A commercial roof proposal may describe a membrane as white or reflective without identifying the exact product tested. Ask for the manufacturer, product name, color and rating identifier. Use those details to find the proposed surface in the Cool Roof Rating Council’s Rated Roof Products Directory before comparing it with another bid.
Read across one product row
Solar reflectance describes how much incoming solar energy the surface reflects. Thermal emittance describes how readily the surface releases thermal energy as radiation. They describe different properties. Copy the column labels along with the numbers so a reflectance figure in one quote never gets compared with an emittance figure in another.
Keep initial and aged values separate
The directory distinguishes initial results from aged ratings. Compare initial with initial and aged with aged. If the figure you need is missing, ask the supplier what rating is available for the specific product and color. A related product from the same manufacturer may have a different surface.
Record the directory entry and date alongside your bid comparison. These ratings describe the surface, while insulation, the roof assembly and local conditions also matter to a building’s performance. Ask the designer how those factors enter the project decision. For broader context on selecting a system, see our guide to roofing material choices.
