An often overlooked aspect of selecting a commercial roofing system is the roofing material’s ability to resist unwanted biological growth. ASTM G21 is an industry standard test used to analyze the degree of biological growth on different membranes.

How the Testing Works:
Samples of the roof roofing material are placed onto the surface of ASTM G-21 nutrient salts agar and sprayed with a mixed spore suspension of five fungal cultures. The nutrient salts agar provides all of the trace nutritional elements needed by fungi to support growth. However, to achieve heavy growth, the fungi must use the test material as its primary carbon source.  Inoculated samples are incubated and examined for fungal growth each week for a total of four weeks.

The Results:
After exposure to this testing, all of Carlisle’s white and black EPDM roofing membranes had a zero or “No Growth” rating. Keeping buildings and their occupants safe and healthy is central to sustainable design principles, and EPDM continues to deliver sustainable benefits including unmatched long-term service life, hail damage resistance, and excellent resistance to unwanted biological growth. Learn more about EPDM and the reasons to consider using it on your next roofing project.

For more information, visit www.carlislesyntec.com, or contact Ron Goodman at Ron.Goodman@CarlisleSynTec.com to discover the benefits of single-ply EPDM roofing membranes.