Standard bitumen membranes become brittle in cold temperatures and can crack under freeze-thaw cycling. SBS (Styrene-Butadiene-Styrene) polymer modification gives elastomeric membranes their key property: they stretch and recover rather than crack. In Gatineau’s climate, where rooftop temperatures swing from -30°C in January to +60°C on a July rooftop, this elasticity is the difference between a roof that lasts decades and one that fails within years.
The Two-Layer System: How It’s Installed
A complete elastomeric membrane installation uses two layers. The base ply is torch-applied directly to the roof deck or insulation board, creating the primary waterproofing layer. The granulated cap sheet is torch-applied over the base ply — its mineral granule surface provides UV protection, impact resistance, and additional waterproofing. All seams are overlapped and fully welded. Torch welding requires certified technicians; Cossette roofers hold the specific certifications required under Quebec law.
Where Elastomeric Membrane Is Used on Gatineau Homes
Many Gatineau and Hull homes have flat or low-slope sections: attached garages, rear additions, enclosed porches, or sunrooms. These sections are the most common sources of water infiltration calls in the region. A properly installed two-layer elastomeric membrane system on these areas provides 35–40 years of reliable waterproofing.
Elastomeric vs. TPO vs. EPDM in Quebec
EPDM (rubber membrane) and TPO are alternatives used more commonly in large commercial applications and in the United States. SBS elastomeric membrane has a longer track record in Quebec’s climate and is the dominant residential and small commercial flat roofing system in the province. Cossette installs TPO on larger commercial buildings where it is specified; SBS is the default recommendation for residential flat roofs.
Frequently Asked Questions
Can elastomeric membrane be installed in Quebec winter?
Torch application of SBS membrane is temperature-sensitive — most manufacturers and Quebec building standards recommend above 5°C for installation. Cold-weather installation requires additional preparation and may involve heating the deck. Cossette schedules flat roofing work accordingly and advises on timing during the estimate.
Does elastomeric membrane need maintenance in Gatineau?
Biannual inspection (spring and fall) is recommended to check seams, flashings, and drain clearance. Beyond inspection and drain cleaning, a properly installed elastomeric membrane requires minimal active maintenance for the first 20–25 years of its life.
Can a failing elastomeric membrane be repaired rather than replaced?
Yes, in many cases. Localized seam separations, penetration failures, or small cracks can be repaired if the membrane is less than 20 years old and damage is contained. Cossette assesses repairability during a free inspection — if a targeted repair will perform reliably, that is always the recommendation.