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Ice dams

An ice dam is a ridge of ice at the roof edge that traps meltwater behind it. The water backs up under the shingles and shows up as stains on ceilings and outside walls.

By the Wolfpack Home Services editorial team · Reviewed · How we research

How urgent is it? It is urgent when water is entering the house; the ice alone can usually wait for safe removal.

Do this now

  1. Stay off the roof and off ladders on icy ground — falls cause more harm than the ice dam.
  2. From the ground, use a long-handled roof rake to pull snow off the lowest few feet of roof.
  3. Indoors, catch drips, move belongings, and poke a small hole in a bulging ceiling to drain it into a bucket in a controlled way.
  4. Do not chip at the ice with an axe or hammer, and do not use rock salt — both damage shingles and gutters.
  5. If water is coming in, call a roofer who removes ice dams with low-pressure steam.

What usually causes it

  • Heat escaping into the attic and warming the roof deck
  • Too little attic insulation, or insulation with gaps
  • Poor attic ventilation
  • Bathroom or dryer vents that discharge into the attic instead of outdoors
  • Clogged gutters that hold ice at the eave

What a professional will do

For an active leak, a roofer removes the dam with steam, which melts ice without damaging shingles. The permanent fix is in the attic: sealing air leaks, adding insulation, and restoring ventilation so the roof stays cold. At the next re-roof, ice-and-water membrane along the eaves adds a second line of defense.

How to prevent it

  • Air seal the attic floor and bring insulation up to current recommendations
  • Keep soffit and ridge vents open
  • Make sure bath and dryer vents exhaust outdoors
  • Clean gutters in late fall

Rules and paperwork in Pennsylvania

  • Pennsylvania’s Home Improvement Consumer Protection Act requires most contractors who perform home improvements to register with the Attorney General’s office and to give you a written contract for any job over $500. The registration number belongs on the estimate and the contract — ask for it.
  • Pennsylvania does not issue a statewide license for this trade. Some municipalities register or license it locally, which is one reason to confirm requirements with your own municipality.

Sources: Pennsylvania Office of Attorney General — Home Improvement Consumer Protection Act; Pennsylvania Department of Labor & Industry. Rules change — confirm current requirements with the agency and with your municipality.

Frequently asked questions

Are heat cables a good fix?

They can open drainage channels on a problem eave, but they treat the symptom and use electricity all winter. Air sealing and insulation address the cause.

Do gutters cause ice dams?

No — heat loss through the roof does. Clogged gutters can make them worse by holding ice at the edge.

Is ice dam damage covered by insurance?

Interior water damage from an ice dam is often covered; removing the ice and fixing the underlying cause generally is not. Check your policy.

Go deeper

Our full roofing guide covers how the work is done, what affects the price, and what to ask before you hire, and there is more on roof repair.

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Related problems

This guide is general information, not a substitute for a professional assessing your home. If you are unsure whether something is safe, treat it as if it is not.