Frequently Asked Questions - Flat roofs

Our experts answer the most common questions about flat roofs. This information helps you to better understand roofing systems, service, and repairs. However, each case is specific to your type of roof and building. The advice of a roofing specialist may be necessary for a complete evaluation. Contact us for additional information.

Pitched Roof Commercial
  • General Questions
  • Inspection
  • Insulation
  • Ventilation
  • Covering
  • Water Infiltration
  • Snow Removal
  • Workforce
  • Les Couvreurs Duro-Toit has existed for how long?
    he company was founded in 2006. From the beginning, it has grown at a fast pace due to the quality of its work and its professionalism. Today, our team includes more than 35 members passionate about roofing. Our commitment to each project remains our priority.
  • What certifications does Les Couvreurs Duro-Toit hold?
    Les Couvreurs Duro-Toit meet the highest industry standards regarding flat-roof work. These certifications include:
    CAA Habitation for the quality of the work and the high rate of satisfaction.
    Member of the RBQ, ACQ, CCQ, APCHQ.
    Manufacturers' certifications (BP, SOPREMA, Ventilation Maximum, etc.).
    APCHQ Prevention Mutual.
    Office of Consumer Protection.
    Each employee has his competency cards.
  • When should you change the covering of a flat roof?
    The signs vary depending on the type of membrane; a rooftop terrace and a green roof require different expertise. The elastomer may have folds in the membrane, the covering may be abnormally deteriorated, and joints may be cracked. On the other hand, the asphalt membrane may be missing gravel or have bubbles or cracks in the covering. If you want to have the opinion of an expert, our technical consultants can visit the site to verify the quality of the covering.
  • Regular inspection must consider which elements?
    We must inspect all aspects of the roof, such as the attic, exterior siding, openings, walls, structure, decking, etc. A full inspection will reveal more information to better understand the state your roof and your entire building.
  • When should you inspect a flat roof?
    Every three months, check the openings, mechanical boxes, the membranes, metal flashings, drains, and all other components of the flat roof. Particular expertise is required in the case of a rooftop terrace or green roof.
  • How to calculate the R-value of the insulation?
    The insulation requirements vary depending on the building system. It is suggested to consult the description sheet to know the R-value of the insulation. The data may vary in case of a rooftop terrace or green roof.
  • What is the best insulation system?
    To date, polyurethane is one of the best performing products. It allows you to attain a high R-value in a narrow spacing. It also acts as an air and vapour barrier. As regards thermal roofs, polyisocyanurate panels are among the most efficient on the market.
  • How to ventilate the house if it does not have enough air space?
    You can modify the structure to create an air vacuum which promotes better circulation in the attic. Otherwise, you can simply replace the existing insulation by using an insulator with a high R-value, such as polyurethane. This solution will significantly increase the resistance of the insulation in the attic.
  • How to determine ventilation requirements according to the type of roof?
    Manufacturers have specific factors that they measure to provide the best diagnosis based on the type of roof, as in the case of a rooftop terrace or green roof. These factors are, for example, the spacing available in the attic, the number of square feet of insulated ceiling, and the configuration of the attic. For more information, see our technical consultants. They will inform you on the ventilation requirements for your type of roof.
  • What is the most durable covering for flat roofs?
    Specifically for the temperatures in Quebec, the best choice is the two-layer elastomer. It consists of two hot-melted modified bitumen membranes. It is recommended to use this system for flat roofs and green roofs.
  • What covering is to be avoided for flat roofs?
    There is no bad type of coating. The key is to select the proper coating in recognition of the needs of the building. For example, it is advisable to opt for a more flexible membrane when the building structure is given to change in reaction to temperature changes. In the case of a roof terrace or a green roof, it is best to check with an consultant.
  • How do you spot a water entry point on a flat roof?
    In the case of a steel deck, one can follow the grooves to easily identify the entry point. If you find that water has infiltrated, please consult our specialists roofers, especially in the case of a rooftop terrace or green roof.
  • How do you prevent water seepage?
    An efficient roofing system will not be exposed to the risk of water infiltration. Ideally, it is necessary that the entire system is in good condition, including the ventilation and insulation. Recommended maintenance include snow and ice removal and regular inspections.
  • Why is it important to protect the storm drain from ice?
    Ice can affect the integrity of the building, causing water infiltration. You must clear the drain of ice so that it does not clog. When blocked by ice, water accumulates and creates backups.
  • Why is snow removal necessary for flat roofs?
    When ice forms, the excess weight can weaken the building structure. The risk of collapse or weakening of the structure become possible. It is recommended to remove snow and ice from flat roofs when it surpasses 28 inches.
  • Why entrust snow removal to roofers?
    Flat roofs require particular attention as to the de-icing of storm drains and openings. Roofers know how to identify and properly maintain all components of flat roofs. By entrusting this work to us, you are assured of the thoroughness of the snow removal in addition to being protected should a problem arise.
  • Les Couvreurs Duro-Toit bring together what trades?
    Our company has a team specializing in flat-roof work, both for repairs or new installations. Our workforce includes 35 experts in their fields, whether for laying asphalt shingles, membrane, sheet metal (tinsmiths), and exterior siding. We also have technical consultants, servicemen, estimators, a Security Manager, and office staff to coordinate customer service, construction sites, and billing.
  • How do you ensure safety?
    Each employee is committed to implementing the prevention program and all safe work practices. We also have ongoing development programs on work safety practices. Both for our company and our employees, workplace health and safety is integral to our mission.