Roofers in Ottawa

Roofing is quoted per square - one square is 100 square feet of roof surface, not floor area. A steep or complex roof with multiple valleys and dormers can cost half again as much as a simple gable of the same footprint. When two quotes differ sharply, the usual causes are shingle grade, whether the old layers are being torn off, and how much ice-and-water shield is included.

Job	Typical range
Asphalt shingle replacement, per squareIncludes tear-off and disposal. Architectural shingles sit above three-tab.	$450 – $800
Typical full roof, average detached homeRoughly 18 to 25 squares. Complexity moves this more than size does.	$8,000 – $16,000
Metal roofTwo to three times asphalt, with a service life to match.	$18,000 – $40,000
Flat roof, per square footEPDM and TPO. Access and insulation thickness drive the range.	$10 – $18
Localised repairFlashing, a small leak, a handful of blown-off shingles.	$400 – $1,500
Eavestrough replacement, per linear footSeamless aluminum. Oversized six-inch trough costs more and clogs less.	$12 – $25
Skylight installationRe-flashing an existing skylight during a re-roof is far cheaper than a new opening.	$2,000 – $4,500

Planning estimates for Ontario, not quotes. Always get written quotes against the same written specification.

Questions to ask before you hire

Can I see a current WSIB clearance certificate and your liability certificate of insurance?

Is this a full tear-off, or shingling over the existing layer? (Overlays are cheaper and shorten roof life.)

How much ice and water shield is included, and how far up from the eave?

Are you certified by the shingle manufacturer, and does this quote include the system warranty or only the material warranty?

What happens if you find rotten decking? What is the per-sheet price, and will you show me before replacing it?

Who is on site supervising, and are any parts of this subcontracted?

How is the site protected and cleaned - magnet sweep for nails, plants covered?

Warning signs

Door-to-door solicitation after a storm, especially from a company with out-of-province plates.

A quote that does not specify shingle brand, line and colour.

Any request for a large cash deposit before materials are delivered.

No written scope describing tear-off, underlayment, flashing and ventilation. "Replace roof" is not a scope.