If you own or manage a commercial building in Gatineau or Ottawa, choosing the right flat roof system is one of the most significant maintenance decisions you will make. The two most common options are elastomeric membrane (SBS modified bitumen) and TPO (thermoplastic polyolefin) membrane. Both perform well, but they have important differences in installation, durability, and cost in the Quebec climate.
What Is Elastomeric Membrane (SBS Modified Bitumen)?
Elastomeric membrane has been the standard flat roofing system in Quebec for over 30 years. Made from bitumen reinforced with SBS polymer, it remains pliable at temperatures as low as -40 degrees Celsius and is installed by torch welding, creating fully bonded seams that resist wind uplift and water infiltration. Our flat roofing and elastomeric membrane service covers both residential and commercial applications, with proven lifespans of 35 to 40 years.
What Is TPO Membrane?
TPO is a single-ply synthetic roofing membrane installed in large heat-welded sheets. Its white or light-coloured surface provides strong solar reflectance and energy efficiency benefits, particularly in summer. It is lighter than SBS membrane and easier to install on buildings with complex rooflines or numerous mechanical penetrations.
How Do They Compare in Quebec’s Climate?
Both systems perform well in Quebec, but there are key differences. Elastomeric SBS membrane has a longer track record in the Quebec climate with proven 35 to 40 year lifespans, and its torch-welded seams are highly resistant in extreme cold. TPO excels in energy efficiency and handles UV exposure well, but seam integrity over long Quebec winters is highly dependent on installation quality. The Regie du batiment du Quebec oversees building standards for both systems — always ensure your contractor holds a valid RBQ licence before any commercial roofing work begins.
Which System Is Right for Your Commercial Building?
For most commercial buildings in Gatineau and Ottawa, elastomeric SBS membrane is the recommended choice due to its proven longevity and cold-weather performance. TPO is a strong option when energy efficiency or a reflective roofing system for LEED certification is a priority. Cossette’s commercial flat roof team installs and repairs both systems across the Outaouais and Ottawa regions. Contact us for a free commercial roof evaluation and system recommendation tailored to your building.
Frequently Asked Questions
What is the difference between TPO and elastomeric membrane for flat roofs?
Elastomeric membrane (SBS modified bitumen) is a torch-welded rubberized asphalt system with a proven 35–40 year track record in Quebec’s climate. TPO is a single-ply synthetic membrane heat-welded in large sheets, offering stronger solar reflectance and energy efficiency benefits, particularly in summer.
Which flat roof system lasts longer in Quebec?
Elastomeric SBS membrane has a longer proven lifespan in Quebec, with documented performance of 35 to 40 years. TPO is newer in the Quebec market, and its long-term seam integrity in extreme cold depends heavily on installation quality. For most commercial buildings, elastomeric membrane is the recommended choice for longevity.
Is TPO a good choice for commercial buildings in Gatineau or Ottawa?
TPO is a strong option when energy efficiency, solar reflectance, or a LEED-certified roofing system is a priority. Its white surface reduces cooling loads in summer. However, in Quebec’s cold climate, elastomeric SBS membrane is generally preferred for its superior cold-weather performance and longer proven lifespan.
Does my contractor need a special licence for commercial flat roof work in Quebec?
Yes. The Régie du bâtiment du Québec (RBQ) governs building standards and requires contractors to hold a valid RBQ licence for commercial roofing work. Always verify your roofer’s RBQ licence number before any commercial project begins. Cossette Roofing holds all required licences for commercial flat roof installations.
Does Cossette Roofing install both TPO and elastomeric membrane systems?
Yes. Cossette Roofing’s commercial flat roof team installs and repairs both elastomeric SBS membrane and TPO systems across the Outaouais and Ottawa regions. They provide free commercial roof evaluations and system recommendations tailored to each building’s specific needs and priorities.