Ice dams form when heat from the house melts snow on the roof, and the water refreezes at the cold eaves. The ridge of ice holds back water that can back up under shingles and leak into walls and ceilings. Big icicles and thick ice along the gutters are the warning signs.
How ice dams are usually removed
Many professional crews use low-pressure steam to cut channels through the ice and remove it in sections. Steam is gentler on shingles than chipping with hammers or using high-pressure water. Ask the crew what equipment they use.
What not to do
- Don't chip at ice dams with an axe or hammer. It can easily damage shingles and gutters.
- Don't climb a ladder onto an icy roof.
- Be careful with salt products, which can harm plants, metal and some roofing.
Preventing them next year
Ice dams are often a sign of heat escaping into the attic. An insulation or ventilation contractor can look at the cause once the season is over.
Typical cost
Ice dam removal is often billed by the hour with a minimum. Typical estimates run about $400 to $1,200 for many homes; large dams cost more. See the full cost guide.
Common questions
Why steam and not a pressure washer?
Low-pressure steam melts through ice without blasting the shingles. High-pressure water can damage the roof and force water underneath.
My ceiling is already leaking. What should I do?
Put containers under the drips, move belongings away, and send a request marked urgent with photos. Call your insurer if there's damage.
How long does ice dam removal take?
Anywhere from an hour or two to most of a day, depending on how much ice there is and how many eaves are affected.