How to Design Permeable and Porous Paving

Permeable and porus paving can be done with a choice of materials

Rather than cementing in a large area, permeable paving gives the same stable surface with space for water to drain through. This type of surface cover is not only decorative but avoids run-off, gullies and wasted water. It is eco-friendly and can be very decorative.

Difficulty:

Moderately Easy

Instructions

1. USE MATERIALS THAT LET WATER PASS THROUGH.
   Permeable and porous paving are ways to cover surfaces of earth without creating the heavy washout of water that can happen with impermeable materials like cement or tar surfaces in heavy rain. It creates an even seepage of water over the surface while trapping pollutants and offering a stable surface for walking, seating, parking and building.

2. Permeable interlocking stones courtesy of PICP

   CHECK OUT MATERIALS WITH THE LOOK YOU WANT FOR YOUR LANDSCAPE DESIGN.
   You can use various materials in your landscape to help with your drainage and to create an artistic surface covering.

3. Porous asphalt courtesy of PICP

   CHECK PRICING. You can use expensive or inexpensive materials. Permeable paving can be as simple as using ground road base, gravel or decomposed granite to build flat surfaces like driveways, patios and paths. Bricks, flagstone, rock, gravel, pavers, cast concrete forms and the like can all be used for more elaborate permeable paving.

4. Terra firm ecogrid is a manufactured item that allows you to grow grass that will support the weight of a car.

   INSTALL IT RIGHT.
   Build a base. This is similar to laying a paver or patio patio without cement. There are likely different building codes for different cities, but you will want to make sure your underlayments are strong enough to support the kind of weight necessary. Your base can go down 10" - 12" with road base or other crushed rock-like material if you need to support a lot of weight like a car. Or you can dig down just a few inches coating the surface of the exposed earth with an inch or two of sand if you want to lay more rustic pavers or flagstones and you are not supporting heavy weights or concerned with a possible slight buckling over time.

   You can use forms like the ecogrid or build your own by laying cement blocks on their sides and filling the open designs with grass, gravel or builder's sand.

5. These colored pavers are artistically designed so they look 3-dimensional. (courtesy of PICP)

   GET CREATIVE WITH MIXED MATERIALS OR ARTISTIC DESIGNS.
   You can be very artistic with different paving materials. Arrange them in patterns or even pictures. So long as moisture can penetrate and doesn't wash over the surface, your flat area will be 'permeable'.

6. More artistic uses of pavers (courtesy of PICP)

   USE ARRANGEMENT TO ADD TO ARTISTIC EFFECTS.
   You can fit your materials closely together allowing for slow drainage, use a fine coating of small materials like gravel or crushed stone or asphalt, or you can use flat stones, blocks or flagstone. You can combine any number of these materials to create artistic layouts or you can space areas apart filling the gaps with gravel, stones, lawn or plants.

7. Create your own permeable designs.

   GO FORMAL, INFORMAL OR ANYTHING IN BETWEEN.
   You can use the concept to create your own version of drain-able surfacing. It can look formal or rustic.

8. Another example from the Interlocking Concrete Pavement Institute

   Depending on what you build or how you build it, there may be more or less maintenance involved over time. Contact building material suppliers, hardware stores and paving experts. There are companies devoted to producing materials specifically for permeable and porous construction. With growing concerns over water, drainage, ecologically friendly construction and materials, many new products are becoming available. You are no longer limited to a plain cement surface in the landscaping of your home!

Resources

• Gates & Croft Horticultural Design
• What is porphyry stone?
• Design a landscape plan
• Design steps and stairs
• Design rocks in the landscape