic. Keep the roof deck cold with air-sealing and spray foam, and you break the melt-and-refreeze cycle at its source.
When heat leaks into the attic it warms the roof deck and melts the snow sitting on it. That meltwater runs down to the cold overhang at the eaves, refreezes, and builds a ridge of ice. Water then pools behind the dam and works its way under the shingles — into the sheathing, walls and ceilings. Chipping ice and running heat cables every winter treats the symptom; keeping the deck cold stops it.
Spray foam air-seals the attic — top plates, penetrations, can lights — so warm air stays in the living space instead of warming the deck.
A well-insulated roofline or attic floor keeps the deck near outdoor temperature, so the snow on top doesn't melt in the first place.
No melt-refreeze cycle means no water backing up under the shingles into sheathing, walls and ceilings.
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Heat leaking into the attic warms the roof deck, which melts the snow on top. The meltwater runs down to the cold eaves and overhang, refreezes, and builds a dam of ice that backs water up under the shingles. It's an insulation-and-air-sealing problem more than a roofing problem.
By air-sealing and insulating the attic so heat stays in the living space and the roof deck stays cold. A cold deck means the snow doesn't melt and refreeze at the eaves — you break the cycle at its source instead of chipping ice every winter.
Heat cables and better flashing treat symptoms; they don't stop the melt. Keeping the deck cold with air-sealing and insulation addresses the actual cause. We'll tell you straight what your roof and attic need.
Montana, North Dakota, South Dakota and Wyoming, based out of Glendive, MT — hard-winter country where ice dams are common. Call 406-939-8301.
Get a free attic assessment — we'll find the heat leaks and give you straight numbers.
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