Roof Painting
A Cool Roof is more than just a roof painted with Aluminum. To be a Cool Roof, a roof must be treated with a specialized coating material that is lightly colored and has two unique properties: high solar reflectivity and high infrared emissivity. A cool roof reflects and emits the sun's heat back to the sky instead of transferring it to the building below. "Coolness" is measured by two properties, solar reflectance and thermal emittance. Both properties are measured from 0 to 1 and the higher the value, the "cooler" the roof. Aluminum paint DOES NOT meet this requirement.
Because of aluminum paint’s low infrared emissivity, it makes it very difficult to employ one of the most important tools for detecting trapped moisture in flat roof systems, thermal imaging. The low emissivity of aluminum paint significantly reduces any heat signature that would be indicative of trapped moisture. This is why we employ specialized infrared imagers with a spectral response more able to detect the slight thermal signatures given off by highly reflective aluminized roofs.
Solar reflectivity expresses the degree to which a roof reflects the visible, infrared and ultraviolet rays that comprise solar energy. Surfaces with high solar reflectivity reflect more infrared and ultraviolet rays.
Infrared emissivity refers to the roof's ability to give off its absorbed heat. Highly emissive surfaces are cooler than non-emissive surfaces since they have the ability to shed more absorbed heat at a faster rate.
A Cool Roof reduces the amount of energy absorbed by the roof which helps lower a building's temperature and cuts energy costs.
Aluminum paint has VERY LOW emissivity keeping absorbed heat in your buillding and preventing you form using Infrared Imaging as a valuable diagnostic tool for finding trapped moisture and leaks! Go to NYC CoolRoofs to learn more. Also visit the Cool roof Rating Council for additional information and technical details about Cool Roofs