Ice dams in Central Pennsylvania: causes and fixes

Why ice dams form on Central PA homes and the lasting ways to stop them.

By Esteam Roofer | Updated October 17, 2026

An ice dam is a ridge of ice that forms at the lower edge of a roof and blocks meltwater from draining. The water backs up under shingles and can leak into the attic, ceilings and walls. Central Pennsylvania's cold nights and sunny days are ideal conditions for them.

How ice dams form

Heat from the house escapes into the attic and warms the roof deck. Snow on the upper roof melts, runs down and refreezes at the cold eaves, building a dam. More meltwater then pools behind it.

Warning signs

• • Large icicles along the eaves
• • Ice ridges at the roof edge
• • Water stains on ceilings near exterior walls
• • Peeling paint or wet insulation near the eaves
• • Frost on the underside of the roof deck in the attic

Short-term steps

Use a roof rake from the ground to remove snow near the eaves. Do not chip at ice with hammers or use salt on shingles, since both can damage the roof. If water is coming into the house, call a professional to safely remove the ice and, if needed, tarp the area.

Long-term fixes

1. 1. Air seal the attic floor. Seal gaps around light fixtures, wiring, chimneys and attic hatches so warm air stays in the living space.
2. 2. Add insulation. Adequate insulation reduces heat loss through the ceiling.
3. 3. Ventilate the roof. Balanced intake and exhaust ventilation keeps the roof deck cold.
4. 4. Install ice-and-water barrier. A self-adhering membrane at the eaves, in valleys and around penetrations protects the deck if water backs up.