Not only have asphalt shingles been a steadfast building material since the early 1900s, they make up 80 percent of the roofing materials installed on residential structures each year. The industry continues to enhance roofing materials to meet consumer preferences for new colors, dimensional looks and better protection for the biggest investment we make as homeowners. Most recently, the interest in sustainability has risen to the top, and traditional roofing materials are being transformed into performance surfaces that can reflect sunlight to reduce urban heating or harness the sun to transform smog gases to improve local air quality. 

“There are cool roofing solutions — materials that can help with urban heat-island mitigation — and then smog-reducing granules that can help be part of the solutions for air pollution,” says Frank Klink Ph.D., senior laboratory manager at 3M.

These roofing innovations are a game changer.

“The guys who brought you Post-It notes are thinking about your health also,” says Jonathan Parfrey, founder and executive director of Climate Resolve, a climate advocacy and environmental organization. “With the new roofing materials on the market, you can be more comfortable in your home, safer in your home and doing your part for the environment.”

Cooling down

 “People are really concerned about their health... This is a way — just by choosing the right kind of roof — you can do things to protect your health. We think that’s a great win-win.”

The Environmental Protection Agency defines a “heat island” as an urban area that’s hotter than nearby rural areas, noting a city with a million or more people can annually be 1.8–5.4°F warmer than surrounding areas. Temperatures are often over 20°F warmer in these areas at night than during the day. Heat island impacts can include higher summertime peak energy demand, increased air pollution and more greenhouse gas emissions.

Los Angeles has been aggressive in targeting the problem. Their “cool roof” ordinance, which was implemented a few years ago, requires new roof installations and remodels to be solar reflective and thermal emitting. Cool roofing solutions reflect more sunlight, absorb less heat than a typical roof and can help consumers save on cooling costs year-round.

“You’re going to start making an impact,” says Klink, noting the cumulative effect of cool roofs can really add up.

“Everybody can do a little bit,” says Gregory B. Malarkey, senior vice president of Malarkey Roofing Products®. “The number one thing that speeds the aging of the asphalt is elevated temperatures. If we can reduce the aging rate of the asphalt and protect it from the sun by using roofing granules with higher reflectivity, we can create a shingle that will last longer and perform better.”

Fighting smog

Forty-one percent of Americans live in counties with unhealthy levels of ozone or particle pollution. That’s according to the American Lung Association’s “State of the Air 2018” report, which ranks Los Angeles as the No. 1 city with the worst ozone pollution. That’s one of the cities where smog-mitigating building and construction materials can make a big impact. By integrating smog-reducing technology into a common material like asphalt shingles it makes it easier for communities to adopt.

“Smog-reducing technology uses a catalyst activated by the sun to decrease NOx, a significant contributor to smog,” says Klink. “A photocatalyst coating will be activated by UV sunlight and can react with the NOx that has landed on the roof, removing it from the air and converting it into water-soluble ions that wash away over time.”

 “People are really concerned about their health,” says Parfrey. “This is a way — just by choosing the right kind of roof — you can do things to protect your health. We think that’s a great win-win.”

Both solar reflective shingles and shingles with smog-reducing properties are an affordable approach to mitigating urban heating and reducing smog gases in the local environment.