Although LEED and ASHRAE 90.1 (Energy Standard for Buildings Except Low-Rise Residential Buildings) standards require or reward use of white “cool” roofing to mitigate urban heat island effects, it is not always the best choice of material.
Cool roofs can cast heat where it is not wanted. “Architects and roof consultants need to be aware of potentially adverse thermal effects when choosing roof membranes, particularly where roof surfaces are adjacent to walls that can be affected by bounced sunlight,” says Elizabeth Grant, associate professor in the School of Architecture + Design at Virginia Tech.
Choosing the best material for a commercial roof is a nuanced decision requiring a careful examination of the application. “Roof selection is an architectural issue,” Grant said. “It’s not as simple as slapping a white roof on everything to gain a LEED point.”
The study compared the thermal impact of white and black roofs. The black roof heated the air within 5 ½ inches, but there was no difference in air temperature impact for black or white roofing above that zone. Researchers also found that electrical metallic tubing and glazed and precast concrete wall panels near white TPO roofing were 3 to 9 degrees Fahrenheit warmer than those near black EPDM roofing.
Related Stories
Sponsored | Roofing | Oct 24, 2016
Metal roofing panels reinvigorate town staple
Designers for the project initially thought patching and repairs would be sufficient for the 35-year-old, 17,000 square foot roof, however upon further inspection it was determined that the building needed a new roof.
Roofing | Sep 30, 2016
A Florida-based roofing contractor mixes advocacy and philanthropy
The owner of Venture Construction Group says that caring for his father changed his perspective about work and life.
Sponsored | Coatings | Sep 26, 2016
Valspar products at the forefront of innovation and sustainability
Fluropon SR and Fluropon Pure are two products that help Valspar cultivate a culture of innovation.
Sponsored | Roofing and Fire Safety | Sep 21, 2016
Metal roofing provides exceptional fire resistance
Buildings with great fire resistance will likely have lower insurance costs and be restricted by fewer codes, owing to the decreased risk.
Sponsored | Energy Efficiency | Jul 27, 2016
Metal Roofs Have Solar Advantage
A large roof can become a resource that saves significant money on energy consumption and helps reduce emissions of CO2 and it turns out metal roofs make excellent hosts for solar panels.
Sponsored | Roofing | Jun 29, 2016
Retrofit roofs instead of replacement
When faced with the need to replace a flat roof, many building owners find retrofitting a more viable investment, and so they erect a long-lasting, low-maintenance sloped metal roof.
Shopping Centers | Jun 3, 2016
Developer Robinsons Land adds powerful PV arrays to 10 malls in the Philippines
The Robinsons Starmills mall in San Fernando recently turned on a 2.9 megawatt rooftop PV plant.
Codes and Standards | May 19, 2016
Asphalt roofing group publishes updated shingle installation guide
Technical manual provides best practices for roofing professionals.
Roofing | May 16, 2016
New guide focused on increasing energy and structural performance with raised-heel trusses
Higher trusses simplify attic ventilation, leave more space for insulation.