Toronto and the GTA are great places to live, unless you’re a residential roof. The climate in the area delivers every possible hardship a roof can endure. From blazing-hot 30+ degree temperatures in summer to extended sub-zero chills in winter. Even spring and fall offer their own challenges, when temperatures are warm enough to change snow to rain, but too cool to evaporate the moisture quickly. The result is long periods of moist conditions that can quickly cause unsightly algae and moss growth on your roof.
If there is one condition that can cause more damage than most, it’s the ice dams that can form in winter along the edges of your roof, just above the eavestroughs. If you’ve noticed large, heavy icicles forming from your eavestroughs, they were probably caused by an ice dam
Ice dams are the product of a poorly insulated attic and roof. After snow falls, when outside temperatures are just below freezing, the heat from your house that escapes through your roof can be enough to melt the snow. After it melts, the water rolls off your roof until it gets near the edges. There, with temperatures still below zero, it freezes again, but this time it freezes into ice. The build-up of ice forms a dam, preventing the melted snow from rolling off the roof, which in turn makes the ice dam larger.
Ice dams can be severely damaging to your roof. As it rolls off the roof, water can get underneath the roof’s shingles. When it freezes again, the water expands. The ice underneath shingles can deform the shingle and force it up, which lets in more water, which turns to more ice. The result can be curled, cracked or broken shingles. And the water under damaged shingles can get inside your roof and harm the roof’s deck or supporting structure.
What You Can Do to Prevent Damage From Ice Dams
- Insulate Your Attic and Roof – This not only eliminates the ice dam problem, but it helps you save money by reducing heating costs in the winter and cooling costs in the summer.
- Install Roof & Eavestrough Deicing Cables – Your local hardware store might have heated electric cable that is designed to be installed along the edge of your roof and inside your eavestrough. The cable stops ice from forming and keeps water draining off the roof.
- Make Sure New Roofs are Installed With Ice and Water Shields – A rubber-like asphalt and fiberglass membrane, ice and water shields help prevent water damage that can occur from ice dams. Ice and water shields help to seal your roof below the shingles and can prevent water that gets underneath shingles from damaging the roof’s underlying structure.
As always, if you are planning to do any work on your roof, you owe it to yourself to at least consult a professional. It’s the “roof over your head” after all.