Ice dams usually occur after a heavy snowfall and several days of freezing temperatures. Warm air inside your home leaks into the attic and will warm the underside of the roof causing snow and ice on the roof to melt. The melted water will drain along the roof, under the snow, until it reaches the cold overhang. The overhang tends to be at the same temperature as the outdoors and the melted water will refreeze and form an ice dam and icicles. The ice dam can cause damage to the roof, which will result in water leaks to the inside. Frequently the result will be a water spot on the ceiling under the roof damage.
- Don’t get on your roof to solve this problem, it could be dangerous.
- Avoid standing on the ground and “chipping away” at the ice. Not only could this cause damage to your roof, but you can be seriously injured by falling ice, debris, or tools.
- Contacting a roofing contractor to fix your roof leak will not prevent future ice dams.
- Seal air leaks (Home Sealing) and sealing duct air leaks in your attic to stop warm air leakage (the source of the problem).
- After sealing leaks, add additional insulation in your attic.
- Provide adequate attic ventilation so that the underside of the roof and outside air are at the same temperature. Check to make sure attic insulation is not blocking roof ventilation.
- Clean leaves and other debris from gutters before the first snow. This will help prevent ice build-up in gutters.
(This information is from Home Solutions by Energy Star)