ERA Challenges LBNL Study about White Roofs

The Bethesda, Md.-based EPDM Roofing Association (ERA) is challenging a study released by Lawrence Berkeley National Laboratory, Berkeley, Calif., which cites white roofs as the most “cost-effective” roofing option over a 50-year time span. The study, published in the March 2014 issue of Energy and Buildings, also calls for the phase-out of black roofs.

“Our members make both black and white roofing membranes. We strongly oppose any recommendation that irresponsibly promotes the use of one of our products over another based on faulty science. We question the validity of this study since it is based on a sample size of only 22 roofs, and we are challenging the conclusions that the authors draw from the data,” says Ellen Thorp, ERA’s associate executive director. “Due to the complexity of roof and building science, prescriptive requirements that limit design choices are not in the best interests of architects, design professionals or building owners.”

To help provide clarity regarding roofing-system choice and refute some errors in the study, ERA convened a panel of experts to review the LBNL science and its conclusions. A complete analysis can be found on the ERA website.

Overall, the LBNL study was marked by “a systematic failure to understand that roofs are systems, not a single component,” says Thomas W. Hutchinson, AIA, FRCI, RRC, principal of Hutchinson Design Group Ltd., Barrington, Ill., an internationally recognized expert on roof system design and a Roofing editorial advisor. “Additionally, the study completely ignored
ballasted EPDM systems that, in other studies, have proven to be the roof system that provides the greatest service life and energy savings. To suggest that a comparatively ‘new’ roofing material will have a longer service life than EPDM, a material proven to last over 30 years, is naïve.”

“Our members—Firestone Building Products, Carlisle SynTec Systems and Johns Manville—have a vested interest in providing accurate information to our customers,” Thorp adds. “Their knowledge is based on marketing, installing and maintaining thousands of roofing systems. We hope that architects, specifiers and roofing consultants will continue to rely on their field-based knowledge about the comparative costs and effectiveness of roofing systems, rather than on flawed science based on flimsy and biased data.”

Benjamin Mandel, a research assistant in the Heat Island Group at LBNL and an author of the LBNL study, recently responded to ERA’s remarks on Today’s Facility Manager’s website.
Read Mandel’s reaction at bit.ly/1hcD0HR.