Get a Cool Roof
With traditional dark-colored roofs, light is not reflected and the roof absorbs heat. This heat then penetrates through to the interior building, increasing cooling costs.
Dark roofs absorb and hold more than 80% of solar energy, while white roofs can reflect 75% of solar energy. That makes a white-roofed building cooler and cheaper to air-condition.
With advances in roofing materials, cool roofs no longer need to be white. New technologies in cool roofing have two important physical properties: Solar reflectance and thermal emittance. Solar reflectance is a measure of the solar radiation that is immediately reflected off the roof surface back into the atmosphere without heating the roof itself. Thermal emittance is a measure of solar energy that the roof bounces back into the atmosphere as infrared light after being initially absorbed.
Cool roofing is now available in many different colors, including darker-colored pigments that are highly reflective. Also, cool roofs are manufactured for virtually any type of roof — hip, square, flat, or pointed — in many different forms, including shingles, tiles, modified bitumen, single-ply membrane and field-applied coatings.
It is estimated that 90% of roofs in the U.S. are dark colored. A study conducted by Lawrence Berkeley National Laboratory found that installing a cool roof could reduce the energy cost of cooling equipment up to 52%. Implementing cool roofs nationwide could result in an annual savings of $1 billion in cooling costs.
For more information on cool roofing, visit the Cool Roof Rating Council (CRRC). The CRRC is an independent, non-profit rating entity that measures roofing product surfaces for radiative properties through Accredited Independent Testing Laboratories (AITL). They also provide an online Rated Products Directory and other helpful resources