On beautiful summer days, there’s nothing better than soaking up sunshine. But when we’re trying to beat the heat, we put away the winter blacks and wear our whitest whites. Why? Because white reflects sunlight, keeping us cooler. Roofs are affected in the same way.
The process of building and maintaining a structure includes consideration of how to maximize comfort while reducing energy costs. One of the best ways to do both is to invest in a roof with highly reflective membranes, also known as a cool roof.
Since most dark roofs absorb 90% (or more) of incoming solar energy, roof temperatures can reach in excess of 150°F on those sticky summer days. But much like summer clothes, reflective roofs stay cool and absorb less than 50% of solar energy, which reduces the amount of heat absorbed by the building. That, in turn, reduces the amount of air conditioning demand, which has a multitude of benefits!
BENEFITS OF COOL ROOFS
A cool roof uses a white roof coating (or a light colored roof coating) to reflect sunlight and absorb less heat. Having a roof that reflects heat instead of absorbing it means putting less pressure on your air conditioning. In fact, in some climates, it can completely negate the need for A/C altogether. With lower air conditioning demand, installing a cool roof can potentially save 15-30% on energy bills each month.
These lighter-colored house toppers also offer great curb appeal.
The heat and UV light that dark roofs absorb stress the roof system, resulting in a shorter lifespan. Replacing a roof is both costly and time-consuming, so it’s always best to take steps to ensure the roof lasts as long as possible.
White roof coating is an excellent and environmentally conscious choice. A study by the Lawrence Berkley National Laboratory (reported in the The New York Times) suggests that retrofitting 80% of U.S. air-conditioned commercial buildings with cool roofs would save enough on air conditioning costs to eliminate 6.2 metric tons of CO2 emissions (the output of about 1.2 million cars!). The same study projects it would eliminate 9.9 kilo tons of nitrogen oxides, which roughly equals the output of 600,000 cars. That’s music to Mother Nature’s ears!