Aluminum or steel roofing, which is smarter for Calgary?

Steel wins on price and hail toughness; aluminum wins on corrosion resistance and weight. For most Calgary houses, steel is the smarter starting point, but the gap is narrower than it used to be, and a few specific situations tip the balance toward aluminum.

What each material actually does in Calgary's climate

Steel roofing (typically stone-coated steel panels or standing seam) costs roughly $11 to $16 per square foot installed on a typical Calgary house, putting a full replacement in the $20,000 to $35,000 range. Aluminum runs about $14 to $20 per square foot, so figure $25,000 to $45,000 for the same house. Both are dramatically more durable than asphalt shingles, but they earn that premium differently.

Steel's edge is impact resistance. Calgary sits in Canada's hail alley, and the August 2024 storm alone generated roughly $2.8 to $3 billion in insured losses. A Class 4 impact-resistant steel panel (rated to UL 2218 or FM 4473) is about as tough as a residential roofing product gets. Many insurers offer discounts of up to 50% on home insurance premiums for Class 4 materials, so ask your insurer what discount applies before you choose a product. Steel is also stiffer under heavy snow loads and handles the mechanical stress of Calgary's roughly 128 freeze-thaw cycles a year without flexing as much as lighter materials.

Aluminum's edge is corrosion resistance. It does not rust, which matters most near roads that are heavily salted or on coastal properties. In a landlocked city like Calgary, that advantage is real but modest. Aluminum is also much lighter than steel, which can matter on an older structure where a structural engineer has flagged load concerns, or on a low-slope addition where dead load is tight.

Both metals expand and contract with temperature swings, and Calgary's chinooks can swing temperatures sharply within a day. A properly installed standing seam system uses floating clips that allow movement; a through-fastened panel system on either metal needs fasteners with neoprene washers and correct torque. Ask any roofer quoting you which fastening system they use and why.

Neither material is hail-proof. Large hail can dent both steel and aluminum; aluminum dents more easily than steel at the same gauge, which is another reason steel tends to be the default recommendation in Calgary.

On the permit question: the Alberta Permit Regulation exempts re-roofing from a building permit when the new material is of a similar type, and whether metal counts as similar to asphalt is not spelled out, so confirm with the City of Calgary whether a permit is required before signing a contract. Make sure the contract states clearly who is responsible for obtaining any permit that turns out to be needed.

A fair quote for either material should spell out the gauge and profile of the panels, the underlayment spec (a quality synthetic or self-adhering membrane under metal is standard), how flashings and valleys are handled, whether old decking is included or priced per sheet beyond an allowance, and the manufacturer's warranty period alongside the installer's workmanship warranty.

Before you commit, ask the contractor for a WCB-Alberta clearance letter and check their Alberta prepaid contracting licence through Service Alberta if any deposit is required before the work is finished.

Ask for both metals on the same quote, gauge and profile named, and compare them side by side.