What is a “Cool Roof”?
A cool roof is a roofing system with high solar reflectivity (the ability of the surface to reflect UV and infrared wave lengths of the sun) and high emissivity (the ability of the surface to radiate any absorbed heat). Nearly any roof can be converted into a cool roof through the application of white reflective roof coatings.
Over 90% of the roofs in the United States are dark colored. In full sun on an 85°F day, a black EPDM roof can reach temperatures near 190°F. The photos below show the difference between a white coated cool roof (coated with 838 TOP® White) and an uncoated metal roof on a 85°F day.
Decreasing temperatures of the roof system can contribute to:
- Lowering cooling costs
- Reducing the interior temperature
- Creating a more comfortable environment inside buildings with no insulation
- Slowing deterioration of roofing materials
- Increasing the effectiveness (R-value) of roof insulation
- Reducing air pollution
Typically, the long term financial benefits of a cool roof are also an advantage. Some of the benefits include:
- Coatings are typically not considered a new roof and can be expensed
- Life cycle cost of the roof is lowered because the existing roof is still functioning
- Roof restoration with coatings is significantly less expensive than roof replacement
- Opportunity for energy credits and rebates
- Minimal disruption to occupants and operation inside the building