How Ice Dams Form and How to Prevent Them blog header image
February 10, 2023

Ice dams are one of the most common problems Vermont and New Hampshire homeowners have to deal with during the winter. Ice dams are bad for your home—they can cause a lot of damage, and once they form, it’s hard to get rid of them. 

The best way to protect your home against ice dam damage is to prevent ice dams from forming in the first place. Today, we’re going to talk about what causes ice dams and how you can stop them with attic insulation

What Is an Ice Dam? 

An ice dam is a ridge of ice that can form at the edge of your roof. They prevent melting snow from draining off your roof and away from your home properly. The resulting pools of dammed water can leak into your home, damaging insulation and other building materials, and leading to mold growth. 

Ice dams look like ridges of ice along your roof’s edge, but they’re not always easy to see. Icicles are much easier to notice and are often a symptom of ice dams. If you have a large number of icicles around the edge of your roof (not just on your gutters) you likely have an ice dam problem. 

What Causes Ice Dams? 

Ice dams are caused by a lack of proper attic insulation and air sealing. When your attic isn’t sealed and insulated properly, heat from inside your house will rise up into your attic. This warms up the underside of your roof and causes snow to melt unevenly. The melted snow will flow towards the edges of your roof, where surface temperatures are lower, and refreeze into an ice dam. 

The ice dam will continue to grow as melting snow is fed into it, but it won’t extend beyond the areas of your roof that are below freezing. The water that backs up behind the ice dam will then freeze. It will stay in liquid form and leak into your attic. It can then travel into your walls and ceilings, with the potential to cause extensive damage.

How to Prevent Ice Dams 

Ice dam prevention starts and ends with good attic insulation and air sealing. If you have some minor insulation damage like a compressed section or a gap in your attic insulation, insulation repair services can help you resolve the problem and prevent future ice dams from forming. If there is extensive damage to your attic insulation, or if you are missing a significant amount of insulation, insulation removal and a complete attic insulation replacement may be necessary. 

There are many benefits of preventing ice dams. By keeping ice dams off your roof, you will reduce the risk of water damage to your home and avoid the harmful mold growth water intrusion can cause. By insulating your attic more effectively, you’ll also be able to keep your house warmer in the winter using less heat, which can help you save money on your energy bills. 

The Best Insulation for Ice Dam Prevention 

Spray foam insulation is the best type of attic insulation for ice dam prevention here in New England. Spray foam acts as an insulator and an air sealant in one, allowing it to block heat transfer very effectively. 

Stop Ice Dams from Forming on Your Roof 

Vermont Foam Insulation is the premier spray foam insulation company in southern Vermont and southwestern New Hampshire. We can help you keep ice dams off your roof with an attic insulation upgrade. You’ll be amazed at the difference the right attic insulation will make in your home, and you’ll love working with our friendly, professional team. 

Worried about ice dams? VFI can help! Call 802-367-3113 or contact us to schedule a free site evaluation.

Protect your home against ice dams! 

Upgrade your attic insulation this winter. 

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