An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow (water) from draining off the roof. The water that backs up behind the dam can leak into a home and cause damage to walls, ceilings, insulation and other areas.

What is an ice dam How do they form and what to do about them?

Ice dams and icicles form when the snow melts, runs down your roof and refreezes near the edge. This only occurs when part of your roof warms to above 32 degrees F, warm enough to melt the snow, while the roof edge remains below freezing. This scenario is often the result of a warm attic.

What causes ice dams in gutters?

An ice dam forms when the roof over the attic gets warm enough to melt the underside of the layer of snow on the roof. … Gutters at the eaves can also trap snow and ice. If snow and ice build up high enough in the gutter, it can provide a foundation for an ice dam.