Hardscape Trends: Pervious & Permeable Surfacing

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As part of our Driveways and Walkways issue, LC/DBM takes a look at the growing trend in hardscaping with permeable and pervious surfacing materials. For a variety of reasons, this hardscape niche is trending up. Whether its legislation, LEED credits, erosion control or clients wanting to be environmentally friendly, the end result is the same: The pervious and permeable hardscape products are here to stay. And expect them to become more popular.

According to a 2011 Trend Study by The American Society of Landscape Architects (ASLA), there is a growing interest among homeowners toward more environmentally friendly landscaping, including permeable and pervious surfacing. According to the report: ASLA noted that it when it comes to landscape elements permeable/pervious hardscape, rated at 77 percent of importance.

The LC/DBM Survey

In a recent LC/DBM industry survey, respondents listed storm-water management as the number one market force driving the use of pervious and permeable surfacing material. (See below).

Market forces pushing installer to use pervious / permeable hardscape.

National Associations

According to Robert Garbini, president of the National Ready Mixed Concrete Association, the trend in the pervious surfacing market is one of growth. ''Pervious materials use will continue to advance,'' Garbini declared. ''This will be driven by the sustainability initiatives which will become mainstream. Look at the focus in the international green construction code as one driver. NGO (non governmental organizations) such as the US Green Building Council LEED program will be the drivers. NGOs will accept use of such materials more greater recognition (greater points). Other major drivers are the local municipalities enforcing storm-water provisions looking for ways to maximize the use of land in more dense urban areas as demographics in the US change to push our living environment in that fashion.''

Of the companies in the paver market, 47 percent get less than 10 percent of their business from permeable/pervious pavers and 53 percent get more than 10 percent.

Charles A. McGrath, CAE, Executive Director of the Interlocking Concrete Pavement Institute said, ''Since permeable interlocking concrete pavement (PICP) support low-impact development goals and is a best management practice for controlling storm-water runoff and conserving water resources, many federal, state and local regulations are mandating the use of permeable interlocking concrete pavements. In addition, CALGreen, the International Green Building Code, LEED and other sustainable rating systems are encouraging the use of permeable pavements.''

As for growth in the industry, McGrath added. ''ICPI has been tracking the sales of PICP for the past three years, and have recorded growth from 15 to 20 percent (yearly). We expect this trend to continue.''

Another permeable option is Drivable Grass??????oe. This product employs a thin profile, permeable, and flexible concrete paving mat, which allows water to drain down into the plant material between the grid.

What Industry Experts Are Saying

''More and more municipalities continue to adopt development standards that favor hardscape areas with features including pervious pavers,'' said Aaron M. Reynolds, P.E. Firestone Specialty Products.

• Jim Engelke, ASLA, LEED AP for Soil Retention added, ''Pre-construction and post-construction storm-water run-off BMP mandates affecting even small-scale development will drive the use of more permeable paving.''
• According to Charley Yang, EV Paver Corp., ''More and more cities are requiring that rain-water be retained on-site to eliminate water run-off. Therefore, choosing pervious pavers will no longer be a choice - it will be a requirement.''

Do you predict increased, decreased or similar growth for the permeable/pervious paver market niche?

• ''Legislation is pushing designers to meet more strict goals on storm-water run-off. Parking typically is a big culprit to the issue. By creating green parking you not only remove the main contributor to the issue, but you create multifunctional systems that can treat the building run-off. Also many residential customers are pushing to be green,'' said Jason Lamers of Fiberweb Geosynthetics.
• Nick Jansson, of Soil Retention sees the niche trending up over the next few years, ''There will be increased demand based on government regulation and increased consumer awareness of environmental impacts. He went on to say: ''A decent percentage of our sales comes from LEED project requirements. However, developers and land owners are starting to see the benefit of more usable / buildable land when using permeable surfaces.''
• Terry Crouthamel, Jr. of Chameleon Ways, Inc. likewise sees permeable surfacing increasing, ''Due to increasing regulations regarding storm water run-off, the usage of permeable surfacing materials will increase dramatically.'' His advice, ''Contractors can establish themselves as being a leader in their industry by keeping current with these changes. It gives contractors a tool to develop a niche market, which will only expand and become mainstream in the coming years.''
  
  
  

Is the price difference between impervious and pervious hardscape going to change in the near future? 67% said there would be a decrease in price, 26% said it would stay the same and 7% had no opinion.

Price

According to Jansson, ''The price and return on investment can vary significantly by region. Generally, in areas that have strong storm-water regulation, the installed price can actually be less than traditional paving surfaces such as asphalt and poured concrete. Most cities now tax and limit the size of your building based on impervious coverage area.''

A Trend Contactors Should Embrace

While no one expects that permeable and pervious surfacing will overtake traditional ones in the near future, these products are a growth industry that's gaining market share; and contractors looking to keep competitive should learn how to install these products.

The detail above shows an example of the materials used in a pervious/permeable-surfacing base structure.

Pervious, Permeable and Impervious Pavers

There are three different types of pavers that can be used in traditional hardscapes: Impervious, Permeable and Pervious.

Impervious Pavers

Standard impermeable pavers, such as concrete pavers, force water to run off the paved area into surrounding landscaped areas or storm-water basins. Although it may be the least expensive option, it can become more expensive when factoring in the cost of storm-water mitigation.

Permeable Pavers

This outdoor living project features Belgard Celtic permeable pavers.

Permeable pavers allow water to flow off the surface into surrounding gaps, which are filled with fine, crushed aggregate that permits water to flow into the soil below. The infiltration rate of permeable pavers depends on the gap size and aggregate used.

Pervious Pavers

Pervious pavers allow water to flow directly through the paver body itself. (See company spotlight below) In certain cases, the pavers are manufactured with rock bonded together with a high-strength polymer. The infiltration rate can be 10 times greater than porous concrete, and more than 90 times greater than permeable pavers.

Company spotlight: Xeripave, LLC

By Debra McNamara

By using Xeripave pervious pavers in the most vital 18-percent of the project, costs can be cut while still providing efficient drainage needs.

Founded in 2008 by owner Peter Blundell, Xeripave opened its doors prior to the recession. Upon its founding, the company received numerous reports that contractors found it difficult to address environmental concerns while remaining competitive.

Mr. Blundell noted that what started out as supplying pavers with drainage capabilities was now about turning green into cost-savings.

Back to the Drawing Board

The R+D goal was to create pervious pavers that address environmental concerns while provide consumers a hardscape product with quality and longevity, as well as affordable prices. The outcome was Xeripave Super Pervious (SP) Pavers. The SP pavers claim a flow-through rate of more than one gallon per second per square foot.

Mr. Blundell stated, ''What is unique about Xeripave in comparison to other types of hard surfaces is that the pavers use a clear high-strength polymer that accentuates the natural aggregate colors and gives them an aesthetically pleasing wet look. These pavers have an infiltration rate of 5,400 inches per hour.''

TC Twitchell, Technical Sales Representative, stated, ''We have been working with our customers to find an ecological, cost-effective solution. With good communication throughout the project duration, we are able to find problematic areas containing sloping points. Xeripave is then utilized in the defined areas to prevent water build-up and flooding. The remaining surface can be used with other permeable or impervious surfaces to provide cost savings.''