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Roofing Cost Per Square in Ontario: What the Number Means, What Is in It, and How to Check a Quote Against It
Roofing
The Roofing Square, and Why Every Quote Is Written in It
Roofers measure in squares the way carpenters measure in board feet and nobody else does. One square is 100 square feet of roof surface. Three bundles of shingles cover one square. A 20-square roof is 2,000 square feet and takes 60 bundles plus waste. Once you can count squares, a roofing quote stops being a mystery and starts being arithmetic.
The rate per square, by system
| System | Installed per square | Of which material, roughly | Of which labour, tear-off and overhead |
|---|---|---|---|
| 3-tab shingles | $450 to $650 | $120 to $160 | $330 to $490 |
| Architectural shingles | $550 to $850 | $160 to $240 | $390 to $610 |
| Premium or Class 4 shingles | $750 to $1,100 | $260 to $400 | $490 to $700 |
| Exposed-fastener metal | $850 to $1,300 | $350 to $550 | $500 to $750 |
| Metal shingles | $1,100 to $1,800 | $550 to $900 | $550 to $900 |
| Standing seam | $1,300 to $2,200 | $650 to $1,100 | $650 to $1,100 |
| Flat membrane | $900 to $1,600 | $350 to $600 | $550 to $1,000 |
The split is the useful part. On a shingle roof, the shingles are a quarter of the price; the rest is two to four people for two days, the tear-off, the dumpster, the underlayment and accessories, insurance, WSIB, the truck and the roofer’s margin. Upgrading from a $160 shingle to a $240 shingle moves the per-square price by $80, not by 50%. On metal the material is about half, which is why metal prices swing with the steel market and shingle prices do not.
What is inside the per-square number
- The shingles or panels, with the manufacturer’s starter strip, hip and ridge cap, and the nails or clips.
- Tear-off of one layer and disposal. About $90 to $130 a square of the total. A roofer who quotes “overlay” (new shingles on top of old) is leaving this out and should say so; it is cheaper and it is a worse roof.
- Synthetic underlayment over the whole deck, $15 to $25 a square, and ice and water shield at the eaves and in the valleys, which is a code requirement in Ontario.
- Drip edge at the eaves and rakes, and new pipe boots on the plumbing stacks.
- Labour: a crew of three does 15 to 25 squares a day on a simple roof, less on a steep or cut-up one.
- The roofer’s overhead and profit: insurance, WSIB, the truck, the office, and the margin that keeps them in business to honour the warranty. 20 to 30% of the number.
Not inside it, and listed separately on a good quote: decking replacement, chimney and skylight flashing, ridge venting and soffit work, a second tear-off layer, eavestroughs, and anything structural. The cost guide prices each of those.
Counting your squares
Footprint of the house including the garage, times 1.08 for the overhangs, times the pitch factor, divided by 100. A 1,400 sq ft footprint at 6/12 is 1,400 x 1.08 x 1.118 = 1,690 sq ft = 17 squares. For the material order the roofer adds 10 to 15% for cuts and waste, which is 19 or 20 squares of shingles for 17 squares of roof. You pay the installed rate on the 17, not the 20, and a quote that charges the installed rate on the waste figure is padding. The measuring page has the pitch factors and the method for a roof you cannot see from the ground.
The three-line check for any quote
- How many squares did they measure? It should be on the quote. If it is within one square of your own count, fine. If it is three squares more, ask whether that is the roof or the material order.
- What is the total divided by the squares? That is the per-square rate. If it is inside the table above for the system named, the price is fair. If it is under, something is missing. If it is over, something extra is in there and it should be on its own line.
- What is on its own line? Decking unit price, flashing count, venting, second layer. If those are missing, the per-square rate is not what it looks like, because they will be added in week one.
Three quotes, three per-square rates, and the one that is 30% under the other two is the one to read twice. The quote checklist does this line by line.
Questions people ask
How much is roofing per square in Ontario?
$550 to $850 per square installed for architectural shingles in 2026, $450 to $650 for 3-tab, $850 to $2,200 for metal depending on the system. Before HST, including tear-off of one layer.
How many bundles of shingles in a square?
Three for most architectural shingles, sometimes four for the heavy premium lines. A 20-square roof is 60 to 66 bundles before waste.
How much is labour per square for roofing?
Labour alone, if a roofer prices it that way, is $200 to $350 a square for shingles in Ontario, more on steep or complex roofs. Most quotes do not split it; the installed rate is the useful number.
Is roofing priced on the roof area or the material?
On the roof surface. The material order includes 10 to 15% waste that you pay for as material but not at the installed rate. Ask which number the quote uses.
Why is 3-tab barely cheaper than architectural?
Because the shingle is a quarter of the price and the labour, tear-off and overhead are the same either way. The $100 a square saved buys a roof that lasts 8 fewer years.
Count, divide, compare
Squares on the quote, total divided by squares, extras on their own lines. Three minutes with each quote and the odd one out stands up on its own.
Sources and further reading
- Your rights when starting home renovations or repairs: Ontario government. The 10-day cooling-off period, the 10% estimate rule, and what a contract has to say.
- Canadian Roofing Contractors Association: the national association; its roofing specifications are what good quotes are written to.
