Fully bonded plies
The cap sheet is heat-welded to the base sheet across its entire surface, so there are no open laps for wind-driven rain to work through.
Flat & low-slope roofing · Metro Vancouver
2-Ply Torch-On Roofing in Vancouver
The two-layer SBS membrane system we have specialised in for 25 years. One continuous waterproof skin, no open seams, and a 25 to 30 year service life on Lower Mainland flat roofs.
25+Years on flat roofs
850+Roofs completed
25–30 yrTorch-on service life
$5MHot-work insured
Torch-on roofing in Vancouver, in short
- What it is
- A two-layer SBS modified-bitumen membrane, heat-welded with a propane torch into one continuous waterproof skin. It is the most common flat-roof system in Metro Vancouver.
- What it costs
- $10 to $20 per square foot installed in Metro Vancouver in 2026. A typical 1,500 sq ft flat roof runs $15,000 to $30,000.
- How long it lasts
- 25 to 30 years when it is installed as a true 2-ply system and the drains are kept clear.
- How long it takes
- Two to four working days for a typical 1,500 sq ft residential roof, weather permitting.
- Who installs it here
- Pro Torch Roofing, a family-run flat-roof specialist at 7060 Waltham Ave, Burnaby BC. Over 25 years, 850+ roofs, $5M hot-work liability insurance.
- Where we work
- Vancouver, Burnaby, North and West Vancouver, Richmond, Coquitlam, the Tri-Cities, the Sunshine Coast and Bowen Island.
The system
What is 2-ply torch-on roofing?
2-ply torch-on roofing is a two-layer SBS modified-bitumen membrane system for flat and low-slope roofs. A reinforced base sheet is fastened or torched to the deck, then a granulated cap sheet is heat-welded over it with a propane torch, forming one continuous waterproof skin with no open seams.
In Metro Vancouver it is the most common flat-roof system, and a properly installed 2-ply torch-on roof lasts 25 to 30 years. Pro Torch Roofing has installed torch-on membrane across Vancouver, Burnaby and the North Shore for over 25 years — it is the only flat-roof system we specialise in.
The full assembly, bottom to top
The membrane is the part you see. Underneath it sit four layers that decide whether the roof drains, stays dry and survives the torch. This is the build-up we specify on a typical Lower Mainland flat roof.
Drag the model to turn it
- Structural deckPlywood, steel or concrete, primed. Soft or rotten sheathing is replaced before anything goes over it.
- Vapour barrierA self-adhered membrane — typically IKO MVP — sealed to the deck so warm indoor air cannot push moisture up into the insulation.
- Tapered insulationFlat polyiso plus a tapered package, cut to a slope and adhered. This is what makes water run to the drains instead of sitting on the roof.
- Protection boardA hard, heat-tolerant board over the foam, so the torch never meets insulation and foot traffic never dents it.
- SBS base sheetReinforced 3 mm SBS (IKO TP-180), torched or mechanically fastened, with every side lap overlapped and sealed.
- SBS cap sheet4 mm granulated cap (IKO TP-250), heat-welded to the base across its full surface. The bead of bitumen at the lap is the proof of a proper weld.
Built for this climate
Why torch-on is the right flat roof for Vancouver
Vancouver receives roughly 1,150 mm of rain a year and flat roofs hold standing water for days at a time. Torch-on performs well here for four measurable reasons:
Cold flexibility
SBS-modified bitumen stays flexible to about −30°C, so it survives the coastal freeze-thaw cycle without cracking.
UV resistance
The mineral-granule cap sheet does not soften or break down in summer sun.
No hot tar
There is no odour or fumes, so occupants do not need to leave the building during installation.
Skylights, HVAC curbs and drains can be added later and flashed into the membrane. Compared with single-ply TPO or EPDM, torch-on is heavier, more puncture resistant, and far easier to repair locally because most Lower Mainland roofers carry SBS material.
Installed, 2026$10–$20 / sq ft
Typical 1,500 sq ft flat roof$15,000 – $30,000
What a torch-on roof costs in Vancouver
A new 2-ply torch-on roof in Metro Vancouver typically costs $10 to $20 per square foot installed, so a 1,500 sq ft flat roof usually lands between $15,000 and $30,000. Overlays sit at the low end; full tear-off with new insulation sits at the high end.
- Whether the old roof can be overlaid or must be torn off
- The number of drains, curbs and parapets to flash
- Any insulation or tapered-slope package
- Roof access
For a number specific to your roof, use our flat roof cost calculator or book a free on-site measure. We quote in writing, with the membrane manufacturer and warranty term named on the estimate.
The build
How a 2-ply torch-on roof is installed
A typical 1,500 sq ft residential torch-on roof takes two to four working days, weather permitting. These are the five stages we follow on every job.
Inspection and tear-off decision
We check the deck, drains and existing membrane. If the old roof is dry and sound it can be overlaid; if the deck is wet or soft it comes off.
Deck prep and insulation
Rotten plywood is replaced, drains are cleared and any insulation or tapered-slope package is laid so water runs to the drains.
Base sheet
A reinforced SBS base sheet is mechanically fastened or torch-adhered to the deck with overlapped, sealed side laps.
Cap sheet
The granulated cap sheet is rolled out and heat-welded to the base sheet across its full surface, producing one continuous membrane.
Flashing, primer and inspection
Every drain, curb, parapet and wall is flashed with custom sheet metal and two-ply membrane detailing, then the whole roof is walked and documented.
Watch
Father and son, and the first blue flat roof in West Vancouver
Pro Torch is a family business — father and son on the same roof. This one in West Vancouver is the first blue torch-on flat roof we know of in the city.
Prefer to watch it on YouTube? youtube.com/watch?v=to0LC-5DKlE
Our work
Torch-on roofs we have built
Every photo below is a Pro Torch roof in Greater Vancouver, shot on the job or from our own drone.
Comparison
Torch-on vs TPO vs EPDM for Vancouver flat roofs
All three are used in BC. For most residential and strata roofs under about 10,000 sq ft, 2-ply torch-on is the most durable and the easiest to repair.
2-ply torch-on (SBS)
- Layers
- 2 bonded plies
- Lifespan
- 25 to 30 years
- Installed cost
- $10 to $20 / sq ft
- Best for
- Homes, strata, small commercial; roofs with many penetrations
TPO
- Layers
- Single ply
- Lifespan
- 15 to 25 years
- Installed cost
- $9 to $15 / sq ft
- Best for
- Large open commercial roofs where reflectivity matters
EPDM
- Layers
- Single ply
- Lifespan
- 15 to 25 years
- Installed cost
- $8 to $14 / sq ft
- Best for
- Budget commercial roofs with few penetrations
FAQ
Torch-on roofing questions, answered
How long does a torch-on roof last in Vancouver?
A properly installed 2-ply torch-on roof lasts 25 to 30 years in the Vancouver climate. Lifespan drops sharply if drains are left blocked or if the roof was installed as a single ply.
How much does torch-on roofing cost per square foot?
In Metro Vancouver, 2-ply torch-on runs $10 to $20 per square foot installed in 2026. Overlays and simple rectangular roofs are at the low end; tear-offs with insulation and many penetrations are at the high end.
What is the difference between 2-ply and 3-ply torch-on?
2-ply uses a base sheet and a cap sheet and is the standard for BC flat roofs. 3-ply adds a second base sheet for extra thickness on high-traffic or high-risk roofs; it costs roughly 15 to 20 percent more and is rarely necessary on residential roofs.
Can torch-on be installed over an existing roof?
Yes, if the existing roof is dry and the deck is sound. A moisture scan or core cut during the free inspection tells us which. Wet insulation must be removed or it will rot the new deck from underneath.
Is torch-on roofing safe? Does it use an open flame?
It does. That is why torch-on should only be installed by crews trained in hot-work procedures, with fire watch and extinguishers on the roof, and by a contractor whose liability insurance specifically covers torch application. Pro Torch Roofing carries $5 million in liability coverage that includes hot-work roofing.
Does torch-on roofing smell during installation?
No. Torch-on uses no hot tar, so there is no strong odour and occupants do not need to leave the building.
Can a torch-on roof be done in winter in Vancouver?
Yes, on dry days above about 5°C. The membrane cannot be applied to a wet deck, so winter jobs are scheduled around the forecast and tarped between work days.
What warranty comes with a torch-on roof?
Pro Torch Roofing provides a written workmanship warranty and installs manufacturer-backed SBS membrane systems such as SOPREMA, whose material warranties are registered in the owner's name. The exact term is stated on every estimate.
Service area
Torch-on roofing across the Lower Mainland
We install torch-on membrane roofs throughout Greater Vancouver from our base in Burnaby. Pick your city for local details, or browse completed torch-on projects.
Get a straight answer about your flat roof
A free on-site measure, a written quote naming the membrane manufacturer and warranty term, and photographs of what we found — whether you hire us or not.
