Here in New England, ice dams are a common and unfortunate problem that plagues homeowners during the winter months. They can cause a lot of damage to roofs, and even lead to severe leaks and interior damage.

What is an ice dam?

Ice dams are an ice formation that occurs around the edge of the roof and blocks water from running off. Ice dams and icicles form when the snow melts, runs to the edge of the roof, and refreezes near the edge. Although usually the indicator of a warm attic, this typically occurs when part of the roof warms enough to melt the snow but the roof edge remains below freezing.

The heat inside the house escapes through the ceiling into the attic. It warms the wood and shingles directly above it and the snow melts over that section of the roof. When the melted snow (now water) runs down the roof, it hits the cold edge not warmed by the attic where it freezes. As the snow melts and the water runs down the roof, this accumulation of frozen water can grow, leading to a large ice dam.

What kind of damage can ice dams cause?

Ice dams are extremely heavy. They can tear off gutters and pose a serious safety risk to people and pets walking beneath them. The melting and freezing water can loosen shingles on the roof causing significant damage. Ice dams can also cause water to back up and pour into your house. The damage from a leak can be devastating - peeling paint, warped floors, stained and sagging ceilings, and soggy insulation which becomes a magnet for mold and mildew.

How to prevent ice dams

There are a few ways to prevent ice dams from forming. The easiest way is to rake the lower 3 to 4 feet of your roof after it snows. Lightweight roof rakes usually cost less than $30 at many home improvement stores. Raking immediately after snow when the snow is still soft will help reduce ice buildup. Remember to be gentle - you don’t want to pull off shingles!

Adding insulation to the attic can also help. Since the idea is to stop the transfer of heat through the roof, an extra 8 to 10-inch layer of attic insulation will not only help prevent heat transfer, it will also help keep heat inside the house, which could help reduce winter heating costs.

If you already have ice dams, there are a couple of things you can do. Calcium chloride is used for melting ice on driveways and sidewalks, but it can also be used for melting ice dams. Fill long socks or the legs of pantyhose with calcium chloride and then tie off the ends. Position the tube vertically over the dam with the sock’s end hanging an inch or two over the roof edge. It will melt a tube-like channel through the ice dam, which will allow additional water that melts to run safely off the roof.

You can also try removing the ice dam by breaking it into smaller chunks. Although it is tempting to use a sharp tool, use a blunt mallet and tap gently. This will ensure that you don’t damage your shingles. Breaking up an ice dam is slow, dangerous work, so you may consider hiring someone experienced at roofing.

Zammito Insurance is always available to answer your questions regarding home insurance as well as auto, business, and renter's insurance. Give us a call at (781) 762-6732 to find out more.