How much does it cost to replace a garage roof in Ottawa?

Replacing a garage roof in Ottawa is one of those maintenance projects that homeowners tend to put off until leaks or visible deterioration force the issue, but the cost is generally quite manageable compared to a house roof replacement. The price depends on the size of your garage, the roofing material you choose, and whether the underlying decking and structure need repair.

For a standard single-car detached garage with roughly 200 to 250 square feet of roof area, a complete tear-off and re-shingle with architectural asphalt shingles costs between $2,800 and $4,500 in Ottawa. This includes removing the old shingles, inspecting and replacing any damaged plywood decking, installing ice and water shield along the eaves and valleys, laying new underlayment, and installing the new shingles with proper ridge and hip caps.

A double-car garage with 400 to 500 square feet of roof area typically runs between $4,500 and $7,500 for the same scope of work. Larger garages with steeper pitches or more complex rooflines involving dormers, valleys, or multiple planes will land at the higher end of that range because the additional complexity means more labour hours, more waste material, and more flashing details.

The roofing material you choose has a big impact on both upfront cost and long-term value. Standard three-tab asphalt shingles are the most affordable option at roughly $3.50 to $5.00 per square foot installed, though fewer Ottawa roofers stock them as the industry has largely moved to dimensional shingles. Architectural asphalt shingles, which are now the standard, run $4.50 to $6.50 per square foot installed and offer better wind resistance, a longer warranty, and a more attractive appearance. Premium designer shingles with enhanced profiles push up to $7.00 to $9.00 per square foot.

Common Add-On Costs

Decking replacement is the most frequent unexpected cost in a garage roof project. Once the old shingles come off, roofers often find that some or all of the plywood sheathing has deteriorated from moisture infiltration. Replacing individual sheets of plywood costs $60 to $90 per sheet installed, and if the entire deck needs replacement, add $1,200 to $2,500 for a single-car garage or $2,000 to $4,000 for a double.

Fascia and soffit repairs are commonly bundled with a garage roof replacement since the roofers already have ladder and scaffold access. Replacing rotted fascia boards runs $15 to $25 per linear foot, and new aluminum soffit is $12 to $20 per linear foot installed. A full fascia and soffit refresh on a single-car garage adds $800 to $1,800 to the project.

Gutter replacement or installation is another natural add-on. Many detached garages in Ottawa either lack gutters entirely or have old gutters that have pulled away from rotted fascia. New five-inch seamless aluminum eavestrough on a single-car garage costs $400 to $800 installed, including downspouts and extensions to direct water away from the foundation.

Ice damming is a real concern for Ottawa garages, particularly those that are heated or partially heated. Proper ice and water shield membrane along the first three feet of the eave line is code-required in Ontario and should be included in any reputable roofing quote. If your garage has had ice dam issues in the past, extending the membrane further up the roof or improving attic ventilation with ridge and soffit vents adds $300 to $800 but prevents damage that could cost thousands down the road.

Most Ottawa roofing contractors can complete a garage roof in a single day for a straightforward project, which keeps labour costs relatively contained. The best time to schedule the work is late spring through early fall, though some contractors offer modest discounts for bookings in the shoulder seasons of April and November when their schedules are lighter. If your garage roof is showing signs of wear, getting a couple of quotes sooner rather than later through Garage IQ is a smart move before a small problem becomes an expensive one.

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Looking for experienced contractors? The Ottawa Construction Network connects Ottawa homeowners with qualified professionals:

• 613Bins
• RenoMotion Inc.
• Rrenovatios
• MAK Construction and Development Inc
• BFI Renovations