An ice dam, or wall of ice along a roof’s edge, is created by melted snow that has refrozen. The process continues as water and melting snow cannot drain, creating hazards for anyone walking below and possibly causing water to be forced under the shingles and eventually into your home. Your insulation, walls, and ceilings can sustain serious damage.
Believe it or not, there are causes of ice dams that originate in your home. Heat can be generated by roof overhangs, tree coverage, improper or insufficient insulation, a poorly ventilated attic, or how your roof faces the sun. Mother Nature isn’t the only culprit. But even too much snow on the roof can trigger melting that leads to ice dams, as can a mild winter day.
To prevent ice dams, you can follow these steps in winterizing your roof:
- Clean the gutters before the winter season starts. This opens a clear path for water and debris to escape rather than create a substrate for snow and ice to build up on.
- Improve roof and attic ventilation. The colder the attic is, the less likely heat will build up in the attic space and rafters.
- Insulate your attic so heat does not escape through the roof, create ice dams, and waste your energy and increase your heating bills.
Removing heat sources such as uninsulated recessed ceiling can lights or folding attic stair openings can prevent ice dams. Properly selecting, installing, and placing bathroom vent fans can avoid problems as well. Ice dams can also be prevented by placing heating ducts where warmer air can’t reach the roof as easily.
A couple of home improvement tasks can combat the problem too. Installing a water-repellant roof membrane can help protect your home. An air barrier between the attic and the rest of the house can also help. This can be achieved with a whole-house fan opening or a foil-faced cover placed over an uninsulated attic hatch.
When Winter Weather Sets In
If you haven’t taken preventative measures, or a winter storm drops an excessive amount of snow, use a roof rake to remove it before it melts and refreezes. This avoids having to go up on the roof. A flat shovel attached to a long pole, a rake works best when snow is fresh and fluffy. Don’t wait until the snow freezes, when it is harder and more solid. Remove as much snow as you can; raking even a few feet of snow off the edge can do the job.
Removing an Ice Dam
Removing ice dams is extremely dangerous. Your best bet is to call a professional roofer who has the experience, tools, and equipment to safely free your roof of ice. But if at all possible, you can try:
- Applying calcium chloride or other ice-melting product directly to the ice.
- Spraying warm water onto the ice, which works best on isolated problem spots.
- Chipping away at the ice with an ice pick or rubber mallet; creating a channel for drainage rather than breaking the entire ice dam apart.
One novel approach is to fill nylon stockings with a chemical deicer, tying the open end, and placing them several feet apart on the roof, perpendicular to the edge, to create channels for the ice to melt. However, this method is only a short-term solution.