GREEN DRIVEWAY DESIGN TIPS USING PERMEABLE PAVERS
Here in Northern California, we lead the way in environmentally sound practices. When it comes to hardscaping, using permeable pavers, also known as pervious or porous concrete for your outdoor hardscaping projects is the perfect way to do your part to help protect the environment.
The next time it rains, step outside and follow its journey. The rainwater flows down your roof to your gutters and downspouts. If you have a concrete slab or asphalt driveway, the water flows from your downspouts to the driveway where it picks up pollutants like petroleum and lawn pesticides. It travels to the street where it flows down a storm drain eventually finding its way into a nearby river or lake.
Replacing your asphalt or concrete driveway with environmentally friendly permeable pavers is a much greener option. Permeable pavers redirect rainwater into the ground where microorganisms in the soil are able to digest pollutants, purifying the water as it’s returned back to the aquifer. Allowing water to pass through the pavers also helps prevent erosion of nearby waterways caused by runoff.
By replacing your impervious concrete slab, or asphalt driveway with eco-friendly permeable pavers, you’ll be supporting the environment by recharging groundwater supplies when it rain, and you’ll also visually soften your property with a beautiful driveway design!
ALL ABOUT PERMEABLE PAVERS
Permeable concrete is not a new invention. First seen in the 1800s in Europe, it was used for structural purposes like load-bearing walls, infill panels, and pavement surfacing. It became popular again after World War II when cement was scarce.
In the U.S. pervious concrete and permeable pavers were proposed in the 1960s as a way to reduce floods, raise water tables and replenish aquifers. In the 70s the EPA began testing to determine its cost and efficiency. The first viable design guide was written in 1977 and provided the groundwork for permeable pavement education and is still referred to today!
Today, permeable concrete is used in multiple cities throughout the US and residential use has grown drastically in the past ten years.
Permeable pavers are made using cement, a coarse aggregate, and water, with little to no fine aggregates like sand or clay. That’s why permeable concrete often has a rough, uneven appearance. The American Society for Testing and Materials has set standards for both pervious and impervious concrete.
The ASTM standard calls for the following percentages of air content or voids within pervious concrete:
• 20% +/- 5% for low porosity, high strength
• 30% +/- 5% for high porosity, low strength
The higher void percentage for pervious concrete lets stormwater easily pass through the material and seep into the ground below. Typical flow rates can range from two to 18 gallons per minute.
BUILDING A PERMEABLE DRIVEWAY
The first step in installing a permeable paver driveway is deciding which design will work best for you. You have a wide range of choices today when creating a permeable paver driveway design. Open-cell pavers are concrete pavers with holes that can be filled with a pervious material like vegetation, which can soften your design and add a bit of green to your driveway.
However, it’s really what’s underneath the pavers that counts! A solid base is a key to minimizing heaving and cracking. The typical construction starts with a 6-inch sub-base of 1 1/2” clean rock, topped with a 4-inch base of 3/4” clean rock to make the driveway strong and stable enough to handle vehicles. The permeable pavers go on top of that. If you need to control water flow, a polyurethane liner should be used near any foundation walls or concrete needs to be protected.
Tabs are formed into each paver to provide the correct joint width. Joints are filled with aggregate to allow water to pass through. Ceramic pavers can actually be porous as well allowing water to pass directly through the pavers as well as the gaps.
When creating your driveway design you can mix and match surfaces, for example, open-cell pavers filled with gravel alternating with concrete strips to add visual interest. When you’ve decided on your design and the system and are ready to install it, make sure you focus on drainage s well as aesthetics, and redirect as much water from your patio, downspouts, and roofline to the new permeable area so you can capture as much water as possible.
CALL BAYSIDE PAVERS FOR ALL OF YOUR BAY AREA HARDSCAPING NEEDS
If you’re considering replacing or installing a new eco-friendly permeable paver driveway, give the experts at Bayside Pavers a call at (925) 293-7419 and schedule a free consultation to discuss your project. We carry permeable pavers from some of the top manufacturers in the industry including McNear, Belgard Hardscape, Basalite, Calstone, and Pavestone. We’re always happy to answer your questions and can help you to create the outdoor living space you’ve always wanted!
If you live in the East or South Bay areas, stop by our Concord, CA location at 2455 Bates Ave., Ste K.
For North Bay residents, our Santa Rosa location at 1619 4th Street, Ste 12 is ready to help!