Preventing Ice Dams: What Can You Do?

ice-dams roof with snow and ice

Preventing ice dams is an important job — it could mean saving thousands of dollars on home repairs and extending the life of your roof.


What can you do to make sure your home stays dry this winter and isn’t plagued by ice dams and water damage?

What Is an Ice Dam?

An ice dam forms when melted snow refreezes at the edge of a home’s roof. The snowmelt runs down the roof and freezes into a dam of ice that prevents any more water from running off the roof.

As snow continues to melt, more water backs up and freezes when it runs into the dam, creating long icicles that hang down from the roof’s edge. Eventually, the melting snow backs up into the attic and the home, causing water damage.

Why Does This Happen?

All ice dams need to form are freezing temperatures outside and warm air in an attic. The warm air in the attic heats the underside of the roof and causes the snow to melt. The subzero conditions outside cause the water to freeze before it has a chance to make its way through the gutters.

What’s the Damage?

If this process continues unchecked, the water that is pushed back underneath the shingles eventually seeps through the roof deck and wets attic insulation. This can lead to mold growth and decay. If water leaks into the ceiling of the home’s living spaces, it can cause the plaster to stain and crumble.

What You Can Do

The only way to prevent ice dams is to remove one of the two conditions that contribute to their formation. Since you can’t change the outdoor temperatures, you must address the temperature of your attic. A cold attic means that snow won’t melt and ice dams will be avoided.

Here are two ways you can lower the temperature of your attic:

  1. Add Attic Vents: Every roof needs adequate ventilation. This allows any warm air from your home to quickly meet cold air and exit the attic space. Have a qualified roofer examine your attic to see if your ventilation design is correct. If not, adding soffit or side vents is an effective solution.
  2. Add Attic Insulation: You can also add insulation to the attic floor, especially around light fixtures and other vents. Make sure that the ways for warm air to leak into the attic are limited.

Contact the Roof Doctor for more information about preventing ice dams, and get a free roof repair estimate today.

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