Torch-On vs. TPO roofing: which system fits your building?
Torch-on SBS is a reinforced asphalt membrane known for robust layered construction; TPO is a single-ply thermoplastic with heat-welded seams. Deck, fire risk, odour, building use, climate, crew capability and maintenance determine the fit. The written scope should state the assumption that changes the answer.
Installation method
Torch-on uses controlled flame and requires hot-work procedures. TPO uses hot-air welding, with attachment and insulation design tailored to the deck and wind exposure.
Service and repair
SBS is familiar for many repair crews and resists puncture through multiple layers. TPO seams can be tested and rewelded, while surface contamination and membrane compatibility require care.
Occupied-building constraints
Air intakes, odour sensitivity, combustible transitions and tenant operations can rule out an otherwise suitable installation method.
Side-by-side comparison
| Decision factor | Torch-on SBS | TPO |
|---|---|---|
| Membrane | Multi-layer reinforced asphalt | Single-ply thermoplastic |
| Seams | Heat-fused laps | Hot-air welded laps |
| Site concern | Hot-work and combustible details | Weld quality and membrane compatibility |
| Useful fit | Robust, repairable low-slope assemblies | Large roofs needing heat-welded single-ply |
| Confirm | Fire controls, substrate, drainage | Attachment, insulation, wind and trained crew |
Details worth checking
- Deck type
- Existing assembly
- Fire and odour constraints
- Drainage
- Rooftop traffic
- Installer training
- Warranty and maintenance support
Continue with a related roofing topic
What is the best roofing system for a commercial building?
The best commercial roofing system is the one compatible with the deck, insulation, slope, drainage, rooftop use, interior operations, fire and odour constraints, maintenance and budget.B.C. roofing advice
Roofing advice is most useful when it gives a direct answer, explains the conditions that change it and points to a practical next step.How long does a flat roof last in British Columbia?
Many SBS, TPO and EPDM roofs are planned for multi-decade service, but actual life depends on drainage, seam quality, wet insulation, rooftop traffic, exposure and maintenance.Apply the information to the actual roof
Share the property, roof type, observed condition and decision timeline. A site-specific review can confirm which parts of the guidance fit and where the scope needs to change. SBS is familiar for many repair crews and resists puncture through multiple layers.
Share your project details