Los Angeles Pavements Coated With Solar-Reflecting Paint to Combat ‘Urban Heat Island Effect’

In Los Angeles, California, where temperatures tend to stay warm year-round, you can feel a significant difference in heat when you’re along the coast or outside the city versus when you’re in denser parts of the city. This phenomenon, known as the urban heat island effect, can make daytime temperatures in densely packed areas 1°F to 7°F warmer than nearby areas. Los Angeles is working to combat this by applying a solar-reflecting paint on 1 million square feet of roads in the city.

The GAF Cool Community Project, an initiative by roofing and waterproofing manufacturer GAF, has painted roads, parking lots, and even playgrounds in the Los Angeles neighborhood of Pacoima with the solar-reflective, epoxy acrylic paint. GAF partnered with local organizations, governments and scientists for the project.

“Pacoima is one of the hottest parts of L.A. County and hasn’t gotten the kind of investment like a lot of other communities,” Jeff Terry, vice president for corporate social responsibility and sustainability at GAF, said, as reported by Bloomberg. “One of the challenges with urban heating is that it doesn’t stop at night. Hopefully we’re going to make this place a little bit more livable for the residents.”

In Pacoima, asphalt temperatures may reach over 140°F. But one study from 2020 noted that reflective coatings reduced surface temperatures on Los Angeles streets by over 10°C (50°F). Fast Company reported that the Pacoima surface temperatures have already declined by 10° to 12° with the new reflecting coatings.

The paint uses Invisible Shade, a coating created by GAF-owned company, StreetBond. The Invisible Shade has additives that reflect visible and infrared light to combat heat. The coating is available in 14 colors or can be customized. While in most areas of Pacoima, the applied coatings are gray, the initiative partnered with a local artist to create unique murals for some areas, like playgrounds, parking lots, and a basketball court, which was painted in a blue to pay homage to the Dodgers.

The initiative will monitor the neighborhood temperatures over the next two years to determine its effectiveness. If successful, more reflective coatings may be applied in other neighborhoods.

“The ultimate goal is not just to lower the ambient temperature of the community but to see how it impacts the livelihoods of people in the community,” Terry said, as reported by Fast Company.

The Cool Community Project may also install solar-reflective roof shingles on local residents’ homes to reduce interior temperatures. While making these adjustments could help, experts note that other measures to reduce heat island effect, like planting more trees, are also necessary.