Blog
20 July 2026
Flat roofs are found on many buildings in Pierrefonds, in Montreal: apartment buildings, plexes, businesses, industrial buildings and flat-roof houses. Whether it is new construction or a roof that needs redoing, durability depends on the materials chosen, the quality of the installation and the maintenance that follows.
Here is what makes a durable flat roof, the concrete benefits of a well-installed system and the signs that it is time to act.
A durable flat roof is not just a horizontal surface sitting on a building. It is a complete system designed to withstand Quebec’s climate: snow buildup, freeze-thaw cycles, heavy spring rains and intense summer heat.
To last, a flat roof must combine several elements:
Each of these elements plays a role in the roof’s longevity. A weakness in just one spot is enough for water to find its way in.
Elastomeric membrane is made of SBS modified bitumen. This blend keeps it flexible, even in cold weather, which reduces the risk of cracking during large temperature swings. It is installed as a two-ply system: a base sheet that provides the basic waterproofing, then a granulated cap sheet that protects the whole assembly from UV rays.
Depending on the building, the membrane is torch-applied or installed as a self-adhered membrane. Toitures OBM uses Soprema systems, for example mechanically fastened conventional or self-adhered conventional systems.
A well-installed membrane, working drainage and adequate insulation reduce the risk ofwater infiltration, mould and structural deterioration. Investing in quality from the start helps avoid repeated repairs later on.
Roof insulation directly affects heating and air conditioning. A well-insulated roof helps keep heat inside in winter and limits overheating in summer. Dry insulation is essential: when wet, it loses much of its effectiveness.
The condition of the roof is one of the items checked during a pre-purchase inspection. A flat roof in good condition, maintained and documented, helps preserve a building’s value.
Some signs are unmistakable: moisture stains on the ceiling, blisters or separation on the membrane, water that sits for several days after rain, visible cracks or granules disappearing over a good part of the surface. Each of these clues calls for an inspection.
A small crack may seem harmless. Left as is, it can become a source of water infiltration that affects the insulation, the wooden components and even the interior walls. The longer you wait, the bigger the work becomes. Depending on the condition of the roof, the solution may be a localized repair, resurfacing or a complete roof replacement.
Even the best-installed roof needs maintenance. An inspection at least once a year, ideally in spring after the winter, makes it possible to check the roof drains and water drainage, seams, upstands, penetrations and the overall condition of the membrane. Cleaning the roof drains, especially in the fall, reduces the risk of water buildup.
With regular maintenance, an elastomeric membrane can protect a building for several decades. When the surface wears, resurfacing (cleaning, preparing the existing membrane and adding a new cap sheet) can extend its service life before a roof replacement becomes necessary.
Toitures OBM is a roofer specializing in elastomeric membrane flat roofs, based at 1215 rue Tellier in Laval. The team works in Pierrefonds and the rest of Montreal, as well as in Laval and on the North Shore. Its services: elastomeric roof replacement, new flat roof construction, repair, resurfacing, maintenance and inspection, for commercial, industrial and multi-unit buildings as well as residential flat roofs.
Toitures OBM is Soprema PAQ+S certified and CAA-Québec Recommended, and holds RBQ licence 5778-2823-01. Before recommending anything, the team assesses the condition of the roof and the needs of the building to avoid unnecessary work, then explains its recommendations clearly. Financing is available through Financeit.
Standing water and lack of maintenance. Clogged roof drains, loose upstands or a small crack left unrepaired can soak the insulation and wear out the membrane prematurely.
Yes. Toitures OBM carries out new flat roof construction with two-ply elastomeric membrane systems, taking insulation, slopes and water drainage into account from the design stage.
No. It is suitable for a membrane that is still sound but has a worn surface. If the membrane has come loose over large areas or the insulation is wet, a roof replacement is more appropriate. The inspection settles the question.
A durable flat roof protects your building, reduces unexpected maintenance costs and helps preserve its value. To have your roof assessed, contact Toitures OBM at 514-449-5469, Monday to Friday from 8 a.m. to 5 p.m., or request a free quote.
OBM Roofing
Elastomeric membrane specialists for commercial, industrial and multi-unit buildings in Laval, Montreal and the North Shore.
