2014 Habitat for Humanity Builders Blitz Is Underway
June 5, 2014
Moving into the Evergreen: Green Living
March 19, 2011
Two Homes, One Week
June 19, 2014
Permeable and Pervious Paving
May 9, 2011
Winter Park has very strict rules regulating the amount of your lot that can be impervious – or the area of surfaces that do not allow water to percolate through them. Your house, driveway, walkway, sidewalk, and patios are examples of typical impervious surfaces. Among others, these rules are in place to help reduce flooding and protect water quality in our lakes and aquifer. The more water that is allowed to percolate into your own yard/soils, the less there is to run off into the streets and ultimately into our local lakes. Learning about some available permeable products will help you comply with the City regulations when you want to enlarge your homes or extend your patio or driveway and also help improve our local environment.
It is common to see mulch and gravel driveways on Winter Park homes and these are low-cost options for minimizing impervious areas. The feature home in this issue of Winter Park Home utilized several areas of decorative gravel with edging as walkways. For those of you that don’t like the idea of loose mulch or gravel, a product called EcoSystems Grout may be appropriate. This permeable grout system adheres gravel or sand together, while letting water drain through. This specialized system can be used to create attractive walkways and sitting areas, while allowing water drainage. EastWest Pavers did several projects for me using this specialty permeable grout and has some photos to display the projects on their website.
For residents that desire a more traditional look and harder surface to walk, drive, or play on, you may consider pavers and concrete. A common misconception of these traditional pavers and bricks is that they are pervious, when in fact they are actually impervious. Water will not drain through them because of their tight joints and the layer of compacted concrete fines (base) underneath. There are now permeable and pervious paver options available though. Some of the largest brand name manufacturers that sell these products, include: CobbleSystems, EcoSystems Grout, Flagstone Pavers, Tremron, Oldcastle Coastal, Cemex, Hanson, American Pavers, BrickAmerica, and Harwood Brick. Each of these brands should have testing and supporting documentation to prove the pervious/permeability nature of their product. You will need this information when applying for a permit from the City.
According to the Interlocking Concrete Pavement Institute (ICPI), permeable pavers are separated by joints filled with small stone. There are no small or fine particles in the base of the pavers, but rather gravel or crushed stone. The gaps between the pavers create a pathway for water to drain through the surface and into the gaps of the underlying stones. So, instead of water running down your driveway into the street, it will drain down into the ground. My first permeable paving job was installed in Winter Park in the middle of 2006 and it still performs well in any type of rain event. I discussed this certified green renovation project in Issue 2, 2007 of Winter Park Home, titled Green Renovation Case Study.
Two other available products are pervious pavers and pervious concrete. Note the difference in terminology – pervious vs. permeable. The pervious options are actually porous and allow water to go through them. These products remind me of rice crispy treats and are another good way of capturing stormwater. A few contractors have become adept at pervious and permeable installations and it is vital you hire one with the appropriate experience. A pervious or permeable paver will not perform as designed, if it is not installed correctly. One step you can do to ensure your contractor is following the correct steps is to get a building permit. Not only is this a requirement when adding pavers or concrete, this step ensures you are complying with the local regulations and also provides a good review process for the product you are using and your contractor.
As the important environmental benefits of pervious surfaces have become known, so have the options for pervious and permeable paving. No matter which brand you end up using, the products are only as good as their installer. The right permeable product and a good installer will give you a great surface to help you further enjoy our great climate for indoor / outdoor living.