Roof Replacement

Overview

A roof replacement is one of the most critical investments a Canadian homeowner can make. Our climate subjects roofs to extreme conditions — heavy snow loads, ice damming, wind-driven rain, and intense summer UV. When shingles start curling, granules fill the gutters, or leaks appear in the attic, it is time to act.

Most Canadian homes are roofed with asphalt shingles, which offer a good balance of cost and durability. Architectural (dimensional) shingles have largely replaced three-tab shingles as the standard, offering better wind resistance and a 25 to 50 year warranty. Metal roofing is growing in popularity, particularly in areas with heavy snowfall, as it sheds snow efficiently and can last 50 years or more.

A full replacement involves stripping the old roof down to the deck, inspecting and repairing the sheathing, and installing new underlayment, ice and water shield, and roofing material. This is not a DIY project — it requires professional crews, proper safety equipment, and knowledge of building code requirements.

What to Expect

• Roofing contractor inspects the existing roof and provides a written estimate
• Building permit application where required by your municipality
• Tear-off of old shingles and underlayment
• Deck inspection for rot, sagging, or damage
• Installation of ice and water shield along eaves and valleys
• Synthetic underlayment across the entire deck
• Drip edge and flashing installation
• Shingle or metal panel installation
• Ridge vent installation for proper attic ventilation
• Final cleanup including magnetic nail sweep of the yard
• Timeline of 1 to 4 days for most homes

Cost Factors

Roof size (measured in squares, where one square equals 100 square feet) is the primary cost driver. Steep slopes require additional safety equipment and slow production, adding to labour costs. The number of layers to strip, deck condition, and complexity of the roof (valleys, dormers, skylights) all affect pricing. Material choice matters significantly — basic architectural shingles cost far less than premium designer shingles or standing-seam metal. Geographic location influences labour rates, with Vancouver and the GTA at the higher end.

How to Save Money

• Get quotes from at least three reputable roofing companies
• Schedule the work during the off-season (late fall or early spring) when demand is lower
• Choose standard architectural shingles rather than premium or designer lines
• Ask about manufacturer rebate programs, which Canadian distributors occasionally offer
• Ensure proper attic ventilation is installed to extend the new roof's lifespan

Hiring Tips

• Verify the roofer is licensed, insured, and carries workers' compensation coverage
• Ask for the manufacturer's warranty and the contractor's workmanship warranty separately
• Confirm the roofer will install ice and water shield as required by the National Building Code of Canada
• Request proof of disposal at a licensed facility — illegal dumping is the homeowner's liability
• Check reviews on Google, HomeStars, and the Better Business Bureau

FAQ

How long does a roof last in Canada?

Architectural asphalt shingles typically last 20 to 30 years in Canadian conditions. Metal roofing can last 40 to 60 years. Actual lifespan depends on attic ventilation, sun exposure, and maintenance.

Do I need a permit to replace my roof?

Requirements vary by municipality. Many Canadian cities require a permit for a full roof replacement, while some exempt like-for-like shingle replacements. Check with your local building department before work begins.

Can I roof over existing shingles?

While some municipalities allow a second layer, most roofing professionals recommend a full tear-off. Adding weight to the structure and hiding potential deck damage can lead to bigger problems down the road. The National Building Code limits roofing to two layers maximum.