What are ‘permeable’ pavers?

belgard paver1Permeable pavers let water soak—or permeate—right through them, so it seeps into the ground instead of running off into the street and down the sewer.

Permeable pavers are made of clay or concrete and separated by joints filled with small stones. Water enters the joints between the pavers and is filtered through crushed stone layers. The water, minus the filtered-out pollutants, is absorbed into the soil. The pavers can be used for patios, driveways, walkways, pools and other areas where traditional pavers may create an unnatural volume of runoff from snow and rain.

There’s not much snow and rain in Arizona, but some homeowners install permeable pavers to help what little we get soak back into the dry earth.

Another newcomer to the paver market: “drivable” grass. Drivable grass consists of tile-like, 2x2-feet concrete squares connected into a mat by a grid system.  Landscapers or homeowners can plant grass through lattice-style holes and cracks to allow for root penetration through the mat into the soil.  The mat’s porous nature enables moisture to filter into the underlying soil, increase storage of rain water and minimize the runoff of water and spilled motor oil.

These grass mats are used mostly for driveways, as you can drive and park your car right over the pavers. Caution: Some find drivable grass unsightly because the concrete pavers heat up and can turn the grass growing in between them brown. Installing the grass pavers is also more expensive and time-consuming than pouring a concrete driveway or laying traditional pavers.

Some alternatives to using grass in the grid system include sand, gravel, ground cover, artificial grass, and sod in low-use areas.