Why Toronto’s Climate is Really Bad for Your Roof

The asphalt shingles of your roof get really bad treatment from the climate in Toronto & the GTA.

Below freezing winter temperatures can make shingles brittle, which means they are more likely to crack or break. When they do, it is easier for moisture to get in underneath the shingles. When it freezes, the shingles are lifted from the roof base, which causes more cracks and breaks – and more moisture gets in.

Another common and damaging winter problem is ice dam formation. When a roof is poorly insulated, the snow that falls on it can melt even though outside temperatures are below freezing. The melted snow runs off the roof and, when it gets to the roof overhang, near the eavestrough, it can re-freeze. That frozen run-off can get under your shingles and also damage your eavestroughs.

Instead of making them brittle, summer’s heat has the opposite effect on shingles, making them more pliable. That pliability makes them susceptible to warping. Winds can catch the raised corner of a warped shingle and lift up the entire shingle. Debris and moisture can then get in underneath to potentially permanently disfigure the shingle or, in the case of moisture, to get into your home.

The Real Problem With Toronto’s Weather

While the extremes of heat and cold are tough on your roof, the real problem with Toronto’s climate is the frequent cycling of cold and warm temperatures. Freeze/thaw cycles not only subject your roof to the extremes of temperature, but also to the expansion and contraction that occurs as temperatures go from hot to cold and back again.

Recent milder winters in the area mean your roof can endure many freeze/thaw cycles in a single season.

Toronto’s climate means homeowners must be more vigilant about looking for signs of damage and/or potential problems on their roofs.