Why You Should Never Leave Snow on Your Roof


Not so fast! The stress of winter weather is not over just yet! Unfortunately, just because snowfall is less consistent doesn’t mean it’s done causing chaos. The often low temperatures cause snow to build up on your roof. This can cause significant damage and pose a large risk.

It was recently discovered by the Insurance Institute for Business & Home Safety (IBHS) that a large accumulation of snow on a roof can cause ice dams which can wreck your roof and your home as a whole.

You may be wondering how an ice dam forms, or more importantly what it is. To answer that question, you need to know the following information; Ice dams form in weather that is extremely cold. If there is a layer of snow on the roof while the weather is near freezing, ice dams are a risk. Naturally, when you heat your home, that temperature rises to your attic and reaches the roof. The snow on the roof melts slightly, and water begins to fall from under the snow and down the edge of the roof.  Remington Brown is a senior engineering director with IBHS. Brown explains how the lower edge of a roof is often the coldest because it reaches farther past the warm interior of the home. This results in the lower edge refreezing under the snow and forming a thin layer of ice.

This concept explains why when this process happens over and over, the once thin layer of ice begins to build up and an ice dam is eventually created. After a while, the ice dam expands to a maximum limit where it can only hold so much water on the roof. The water begins to pool at the top of your home and you may not even know it. The growth of the dam can expand to drastic measures. The strong force of that water on the roof can travel under the roof coverings. Parts of the roof like the shingle may send the water into the attic or worse, down the walls of the house.

To avoid this awful mess, it is recommended that you follow these 3 steps:

  1. When on the ground, use a snow rake. A snow rake with wheels will work best to remove snow from the roof. The wheels keep the blade of the rake over the roof cover to minimize scraping of materials that are not snow or ice. Be cautious by making sure you avoid any areas where power lines enter your home.
  2. If you do not feel comfortable completing this process yourself, it is always possible to hire a trained and licensed professional to remove the snow from your roof.
  3. Always use professionally installed, heating cables on your eaves, gutters, and downspouts. Even around roof drains that are found on flat roofs. Be sure that the heating cables are UL Listed, FM Approved, or CSA Certified. This is important because these cables won’t remove an ice dam, however, they can create effective channels that allow water to drain off not only easily, but safely.