White Roof Reflectivity

A cool roof generally has a reflectivity higher than 65 percent or 65.

White roof reflectivity.

Coatings are like very thick paints that can protect the roof surface from ultra violet uv light and chemical damage and some offer water protection and restorative features. Volunteers have taken white paint to nearly 7 million square feet of tar roofs in the city though that is still only about 1 percent of the potential roof area. It has become a leed leadership in energy and environmental design standard of the u s. Reflectivity is expressed as either a percentage of the sun s rays reflected or the decimal equivalent of that percentage.

White thermoplastic membrane roofs pvc and tpo are inherently reflective achieving some of the highest reflectance and emittance measurements of which roofing materials are capable. Commonly referred to as cool roofing it has received a stamp of approval from the state of california which has adopted its use in its building codes. Citation needed a roof made of white thermoplastic for example can reflect 80 percent or more of the sun s rays and emit at least 70 of the solar. Products are available for most roof types.

There are many small scale initiatives in cities to make roof surfaces more reflective. Green building council and has been mandated by government officials in chicago. New york for instance introduced rules on white roofs into its building codes as long ago as 2012.