How Do Ice Dams Cause Water Damage Inside a Home?

An ice dam is a ridge of ice that builds up along the edge of your roof, usually at the eaves or gutters. It forms when snow on the upper part of the roof melts and then refreezes where the roof surface is colder, typically near the overhang. This cycle repeats, creating a barrier that traps water behind it.

The melting happens because warm air from inside your home escapes into the attic, heating the roof deck from below. The lower edge of the roof stays cold because it extends past the heated area. So, the snow melts above, but the refreezing happens lower down, creating the dam.

You may notice water stains on your ceiling that grow larger over time. Paint might bubble or peel, and drywall can feel soft or spongy when you press on it. In the attic, you might see frost on the underside of the roof deck or damp insulation with a musty smell.

Check for icicles hanging from the eaves, as they often accompany ice dams. Also look for ice buildup along the roof edge in winter. If you see these signs, act quickly to prevent further damage. Removing snow from the roof can help, but do so carefully to avoid injury.

If water has already entered your home, start by drying the area to limit mold growth. Use fans and dehumidifiers to pull moisture out of the air. Remove wet insulation if it is soaked, and cut away damaged drywall to allow the framing to dry. Do this only if the area is safe to access.

For significant damage, local water damage pros can help with thorough drying and repairs. They can inspect the extent of the water damage and handle tasks like ceiling repair, insulation replacement, and mold prevention. Policies vary, and your insurer decides what is covered, so check your policy to see what is included.