Flat and low-pitched roofs contribute to the creation of thermal islands in summer, due to the black or dark surfaces that absorb the energy of the sun. These localized hothouse effects increase the surrounding air temperature by several degrees. Simply installing light colured or white roofing materials can reduce the effects on human health and save energy on air-conditioning, reducing GHG emissions.

Our recommendations :

1. Elastomeric membranes are asphalt membranes combined with elastomer (flexible polymer). Their lifespan is approximately 21 years in Canada: good quality products that are well installed can last longer. Choose white membranes: they reduce thermal islands and the heat transferred to the building in summer, which allows you to save energy on air-conditioning.
2. Well-installed green roofs are a very eco-responsible solution because they reduce impact to human health by reducing the effect of thermal islands. They also encourage biodiversity, reduce water runoff pollution and improve roof insulation, cutting energy consumption for heat and air-conditioning. But the structure of existing houses usually has to be significantly reinforced to support the additional weight, which could lead to high costs. These roofs require regular maintenance and sometimes irrigation.
3. Multilayer asphalt membranes are composed of several layers of felt saturated with bitumen, with the top layer covered with gravel. They are economical and widely used, but less ecological than other alternatives because they are made with non-renewable resources and are not recyclable. Their lifespan (average of 15 to 20 years) depends on the quality of the installation. Use white gravel rather than grey, to reduce the effect of thermal islands and the amount of heat transferred to the attic in summer.

Return to Roofing and exterior cladding ←