The Popularity of Permeability

Source: www.TurfMagazine.com

Interest in permeable pavers is growing because of increased attention to reducing stormwater runoff and client demands for eco-friendly landscaping practices. With permeable pavers, water permeates through the pavers’ joints and into a specialized open-graded base system where it can be absorbed by the earth. These benefits are driving the popularity of this material.

Residential, commercial and municipal permeable pavers reduce stormwater runoff and capture the pollutants they carry, says Jessica Chase, CAE, director of marketing and membership for the Interlocking Concrete Pavement Institute (ICPI) based in Chantilly, Virginia. “Permeable interlocking concrete pavements (PICP) are made with a notched design that creates a series of openings filled with small stones which allow rainwater—even heavy rainfall—to drain through the pavement surface and infiltrate the soil below where contaminants are naturally filtered,” she explains.

There are a number of benefits. Besides preventing stormwater runoff, by allowing water to return to the earth, the soil is being replenished, which is a benefit in itself. Many also cite the reduction of pollutants entering the waterways. Permeable pavers are great for people who are environmentally cautious, and new zoning restrictions and regulations regarding impervious ground areas are also making them key solutions in many applications, Chase says.

Mark Antunes, technical information representative with EP Henry, agrees that the law is part of the driving force behind the permeable paver trend. “Federal law now limits the amount of area that can be developed as an impervious surface,” Antunes says. “But turning to permeable pavers solves that problem. You can still have a patio, pool deck, driveway or walkway, and it’s not counting against that regulatory number.”

Permeable interlocking concrete pavers can be used on any low-speed or pedestrian application. Many commercial projects feature permeable pavers in parking lots. PHOTO: CULVER’S LAWN & LANDSCAPE

While most contractors would recommend permeable pavers to solve a stormwater or regulatory problem, they can also benefit the client and the overall community, says Glenn Herold, permeable paver expert for Belgard Hardscapes. Community benefits include recharging the local groundwater supply, improving water quality by natural filtration, cooling the earth and reducing overall landscape water usage.

Applications abound

In the past, interest in permeable pavers may have been more prevalent in certain regions, but recently the trend has evolved. Michael Hennessey, president of Hennessey Landscape Services, Inc. in Plaistow, New Hampshire, says permeable pavers have already been used in shore land work, wetland areas and on environmentally sensitive jobs. He sees them growing beyond those applications.

“They are becoming a more specified material, and are often required by conservation commissions,” Hennessey says. “Overall the environmental community is growing, and the government is becoming more aware of the need for permeability in construction. Interest is coming from the top down.”

While some contractors see the most interest in permeable pavers on the commercial side, they seem to be gaining popularity residentially, as well. “It’s coming on pretty strong in the residential market for us,” says Mike Platner, commercial project estimator for Culver’s Lawn and Landscape, Inc., in Marion, Iowa. “We’ve done quite a few driveways and patios utilizing permeable pavers, and we’re getting positive feedback. I see that market increasing.”

With some training and hands-on experience, contractors can become proficient in designing and installing permeable pavers, creating environmentally friendly surfaces that are both attractive and safe. PHOTO: PINE HALL BRICK

Platner recalls one residential project where permeable pavers were a key solution to a water collection problem. The client’s asphalt driveway was at least 20 years old and had tire ruts that were collecting water and icing up in the winter. That was causing major trouble. Permeable pavers ended up not only being a solution for the water collection but brought tax incentives as well, because residents in that area were being taxed for stormwater runoff, so keeping water on the property was a big concern.

“I would estimate that client is now keeping almost 90 percent of the water that falls on his property,” Platner says. “That has made the tax incentive a big deal.”

In addition, the icing issue has been solved. The client’s driveway is no longer icing up, and snow removal has become incredibly easier. “Driveway cleanup time has been significantly decreased because the surface is now smooth with no ruts, and water is not collecting and freezing,” Platner points out. “After the first snowfall, within three hours there was no snow left at all. It had completely melted and run into the pavers, so there was no refreezing to cause trouble later. The client was quite pleased.”

According to Chase, PICP can be used on any low-speed or pedestrian application, including driveways, patios, sidewalks, walkways and low-speed roads. Many commercial projects also utilize permeable pavers for parking lots, Herold adds.

Although word is spreading about permeable pavers, most contractors will still have to educate their clients. “I do think the trend is growing, but we still need to tell our clients what they are,” says Craig Kittleson, owner of Kittleson Landscape, Inc., in Blue Mounds, Wisconsin. “Many clients have never heard of them and, even if they have, they don’t understand what they are.”

Hennessey says most clients need more information in order to understand the benefits. “They definitely don’t understand all of the ramifications of using impermeable surfaces and do need quite a bit of education,” he says.

Selection and maintenance

While there are a lot of benefits to utilizing permeable pavers, they aren’t without gripes. Some contractors feel the selection is still lacking. “It’s definitely beginning to change, and there are more and nicer products available in terms of design and color,” Kittleson says. “But there’s a way to go when you compare it to the rest of the market.”

Hennessey agrees. “It’s still very limited in colors and design,” he says. “Manufacturers are coming out with new types every year, so it’s catching up, but they should focus additional resources to expand on this new segment of the hardscape market.”

Figuring out long-term maintenance may also be an issue. Over time, the pavers do need to be cleaned of any debris that may have collected within the system. While most pavers can go many years without any maintenance or repairs, they will eventually need a vacuuming by a vacuum truck or specialty vacuum service.

“Vacuuming probably only needs to happen every seven to 10 years,” Platner says. “In the meantime, most homeowners do maintain their pavers on their own with basic preventive maintenance, such as clearing off the surface if a lot of debris is collecting there.”

In time, Kittleson says the maintenance of permeable pavers could be a revenue generator for contractors. Right now, they’re just too new for long-term maintenance to be a big concern. But ultimately, the vacuuming could be an add-on service.

“It’s a supply and demand thing, and there’s just not enough installed out there right now for the maintenance to be a big thing,” Kittleson says. “But I see that coming in time. While we would power wash regular pavers, I don’t believe that is a good idea for permeable pavers. You don’t want to push dirt further in; you want to extract it. As a result, it’s a little bit more of a specialized service.”

Looking ahead

Going forward, the interest in permeable pavers will grow. According to Chase, national, provincial, state and local regulations to reduce stormwater runoff are providing continued increase in demand for PICP. “A significant increase in PICP residential sales can likely be attributed to the increasing popularity of municipalities issuing stormwater credits and reimbursements to homeowners who reduce their impermeable surfaces with PICP,” Chase adds. “According to our annual industry sales survey, 38 percent of permeable pavers were sold to the residential market in 2013, representing a 13 percent increase over last year.”

Antunes adds there is also a genuine interest in the pavers for their environmental benefits, and he sees that interest growing. “We have a lot of people calling EP Henry, who are very interested in wanting to install permeable pavers not because they have to, but because they want to,” he says. “They want to do the right thing for the environment. They recognize the ground is not an inexhaustible source of water, and that we’ve already covered so much of it with impervious materials like asphalt, concrete, and buildings. It’s becoming harder to recharge the aquifer that supplies ground water for wells and plant life. That’s critically important and will be a contributing factor to this ongoing trend.”