The Cool Roof Rating Council Standard outlines the methodology that should be used for testing materials.
Wood products should be tested using CRRC-1 Test Method #1. Each material specimen should be organized into arrays of three panels—one light-colored, one medium, and one dark—to capture the widest range of color variation. Measurements should be taken at randomly generated locations across the array until a standard error of 0.02 or less is achieved with a minimum of 30 sample points. (The Cool Roof Rating Council (CRRC) provides an Excel calculation tool and template for use with this method. Contact email@example.com to request these resources.)
Directionally reflective roofing products shall be tested using ASTM C1549 and CRRC’s Standard Test Method for Determination of the Solar Reflectance of a Directionally Reflective Material Using a Portable Solar Reflectometer (see Appendix 3 of the Standard).
What if I need to have a material tested?