Information and solutions for a safe, healthy,
comfortable, durable and energy efficient home

Ice Dams

It’s the first big snowfall of the season and you have knots in your stomach. You’re not alone! In Minnesota, this is the start of ice dam season. Some years ice dams are small and easy to ignore. But other times dangerous icicles form, water seeps through ceilings and walls, mold grows and structures are damaged. Then you might lay awake during a long winter night wondering what to do.

What’s the Problem?

Ice dams appear when heat from inside the home escapes through ceilings, walls, and other materials. It warms the roof and melts snow which then runs down to the colder eaves and freezes into ice. Over time the ice dam grows bigger forcing melted snow backwards up the roof, under roofing material, and into the house. Ice dams will often form dangerous icicles and add excess weight to the roof.

Solving the Problem

Any of these underlying issues may contribute to ice dam formation:

  • Poor attic insulation and/or ventilation
  • Air leaks around wires, pipes, recessed lights and wall/ceiling vents
  • Air leaks in attic doors, hatches or storage drawers in knee-walls
  • Warm exhaust from kitchen/bath fans and clothes dryers improperly vented into the attic
  • Uninsulated and/or leaky ductwork in the attic

The right time to prevent ice dams is when you don’t have them. If you start work on the solution anytime spring through early fall, you can make informed, unrushed decisions. The first step is to invest in home performance assessment (energy audit) by a Certified Energy Professional who will use diagnostic testing to find what’s causing your ice dams. Without this proper diagnosis you might spend time and money on the wrong solution.

The Energy Pro should do 3 assessments resulting in a prioritized solution plan:

  1. A thorough visual inspection inside and out – Indentifies the source of air leaks and insulation/ventilation problems. Provides visual aids for contractors.
  2. Infrared thermal imaging – Same as number 1.
  3. A blower door test – measures how leaky the home is overall

The cost for solving your ice dam problem will vary. The least expensive work may be done inside the attic when there is not a vaulted ceiling, flat roof or finished attic space. When those features are present, the challenges and expenses increase. Builders or remodelers may sometimes ignore ventilation problems in these more complex situations.

Another option is to air seal, insulate and ventilate from the outside. While more expensive, it can all be done without disruption to the inside of your home. This may be worth the investment if your problems are severe.

After the work is complete be sure to bring back the Energy Pro to assess the results and do a test for ‘combustion spillage’ that checks for toxic gases like carbon monoxide and other pollutants possibly coming from furnaces, water heaters, and fireplaces.

Next Steps

  1. Read Important First Step
  2. Find a Certified Energy Professional
  3. Hire a contractor to complete the work
  4. Hire the Energy Pro to retest at the end of the project
  5. Visit these sites to build your confidence and knowledge;

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