Tech Today

Roofs' reflectivity listings

Underwriters Laboratories (UL) Inc. is introducing a new classification program category for roofing products' radiative properties. This new UL classification provides product manufacturers and roofing professionals with a widely recognized third-party source for testing, reporting and disseminating products' solar-reflectance and thermal-emittance properties.

UL Category TGFE

In addition to UL's existing certification categories for its fire, impact and uplift ratings, UL has established a new category—UL Category Code TGFE, Roof Covering Materials, Solar Reflectance—addressing surface radiative properties for low- and steep-slope roofing products. For the purposes of this new category, low-slope products are defined as those intended for use at slopes of 2-in-12 (9 degrees) or less; steep-slope products are those used at slopes greater than 2-in-12 (9 degrees).

Solar-reflectance measurements are made according to ASTM C1549, "Standard Test Method for Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer." Solar reflectance is identified as the fraction of solar flux reflected by a material's surface expressed within the range of 0.00 and 1.00. A 0.00 value represents no measured reflectance; a 1.00 value represents 100 percent measured reflectance.