A public-private research initiative in Pacoima, California, a section of Los Angeles, is testing a new type of maintenance pavement coating on roads and hardscapes to improve longevity and mitigate urban heat. After the promising results of the first phase, a second phase is now underway.
GAF, a Standard Industries company and one of North America’s largest roofing and waterproofing manufacturers, launched the GAF Cool Community Project, a community-wide research effort to understand the impact of solutions for cooling in heat and urban livability and providing information about other cities. start implementing The company worked with Pacoima Beautiful and the Los Angeles Bureau of Street Service on the project.
Jeff Terry, GAF’s vice president of sustainability, says a lot of research has been done to mitigate urban heat, but no one has taken a whole community approach to doing it. He says this project started with researchers looking at every hard surface in the 10-square-block community, then installing a solar-reflective pavement coating on every road and parking lot and playground. “This project and the research associated with it will help us understand if we can actually reduce the environmental heat that is happening in this community,” he says.
The multi-phase project began in July 2022. The first phase focused on the application of more than 1.2 million square feet of StreetBond DuraShield Invisible Shade solar reflective pavement coatings in an 18-block area squares of Pacoima in Los Angeles.
Coatings were applied to neighborhood streets, parking lots, a community basketball court, and an elementary school playground. GAF partnered with climate scientists to measure the impact of the coatings, including air and surface temperatures, as well as albedo, the measure of the sun’s energy being reflected.
Two newly installed weather stations, existing NASA satellites, drone measurements, continuous mobile sensor monitoring, and spot measurements are actively collecting data. A nearby control zone is also being monitored. Results after 12 months show that the cool pavement coatings reduced the surface temperature by 10º F on sunny days. The project team says it also found that the coated pavements heated up more slowly and cooled down faster than the uncoated area.
Ambient air temperature also dropped an average of 2.1°F during the day on sunny days and up to 3.5°F during the day of an extreme heat event, project officials say, adding that overall the coatings helped reduce 25-50. % of the urban heat island effect during temperature peaks.
“All the positive results have led to greater demand from local residents for more coatings in public spaces, with residents sharing that it feels cooler in their neighborhood, and they can now get outside more and enjoy the outdoors again these shared spaces together.” says Melanie Torres, Pacoima Beautiful community organizer.
“The key figure to understanding the cooling and interventions that GAF provides is albedo,” says Eliot Wall, Senior Director of Pavement Solutions at GAF. “These solutions help through multi-metal oxides, reflecting infrared wavelengths to reduce the heat that is stored in these harsh landscapes.”
Wall says that on used streets like Pacoima’s, the coating should last at least five to seven years before it needs to be touched up or reapplied. But if the coating is applied to a new road, it can extend its life cycle by up to nine years.
Streetbond Durashield floor coating is a two-component water-based epoxy modified acrylic coating. GAF says the proprietary blend has properties including flexibility, tack, color stability and chemical resistance that optimize the preservation of asphalt pavements while protecting the pavement from the harmful effects of oxidation from UV exposure.
Manufactured in Phoenix, AZ, the coating comes in light, fun colors for recreational areas and darker colors for the streets. The coating can be applied directly on top of pre-existing asphalt using a handheld sprayer or off the back of a work truck with a spray machine.
Phase 1 of the Pacoima project ended last October when the remaining 18 road blocks were covered with StreetBond. Phase 2, currently under construction, involves covering five residential roofs with Cool Roof solar reflective coatings. The cost of the project hasn’t been tallied, Wall says, but GAF is donating materials and labor.
In addition to Pacoima, GAF has applied 10 million square feet of StreetBond DuraShield to Los Angeles streets as part of the city’s Cool Streets program, Wall says. The company has also completed projects in San Antonio, Las Vegas and Phoenix.
Looking ahead, Wall says GAF is working with a handful of California cities, but he can’t name them until the projects are officially secured. He says the coating season is between April and October and he hopes to have several more projects ready by then.
“Pacoima was the first of its kind and we are exploring opportunities in other hot cities,” adds Wall. “About 77 percent of the roads in the United States are residential, and what we’re seeing as future opportunities is to integrate into the existing pavement maintenance budgets that cities already have to deal with with products like a layer of slurry or a sealcoat, and instead of using Durashield.”
