Skip to content

Ice Dam Season Is Approaching

November 01, 2011


ST. PAUL, MN – It is too early to predict the severity of ice dams this winter, but it is not too early to take action and prevent costly damage to your home. That is the message the Minnesota Department of Commerce is trying to get across in a consumer alert released today, providing homeowners the information and resources they need to prepare for the winter months ahead.

“With winter just around the corner, make no mistake: ice dam season is approaching,” said Commerce Commissioner Mike Rothman. “Minnesota homeowners should act now to make the necessary preparations to avoid thousands of dollars in possible damage to their homes. By sealing air attic leaks, consumers can not only prevent ice dams, but also save energy and save money on heating bills all winter.”

Many Minnesota consumers learned the hard way last season why it is important to take precautionary measures. Last winter saw a record number of problems caused by roof ice dams, including damaged shingles, sodden insulation, and ruined walls and ceilings. Although sometimes thought of as a problem with roofing or attic ventilation, ice dams are actually caused by the presence of warm, moist air in the attic, combined with snow on the roof and the right weather conditions. Last year’s abundance of snow contributed to ice dam problems—and made visible the underlying causes of ice dams.

Cause of Ice Dams 

Ice dams occur when heat leaks into the attic and melts the underside of the snow on the roof. The melted snow then flows down the roof surface until it reaches a cold spot (such as the eaves or soffit), where it forms a frozen dam, behind which more snowmelt and ice pile up. The ice buildup can back up under the shingles, damaging them and allowing water to leak to the ceilings and walls below.

To avoid these types of problems and eliminate most ice dams, attic air leaks around wires, plumbing vents, light fixtures, or chimneys must be sealed with caulking or spray foam, and attic insulation should be installed to a minimum R-50.

A first step in solving ice dams—and to making your home more energy efficient—is to have an advanced energy audit. The audit will use equipment such as infrared cameras to identify air leak locations and will suggest action steps to prevent ice dams. Advanced energy audits are provided by your gas or electric utility, members of the Minnesota Building Performance Association (www.mbpa.us), and nonprofit community energy groups such as the Neighborhood Energy Connection (thence.org), the Center for Energy and Environment (www.mncee.org), and the Duluth Energy Efficiency Program (duluthenergy.org). Once the problem areas are diagnosed, hire a licensed contractor to do the work needed.

 

What NOT to do in Addressing Ice Dams


•  Installing heating cables will shorten the life of your roof and cost you money to operate.

•  Removing ice with shovels, chippers, chemicals, or heat can damage shingles, gutters, and other 
    building components—and can be very dangerous. If it needs to be done, hire a licensed roofing
    contractor.

•  Adding roof vents—including powered vents—will not eliminate ice dams, and often exacerbates 
    the problem.

•  Additional insulation—especially on the top plate of exterior walls—can reduce heat transfer to the
    roof deck, but insulation alone is insufficient. Typical attic insulation will not stop air leaks or
    prevent ice dams.

For more information on ice dams from the Minnesota Department of Commerce, Division of Energy Resources, read our fact sheet “Ice Dam Solutions.” For more information on ways to conserve energy in your home, check out our “Home Envelope,” energy guide or visit www.energy.mn.gov.