Cost to Replace a Roof: 7 Factors Every Canadian Homeowner Must Know

Cost to Replace a Roof: 7 Factors Every Canadian Homeowner Must Know

Most Ontario homeowners pay $10,000 to $16,500 to replace an asphalt shingle roof, and most land somewhere between $8,000 and $20,000. Premium materials or a complicated roof can push the bill past $30,000. Many homeowners underestimate the final number by several thousand dollars because the costs that matter most only show up once the old roof comes off.

This guide covers the seven factors that set your price, how to estimate your own roof before calling a contractor, and how to pay for it.

P.S. If a roof replacement is pushing your budget to its limit, your home equity might be the answer. Lotly helps Ontario homeowners access secured home loans from $10,000 to $1,000,000, with all credit scores and income types welcome. See your options here.

What's the average cost to replace a roof in Canada?

A full architectural asphalt shingle replacement typically costs $10,000–$16,500 in Ontario, or about $5.50–$8.50 per square foot installed. Quotes are usually given before HST.

Estimates based on 2026 Ontario contractor pricing. Actual costs vary by region, roof size, and contractor.

The seven factors below explain where your roof lands in those ranges.

Factor 1: How does roof size affect the cost?

Size is the single biggest cost driver. Roofers price in "squares," where one square is 100 sq ft of roof area, and most Canadian homes have 15 to 30 squares. At $550–$850 per square installed for architectural shingles, going from 15 to 30 squares adds roughly $8,000–$13,000 with identical materials.

To estimate your squares, multiply your home's footprint (including overhangs) by a pitch factor, then divide by 100:

Google Earth's measuring tool or an app like RoofSnap can give you a footprint without climbing anything.

Factor 2: Which roofing material should you choose?

Material is the second-largest variable, and it sets how long you'll go before paying for another roof. Architectural asphalt is the Canadian standard: thicker and more durable than 3-tab for a modest premium, and the best value for most homes. Metal costs $15,000–$35,000 installed but lasts 40–60 years and sheds snow well, reducing ice dam risk, so it makes sense if you're staying put. Cedar, slate, and tile suit heritage and high-end homes; cedar runs $18,000–$40,000 and slate or tile can top $50,000. Flat roofs on townhomes and some condos cost $6,000–$15,000, where drainage matters as much as the membrane.

Factor 3: How much do labour and location add?

Labour is typically 40–60% of the total, so where you live matters almost as much as material. GTA contractors often charge 15–25% more than rural Ontario because of higher overhead and demand.

Get three or more written estimates, and confirm each contractor has liability insurance and WSIB coverage. A cheap quote from an uninsured crew leaves you exposed if someone gets hurt on your property.

Factor 4: How does roof complexity change the price?

Pitch is the main complexity driver. Roofs steeper than 8:12 need harnesses, scaffolding, and slower work, which adds 20–40% to labour. Most Canadian homes sit between 4:12 and 8:12, which is baseline pricing.

Dormers and valleys, skylights ($200–$600+ each to flash), multiple roof levels, and tight lot lines that limit equipment access all add time. List every feature that breaks up your roofline before getting quotes; if a contractor doesn't ask about them, that's a warning sign.

Factor 5: Should you tear off the old roof or overlay it?

Tear-off is almost always the right call. The Ontario Building Code caps residential roofs at two layers of asphalt shingles, so if you already have two, a full tear-off is mandatory.

Tear-off and disposal typically cost $1–$3 per sq ft, or roughly $1,500–$4,500 on a 1,500 sq ft roof. That cost buys you an inspection of the decking for rot and moisture before it's sealed under new shingles. An overlay is cheaper upfront but can hide damage, shorten the new roof's life, and void manufacturer warranties. If problems surface later, you pay to remove two layers instead of one.

Factor 6: What hidden repairs should you budget for?

This is the factor that catches most homeowners off guard, because contractors can't see what's underneath until the old roof is off.

• Decking: Rotted plywood or OSB costs $2–$5 per sq ft to replace. Partial replacement on a 2,000 sq ft roof can add $2,000–$4,000.
• Fascia and soffit: $500–$2,500 depending on the damage.
• Ventilation: Ridge vents, soffit vents, and attic fans run $300–$1,500. Skip them and your new roof wears out faster.
• Ice and water shield: The Ontario Building Code requires eave protection in most of the province, and valleys need it too. Budget $500–$1,500.

Add a 10–15% contingency to your quoted price. Hidden damage turns up more often than not.

Factor 7: Do you need a permit, and what warranties matter?

Permits: A like-for-like re-shingle usually doesn't need a building permit in Ontario. Toronto, Mississauga, and Brampton all exempt replacing roofing material when no structural work is involved. You'll need one if the job alters the structure, changes the pitch, adds a skylight, or replaces decking extensively. Check with your local building department before work starts, and remember the work must still meet the Building Code either way.

Warranties: You need two. A manufacturer warranty covers defects in the shingles, typically 25–50 years for architectural asphalt. A workmanship warranty covers the installation, typically 2–10 years. Ask whether both are transferable, since that's a selling point if you move in the next decade, and get every term in writing.

Timing: Asphalt shingles need warmth to seal properly, so late spring through early fall is the best installation window. Some roofers offer 10–20% off late-fall or early-spring bookings when their schedules open up. If your roof isn't leaking, it's worth asking.

How do you estimate your own roof replacement cost?

Work through these steps before your first contractor call:

1. Measure your home's footprint, including overhangs.
2. Multiply by your pitch factor from Factor 1.
3. Divide by 100 to get squares.
4. Multiply by the cost per square for your material.
5. Add premiums for steep pitch, dormers, skylights, or difficult access.
6. Add 10–15% contingency, plus known extras like ventilation upgrades and any permits.

Example: A 1,800 sq ft footprint with an 8:12 pitch gives 1,800 × 1.20 = 2,160 sq ft, or 21.6 squares. At $650 per square for architectural shingles, that's about $14,000. With a 12% contingency, budget roughly $15,700 before HST.

Why is the cheapest quote often the most expensive?

Contractors who underquote usually cut corners where you can't see from the ground: underlayment, flashing, and ventilation. You won't know until the roof fails early.

Compare quotes on cost per year of roof life instead of the total:

• A $9,000 roof lasting 15 years costs $600 a year
• A $13,000 roof lasting 30 years costs $433 a year

The pricier roof is about 28% cheaper per year. Ask each contractor about the underlayment spec, the ventilation plan, and the workmanship warranty term. Those answers say more about long-term value than the bottom line does.

When should you replace your roof instead of repairing it?

• Age: Asphalt roofs past 20–25 years are near the end of their life even if they look fine from the ground.
• Widespread damage: Curling, cracking, or missing shingles in multiple areas, not one isolated spot.
• Granule loss: Granules collecting in your eavestroughs mean shingles are losing UV protection.
• Sagging: Any visible dip in the roofline suggests decking or structural damage and needs urgent attention.
• Recurring leaks: If you've patched the same area more than twice, the system is failing underneath.

Does a new roof increase your home's value?

Yes, though you won't recoup the full cost. The 2025 Cost vs. Value Report puts asphalt roof replacement at about 68% of cost recouped at resale and metal at about 50%. That's U.S. data, so treat it as directional for Canada.

The bigger value is avoiding the downside. An aging roof is one of the top deal-breakers in home inspections and triggers price negotiations or conditions on offers. Many Canadian insurers also limit coverage, or switch to actual cash value, on roofs older than 20–25 years. A new roof can lift your appraised value too, which increases your available equity. Lotly's guide to how a home appraisal works explains how.

How do you pay for a roof replacement?

If you have savings set aside for home maintenance, use them and avoid interest entirely. If that would leave you without an emergency cushion, financing is reasonable for a predictable, value-adding expense like a roof.

Contractor payment plans through third-party lenders often carry 15–29% interest, which can add thousands. Credit cards are worse for big balances: a $12,000 roof on a 19.99% card paid off over three years costs about $16,000.

Rebates won't cover the roof itself. Ontario's Home Renovation Savings Program doesn't fund roofing, but it does offer up to $7,700 for attic insulation, which is worth pairing with a roof job while the attic is accessible. Insulation falls under the program's assessment stream, so book the energy assessment before work starts. Lotly's roundup of grants for Canadian homeowners covers other programs.

Home equity is usually the cheapest option for Ontario homeowners with built-up equity. If you're also carrying high-interest debt, one secured loan can handle both. Say you owe $22,000 across three cards averaging 19.99% and need a $14,000 roof. A single $36,000 secured home loan funds the roof and pays off the cards, leaving one monthly payment at a lower rate. Lotly's guide to debt consolidation loans explains how it works, and the home renovation loan guide compares other ways to fund big projects.

"I'm still in shock. The financial stress has been impacting my health. I see a light and I'm so grateful!" — Jennifer A

Ready to fund your roof? Lotly makes it straightforward

Lotly's secured home loans give Ontario homeowners $10,000 to $1,000,000 against existing equity, with all credit scores and income types accepted, including self-employed and non-traditional income. Funding typically takes about two weeks once documents are in.

"When things didn't go our way, Lotly went above & beyond to try other ways and got us approved." — Janifer F

Three things to take away:

• Build your own estimate before quotes arrive. Squares × cost per square, plus complexity premiums and a 10–15% contingency, gives you a number to judge every quote against.
• Judge quotes on cost per year, not total price. A cheap roof that fails in 15 years costs more than a quality roof that lasts 30, and the corners cut on cheap jobs are the ones you can't see.
• Fund the roof and clear expensive debt in one move. A secured home loan can cover the project, including surprise repairs, and consolidate high-interest balances into one lower monthly payment.

P.S. If you're ready to see your options, Lotly makes it simple. One form, real solutions, and a team that works in your corner. Book a free consultation to see how you can get started today.

Frequently asked questions

How much does it cost to replace a roof on a 1,500 sq ft house in Ontario?

Roughly $9,000–$15,000 for architectural asphalt shingles, depending on your pitch, region, and how much hidden repair work turns up. GTA homeowners should budget toward the higher end.

How long does a roof replacement take?

Most asphalt roofs take 1–4 days once work begins. Metal roofs, complex rooflines, or major decking repairs can stretch to a week.

Do I need a permit to replace my roof in Ontario?

Usually not for a like-for-like re-shingle with no structural work. You'll need one if you're changing the structure or pitch, adding a skylight, or replacing decking extensively. Confirm with your local building department.

Can I finance a roof replacement with bad credit?

Yes. Lotly's secured home loans are built for homeowners with all credit backgrounds. If you have equity, you may qualify regardless of credit score or income type. Start your application here.