HomeReno Cost

Methodology and sources

How we estimate roof replacement cost

Every estimate combines national unit costs with a local labor adjustment for your province. This page shows the formula, source inputs, limitations, and review notes behind the calculator.

6
line items
13
provinces
3
sources

Methodology summary

Transparent formula

Quantities are driven by your roof size, pitch, number of stories, material grade, and whether the old roof is removed; the project band is ±15%.

Regional labor only

Labor multipliers affect the labor share of each line item; materials stay nationally priced.

Clear limitations

These are planning estimates, not live contractor quotes or guarantees.

The formula

For each line item we multiply a quantity by a national unit cost, then apply a quality-grade factor. A regional labor multiplier is applied to the labor portion only; materials are priced nationally. We show the itemized result as a ±15% range.

National unit costs

Line itemNational unit costSource
Tear-off$1.50 / sq ftsource
Underlayment$0.55 / sq ftsource
Roofing material$2.66 / sq ftsource
Installation labor$3.41 / sq ftsource
Flashing & vents$0.41 / sq ftsource
Disposal$0.41 / sq ftsource

Regional labor multipliers

Each province's labor multiplier is its median roofer wage relative to the national median, from the Government of Canada Job Bank wage data (Roofers and shinglers, NOC 73110) — territorial wages are suppressed by Job Bank, so the three territories use a disclosed northern-premium proxy. Multipliers are bounded to a sane range and applied to the labor share of each line item, so materials stay nationally priced while labor tracks local wages.

Data vintage and limitations

Compiled June 2026 from public cost aggregators and government wage data. These are derived estimates, not live contractor quotes. Local prices vary with project complexity, access, and material availability; always confirm with a licensed contractor before budgeting.

Sources