Is the Removal of Ice Dams on the Roof Necessary?

Causes

• Ice dams occur when the air temperature is at or below freezing, there is snow present on a roof, and differing temperatures exist on the same roof surface. Warm air that escapes through the highest points of a roof's peaks, melts the snow towards the top of the roof. The water then runs down the roof's pitch and re-freezes as it encounters both the colder air and the colder lower surface of the roof. This causes an impediment to any water trying to run off and, as a result, the dam continues to grow as this process continues.

Potential Damage

• Ice dams that remain unchecked and continue to grow can cause significant gutter, roof and potential ceiling damage to homes and structures. The weight of the ice can cause the collapse of roof edges and eaves. The snow and ice that continue to melt behind the dam can leak through a roof and onto ceilings below. Mold and mildew can develop and build up as a result of leaks and continue to pose a health risk throughout the year.

How to Remove Ice Dams

• Once ice dams have formed, an assessment as to their severity should be made to determine countermeasures. If temperatures are to continue to rise, you may not need to. If they do need to be removed, it should be done carefully. Any snow that still remains on the roof should be removed in such a way so that further ice damming is prevented. Channels should be cut into the ice dams to allow melting water to have a path to escape. This can be done by chipping, but is more easily accomplished with a stream of water from a hose.

Prevention

• Proper ventilation and adequate insulation are the best measures for thwarting the development of ice dams. Soffit and ridge ventilation that runs along the entire span of the roof can be a way to naturally counter many conditions that favor the development of ice dams. They help keep the surface of the roof cool so that the initial melt does not take place. Sufficient roof insulation at least 12 inches in depth, with an R-value of 38, is also highly effective in the prevention of ice buildup on roofs.