Black Roofing vs. White Roofing
If the high solar reflectance and thermal emittance offered by white membranes are “better”, why isn’t the decision black and white? Here are three reasons…
Reason No. 1: Surface Temperature vs. Durability
Some manufacturers propose that a white membrane equals greater durability, which is a misleading claim. Although it may be necessary (by law) or desirable to use a white membrane, that membrane isn’t necessarily more durable than a black membrane. In a 1991 study, Labratory Evaluation of EPDM Roof Membranes: A 17-Year History of Performance, by Brian D. Gish, and Kathleen P. Lusardi, of Carslile Syntec Systems, it was proven, “an EPDM membrane does not need to be protected from the suns radiant heat”, and, “EPDM may need 50 years of exposure to drop below… performance requirements”.
Reason No. 2: Heating Benefits in Cold Climates
There are scientific and common-sense arguments about the comparison of black and white roof membranes in temperate climates. For many buildings in temperate climates, there is no air conditioning and no reduced air-conditioning energy benefit for the use of a white roofing system. Contrary, there are some heating benefit to black roofing in the winter.
Reason No. 3: Environmental Benefits of Durability
The environmental benefits of any roof can be thought of as part of the quality and value understanding of the cost and durability. If your choice of roof type is limited to solar reflectant standards (mandated in some cities) your decision is limited and directed to chose a white roofing membrane. However, if your decision could be limited to select a roof membrane wit an empiracally proven service life, you’re more likely to determine that a black membrane is appropriate. Currently, there is not enouogh thorough understanding, or information accumulated, to better understand the actual environmental costs of any black roofing membrane compared to a white membrane; such as: environmental risks of manufacturing, installation, and disposal/recycling.