Roofing pack: estimate, check, and order
A complete re-roof job in one page for Canadian contractors, renovators, and serious DIY builders. Run the calculator, work the pre-job checklist, fill in the material list in purchasable units, and take the print page to the truck or the supplier counter. All results are estimates.
Standalone calculator: Roofing shingle estimator. This hub bundles the same math, with a unit toggle added, plus the job paperwork around it.
Roofing shingle calculator
Enter the building footprint, including eaves overhang, and pick the pitch factor closest to your roof. Unlike the current standalone roofing page, which is metric only, this hub version adds the metric and imperial toggle required for every BuildTrue trade pack. See the integration note. This is a full duplicate page section, not an embed of the standalone page.
Canada default is metric. Switch at any time: the values on screen convert so the physical size stays the same. Results show both systems.
Formula: roof area = length x width x pitch factor. Area with waste = roof area x (1 + waste / 100). Bundle coverage stated: one bundle covers about 3.1 sq m (about 33.3 sq ft), and 3 bundles make one square. One square equals 100 sq ft, which is 9.2903 sq m. Underlayment guide: one roll covers about 37.16 sq m (400 sq ft). Whole counts use an epsilon safe ceiling.
Pre-job checklist
Site prep
- 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 template
Roofing material list template. Quantities are in purchasable units. Fill in the quantity column from your calculator result, then confirm your waste allowance before you order.
| Item | Specification or size | Purchasable unit | Quantity | Notes |
|---|---|---|---|---|
| Shingle bundles | Architectural shingles, about 3.1 sq m coverage per bundle | Bundle | ____ | Calculator count includes pitch adjustment and your waste allowance. About 3 bundles make one square. |
| Underlayment | Roll coverage about 37.16 sq m (400 sq ft) | Roll | ____ | Calculator count. Ice and water membrane at eaves is counted separately by linear length. |
| Ice and water membrane | Self adhered membrane for eaves and valleys | Roll, sold by length | ____ | Measure eave and valley linear length on site and divide by roll length. |
| Drip edge | Metal drip edge for eaves and rakes | Piece, sold by length | ____ | Total eave plus rake length, divided by piece length, rounded up. |
| Ridge cap | Cap shingles or ridge bundles | Bundle or piece | ____ | From measured ridge and hip length, at the coverage stated on the bundle. |
| Roofing nails | Coil or hand nails as your system uses | Box or pail | ____ | Estimate from bundle count using the fastening pattern for your wind zone and product instructions. |
| Flashing and vents | Step flashing, stack boots, vents as counted on site | Piece | ____ | Count every penetration and wall intersection during the measurement visit. |
Print the companion checklist page in this pack for a paper copy you can take to the supplier counter.
Pro tips
- Measure the roof from the ground twice and once on the roof before ordering. A footprint that misses the overhang under-orders every single line item.
- Tear off only what the crew can dry in the same day, every day. Weather forecasts are optimism; a half open roof in a night storm is a claim, not a story.
- Keep bundle counts by roof plane on the job sheet. Running short on the last plane usually means one plane quietly ate the waste allowance.
- Replace flashing that is tired while the roof is open. Reusing bent step flashing to save an hour is the most common source of a leak call two winters later.
- Check the attic for daylight at valleys, stacks, and the chimney after tear off. Deck problems are cheapest in the hour the roof is open.
- Stage bundles spread across the roof structure, never stacked in one bay. A neat pile in the wrong place can overload a truss or a rafter span.
- Photograph the dry-in stage, membrane laps, and valley work before shingles cover them. That record answers most warranty questions years later.
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Print version: Roofing checklist and material list for print. Worked example: Roofing worked example with hand checked numbers.