How long does a metal roof last in Prince Edward Island?

Salt air and fog

Salt air shortens the life of a steel roof: it is highly corrosive to steel once the protective coating is scratched or cut. Fog is part of coastal life here; the Nova Scotia Museum's Natural History of Nova Scotia puts fog on the province's coasts 15 to 25 per cent of the year. Aluminum cannot rust, because it forms its own protective oxide layer, so a house on the shore doesn't need a different roof from one inland.

Wind-driven rain and storms

Wind is what usually takes an asphalt roof early. Hurricane Fiona, on September 24, 2022, caused over $800 million in insured damage, the most costly extreme weather event ever recorded in Atlantic Canada, according to the Insurance Bureau of Canada. Research by the Insurance Institute for Business & Home Safety found that most asphalt shingles begin to lose wind performance between years five and 10, and that shingles losing their sealant bond is the single greatest cause. Interlock® panels lock on all four sides with no tab for the wind to lift, and wind resistance is warranted to 193 km/h (120 mph) installed to manufacturer specification. Hurricane-force wind damage is a matter for your home insurance and is excluded from our labour warranty.

Winter thaws and freeze-thaw

Maritime winters swing above and below freezing. Storms that track over New Brunswick bring warm southwest winds and thaws to Nova Scotia, and mild ocean air regularly replaces the cold, according to the Nova Scotia Museum. Water that gets into a roofing material freezes, expands and thaws, over and over: asphalt granules loosen and wood splits. Aluminum absorbs no water, so there is nothing in the panel for freeze-thaw to work on.

Heavy, wet snow

Coastal snow is often heavy and wet, and it can load a roof for days before rain or a thaw takes it away. Metal sheds snow; where a slide would land on an entry, a deck or a walkway, snow guards go in, planned at the estimate, not after the first slide.

Ice dams

Ice dams come from heat escaping into the attic and from ventilation, not from the roof covering, and no roof prevents them on its own. Ice damming is a stated exclusion of the material warranty. We look at your attic ventilation and insulation with you.

A short season for asphalt

Asphalt shingles need warmth to seal. The Insurance Bureau of Canada advises replacing asphalt shingles in weather of at least 10 °C to improve their quality and longevity, and a Maritime roofing season has fewer of those days at each end. Interlock® panels are locked mechanically, not sealed by heat.