Permeable Paving - Patios, Driveways & Walks

Permeable Pavers may not be the first choice of most people today when thinking of a Driveway, Patio, a Walk or Walkway, but things are changing. As more and more open space is covered with paving, areas that use to soak up rainwater are now impervious. More water is put into the streets, storm sewers, and waterways immediately during, and after a storm instead of soaking into the ground and slowly working it way back into the water system. The EPA, and in Pennsylvania the DEP have regulations that call on municipalities to limit the amount of impervious area on properties in their jurisdiction. This is to help prevent flooding that can result from too much paving and building. Impervious areas include the house, the driveway, walks, patios, sheds, and pools. Even decks in some areas are considered impervious. Although pavers, flagstone and other natural stone, and clay brick might not be installed in the mortar or over concrete, they are usually counted as impervious because of the compaction of the ground necessary for proper construction. Most of the rainwater will run off the top, much the same as if it were concrete.

This is why environmentally friendly permeable paving is gaining in popularity. Most municipalities – but not all – will allow Permeable Pavers for Driveways, Patios, and Walks when a property is at its limit for an Impervious area. In a permeable system, the base is constructed of clean stone over an un-compacted subsoil that will absorb the rainwater that comes through. The base stone layers are constructed thick enough to hold up to the traffic that it will receive, and the base stone is compacted. The pavers are installed on a layer of 3/8-in. stone (not sand) with a larger joint than with impervious pavers and these joints are filled with small stone (never sand) to allow for water to run through.

Some additional benefits of permeable paving:

  • Environmentally friendly. Fits in nicely with a responsible, sustainable lifestyle.
  • Qualifies as a Best Management Practice and can help earn credit towards LEED certification.
  • Snow and ice that melts in Winter will disappear below the paving surface, lessen the need for salt and make for a safer surface. This could have many commercial applications in business districts.
  • Can eliminate the need for a drainage pond or collection basin in a parking lot. This can make additional space available for parking.
  • For the last few years, new styles and colors have been added each year, and the look of permeable pavers can rival regular pavers. Check out manufacturers websites for more up to date information. To order the current year’s catalog see E. P. Henry, Techo-Bloc or other paver companies websites.
  • See construction detail below. Because water has to drain through, the construction is very different than a regular paver job.

Permeable Paver Walk and Driveway – Bala Cynwyd, Montgomery County, PA 19004

This permeable walk and driveway was constructed for a customer in Bala Cynwyd, PA. He wanted to build an addition on his house, and in order to do so, he had to eliminate some impervious paving outside the house. He was able to do this while still retaining the paved walking surfaces he had before the addition.
Shown here are steps during construction:

EP Henry Eco Paver Permeable Paver Walk – Bala Cynwyd, Montgomery County, PA 19004

EP Henry Eco Paver Permeable Paver Driveway – Bala Cynwyd, Montgomery County, PA 19004

Here is a video showing how the system works and the water runs into the paving.