Flat Roof Options
Since no roofing system is suitable for all buildings and all needs, it is advisable to hire an expert to evaluate all the issues. The list below summarizes the major recognized systems available and proven in Quebec.
See also below our COMPARATIVE TABLE of major conventional flat roof systems.

ROOFING TYPE | AVERAGE PRODUCT LIFE (1) | ANNUAL COST (2) | PURCHASE PRICE (2) | RELIABILITY (3) | VERSATILITY (4) | REFLECTIVITY (5) | ENVIRONMENTALLY FRIENDLY (6) |
TPO Membrane | good | very low | low | average | good | very good | very good |
Modified bitumen membrane (elastomer) | good | average | high | reliable | very good | average | low |
EPDM Membrane | good (1) | low | high | average | good | good | good |
Built-up roof (asphalt and gravel) | low | high | low | very reliable | low | low | very low |
PVC Membrane | good | low | average | average | good | very good | low |
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Product life is not only based on the sustainability of the material itself but also on its seams, for example EPDM membrane itself is very durable but its glued joints last often less than with other systems..
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Cost classification is based on a small area (less than 200 square meters or 2000 square feet). Beyond that, mechanically attached systems become more and more economical, even compared to ballasted systems.
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Reliability includes resistance to fire, impacts, punctures, tears and natural elements.
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Versatility considers ease of installation in all circumstances and the ease of modification and repair.
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Reflectivity depends largely on the effectiveness of the system to self-clean.
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CClassification of the ecological value of a system is not only based on its recyclability since some materials are recyclable but not recycled, such as elastomer in Quebec. This value is greatly affected by sustainability but also by the amount of energy required in the material’s life cycle.