Cool roofs are not a new thing. In many parts of the world, people have understood the benefits of white outer walls and roofing for thousands of years. In the warmer climates of the Mediterranean and the Middle East, white buildings are the standard, not the unusual. Roofing materials and roof coatings for leak repair and leaks maintenance like liquid roof coatings and liquid rubber coatings are now also coming in white.
The U.S. Department of Energy began doing research in the 1980s concerning the benefits of more reflective roofing in urban environments. The goal was to reduce “heat islands” caused by black roofing and a combination of other factors in large cities.
In 2001, California changed its code to require cooler roofing on all low-slope buildings, primarily commercial and apartment buildings in and around cities. California’s goal was to reduce electricity consumption and prevent the need for the rolling blackouts that occurred during the summer of 2001.
Today, cool roofing products dominate the commercial and residential roofing market, partly because of the introduction of more reflective materials and different colors. White is no longer the only color to choose from.
The main benefit of cool roofs is lower summertime utility bills because of a reduced need for air conditioning. Owners of large buildings may be able to decrease the size of their air conditioning units. The lifespan of an existing air conditioning unit may be increased as the demand placed on the unit is decreased.
Certain types of products may expand the lifespan of the roof itself. For example, EPDM and other coatings applied to an existing roof provide additional protection from the elements. EPDM coatings create a more water resistant surface helping to prevent leaks and the need to replace the roof deck.
There are other indirect benefits. As more buildings in a city turn to cooler roofing products, the temperature around the city decreases. Vehicles require less air conditioning and use less gasoline.
People outdoors in the community are more comfortable. There is less smog and public health improves. Cool roofs indirectly reduce power plant CO2 emissions by reducing total electricity consumption.
Many different types of roofing materials are rated by the Cool Roof Rating Council (CRRC) for their ability to reflect solar radiation and emit heat rather than trapping it. In addition to the coatings that can be applied to nearly any type of existing roof, there are also new kinds of shingles, slate, tile and rubber polymers.
A good roofing contractor can help you compare the cool roofs that will work for your building. You may have lots to choose from.