An ice dam is a ridge of ice that forms along the edge of a roof, preventing melting snow from properly draining off the roof surface. This condition is most common in cold climates with heavy snowfall.
Ice dams typically form when heat escapes from the attic, warming the roof surface and causing snow to melt. As the water flows down toward the colder roof edge, it refreezes, gradually forming a blockage.
Once an ice dam forms, water can back up behind it and seep under shingles, leading to leaks, interior damage, and mold growth.
Preventing ice dams involves improving attic insulation, ensuring proper ventilation, and sealing air leaks that allow heat escape. Roof design and ventilation systems play a critical role in reducing risk.
Removal must be handled carefully to avoid damaging roofing materials. Professional steam removal or controlled melting methods are commonly used.
