Do this first
What to do right now
- Do not climb onto a snow-covered or iced roof. This is the single most dangerous DIY job on this list.
- Do not chop, hammer or axe the ice. You will destroy the shingles underneath and very likely still not stop the leak.
- Do not use rock salt or a propane torch on the roof, salt corrodes fasteners, flashing and gutters, and open flame near dry sheathing speaks for itself.
- Inside, protect the room below: buckets, floor tarp, furniture moved, and power off to any fixture near the water.
- If you can reach the lower roof safely from the ground, a roof rake with wheels can pull snow off the first three or four feet of eave and slow the dam down.
- Call for professional low-pressure steam removal, steam melts the ice without stripping the granules off the shingles.
How an ice dam actually forms
An ice dam is a heat-loss problem wearing a weather costume. Warm air escapes from the living space into the attic through recessed lights, bath fans vented into the attic, attic hatches, top plates and gaps around plumbing stacks. That warm air heats the underside of the roof deck. Snow sitting on the warm upper part of the roof melts, the water runs down to the eaves and the overhang, which is over open air, not over heated space, and therefore cold, and it refreezes there. Repeat that cycle for a few days and you get a ridge of ice several inches thick with a pond of standing water behind it. Shingles are designed to shed running water, not to hold back a pond, so the water works back up under the courses and into the house.
Why removal alone is only half the job
Steaming off the dam stops today's leak. If the attic still leaks heat, the dam comes back with the next storm. The durable fix is almost always some combination of air-sealing the ceiling plane, topping up insulation to a modern depth, and making sure the soffit vents are actually open, insulation stuffed into the eaves is the most common reason a "well-ventilated" attic in an older Pennsylvania home is not ventilated at all. Where the roof is being replaced anyway, ice-and-water membrane along the eaves is standard practice in this climate.
What this means for older houses
Pennsylvania has some of the oldest housing stock in the country. Houses built long before attic air-sealing was understood, knee walls, dormers, cathedral ceilings with no vent channel, additions with complicated rooflines, are dramatically more prone to ice dams than a simple modern gable. If your house has dormers or a finished attic, expect the diagnosis to be more involved than "add insulation".
Insurance and ice dams
Most Pennsylvania homeowners policies do cover sudden interior water damage caused by an ice dam, and many cover the cost of tearing out to reach the leak. They typically do not cover removing the ice itself, and they do not cover the insulation or ventilation upgrade. Document the damage and call your carrier before you start ripping out drywall.
