Understanding what an ice dam is, and taking the necessary precautions to prevent one from forming, is an important part of preparing your home for winter weather. Knowing how to remove an ice dam, or better yet prevent one, is a crucial step in protecting your roof and home from potential damage during the winter months.
What Is an Ice Dam?
Ice dams may form when water from melting snow freezes into ice at the edge of your roofline. Without proper roof snow removal, the ice that develops may grow large enough to prevent water from properly draining off the roof. When water is unable to drain from the roof, it often backs up underneath shingles and flashing and makes its way into your home.
Preventing Ice Dams
An ice dam may develop 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 access points 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.
- 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.
- Clear gutters and downspouts. Prevent water from accumulating and possibly freezing in your gutters by cleaning leaves, debris and snow accumulation 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.
- Remove snow accumulation from your roof. 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.
- Remove ice dams as soon as you spot them. Check your roof often and know how to help identify and remove an ice dam.
How to Identify an Ice Dam
Most ice dams develop on the edge of your roof, but they may also form in other locations, depending on the slope, orientation and style of your roof. Be sure to monitor the weather and your roof for signs of ice dam formations.
- Look closely at the icicles around the exterior of your house. If the icicles are confined to the gutters and there is no water trapped behind them, then an ice dam has likely not formed. Nevertheless, icicles can be a precursor to ice dams. Depending on their location and size, icicles may also pose a danger if they fall off. Whenever possible, and if safe to do so, remove icicles from the exterior of your home, making sure not to stand directly beneath them. If you cannot safely reach the icicles from the ground, consider hiring a contractor to assist in their removal.
- Check for water stains or moisture in your attic or along the ceiling or exterior walls of your house. Water stains or moisture may be an indication that an ice dam has formed and water has penetrated the roof membrane.
How to Remove an Ice Dam
Removing an ice dam from your roof immediately after spotting the signs can be critical to helping prevent damage to your home. One way to remove an ice dam is to melt it using calcium chloride ice melt.
- Using a roof rake, remove snow 3–4 feet from the edge of your roof, being careful not to damage the roof covering. Be sure the snow you remove from the roof is not blocking walkways or exits.
- Use a calcium chloride ice melt product, which you can generally purchase from your local hardware store. Be sure not to use rock salt or sodium chloride, which can damage your roof.
- Fill a nylon stocking with the calcium chloride ice melt.
- Safely place and position the calcium chloride-filled nylon stocking vertically across the ice dam so that it can melt a channel through the ice.
- Cover and protect any shrubbery and plants with lightweight tarps near the gutters or downspouts for the duration that the calcium chloride stockings remain in place. This is important because the calcium chloride-saturated water dripping from the roof may damage the shrubbery and plants.
If you have any questions regarding ice dams or would like to speak to a member of our staff, contact us today.