The first steps you should take:
Clear downspouts. An easy way to help snow and ice drain off your roof is to make sure the area around your downspouts is clear. This will make it possible for your gutters to drain when snow does melt. It will also help prevent flooding when the snow and ice melts.
Remove snow from your roof after every storm. Use a roof rake to clear the first three to four feet of snow from your roof immediately after each winter storm to prevent ice dams from forming. While the amount of snow and ice that your roof can handle may vary depending on a number of factors such as the roof type, age and condition of the structure, a good rule of thumb is if there is more than a foot of heavy, wet snow and ice on your roof, you should try to have it removed.
Ultimately, the best prevention for ice dams is to eliminate the conditions that make it possible for them to form in the first place.
Insulate your attic. Make sure your attic is well insulated to help prevent the melting-and-freezing cycle that causes ice dams to form. Check and seal places where warm air could leak from your house to the attic, including vent pipes, exhaust fans, chimneys, attic hatches and light fixtures.
Install a water-repellant membrane. When replacing a roof, make sure to install a water membrane underneath the shingles. This acts as an extra barrier that helps prevent water from seeping inside the building.
If all the above steps don't resolve the problem and leaks continue, then employing an electrician to install electrical heat tape on the first three feet of roof and inside the gutters will help melt the ice dams. As stated in other parts of this article, clearing a channel through the ice dam will allow the water to fold off the roof.
Roof snow removal:
Clearing the first three to four feet of snow from your roof immediately after each winter storm can help prevent ice dams from forming.
If you have a flat roof that is easily reached from an interior stairway, you may want to shovel the roof. When de-icing, remember to put safety first any time you are on a roof, especially one that is covered in snow and ice. If you have any doubt, leave it to the professionals.
If you have a sloped roof, it may be possible to remove the snow and ice using a roof rake, a long-handled tool designed specifically for this purpose. Stand on the ground and pull as much of the snow off the eaves as you can safely reach. It is not necessary to remove all the snow; removing the first three to four feet of snow closest to the gutters will help alleviate these issues.
If you cannot reach the roof, many homebuilders, landscaping and roofing contractors, and property maintenance companies will remove snow and ice from roofs. Before hiring a contractor, we encourage you to check references. Always be sure your contractor is insured and bonded.
We do not recommend using a ladder in snowy and icy conditions. This can be extremely dangerous and is best left to professionals.
Removing ice dams
Just because an ice dam is present does not necessarily mean water has penetrated the roof membrane. However, it is always best to remove ice dams before they have the opportunity to cause damage. To determine if you have damage, look for water stains or moisture in the attic or around the tops of exterior walls on the top floor.
If you can reach the roof safely, try to knock the ice dam off with a roof rake, or cut a channel through the ice to allow standing water to drain.
If you cannot reach the roof safely, consider hiring a contractor to remove it.
Another method is to fill a nylon stocking with calcium chloride ice melt and place it vertically across the ice dam so that it melts a channel through the dam. If you try this method, make sure you can safely position the ice melt on your roof, and make sure to use calcium chloride, not rock salt. Rock salt will damage your roof. Also be aware that shrubbery and plantings near the gutter or downspout may be damaged.
Look carefully at large icicles. If the icicles are confined to the gutters and there is no water trapped behind them, this does not indicate the presence of an ice dam. However, large icicles can pose a danger to people when they fall off. Try to safely knock the icicles off from the ground, making sure not to stand directly beneath them. If you cannot reach them safely from the ground, consider hiring a contractor to help.
Property owners are normally responsible for the cost of preventive maintenance. Keep in mind that the cost of snow removal is likely to be considerably less than the cost of roof damage or interior property damage caused by water leaks. Too many ice dam claims within a household will lead an insurance company to possibly non-renew coverage for the homeowner.
As always, be safe.