Ontario asphalt roof costs area times the installed allowance plus confirmed extras and tax; the default example is about CA$15,800.
Square feet, roofing squares and the slope
Canadian roofing quotes often use square feet or roofing squares. One roofing square is 100 sq ft. Enter the covering's measured surface area, rather than the floor area of the house. If you have footprint dimensions instead, the roof angle converts that plan into a slope area. Eaves and other overhangs belong in the measured dimensions; separate wings, dormers and intersecting roofs need their own takeoff.
The local switch changes square feet to square metres without changing the physical roof. Canadian source rates remain per square foot, and a confirmed installed rate should be entered in CAD per sq ft even when area is displayed metrically. The global unit preference does not control this page. The output includes both the per-area price and the price of a 100 sq ft roofing square.
Worked example: Ontario asphalt, 2,000 sq ft
The Ontario net triple is CA$3.98 / CA$6.99 / CA$10 per sq ft. The typical installation allowance is 2,000 × CA$6.99 = CA$13,980. Ontario HST adds CA$1,817.40, giving CA$15,797.40, displayed as approximately CA$15,800. The roof is 20 roofing squares. Confirmed additional tear-off, deck repair, eave protection and ventilation quotes are zero in this example.
Asphalt roof replacement cost references
| Guide | Published installed CAD/sq ft | Tax basis |
|---|---|---|
| HomeStars | CA$5–12 | Unspecified |
| RenoAssistance | CA$4–8 | Unspecified |
Read 1 October 2026: HomeStars roofing costs and RenoAssistance roof replacement. The calculator broadens each net interval to allow either published tax interpretation before blending. Province changes can therefore change the inferred net allowance as well as the tax line. A confirmed before-tax installed quote removes that uncertainty.
No separate 3-tab or architectural premium has been verified for this model. The asphalt choice is a general installed allowance. Ask the contractor to identify the actual shingle system, underlayment, flashing details and warranty conditions. Tear-off may already be included in a guide's installation scope. If it is an extra, the field takes a whole-roof quote per layer and multiplies it by the number of layers being removed.
Provincial tax on an installed roof
The CRA rates apply according to place of supply. Ontario HST is 13%, Nova Scotia 14%, and New Brunswick, Newfoundland and Labrador, and Prince Edward Island 15%. Federal GST is 5% in the other jurisdictions, with the relevant provincial rules added where applicable. Quebec uses GST plus QST, and Saskatchewan construction services attract PST as well.
For an ordinary installed roofing contract, BC contractor rules and Manitoba Bulletin 008 put the material sales tax into the contractor's inputs. The calculator adds federal GST to the net contract instead of adding retail PST a second time. Materials-only purchases need their own tax treatment.
Ice-dam prevention combines air sealing, insulation, ventilation and appropriate eave details. An extra membrane quote alone does not establish local-code compliance. Have the roofer check the applicable province's requirements.
Compare the metal roof cost calculator Canada, measure slope with the roof pitch calculator, find area with the roofing calculator, and plan drainage with the gutter slope calculator.