Confirm safe access and fall protection plan for the actual pitch and height before any material is ordered. If the plan is not solid, the job does not start.
Inspect the deck from the attic side where possible: soft spots, prior leaks, and ventilation state change the scope before tear off.
Plan tear off, disposal, and weather cover. A roof opened in the morning must be dry-in capable the same day.
Protect landscaping, siding, and ground level work areas, and agree the bin or trailer location with the owner.
Confirm the delivery placement. Bundles staged on the roof need a load plan; bundles on the ground need a carry plan.
Measurements to confirm
Building length and width at the roof line, including eaves overhang. The calculator starts from footprint, so add overhang to both dimensions.
Pitch, measured on the roof or from the attic, matched to the nearest pitch factor in the calculator.
Ridge length, valley count and length, and hip length if present. Complex roofs waste more than the default allowance.
Waste allowance. Ten percent suits a simple gable; valleys, hips, and cut up roofs argue for 12 to 15 percent or more.
Ventilation and flashing count: vents, plumbing stacks, chimneys, and wall intersections that need step or counter flashing.
Permits and code notes for Canada, general level
Re-roofing like for like often needs no permit in Canadian municipalities, while structural changes, new roof lines, and added load commonly do. The rule is local.
Ice and water protection at eaves, underlayment coverage, and ventilation are code and manufacturer specification matters that vary by climate zone and product.
General information only, not code advice. Confirm local code and permit requirements with your municipality and a qualified professional before you build.
Material list
Item
Specification or size
Purchasable unit
Quantity
Picked up
Shingle bundles
Architectural shingles, about 3.1 sq m coverage per bundle
Bundle
Underlayment
Roll coverage about 37.16 sq m (400 sq ft)
Roll
Ice and water membrane
Self adhered membrane for eaves and valleys
Roll, sold by length
Drip edge
Metal drip edge for eaves and rakes
Piece, sold by length
Ridge cap
Cap shingles or ridge bundles
Bundle or piece
Roofing nails
Coil or hand nails as your system uses
Box or pail
Flashing and vents
Step flashing, stack boots, vents as counted on site
Piece
Estimates only. Verify quantities, layout, and local requirements before ordering or building. Permits and code notes: General information only, not code advice. Confirm local code and permit requirements with your municipality and a qualified professional before you build.