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
| Feb 17, 2012
AGC advocates for federal procurement reform
Ensure that small business goals take into consideration actual small business capacity in relevant specialty markets.
| Feb 17, 2012
Codes not to blame for Anchorage roof collapses following heavy snows
Design or construction problems likely contributed to the collapses, according to city officials.
| Feb 17, 2012
Comment period opens March 1 for LEED 2012 update
USGBC says that LEED's strength comes from its continuous evolution.
| Feb 17, 2012
OSHA training videos on proper respirator use available online
17 short videos to help workers learn about the proper use of respirators on the job.
| Feb 17, 2012
Union/employer collaboration on the rise aimed at exceeding OSHA safety standards
Unions have learned to help employers win contracts with bids made competitive through good safety practices.
| Feb 16, 2012
Gain greater agility and profitability with ArchiCAD BIM software
White paper was written with the sole purpose of providing accurate, reliable information about critical issues related to BIM and what ArchiCAD with advanced technology such as the GRAPHISOFT BIM Server provide as an answer to address these issues.
| Feb 9, 2012
Initiative to sell off under-used federal property gaining momentum
The bill is similar to a White House planto cut $8 billion worth of building costs by the end of the 2012 fiscal year, and to establish a panel to identify other sites worth selling or donating to nonprofits or state and local governments.
| Feb 9, 2012
Computer tool helps engineers design roof cladding using Canada's building code
Easier to design roof cladding that can withstand winds in a given area.
| Feb 9, 2012
Webinar focuses on lessons learned from LEED-certified industrial project
This case study will focus on strategies used to save the client money, achieve certification, and effectively market success once the project was complete.
