Roofing contractors have installed cool roofing products on commercial, industrial, and residential buildings for more than 20 years. Cool roofing isn't a style, nor is it a fad. It's a building practice that can lower a building's energy costs and positively support the environment.
Learn how a few simple adjustments in materials and roofing practices could reduce a building's energy costs and improve climate and community.
Cool Roofs, Explained
"A cool roof is designed to reflect more sunlight than a conventional roof, absorbing less solar energy," explains the U.S. Department of Energy. In turn, this roof helps lower the temperature of the building. The concept is similar to wearing light-coloured clothing in hot weather. Your clothing reflects the sunlight and helps keep you cool. A cool roof reflects sunlight and helps keep the roof and overall building cooler.
Many types of roofing materials offer "cool" roof options depending on the product color and formulation.
"The surface solar reflectance of the roofing product—the outermost layer of the roof exposed to the sun—determines whether the roof is cool or not," says the U.S. Department of Energy.
“A (cool roof) or sustainable roof may be characterized as one that gives due consideration to energy, durability, and the environment throughout its lifecycle,” says the National Research Council of Canada.
For low slope roofs, viable cool roofing products include:
• High SRI rated single-ply membrane
• High SRI rated modified bitumen membranes
• Reflective coatings
• Metal roofs using light colors
• Green (vegetative) roof coverings (while vegetative roofs aren't reflective, they are still heat-mitigating)
• Roof Mounted photovoltaics (PV)
A roof has to meet particular criteria to be designated "cool." The requirements vary depending on the classifying organization and local government, so check with a qualified contractor or design professional before making assumptions about a roof's official rating.
While cool roof coatings or materials can be retrofitted onto a building during a repair or replacement, the easiest and most affordable way to get a cool roof is by planning for it in the construction phase. Cool roofs can cost about the same as non-cool alternatives.
The Benefits of Cool Roof Systems
Cool roofs benefit building owners, occupants, and the community surrounding them.
If you operate or own a building with a cool roof, you can expect:
• Reduced air conditioning needs, and thus lower energy bills. Energy Star® estimates a cool roof can reduce cooling demand by 10–15%. Energy bills are further supported by the fact that cool roofs help reduce thermal heat gain/thermal emission into the space directly beneath the roofing layer.
• More efficiency out of smaller or older air conditioning units.
• Longer roof service life. Cool roofs reflect harmful ultraviolet and infrared radiation that damages many roofs over time.
• Potential tax rebates. Check for local rebate and grant programs in your area.
If you live or work in a building with a cool roof, you can expect:
• A more comfortable indoor environment, especially if your space isn't air-conditioned.
• Improved health and safety, as cool roofs reduce temperatures inside buildings helping prevent heat-related illnesses.
If you live in a community near a building with a cool roof, you can expect:
• Reduced air pollution and greenhouse gas emissions, according to the EPA.
• Reduced “urban heat island” effects. According to Health Canada, the average air temperature of medium to large cities in North America is generally 1°C to 3°C warmer than the surrounding countryside, and up to 12°C warmer in some places. Cool roofs can help mitigate this impact.
• Improved air quality. According to the Berkeley Lab, "Cool roofs decrease urban air temperatures and thus slow the formation of ground level ozone," which is the main ingredient in smog.
• Less strain on the electrical grid and decreased risk for power outages. The Berkeley Lab adds that less use of air conditioning helps mitigate peak energy demand during heat waves and hot summer days.
Learn More About Cool Roof Systems
Contact a Elevate representative near you to learn more about cool roofing solutions for commercial buildings. Also, check out resources from the Cool Roof Rating Council, a 501(c)(3) non-profit organization that fairly evaluates solar-reflective wall and roofing products. Their website features information about financial incentives and codes for cool roofs, and resources for contractors and building owners.