Icicle dripping off a roof

3 Ways to Prevent Ice Dams

If you think ice dams are an annoying and destructive fact of life in winter, we have news! Roof damage can be prevented. The destructiveness of ice dams comes from the fact that they trap the snow and melted ice, preventing it from draining off your roof promptly. This delay allows the water to soak into your roof and get into your home, causing interior damage.

Damage from ice dams can include wood rot, structural problems, and unhealthy mold growth. Snowmelt can also ruin insulation, your home's siding, drywall and more. Unfortunately, you may not notice the leaks and water absorbed by your home, until serious damage has already been done. To keep your house from forming ice dams this winter, below are the most effective tactics.

Where to Look for Ice Dams

Ice dams tend to form in or on:

  • Roof valleys
  • Nearly flat, low-angle roof designs
  • Around your skylights or fireplace chimney
  • Eaves of the roof (where ice dams form)

How Ice Dams Form on Your Roof

As snow melts on your roof, the water/runoff flows to the edge or to the roof's low points. Near the roof edge (the eaves) your roof is colder, so the meltwater re-freezes. Over time, a “dam” builds up, blocking water drainage. The backed-up, pooled water then sinks into the roofing and damages your home. If your roof could stay the same temperature as the outdoor air, you wouldn't have ice dams.

Ice Dam Prevention Tips

To keep ice dams from occurring on your roof this winter, try:

1. Using a snow rake (also called a roof rake) to clear away snow accumulation on your roof. This, and our other ice dam avoidance tips, also helps keep gutters from filling with water, then with ice, which can break off and cause exterior roof damage.

2. Applying heat tape along the edges of your roof. This sounds like an elegant solution, but you can’t just set it and forget it with heat tape. Also called heat cables or ice cables, heat tape requires precautions, monitoring and professional installation for safety. Heat tape helps keep ice, and ice dams, from forming on the roof of your home, but won't eliminate them entirely. The tape creates channels to allow drainage of meltwater to lessen ice buildup. Heat tape may be simpler than making your home more energy efficient (the tip below), but tape can increase your electricity bills. They don't look so great in your home, either.

3. Keeping your roof cool with energy efficient home improvements. In winter, your home’s warm interior can warm up your roof surface. This is especially common if the house lacks enough insulation or air vents. (Beyond causing ice dams, lack of attic vents and insulation also wastes energy and sends your utility bills literally through the roof. It can even ruin your indoor air quality.) Ice dams won’t form if the roof is the same temperature as the outdoors. To achieve this, you may need to better seal your home's envelope or achieve balanced airflow to prevent home heating from warming the roof. Consider having a professional home inspection to locate household areas that could be affecting energy efficiency and causing ice dams on the roof.

The Simplest Ice Dam Prevention Method

Avoid the risks of climbing onto the slippery roof and doing heavy exercise in mid-winter to prevent ice dams. Your shoulders may thank you if you take this advice -- Request service from the Mr. Handyman near you online or call (877) 256-3376 to get expert help preventing ice dams at your home or business.