Snow acts like a layer of insulation on the roof above your attic. When snow melts above a warmed attic, water moves down to the cooler roof edge and soffit, and freezes. Unless this water is allowed to drain properly, the resulting freezing can create ice dams on your roof.
Ice dams can damage the walls, ceiling and insulation of your home, and in some cases even the contents of your home. As the ice dam spreads up the roof, water eventually works its way under shingles and enters the attic.
Once it enters the attic, it can damage the roof, ceilings, walls and contents of your home. If your ceiling insulation becomes wet, it loses its insulation value and can lead to a rise in the temperature of the attic, accelerating the growth of the ice dam.
Preventing ice dams
Proper ventilation and insulation of your attic can help keep the attic cool and may help avoid ice dams. Exhaust fans, ducts, chimneys, attic hatches and pipe penetrations can leak heat into your attic and contribute to the problem. Sealing around these areas may also help. It's always best to contact a reputable contractor in your area for assistance.
The following tips can help you to prevent ice dams from forming on your roof:
- In the fall, thoroughly clean all leaves and debris from your home’s gutters and downspouts. This will allow melting snow to flow as intended.
- Throughout the winter, keep the snow load on your roof to a minimum. Keeping snow off your roof helps reduce the chance of your roof collapsing due to an excessive snow load.
- Keep gutters and downspouts free of snow, ice buildup and icicles. This will allow a ready path for melted snow on your roof to drain, eliminating the potential for ice dam formation. This will also reduce the weight of ice and snow on the gutters and downspouts. Excessive weight can cause gutters and downspouts to pull away from the house or become damaged.