On a 75-degree day last month, the SAE School playground outside Atlanta underwent a dramatic transformation. Students and volunteers equipped with brushes and rollers covered the school’s black asphalt basketball courts and playground with a bright coat of blue and brown paint.
Donated by GAF and its subsidiary StreetBond, the paint is actually a solar reflective coating, and the paint was about more than just aesthetics.
Before the coating was applied on this moderately warm day, the temperature near the asphalt measured about 120 degrees – a hellish environment common to many paved playgrounds of parks and schools in the U.S. Shortly after the coating was applied, the temperature at SAE The school’s playground dropped 12 points.
“Is it still hot? Yes. But is it as hot as it was? Absolutely not,” says Shannan Tilson, co-founder and director of operations at the school. “I don’t feel like I’m in an oven.”
Nor are school children, whose young bodies are especially vulnerable to the increasingly frequent days of extreme heat in places like Atlanta. Back asphalt is like a magnet for heat and contributes significantly to thermal radiation in cities, known as the urban heat island effect.
“The asphalt itself essentially acts as a heat sink,” says Eliot Wall, general manager of StreetBond for GAF. “Even when the ambient temperature is recorded at 75 or 85 degrees, the bare black tar can be 120 or 130 degrees. So that’s a really important difference.”
GAF and StreetBond solar reflective coating has been applied to streets, playgrounds, bus lanes and bike lanes around the world. Recently the material was used to cover more than 1 million square feet of surfaces in the Pacoima community of Los Angeles.
Wall says the coating is effective at reducing heat and also helps extend the life of the asphalt underneath, which ironically degrades when exposed to the extreme temperatures it creates.
The 10-year-old SAE School is the latest to receive the solar reflective treatment. A private project-based learning school for students in preschool through eighth grade, SAE has spent the past few years integrating environmental and sustainability issues into its curriculum. It also adds energy-efficient and climate-sensitive equipment to the school’s facilities and runs entirely on solar power.
When GAF approached SAE about using solar reflective asphalt, school officials decided to make the project a learning experience.
GAF came to the school about two months before the installation to do a test run, applying the coating to a spot in the school parking lot, with the help of student painters. The company also donated some digital thermometers, which the students used before applying the coating and in the following days, to check the ambient temperature in the area.
“They could see the temperature difference and write it off,” says Scott Starowicz, SAE co-founder and chief financial officer.
SAE students even participated in the paint design. they submitted designs and voted for a winner, using the blue of the school’s colors and the shapes of the school’s mascot dragon. The new playground surface, which Tilson calls the “blue roof,” is now regularly 12 degrees cooler than nearby blacktop sections.
But that too will soon change. School officials say they plan to spread StreetBond’s solar-reflective coating on another blacktop heatsink: its large parking lot.