Modified Bitumen Roof Cost Calculator (Canada)
Estimate Canadian 2026 modified-bitumen flat roof cost (SBS torch-on, APP torch-on, SBS self-adhered, cold-applied) by area, layering, reinforcement, insulation, drains and storey. Aligned with CSA A123.21 and the CRCA Roofing Specifications Manual.
Modified Bitumen (SBS / APP) Roof Cost Calculator
Estimate Canadian 2026 modified-bitumen flat roof cost (SBS torch-on, APP torch-on, SBS self-adhered, cold-applied) by area, layering, reinforcement, insulation, drains and storey — sized to CSA A123.21 and CRCA Roofing Specifications Manual.
Estimated modified-bitumen roof cost
$21,695
Range: $18,441 – $26,034
cap sheet + base plies + insulation + tear-off + drains + flashing + walk pads + permit + disposal
Cap sheet
$6,710
Base plies
$4,070
Polyiso insulation
$4,000
Tear-off
$3,500
Drains
$790
Flashing
$1,375
Walk pads
$540
Permit
$240
Disposal
$470
What this calculator estimates
This calculator quotes the all-in installed cost for a 2026 Canadian modified-bitumen flat roof — SBS or APP polymer-modified bitumen membrane. It separates the bill into the line items CRCA-member contractors actually invoice:
- Cap sheet — top mineral-surfaced sheet, priced per sq ft and scaled by application method, carrier, storey, and access.
- Base plies — 0, 1, or 2 non-cap plies (recover / 2-ply standard / 3-ply premium).
- Polyiso insulation — R-25 (5 in) to meet NBC 9.36 / OBC SB-10 minimums.
- Tear-off — removing the existing roof down to the deck.
- Drains — new cast-iron bowl drains with clamping rings and overflow scuppers per NBC plumbing.
- Perimeter flashing — cant strip plus base flashing wrapped up parapets and curbs.
- Walk pads — factory-cast walk pads between hatch and HVAC.
- Building permit — municipal fee for commercial re-roof.
- Debris removal — tip fee.
- Weekend / after-hours premium — 25% surcharge.
A minimum mobilisation charge of CAD 1,850 applies in most Canadian metros.
How to use it
Same workflow as the en-us version, but pricing anchored in Canadian rates (CRCA Q1 2026 survey, RSMeans Canada). Use sq ft for area (Canadian commercial roofing still defaults to imperial). Polyiso R-values use ASTM C518 LTTR per CCMC listing.
Typical 2026 Canadian mod-bit cost ranges
These reflect 2026 nationwide pricing from CRCA’s Q1 2026 Roofing Market Survey, RSMeans Canada 2026, Altus Group 2026 Construction Cost Guide, and Q1 2026 contractor quotes from major Canadian metros.
| Scope (2-ply SBS torch, polyester, single-storey, moderate access, R-25 ISO, tear-off, 2 drains, 100 lf flashing) | 2026 installed price |
|---|---|
| Small commercial (2,500 sq ft) | CAD 18,500 – 32,500 |
| Mid-size commercial (5,000 sq ft) | CAD 36,000 – 62,500 |
| Large commercial (10,000 sq ft) | CAD 70,000 – 122,000 |
| Industrial / warehouse (25,000 sq ft) | CAD 170,000 – 295,000 |
| 1-ply cap-only recover vs 2-ply | 40% cheaper at membrane line |
| 3-ply premium vs 2-ply | 50% more at membrane line |
| APP torch vs SBS torch | 5% cheaper at membrane line |
| SBS self-adhered vs SBS torch | 12% more at membrane line |
| SBS cold-applied vs SBS torch | 8% more at membrane line |
| Hot-mopped vs SBS torch | 10% cheaper at membrane line |
| Fiberglass vs polyester carrier | 12% cheaper at membrane line |
| Composite vs polyester carrier | 22% more at membrane line |
| Add R-25 polyiso insulation | +CAD 2.00 / sq ft |
| Add tear-off | +CAD 1.75 / sq ft |
| Add new roof drain (each) | CAD 395 – 700 |
| Add perimeter cant + base flashing | CAD 13.75 / lf |
| Add walk-pad tile (each) | CAD 135 |
Add 15% for two-storey, 35% for three-storey, 10-30% for difficult access. Add 8-12% premium in Yukon, NWT, Nunavut (mobilisation cost, shorter install season).
Cost drivers
Same dynamics as the en-us version, but pricing anchored in CRCA rates and Canadian climate considerations. Vapor-barrier line item is mandatory in nearly all Canadian climate zones (skip only in southern BC coastal). Tapered ISO build-up is mandatory per NBC 9.26 to deliver 1/4 inch per foot slope to drains.
Per-locale code and standards (Canada)
- National Building Code of Canada (NBC) Part 9 / Part 5 — Roof assemblies, wind uplift, drainage.
- NBC 9.26 — Roofing and flashing for low-slope roofs in housing.
- NBC 9.36 — Energy efficiency (now harmonised with NECB 2020); above-deck insulation minimums by climate zone.
- National Energy Code for Buildings (NECB) 2020 — Above-deck insulation R-value minimums for commercial.
- Ontario Building Code (OBC) SB-10 — Energy efficiency targets (Ontario).
- Quebec Building Code Chapter I.1 / Chapter X — Provincial roofing and energy.
- BC Building Code (BCBC) 9.36 — Provincial energy code.
- CSA A123.21 — Modified bituminous membranes — material specification.
- CSA A123.22 — Self-adhered modified bituminous membrane specification.
- CSA A123.3 — Asphalt-saturated organic roofing felt.
- CSA A123.4 — Asphalt for constructing built-up roof coverings and waterproofing systems.
- CAN/ULC-S107 — Standard methods of fire tests of roof coverings.
- CCMC Evaluation — Required for all mod-bit systems by most provincial code authorities and commercial insurers.
- CRCA Roofing Specifications Manual — Industry-standard detailing for modified bituminous and BUR roofs.
- Provincial OHS regulations — Hot-work permit requirements vary (Ontario MOL, Quebec CNESST, BC WorkSafeBC, Alberta OHS).
Diagnostic step-by-step
Same as en-us, plus: check for ice-dam damage at parapet edges (prairie provinces), check for hail damage on cap-sheet granules (Calgary, Edmonton hail belt), and verify vapor-barrier integrity at any rooftop penetration (mandatory in nearly all Canadian climate zones).
Avoiding scams and overcharging
Same as en-us, plus: verify CCMC evaluation number on every product, verify CSA A123.21 listing, and verify the contractor’s CRCA / OIRCA / provincial roofing association membership. Get provincial OHS hot-work permit competence proof.
Related calculators and guides
- Built-up roof cost calculator — for traditional multi-ply BUR
- Flat roof replacement cost calculator — for EPDM, TPO, PVC alternatives
- Roof coating cost calculator — for restoration coating
Sources: CRCA 2026 Roofing Market Survey; CRCA Roofing Specifications Manual; RSMeans Canada 2026 Building Construction Cost Data; Altus Group 2026 Construction Cost Guide; NBC 2020 Parts 5 and 9; NECB 2020; OBC SB-10; BCBC 9.36; CSA A123.21, A123.22, A123.3, A123.4; CAN/ULC-S107; CCMC evaluation reports; provincial OHS hot-work codes (Ontario, Quebec, BC, Alberta); HomeStars and Renomii 2026 Commercial Roofing Cost Reports.
Frequently asked questions
How much does a modified bitumen roof cost per square foot in Canada in 2026?
Most Canadian 2-ply SBS modified-bitumen flat roofs price between CAD 7.20 and CAD 13.00 per square foot installed in 2026 for a polyester-reinforced cap sheet over one base ply, with R-25 polyiso insulation, tear-off of the existing roof, perimeter flashing, and a typical drain count. A 1-ply cap-only recover (over a sound substrate) drops the membrane line by roughly 40%. A 3-ply premium build-up adds roughly 50% to the membrane line. APP torch-on runs 5% under SBS torch; SBS self-adhered (Soprema Sopralast Stick, IKO Innovi SA) adds 12% for the peel-and-stick adhesive layer. Fiberglass carrier runs 12% under polyester. Source: CRCA 2026 Roofing Market Survey, RSMeans Canada 2026, Altus Group 2026 Construction Cost Guide, and Q1 2026 contractor quotes from Toronto, Montreal, Vancouver, Calgary, Edmonton, Ottawa, Winnipeg, and Halifax.
What is the difference between SBS and APP modified bitumen?
Both are bitumen sheet membranes manufactured by laminating polymer-modified bitumen onto a polyester or fiberglass carrier. SBS (styrene-butadiene-styrene) is rubber-modified — stays flexible down to -25 °C, which makes it the dominant choice for Canadian climate (the membrane survives a Winnipeg or Edmonton winter without cracking at laps). SBS can be applied four ways: torch-on, self-adhered (Soprema Sopralast Stick, IKO Innovi SA), cold-applied with field adhesive (Soprema Sopralène Stick), or hot-mopped with Type IV asphalt. APP (atactic polypropylene) is plastic-modified — best high-temperature stability, used in southern Ontario industrial buildings with significant rooftop heat load. APP is torch-applied only. For 2026 Canadian commercial, SBS dominates (roughly 85% market share) because of the cold-climate elongation advantage. APP retains share in southern Ontario industrial and over existing high-temperature roofs. CSA A123.21 specifies both as acceptable for low-slope waterproofing.
What is a cap sheet vs base ply in Canadian practice?
A Canadian modified-bitumen roof is built up from two or three sheets per CRCA Roofing Specifications Manual: a base ply (the bottom layer, typically a smooth-surfaced SBS or APP sheet 130-160 mils thick), an optional interply (a second non-cap layer for 3-ply premium builds), and a cap sheet (the top layer, 150-220 mils thick with a factory-applied granule surface for UV protection). The cap sheet is roughly 60% more expensive per square foot than a base ply because the mineral granules and heavier polyester carrier add material cost. A 2-ply system (base + cap) is the CRCA standard for new construction. A 1-ply cap-only system is used for recover work where the existing membrane provides the base. A 3-ply system (base + interply + cap) is specified for prairie provinces (hail and ice-dam stress), the maritime provinces (salt-air exposure), and any project where the owner wants maximum redundancy.
What is included in a Canadian mod-bit re-roof quote?
A complete CRCA-spec mod-bit re-roof scope includes: (1) tear-off of the existing roof down to the deck or insulation; (2) deck inspection and patching of any rotted plywood or spalled concrete; (3) vapor barrier on the warm side (mandatory in Canadian climate zones 4-8); (4) tapered ISO board insulation to deliver 1/4 inch per foot positive slope to drains per NBC 9.26 / CRCA; (5) coverboard (1/4 in gypsum or HD polyiso) over the insulation; (6) base ply mechanically fastened or self-adhered to the substrate; (7) one or two non-cap plies, lapped 4 inches at sides and 6 inches at ends; (8) cap sheet with mineral granule surface, lapped the same way; (9) cant strips at every 90-degree corner; (10) base flashing wrapped up parapets, curbs, and pipe penetrations a minimum of 8 inches and counter-flashed with prefinished metal; (11) new or refurbished drains, scuppers, and overflow scuppers per NBC plumbing; (12) edge metal cleat and prefinished cap; (13) walk pads around HVAC plant; (14) all flashings, pitch pans, lead pipe boots, and curb wraps; (15) municipal building permit, inspection, and 10-20 year manufacturer warranty. A quote that omits any of these line items is incomplete.
How long does a mod-bit roof last in Canadian climates?
Service life depends on the modifier, the layering, the surfacing, and the climate region. SBS torch-on 2-ply with mineral cap typically lasts 22-27 years in southern Ontario, Quebec, and BC interior (mild climate, lower thermal cycling), 18-23 years in prairie provinces (Manitoba, Saskatchewan, Alberta — severe thermal cycling, hail), 16-20 years in maritime provinces (NB, NS, NL — salt-air exposure), and 12-16 years in arctic and sub-arctic regions (Yukon, NWT, Nunavut — extreme temperature swings, freeze-thaw cycles). APP torch-on lags SBS by 2-3 years in cold-climate provinces but matches in southern Ontario. SBS self-adhered systems lag torch-on by 2 years. A 3-ply premium build-up adds 5 years across all regions. Reflective coatings applied in year 5-7 extend service life 3-5 years and qualify for ENERGY STAR Cool Roof and provincial LEED credits. The most common failure modes are: (1) parapet flashing failure in heavy thermal cycling; (2) ponding water; (3) drain bowl cracking; (4) ice-dam damage at parapet edges in prairie provinces.
Do I need a vapor barrier on a mod-bit roof in Canada?
Yes, on virtually all Canadian climate zones. NBC 9.26 / CRCA Roofing Specifications Manual require a vapor retarder on the warm side of the insulation for any low-slope roof in climate zones with more than 4000 heating degree-days (essentially all of Canada except southern coastal BC). The vapor retarder prevents moisture-laden interior air from migrating into the roof assembly, condensing on the cold underside of the membrane, and saturating the polyiso. Wet polyiso loses 50%+ of its R-value, leading to ice-dam formation at the parapet edge in winter. Typical Canadian spec: 6 mil polyethylene sheet (residential) or self-adhered SBS vapor barrier (commercial), with all penetrations sealed with vapor-barrier sealant. Skip the vapor barrier in southern BC coastal zone only if the building has mechanical dehumidification.
Should I torch, self-adhere, or cold-apply in Canada?
Torch-on is the fastest (a 2-person crew can install 1,500-2,500 sq ft per day) and produces the strongest bond. Downside: provincial Occupational Health and Safety hot-work permitting (varies by province; toughest in Ontario and Quebec), fire watch for 4 hours after work stops, and outright prohibition on some buildings (timber-frame, occupied schools, anywhere with combustible insulation directly beneath). Self-adhered (Soprema Sopralast Stick, IKO Innovi SA) has no flame, installs cleanly in cold weather (down to -10 °C with cold-climate primer), and is ideal for occupied buildings, schools, and combustible substrates. Downside: roughly 12% more expensive at the membrane line. Cold-applied (Soprema Sopralène Stick) uses field-applied adhesive — no flame, faster than self-adhered, but slower than torch. For 2026 Canadian commercial, our recommendation: torch for unoccupied new construction with non-combustible decks in mild weather; self-adhered for any occupied building, school, or hospital, and for any winter install below -5 °C; cold-applied for shoulder-season installs and sensitive sites.
What manufacturers supply mod-bit in Canada?
The Canadian mod-bit supplier base is dominated by Soprema Canada (Quebec-based subsidiary of French Soprema group — Sopralène torch, Soprastick self-adhered, Sopralast premium cap), IKO Industries (Canadian manufacturer Brampton ON — Torchflex SBS torch, Innovi self-adhered, MultiPly 3-ply systems), BP Canada (Quebec-based manufacturer — Bitupore SBS torch and self-adhered, Polybitume APP), GenFlex / Tremco / Carlisle (US suppliers via Canadian distribution), Bauder Canada (German group via Toronto distributor), and Polyglass (Italian group via Vancouver and Toronto distribution). All major suppliers carry CCMC evaluation, CSA A123.21 listing, and 15-20 year manufacturer warranties when installed by CRCA-member contractors. CRCA, Ontario Industrial Roofing Contractors Association (OIRCA), and provincial equivalents maintain installer certification programs.