Blog
1 June 2026
In Anjou, in Montreal, owners of apartment buildings, commercial buildings and flat-roof homes all face the same reality: a flat roof is unforgiving of neglect. Water drains slowly, snow piles up and the membrane goes through freeze-thaw cycles year after year.
Elastomeric roofing, made of SBS modified bitumen membranes installed in two plies, is a proven solution for this type of roof. Here is how it works, which signs should get your attention and how a project with Toitures OBM unfolds.
On a flat or very low-slope roof, water doesn’t drain off quickly on its own. The covering must therefore form a continuous, watertight surface that can hold water and snow for long periods. The elastomeric membrane meets this need.
The SBS polymer added to the bitumen makes the membrane elastic. It can follow the building’s expansion and contraction as temperatures swing without cracking, which matters in the Quebec climate.
The two-ply system consists of a base sheet and a granulated cap sheet. The seams of the two plies are staggered, and the granulated surface protects the membrane from UV rays. If the top ply is damaged, the base sheet continues to do its job.
An elastomeric membrane lends itself well to localized repairs and resurfacing. When a problem is caught early, it can often be corrected without replacing the whole roof.
Several clues, visible from inside or on the roof, call for an inspection:
A single one of these signs doesn’t mean the whole roof has to be redone. Rather, it indicates that an on-site assessment is advisable to find the cause.
Acting early often makes the difference. A leak that lasts several seasons can soak the insulation, damage ceilings and affect the roof structure. In an apartment building, it can also disturb the top-floor tenants. A small repair done at the right time generally costs less and is less disruptive than a larger job.
Depending on the condition of the roof and the needs of the building, Toitures OBM may propose one of these services.
It addresses a localized leak, a crack, a loose section or resealing around roof drains and penetrations, when the rest of the membrane is sound.
When the membrane is ageing but still watertight, resurfacing includes cleaning, preparing the existing membrane and applying a cap sheet.
When the membrane reaches the end of its life or leaks keep multiplying, a roof replacement replaces the system with a new two-ply roof. Toitures OBM installs Soprema systems, such as the mechanically fastened conventional system or the self-adhered conventional system.
Toitures OBM also builds flat roofs for new construction and provides maintenance and inspection of existing roofs: roof drains and water drainage, seams, upstands, penetrations and the overall condition of the membrane.
Every project begins with a thorough analysis of the condition of the roof and the needs of the building. The goal is simple: recommend the work that is needed, and nothing more.
The team examines the membrane, roof drains, upstands, seams and penetrations. It looks for the cause of the problems observed rather than just treating the symptoms.
The owner receives a clear, explained recommendation: repair, resurfacing or replacement, depending on what the roof really needs.
The work follows a structured method: preparing the substrate, installing torch-applied or self-adhered membranes, detailing around roof drains and penetrations, then checking water drainage.
Toitures OBM is based at 1215 rue Tellier in Laval and works in Anjou as well as in the rest of Montreal, in Laval and on the North Shore. The company specializes in elastomeric membrane flat roofing for commercial buildings, industrial and multi-unit buildings, as well as residential flat roofs.
Toitures OBM is Soprema PAQ+S certified, CAA-Québec Recommended and holds RBQ licence 5778-2823-01. The team is available Monday to Friday, from 8 a.m. to 5 p.m., and financing is available through Financeit.
Yes. The elastomeric membrane is designed for flat and low-slope roofs, which includes duplexes, triplexes and apartment buildings. The system chosen depends on the substrate and the insulation in place.
When the problem is localized and the rest of the membrane is in good condition, a targeted repair may be enough. An on-site assessment makes it possible to determine this.
Spring lets you see the effects of winter, and fall lets you prepare the roof before the snow. An inspection is also useful after a strong windstorm.
Have you noticed a leak, or is your flat roof getting old? Contact Toitures OBM at 514-449-5469 or request a free quote through the form. The team will assess the condition of the membrane and explain the possible options.
OBM Roofing
Elastomeric membrane specialists for commercial, industrial and multi-unit buildings in Laval, Montreal and the North Shore.
