My Roof Is Leaking Snow

Ice Dam Formation

• An ice dam can form on the portion of a pitched roof that hangs over the house's side. That portion is called the eaves. When a house’s roof becomes covered in snow and the snow melts and then freezes repeatedly as temperatures change, the result can be a ridge or dam of ice. The part of the roof that sits directly above the house’s attic becomes warmer as the warm air inside the house enters the attic, causing the snow on the roof to melt. Melting snow usually slides down a roof, and the water it produces runs into rain gutters and away from the house harmlessly. An ice dam, however, blocks melting snow above it on the roof, preventing it from draining off the roof.

Water Damage

• The trapped water that sits above an ice dam does not flow down the roof, and instead it goes under the roof’s shingles. As the water makes its way under the shingles, it can penetrate the roof and leak into the attic. Water leaks can soak and ruin drywall ceilings, warp or soften attic rafters and lead to mold growth when temperatures warm. Eliminating the source of the water penetration into the attic and reversing the damage caused by the leaking water are essential.

Temporary Removal

• If you have access to a roof rake, you can use it to remove the snow from your house’s roof, which also removes the source of the water. Climbing onto the roof to shovel off the snow works, but it involves more danger than using a roof rake because the roof is icy. Cooling the house’s attic helps to keep snow on the roof from melting, which stop the leak. You can lower the temperature in the attic by running box fans near the gable vents, drawing in cold, outside air. Chipping away at the ice dam on the roof is an option, but the tools you use for the task can damage the shingles and lead to more leaks.

Long-Term Solutions

• Roofing companies can install heat coils on a roof over the gables, warming up the roof and keeping ice dams from forming. Insulating the attic helps not only to prevent heat loss in your house and lower energy bills but also helps to keep the attic colder in winter so snow of the roof does not melt when snow over the eaves does not melt. Roofing companies also can install a watertight membrane under the roof’s shingles, creating a barrier against water penetration.