Building a hail-resistant exterior in Calgary

Why hail matters so much here

On August 5, 2024, a hailstorm with hailstones reported as large as chicken eggs struck Calgary. Catastrophe Indices and Quantification Inc. (CatIQ) estimated nearly $2.8 billion in insured damage, making it the second-costliest insured event in Canadian history, after the 2016 Fort McMurray wildfire.

If your roof, siding or windows need replacing, choosing materials that resist impact is one of the most practical upgrades you can make in this city.

Class 4 impact-resistant roofing

Impact-resistant roofing is rated Class 4 under the UL 2218 test, in which a 2-inch steel ball is dropped onto the material from about 20 feet. Asphalt, metal and synthetic products are all available with a Class 4 rating.

Ask your insurer whether they offer a discount for a Class 4 roof, and keep the product certification and invoice on file, because you may be asked for proof.

Siding, windows and the details

• Fibre-cement and engineered siding resist impact far better than vinyl, which can crack in cold-weather hail. Kay2's 2026 cost guide puts installed fibre-cement (Hardie) siding at $12 to $22 per square foot.
• Look at window and door frames, capping and vents, since dented aluminum capping and cracked vent covers are common hail repairs.
• Plan eavestroughs and downspouts at the same time, so drainage is right when the exterior is rebuilt.

Stopping ice dams

Ice dams are ridges of ice along the edge of the roof. They form when heat leaking from the house warms the attic, melts snow on the roof, and the water refreezes at the colder eaves. Calgary's chinooks make it worse, because snow melts and refreezes many times over a winter. Water trapped behind the ice can back up under the shingles and into ceilings and walls.

The fix is mostly in the attic, not on the roof. Seal the places where warm air gets into the attic, such as the attic hatch, pot lights, plumbing stacks and bathroom fans. Add insulation, since many older Calgary homes have far less than today's code asks for. Keep the soffit vents clear so outside air can move through the attic. Heating cables treat the symptom, not the cause.

If you are replacing the roof anyway, ask about a waterproof membrane along the eaves under the new shingles. It is the last line of defence when ice does form.

What happened to the City's roofing rebate

Calgary's Resilient Roofing Rebate Program paid $3,000 toward certified Class 4 roofing. It issued about 1,600 rebates before ending in 2022, when its funding ran out. In 2026 the Insurance Bureau of Canada has been calling for it to return, but no City rebate is open as of this writing, so budget without one.

Permits

The City of Calgary does not require a permit to replace or repair roofing materials. Structural changes, new windows in new openings, or work combined with an addition or renovation can still need permits, so confirm the scope with your contractor.

A rebuild is a chance to redesign

Exterior work after hail is often the moment to change the look of the whole home. Kay2 designs and builds exterior renovations across Calgary, from siding and stone to windows, entries and rooflines. Book a consultation to plan an exterior that looks better and lasts longer.