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
Codes and Standards | Apr 28, 2016
New research finds 30 measures to significantly cut energy use
ASHRAE’s prescription cuts across all building types and climates.
Codes and Standards | Apr 27, 2016
Florida gives developers more time to install first responder radio signal systems
Expensive upgrades can be postponed for several years.
Codes and Standards | Apr 25, 2016
San Francisco becomes first big U.S. city to require solar panels on new buildings
Pertains to commercial and residential buildings shorter than 10 stories.
Codes and Standards | Apr 25, 2016
GSA adopts SITES land development and management rating system
Federal agency will use for properties with and without buildings.
Wood | Apr 22, 2016
Revised 2015 Manual for Engineered Wood Construction available
American Wood Council Document offers design information for structural applications.
Codes and Standards | Apr 20, 2016
OSHA updates eye and face protection standards in final rule
Becomes effective April 26.
Codes and Standards | Apr 18, 2016
Efficiency finance pilot project to spur retrofits on existing buildings
EDF and PG&E team up on interest-free loans for qualified projects.
Codes and Standards | Apr 18, 2016
ASHRAE releases proposed energy standard for historic buildings
Designed to balance with preservation requirements.
Codes and Standards | Apr 13, 2016
Canadian city fines itself for failing to get a building permit for building renovation
Guelph, Ontario, will pay a $1,125 fine to the province.
Codes and Standards | Apr 12, 2016
Construction trade groups sue OSHA over silica rule
Cite concerns about technological and economic feasibility.