White Roof Reflectivity

Reflectivity is expressed as either a percentage of the sun s rays reflected or the decimal equivalent of that percentage.

White roof reflectivity.

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. 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. There are many small scale initiatives in cities to make roof surfaces more reflective. Cool roof coatings are white or special reflective pigments that reflect sunlight.

It has become a leed leadership in energy and environmental design standard of the u s. Green building council and has been mandated by government officials in chicago. 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. Products are available for most roof types.

New york for instance introduced rules on white roofs into its building codes as long ago as 2012. 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. A cool roof generally has a reflectivity higher than 65 percent or 65.