How to Help Prevent Ice Dams

Taking precautions to prevent ice dams is an important part of preparing your home for winter weather. Knowing what an ice dam is, minimizing the conditions that allow one to form and removing an ice dam as soon as you spot one can help prevent serious damage to both the roof and the inside of your home.

Take Action Before Snow Starts Falling

An ice dam may develop during the cold winter months if warm air from your home or attic melts snow on your roof. In freezing temperatures, the melted snow may refreeze once it reaches the colder edge of the roof. Keeping the temperature of your attic at 32°F or below can help prevent snow from melting and ice dams from developing. The following are some steps you can take to help prevent the snow melting-and-freezing cycle that often causes ice dams:

  • Insulate your attic. Be sure your attic is properly insulated to help prevent warmth from escaping through ceilings. Whenever possible, an insulation value of R-40 is recommended.
  • Prevent air leaks. Check and seal any openings where warm air or heat could escape into the attic, such as insulating or caulking around vent pipes, exhaust fans, chimneys, attic hatches and/or light fixtures.
  • Improve ventilation. Increase the number or size of attic, roof or soffit vents that allow cold air to circulate and flush warmer air out during the winter.

  • Install a water-repellent membrane. When replacing the roof covering, install a water-repellent membrane underneath the shingles. This acts as an extra barrier
    that helps prevent water from seeping inside the building should an ice dam form.

Tips to Help Prevent Ice Dams Through the Winter

Ice dams can sometimes form despite your best efforts to keep your roof at the proper temperature. Be sure to monitor the weather and maintain your roof throughout the colder, winter months for additional protection against ice dams, such as:

  • Clear gutters and downspouts. Prevent water from accumulating and possibly freezing in your gutters by cleaning leaves, debris and snow accumulation from in and around gutters and downspouts. Making sure that your gutters are properly pitched can also help prevent the collection of water in low spots and help reduce the potential for ice buildup in gutters.
  • Remove snow accumulation from your roof after every storm. Whenever possible, use a roof rake to clear snow about three to four feet from the edge of your roof soon after each storm. Snow accumulation along the edge of your roof increases the likelihood of an ice dam developing, which prevents water from draining off the roof. This water can then back up underneath roof shingles and make its way into your home.
  • Remove ice dams as soon as you spot them. Check your roof often and know how to help identify and remove an ice dam.

CAUTION: Avoid using a ladder in snowy and icy conditions. This can be extremely dangerous and is best left to the professionals.