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 | Oct 6, 2020
LEED, GBCI rating systems spur resilience-enhancing strategies
Expanded programs, resources address impact of climate change.
Codes and Standards | Oct 6, 2020
International Code Council to hold inaugural online education event
Week-long ICC Learn Live will include panel conversations, keynotes, and breakout sessions around key topics in building safety.
Codes and Standards | Oct 5, 2020
Guides addressing fenestration anchorage updated
First update to decade-old technical documents released.
Codes and Standards | Oct 1, 2020
Deadline extension for LEED 2009 project certifications
Delivery timeline delays due to COVID-19 pandemic prompt action.
Codes and Standards | Sep 29, 2020
New drinking water standard criteria further restricts lead leaching in plumbing products
Tightened standard applies to endpoint devices that dispense drinking water, and other plumbing components
Codes and Standards | Sep 29, 2020
Groups sue CDC over eviction moratorium
Natl. Apartment Assn. and New Civil Liberties Alliance want hearing by October.
Codes and Standards | Sep 24, 2020
Benefits of building enclosure commissioning include reduced costs
Savings achieved in less rework and fewer and shorter punch lists.
Codes and Standards | Sep 23, 2020
Intl. Code Council aims to stay ahead of new tech, efficiency trends, and resiliency
Passive survivability, social resiliency, and community health among the goals.
Codes and Standards | Sep 22, 2020
Air cleaners, chemical and UV treatments among tools to safeguard indoor air amid pandemic
Strategies augment social distancing, increased air flow to combat COVID-19 spread.
Codes and Standards | Sep 21, 2020
No ease of lumber price spikes in sight
Wildfires strike Northwest timber industry in wake of Covid-19 shutdowns.