How to Prevent Ice Dams in the Winter


"Look at those pretty icicles lining the roof."  You might think differently of those sparkling pieces of ice dangling from your roof when you learn what harm they can inflict on your home. Icicles are often a sign of an ice dam problem, but don’t panic just yet. This is a pretty common issue that many homeowners must deal with at some point, and several measures can be taken to get rid of existing ice dams and prevent new ones from forming. If you don’t deal with an ice dam problem promptly, however, you could end up having to pay for some serious damage.


Why Ice Dams Form

Ice dams can form when temperatures across the surface of the roof vary. Warmer patches can result when an attic is inadequately insulated and/or ventilated. When warm air rises to the ceiling inside a home, it either stays inside or escapes into the attic and out through the roof. As the air rises to the top of the attic, it produces warm patches on certain parts of the roof, which can melt the snow and ice in that area.

When the snow melts, water runs down the roof towards the edge, where it often refreezes at the eaves before it's able to run off the roof and onto the ground. This is when icicles form. When more and more ice builds up, thick, heavy ridges (dams) form. Water that pools behind the dams can then seep into your home and cause mold, rot, and water damage. Sometimes ice fills gutters in the winter, and when the weight is great enough, the gutters can break apart from the roof.


How to Combat Ice Dams

Seal Air Leaks

You want to keep your attic and roof cool during the winter. Do this by sealing any air leaks in your attic to keep the warm air below where it belongs. Check your attic floor and around any ductwork, pipes, vents, doors, windows, and lights to make sure no air is sneaking through these areas. The goal is to keep your roof colder than 30 degrees Fahrenheit during the winter so the snow doesn’t melt when the outdoor temperature is below freezing. This will prevent melting and refreezing across your roof that produces ice dams.

Adequate Insulation

Once you’ve sealed any air leaks, check the insulation in your attic to make sure it’s thick enough and still in good shape. The space between the roof rafters and the attic floor should be well insulated. 

Sufficient Ventilation

To keep the temperature across your roof cool and even, you should have a good roof ventilation system in place. It will circulate the air under the roof, blowing in cool air and pushing out warm, humid air. Make sure all vents throughout the home (like those in the kitchen, bathroom, and connected to your drier) vent to the outdoors, not to the attic.


Ice Dam Prevention in Polk County

Do you live in Ankeny, Ames, Huxley, or Des Moines? If you have an ice dam problem, give us a call! We can help you find the source of your problem and take measures to prevent it from recurring in the future. Ice dams can wreak havoc on the home, damaging the roof, siding, and even the interior of your home through water damage. Let us know how we can help!