Ice Dams, Cause, Prevention, and Repair in Idaho, Washington, Montana and Oregon

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Ice Dams, Cause, Prevention, and Repair

When we bought out our split-entry home, it was before natural gas was available in our neighborhood, so we invested in a new 1980’s heating technology, a wood pellet stove, because we could run a vent out of the side of our house and not all the way up through the roof.
Everything was wonderful….until it got cold, and snowy.

At first, we didn’t worry. Above the vent began to grow icicles, until January, when the inside of our bathroom ceiling began to show water damage, the ice dam above the vent was growing, and growing…

How ice dams form.

Ice dams form on houses with poor insulation or from a heat source that causes a warm spot on the roof. A heated attic area, such as an improperly sealed vent, or insufficient insulation, can cause snow and ice to melt. As the meltwater trickles down to the colder areas of the roof, it freezes, forming an ice dam. More meltwater becomes trapped behind the ice dam. And having nowhere else to go, it runs under the shingles and into the house.

Two construction factors that add to the risk.

A low pitched roof, always look for a roof that is pitched at least (although as an old math teacher, I want to call it )..

Small eaves, your overhang needs to be at least 12 inches. In order for an ice dam to cause internal damage, meltwater level must reach the shingles to leak into your home.

Hot homes promote ice dams

Keeping your home warmer, may mean a worse ice dam. If your home is prone to ice dams, you should consider lowering the thermostat during ice dam season. Remember, if you heat with wood, it is easier to overheat your house.

Water travels sideways

Once the level of the meltwater reaches the shingle level it often travels horizontally. That water spot on your ceiling doesn’t mean the roof is leaking directly above, often the water travels sideways.

Prevention is the best

If you know that your roof has warm areas, the time to repair is now.The solutions are not always easy, but essential.

But my insurance covers this

The operative phrase in this case is “sudden and accidental”. Some insurance companies will pay the repairs the first time (minus the deductible). After that, this becomes a known problem, and if the underlying problem is not corrected, the claim will certainly be denied.

Chopping is a risky solution

Jan and I were in our late 20’s, and of course, knowing that we were invincible, we climbed a ladder with ice melt and a hatchet and got the dam to drain before any serious problems.Looking back, we see how foolish that was. This is a job for a professional with a steam gun.
As always, if you have any questions, please contact us at 208-762-2122, or email us at