As we head into freeze-thaw season in Ontario, the risk of ice damming increases. As a property owner, you should do whatever you can to protect your building from experiencing ice damming, because the consequences can be very costly for you. We spoke with our friends at Paul Davis Restoration to bring you a few tips and tricks to avoid ice damming in your home.
What is an Ice Dam?
An Ice Dam is an accumulation of ice that forms at the roofline of a building during the winter months. It occurs when you have poor insulation under your roof. As the heat from inside your house rises, and the head from the sun becomes more intense and frequent, the snow and ice on your roof melt. But because the temperature does still dip below freezing (typically at night), an ice layer builds up at the roofline and blocks the eaves trough (meaning the melting snow has nowhere to go). Since the water is trapped, it can work its way under your roof materials and get into the attic of your home.
You can usually recognize the development of an Ice Dam once icicles begin to form and are hanging from the roof or eaves edge. This is a sign that the heat is melting the snow and the water isn't being evacuated properly by the eaves troughs.
Why is Ice Damming a problem?
Since an ice dam prevents melting snow from draining through the eavestrough and the downspouts, water from melting snow becomes trapped behind the ice and creates a pool of water. Essentially, it acts like the dams in rivers that we're familiar with. A pool of water can then back up under the shingles which are designed for water to run down a roof slope not up a roof slope.
If the pool of water extends past the ice and water shield (usually around 3’), the water will start to drip under the shingles and into the attic. The water then finds its way into your home through existing gaps or down an exterior wall. This will result in interior water damage at the edge of the wall, window or light fixture.
What can be done to prevent Ice Damming?
- Before the snow starts, ensure that the attic is properly vented with appropriate soffit and attic vents.
- Ensuring that the warm air from your home is not entering the attic through poorly sealed attic hatches, incorrectly installed bathroom or kitchen exhaust vents and inadequate vapor barriers or insulation.
- Ensure that the roof vents are not blocked by snow by carefully checking them after large snowfalls.
- Use a snow rake ($50.00 at Canadian Tire) to remove excessive amounts of snow from the roofs edge.