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
75 Top Building Products | Apr 22, 2024
Enter today! BD+C's 75 Top Building Products for 2024
BD+C editors are now accepting submissions for the annual 75 Top Building Products awards. The winners will be featured in the November/December 2024 issue of Building Design+Construction.
Standards | Apr 22, 2024
Design guide offers details on rain loads and ponding on roofs
The American Institute of Steel Construction and the Steel Joist Institute recently released a comprehensive roof design guide addressing rain loads and ponding. Design Guide 40, Rain Loads and Ponding provides guidance for designing roof systems to avoid or resist water accumulation and any resulting instability.
Roofing | Jan 8, 2024
Researchers devise adaptive roof tile concept that adjusts to ambient temperatures
Scientists at the University of California Santa Barbara published a paper that proposes adaptive roof tile technology that can adjust to ambient temperatures. Using a wax motor, tiles could switch from a heating or cooling state enabling savings on heating and cooling costs.
75 Top Building Products | Dec 13, 2023
75 top building products for 2023
From a bladeless rooftop wind energy system, to a troffer light fixture with built-in continuous visible light disinfection, innovation is plentiful in Building Design+Construction's annual 75 Top Products report.
Metals | Sep 11, 2023
Best practices guide for air leakage testing for metal building systems released
The Metal Building Manufacturers Association (MBMA) released a new guidebook, Metal Building Systems - Best Practices to Comply with Whole-Building Air Leakage Testing Requirements.
Sponsored | Fire and Life Safety | Jul 12, 2023
Fire safety considerations for cantilevered buildings [AIA course]
Bold cantilevered designs are prevalent today, as developers and architects strive to maximize space, views, and natural light in buildings. Cantilevered structures, however, present a host of challenges for building teams, according to José R. Rivera, PE, Associate Principal and Director of Plumbing and Fire Protection with Lilker.
Building Materials | Jun 14, 2023
Construction input prices fall 0.6% in May 2023
Construction input prices fell 0.6% in May compared to the previous month, according to an Associated Builders and Contractors analysis of the U.S. Bureau of Labor Statistics’ Producer Price Index data released today. Nonresidential construction input prices declined 0.5% for the month.
Sponsored | Building Enclosure Systems | May 16, 2023
4 steps to a better building enclosure
Dividing the outside environment from the interior, the building enclosure is one of the most important parts of the structure. The enclosure not only defines the building’s aesthetic, but also protects occupants from the elements and facilitates a comfortable, controlled climate. With dozens of components comprising the exterior assemblies, from foundation to cladding to roof, figuring out which concerns to address first can be daunting.
Codes | Mar 2, 2023
Biden Administration’s proposed building materials rules increase domestic requirements
The Biden Administration’s proposal on building materials rules used on federal construction and federally funded state and local buildings would significantly boost the made-in-America mandate. In the past, products could qualify as domestically made if at least 55% of the value of their components were from the U.S.
AEC Innovators | Feb 28, 2023
Meet the 'urban miner' who is rethinking how we deconstruct and reuse buildings
New Horizon Urban Mining, a demolition firm in the Netherlands, has hitched its business model to construction materials recycling. It's plan: deconstruct buildings and infrastructure and sell the building products for reuse in new construction. New Horizon and its Founder Michel Baars have been named 2023 AEC Innovators by Building Design+Construction editors.
