Planning a large patio in your backyard? How about a new driveway? Or maybe a small pad for you and your kids to shoot some baskets?
There’s a lot to love about these ideas, but two things you don’t want are roots breaking through your new concrete or ground that’s too hot to walk on barefoot in summer months (yes, this happens, even in Bellingham and throughout Northwest Washington!).
Pervious concrete helps to mitigate these problems in two major ways:
We’ve all seen this common problem: In search of water, tree roots break through traditional concrete sidewalks, driveways and parking lots, creating unsightly and even dangerous conditions.
But what if the roots had all the water they needed, no matter what was above them?
Pervious concrete helps prevent tree roots from lifting concrete because rainwater is disbursed through the porous surface, saturating the soil and ensuring roots have the water and nutrients they need.
Where pervious concrete is installed around landscaped areas, trees and shrubs don’t have to seek out water — it comes to them, evenly distributed right through the concrete.
Related: Pervious concrete also essentially eliminates harmful runoff. Oil dripped onto traditional
concrete, for example, is washed right into storm drains, while more than 97 percent of oil
dripped onto pervious concrete is trapped and biodegraded before it even hits the soil.
Heat reflection and release:
Have you ever tried to walk across hot concrete with bare feet? It can be bad. Studies have shown that in the sun, traditional concrete can be 30 degrees Fahrenheit hotter than the air temperature. On those mild 80-degree days, the concrete can still be 110. And asphalt? Even hotter at 130! Ouch.
But because of the many small air pockets in pervious concrete, it doesn’t get nearly as hot. Air circulates through the concrete, and there isn’t the mass there to slowly heat up throughout the day.
One study from the American Society of Civil Engineers showed that the temperature of pervious concrete in full sun is equivalent to the temperature of traditional concrete in full shade. That can make a huge difference on hot summer days.
Related: Because of its cooling properties, pervious concrete helps to reduce the detrimental Urban Heat Island effect, which raises the temperature of both air and groundwater in urban areas.