Roof replacement in Ontario

How much does a roof replacement cost?

Roofing is quoted by area, and roof area is always larger than the footprint of the house because of the pitch. A 1,600 square foot bungalow can easily have 2,000 square feet of roof. Steeper roofs cost more per square foot as well, because the crew works slower and needs staging.

On an average Ontario detached home, that puts an asphalt reroof between $9,000 and $18,000. Metal is roughly double, and lasts roughly double, which is the whole argument for it.

What actually drives the price

• Tear-off layers. Stripping two or three old layers costs more in labour and disposal than one. Some homes have been shingled over twice already, which is also a structural load question.
• Rotten sheathing. Nobody knows what is under the shingles until they come off. A good quote prices sheathing replacement per sheet as a stated unit rate, so you are not negotiating mid-job.
• Pitch and height. A steep third-storey roof needs staging and safety rigging. A low bungalow does not.
• Complexity. Valleys, dormers, skylights, and chimneys all mean flashing, and flashing is where roofs leak. Detail-heavy roofs cost more for good reason.
• Ventilation. If the attic is under-vented, shingles cook from below and fail early. Fixing it during a reroof is cheap. Fixing it afterwards is not.

When a roof is actually done

Asphalt in this climate generally gives 20 to 30 years, and the end is visible:

• Granules collecting in the eavestrough or at the bottom of downspouts
• Shingles curling at the edges, or cracked and brittle across the field
• Bald patches where the mat shows through
• Any daylight or staining visible in the attic
• Repeated ice dams, which point at ventilation as much as the roof surface

A roof with ten good years left and one bad valley needs a repair, not a replacement. Be wary of anyone who knocks on your door after a storm and finds a full replacement.

Reading a roofing quote

A quote worth trusting states, in writing:

• The number of layers being removed and where the debris goes
• The unit rate for replacing rotten sheathing, per sheet
• Ice and water shield coverage at eaves and valleys, and how far up
• New flashing at every chimney, wall, and skylight, rather than reusing the old
• The ventilation plan, intake as well as exhaust
• Both warranties: the manufacturer’s on the material, and the roofer’s on the workmanship

The workmanship warranty is the one that matters. Materials rarely fail inside their term; installations do. Our guide to choosing a contractor covers the rest of the diligence, including WSIB and insurance.

Do you need a permit to replace a roof?

A like-for-like reroof does not normally need a building permit in Ontario. You do need one if the roof structure is changing, if the pitch is being altered, or if you are adding dormers or skylights that cut new openings in the framing. See our permit guide for how the threshold works.

Zeybek Construction

General contractors, Ontario

Written by the Zeybek team from more than two decades of renovation and construction work across Ontario, from Toronto and the GTA to Kitchener, Waterloo, and beyond. We build kitchens, bathrooms, whole homes, additions, and commercial spaces, and we handle permits and inspections as part of the job.

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Last updated July 16, 2026. This guide is general information for Ontario homeowners and is not a substitute for a site-specific quote or municipal advice. Costs, rebate programs, and rules vary by municipality and change over time.