As pretty as winter can be, snow and cold weather can cause a variety of problems for homeowners. One of those problems is ice dams. Understanding what ice dams are and how they work will help you prevent future ice damage to your home. An ice dam is a buildup of ice and water caused by snow on rooftops.
Ice dams develop when snow melts in the middle of a roof and refreezes at the edge.
The ice acts as a dam that prevents water from flowing off the roof. While ice dams can result from frozen or clogged gutters, dark shingles that absorb heat, or low roof pitch, they are most often caused by heat loss from the house. The roof above an unheated attic is cold during the winter months. Heat that escapes from interior rooms enters the attic and warms the outside surface of the roof, causing the snow to melt. Because the ice dam blocks the water from flowing off the roof, water eventually builds up and seeps under the shingles, where it can cause both interior and exterior damage to your home.