Allowing ice dams to form on your roof can lead to major structural damage. Learn the signs of ice dams and steps to help prevent this winter hazard.
Ice Dams vs. Icicles
Icicles form when dripping water freezes. They are often found on gutters and eaves of buildings. Ice dams, on the other hand, form on building roofs, usually near the edge. You can have icicles without ice dams and ice dams without icicles. But as Michigan’s MIREADY program warns, significant icicles on your gutter or eaves could indicate the presence of an ice dam.
Both icicles and ice dams can damage your roof, but ice dams are especially dangerous. Ice dams form when snow melts and then refreezes on your roof. The melted water can find its way under the shingles before it freezes again – and water expands when it freezes. Plus, ice dams trap water on your roof, causing it to pool. For these reasons, ice dams can lead to roof leaks, mold and rot.
Insulation and ventilation are key
Ice ponds cannot form unless the snow melts and then refreezes. Proper insulation and ventilation can prevent this cycle. While a warm roof may sound perfect, it’s actually a problem because the outside air is still cold. In fact, different temperatures are what cause the cycle of melting and refreezing. By keeping your roof cool, you can help prevent snow from melting.
According to a guide from Wisconsin’s Focus on Energy program, the best way to prevent ice dams is to improve attic insulation. Places like attic hatches, heating ducts, and ventilation stacks act as attic bypasses, allowing warm air from the rest of your home or building to enter the attic. You may not be able to identify problem areas on your own, but professionals have equipment to help you locate and seal these leaks. The easiest time to fix air leaks is during the initial construction of the building, but you can also deal with this problem when you repair or replace your roof.
Your roof’s R-value indicates its level of insulation, with a higher value meaning better insulation. The National Weather Service says experts typically recommend at least R-30, although a value of at least R-38 is preferable in northern climates. It is also important to have good air flow under the eaves and through the roof vents.
Proper maintenance can help
Proper maintenance can also help prevent ice dams.
The National Weather Service says to clear leaves and other debris from your gutters and downspouts. Throughout the winter, you should also keep gutters and downspouts free of snow, icicles and debris. This allows melting snow to drain properly, preventing it from accumulating on your roof and then refreezing.
The National Weather Service also recommends keeping the snow on your roof to a minimum. It may be possible to use a long-handled roof rake to remove snow from the roof while you remain on the ground—as long as you are careful and aware of potential hazards.
While removing snow from ground level is safe when using the proper tools and techniques, removing ice can be dangerous. When icicles and ice dams break off, they can cause damage and injure anyone in their path. For this reason, you should only use professional ice removal services.
Watch out for warning signs
Once you know what to look for, you can spot ice dams and take steps to mitigate the damage.
- Watch out for icicles. Icicles and ice dams often occur together.
- Compare your roof with your neighbor’s. If your neighbor’s roof is still covered in snow, but the snow has mostly melted on yours and icicles have formed, your roof may lack the insulation it needs to prevent ice dams.
- Look for signs of water damage. Since ice dams often cause leaks, be on the lookout for signs of water damage. This can include water stains, mold or mildew on the roof and walls of your house. Damage to the paint on your home’s siding can also be an indication of water damage.
Property insurance often includes coverage for damage from ice dams. If you have questions about your insurance needs, contact BNC.