Our FAQ

Questions and Answers About Flat Roofs

  • How Do I Choose Between Elastomeric Membrane, TPO, or EPDM?

    It depends on your building, your budget, and your priorities. Elastomeric membrane is the most durable (25 to 35 years) and best adapted to Quebec's climate. TPO and EPDM are lighter single-ply alternatives with a service life of 20 to 30 years.


    Contact us for an assessment — we will recommend the system best suited to your situation.

  • Can a New Membrane Be Installed Over the Old One?

    In some cases, yes. If the wood substrate and insulation are in good condition, it is possible to install a new membrane directly over the existing one, which reduces costs and timelines. However, if the insulation is wet or the decking is damaged, a full tear-off is necessary.


    Our team can assess the situation on-site before recommending one approach or the other.

  • Are White Roofs Mandatory in Montreal?

    In some boroughs, yes. For new construction and non-residential buildings, several Montreal boroughs require a white material or a covering with a Solar Reflectance Index (SRI) of at least 78. For existing residential buildings, the rules vary by borough and roof area.


    Check the requirements for your specific area before choosing your membrane.

  • What Is the Best Season to Replace a Flat Roof?

    Elastomeric membrane can be installed in any season, including winter, thanks to its resistance to temperature fluctuations. For TPO and EPDM membranes, installation conditions are more sensitive to cold. Spring and summer remain the most popular times.

  • How Do I Know Whether to Repair or Replace My Roof?

    If the problems are localized (a delaminated flashing, a small crack, a blocked drain), a repair is generally sufficient. However, if you are dealing with recurring infiltrations despite previous repairs, a membrane deteriorated across the entire surface, or wet insulation, that is a sign that replacement or reconstruction is the better option.


    See our roof reconstruction page for more information.

  • Does ML Pro Toitures Work With General Contractors?

    Yes. We regularly collaborate with general contractors on residential, commercial, and industrial projects. Several of our partners entrust us with their roofing mandates on an ongoing basis.


    Contact us to discuss your project.

Have more questions?
Our team is here to answer them.