Question

We want to replace our small concrete patio with an inexpensive green material. Suggestions?

Asked by Susan Graven, Redondo Beach, CA

We live close to Los Angeles, just two miles from the ocean (mold and termites can be an issue). Currently we have an ugly small cement slab for a patio and a small grass yard. We want to extend the patio with a nicer, inexpensive material that is green. We love to entertain. Suggestions?

Answer

Polly Osborne, FAIA, LEED AP

Answered by Polly Osborne, FAIA, LEED AP

Los Angeles, CA

Polly Osborne Architects

March 22, 2007

The least expensive solution is to break up the concrete slab and re-lay it on sand with a dirt/sand mixture between the pieces of concrete to create a flagstone-like patio with drainage and ground cover between the "stones."

Also available are locally made permeable pavers that are designed to be laid loose over a sand base. There are local contractors who specialize in laying concrete paving stones.

Hardy, drought-tolerant ground covers such as sedum, thyme, or dymonia might do well in your area. Check with the Theodore Payne Foundation for Wildflowers and Native Plants for this application.

If you prefer a more consistent base on which to do your entertaining, consider using pervious concrete. This material uses the same basic materials as regular concrete, but it has a larger-sized aggregate so that the water drains through it. Creating a permeable surface not only reduces pollutants in the waterways, but also reduces the heat sink caused by large expanses of traditional concrete.

Each of these choices comes with a specific aesthetic.

  • If you want a very natural look, the "flagstone" approach is going to be the best.
  • You can use concrete stains to make your old concrete look natural. I do not recommend using natural stone, because it isn’t a renewable resource.
  • Concrete permeable pavers will give you an orderly aesthetic, because you can easily lay out grids and patterns. Because this material is more expensive than salvaged concrete, you can get creative and mix the two.
  • Pervious concrete could also be used with the pavers to create patterns and designs.

With all hardscapes, it is extremely important to build a good base of gravel and sand, and be sure it drains properly. The specifics of this vary from place to place due to soil type and code requirements.

 

For more information:

Theodore Payne Foundation for Wildflowers & Native Plants

Interlocking Concrete Pavement Institute

National Ready Mixed Concrete Association's facts about pervious concrete pavement

The Concrete Manufacturers Association's list of publications on concrete block paving

Tagged In: native plants, porous pavement

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