Athletic and Sports Flooring - July 2011

By Jessica Chevalier

Like an athlete, athletic and sports flooring is expected to perform. Under skates, cleats, 300 pound lineman and even herds of children, it must look good, hold up and protect the athletes who are working on it. Synthetic turf, hardwood and resilient products are the three categories of flooring used in athletic and sports facilities. Specification of any of these materials for an athletic purpose demands an architect or designer well versed in sports work, both because human health is at stake and because many of the systems carry a heavy price tag.

Innovations in sports flooring have greatly reduced the risk of danger to athletes. Hardwood systems for basketball courts must undergo Deutsches Institut für Normung (DIN) testing, which measures a floor’s ability to absorb shock from both the ball and the human body. Synthetic turf has been engineered to reflect sunlight, reducing its surface temperature, as well as to minimize the rug burns that athletes receive from sliding across the surface. Resilient flooring provides the “give” necessary for an athlete to play hard and even fall hard with reduced threat of injury.

Tarkett is one of the world’s largest players in athletic and sports flooring. The company—whose U.S. athletic and sports flooring companies include FieldTurf, TarkettSports and Benyon—reports that the sports category accounted for 13% of its worldwide sales in 2010, the same as in 2009. Last year, Tarkett’s sports surface sales totaled around $350 million.

SYNTHETIC TURF
Synthetic turf can be used for a range of team sports, including baseball, football, soccer and field hockey. The material is composed of synthetic fibers made to look like blades of grass. Synthetic turf was first used in Houston’s Astrodome in 1966. By the 1970s, some football and field hockey stadiums were utilizing the material. And, in the ’80s, a few European soccer clubs transitioned to the surface as well. Tarkett’s FieldTurf, Mondo and Astroturf are significant players in the U.S. synthetic turf market.

The greatest advantage of synthetic turf over its natural counterpart is that it requires less maintenance and extends the number of hours a field can be used. Synthetic turf doesn’t need to be cut, watered or treated with chemicals. And it doesn’t wilt or die. In general, a synthetic turf field has a ten to 15 year life span.

Patrick Maguire, owner of Activitas, is a Harvard-educated landscape architect who specializes in outdoor sports. Five years ago, Maguire renovated Gillette Stadium, the home of the New England Patriots football team and the New England Revolution professional soccer club, and he still serves as its turf consultant. He also renovated Harvard Stadium.

The turf being installed today is the third-generation of the material, and many improvements have been made from earlier incarnations. Since synthetic turf doesn’t absorb the sun as a living plant will, it has a tendency to get hot, sometimes as much as 60 degrees hotter than natural turf. This can pose a danger to players during those afternoon ball games in the dog days of August. To alleviate this problem, synthetic turf manufacturers took a cue from the automotive industry and began incorporating additives that cause the turf to reflect the sunlight, considerably reducing the surface temperature of the material.

Shock pads and infill systems are two other innovations that have helped make synthetic turf safer for the athletes playing on it. The systems create a more resilient surface, reducing the force of impact. Some—but not all—of today’s synthetic turf systems have a shock pad installed below them. In addition to providing an added element of safety, shock pads lengthen the life of a field by reducing compaction. These pads are made from a variety of materials, including polypropylene and rubber. Many are composed of recycled materials. Others are made of virgin materials. These offer a lifespan of up to 50 years, after which they can be recycled.

Shock pads are expected to last through at least two to three replacements of the carpet matrix above them. Though shock pads add to the upfront cost of a system, over years of use they reduce material consumption and waste by increasing the life of the playing surface. Shock pads can add from $0.75 to $2.25 per square foot, depending on the product and thickness. However, this cost can be offset somewhat because it means that a shorter carpet with less infill can be used.

Infill is an important component in a synthetic turf system. Infill is small grains of material that are placed between the blades of the artificial grass—it acts like soil, holding the blades in place and creating a feeling underfoot that is more akin to natural turf. It also helps with energy absorption. Infill should not be visible on the playing surface.

Different amounts of infill are used for different sports. For example, the exposed pile height is generally shorter for field hockey than football, so more infill is added in the pile and less fiber is exposed. This improves ball roll. More infill also helps hold the fiber upright, which increases its lifespan. A fiber that is lying on its side is a fiber that is susceptible to wear and greater UV breakdown.

Sand and rubber, or a combination of the two, are the most common infill options. Maguire estimates that 90% of infill in the U.S. is a sand-rubber combination. The rubber in infill is often recycled automotive tires. Though, technically, most of the rubber and sand used as infill can be recycled, if the turf has been used for a long time, eight to 12 years, it can be difficult to extract the infill from the carpet. Though recycled rubber will, at some point, lose some of its integrity, extending the life of the product as long as possible—and thereby reducing the consumption of virgin materials—is a sustainable benefit.

Thermoplastic elastomer (TPE) is another infill option. The material is recyclable but expensive. TPE increases the resilience, softness and durability of the field. In Italy, coconut husks are gaining in popularity as an infill choice; some in the U.S. are using them as well. As a performance surface, Maguire rates husks as “magnificent, extremely close to being on soil.” But he notes that the husks do get hard if they are not maintained properly. The material must be both kept loose and watered to reduce dust. Husks keep a field cooler than rubber and sand. After their useful life has ended, coconut husks can be composted.

Polyethylene or polyethylene blends account for the bulk of the fiber used to create synthetic turf today. Just as with carpet, the face weights of synthetic turf vary, with the higher weights producing the most durable finished product. Light reflecting and antimicrobial additives are options with most fiber systems.

Synthetic turf is generally more costly up front than natural turf. Standard natural turf runs $2 to $3 a square foot. A high performance natural playing surface averages $5 to $10 a square foot, while a synthetic surface typically runs from $10 to $15. In some cases, however, natural grass can meet synthetic’s price when, for instance, outfitted with heating, cooling and drainage systems.

While synthetic turf may seem like a fairly straightforward specification, it takes a great deal of knowledge to choose the right surface (with the right features) for a particular application. A novice might assume, for instance, that a professional surface would need to be more durable than a playground surface, but that is not the case. In fact, children with flat-soled sneakers do much more damage to synthetic turf than linemen in cleats. Virtually all decisions regarding what type of turf specifiers choose (and what fill) are based upon what the surface will ultimately be used for and whether it will serve a specific purpose or varied uses.

At times, an organization will choose to cover a synthetic turf field with natural turf for a special event. National soccer teams will not play a meaningful game on synthetic turf, so when the New England Revolution has an important competitor coming to town, natural turf must be installed over the synthetic turf at Gillette Stadium. To prevent damage to and soiling of the synthetic field, the organization rolls a geotextile fabric over the field before the sod is laid.

While some of Maguire’s clients are still unconcerned about the green features of a synthetic system, others list it as their top requirement. When New York City’s Battery Park City Authority employed Maguire to design a synthetic field for a location close to where the Twin Towers stood, they wanted the most sustainable field in the world, including locally sourced materials, recycled and recyclable materials.

The rubber crumb used for infill has been a sore spot with regard to sustainability. It has been suggested that the recycled rubber crumb threatens human health and leaches heavy metals into the environment. Though rubber crumb can contain substances that can be hazardous to human health in large quantities, scientific studies have shown that the use of rubber crumb as infill does not pose a threat to human health or the environment. Overall, the industry has been sluggish in making environmental declarations about athletic and sports flooring. Maguire believes that manufacturers are hesitant to roll out new turf systems solely for the sake of sustainability but he has been hearing rumors of new sustainable options that may soon hit the market.

Timothy Bonaparte, partner at Appel Osborne Landscape Architecture in Syracuse, New York, notes that, “If sport surface companies strive to be more sustainable and environmentally sensitive with their product manufacturing and installation procedures, that will certainly benefit the projects we work on.” He has noticed an increase in the use of recycled content in vendor products over the last couple of years.

Maguire says that there was a proliferation of synthetic turf over the last ten years, but he is now seeing a slowdown. Maguire speculates that maybe following the recession, organizations simply can’t swallow the cost of synthetic turf, or, perhaps, that those organizations that are interested in synthetic have already invested in it.

HARDWOOD
There is a limited number of flooring material choices for basketball courts, and the specification of these materials is often made by athletic directors, facility managers and even on the advice of players. Since basketball courts have a lifespan of up to 60 years with proper care, specification shouldn’t be made lightly. Connors Sports Flooring and Robbins Sports Surfaces are two major suppliers of basketball court hardwood flooring.

Maple is the most common choice for basketball courts, accounting for an estimated 95% of the wood used and almost all professional playing surfaces. Oak and bamboo are utilized as well. Some professional stadiums are oak, though few compared to maple. Bamboo is generally reserved for college training areas and is often chosen by those who have a predilection for sustainable materials.

To maintain a hardwood court, experts recommend that grit be regularly removed from the surface using a broom or dust mop. Track off mats should be utilized at entry points from the outdoors. The floors should be cleaned with the proper products. And a recoat of finish should be applied once or twice annually.

Finishes on basketball court floors are either oil modified or water borne. Oil modified finishes offer an amber color for an older look. The materials for oil modified finishes are less expensive than for water borne, but they take longer to apply. For the most part, choice between the finishes is dictated by sustainability and preference. Water borne finishes are lower in VOCs. But people generally make their choice based on what is popular in the area of the country in which they reside. In the San Francisco area, for instance, specifiers have a preference for water borne finishes because they have a greener profile. But in Texas, oil modified finishes are the status quo and, thus, are specified more often.

Underfloor component systems are another integral part of basketball court installations. Sometimes, for example, a 2” wood surface will be installed over a 7” depression, so the installer will have to build a system that makes up the space difference. Wood structures are the most common choice. These systems do affect the playing surface, so they have to be factored into the equation early in the specification process.

RESILIENT
Resilient flooring is used in a variety of spaces in athletic facilities: tracks, gyms, aerobic rooms, training rooms, locker rooms, volleyball courts, basketball courts and multi-purpose areas. Resilient flooring used for sports and athletic surfaces includes rubber, poured in place polyurethane and vinyl.

Julie Sayers, an interior designer in AECOM’s Kansas City office, uses rubber in many sports applications, including weight rooms, training rooms, aerobic rooms, locker rooms, gyms and multipurpose areas. Why? Even under the blades of ice skates, the weight of falling dumbbells or the spikes of cleats, rubber will typically ugly out before it wears out. The average lifespan of rubber flooring is about 30 years.

The flooring will also withstand the abuse of heavy rolling loads (like boats and automobiles) that are often brought into an athletic facility for a show, so Sayers uses rubber flooring in sports complex concourses as well. For a weight room, training room or aerobic floor, Sayers will often choose a 3/8” thick rubber floor from Johnsonite or Mondo. Rubber flooring is available in both rolls and tiles.

Sayers is currently renovating the Louisiana Superdome and plans to install a 3/8” rubber walkway—over the concrete—from the locker room to the field, to protect the players’ cleats.

If a client is unable to afford rubber throughout a facility, Sayers will sometimes use vinyl in operational spaces but never in an athlete area. She has used poured epoxy flooring for concession stands, where slip resistance is a benefit.

Poured in place polyurethane flooring is used in basketball courts, aerobics rooms, volleyball courts, running tracks and multi-purpose areas. Because these floors are poured over a rubber pad, they provide an even, seamless surface with consistent ball bounce, shock absorption and coefficient of friction. They are offered in a wide variety of colors, so they can be customized to match school or facility design schemes.

Multipurpose areas, commonly called cafetoriums, often feature urethane flooring, instead of hardwood. Poured in place flooring is a better choice than hardwood in areas that may get wet or those that might come in contact with chair legs or high-heeled shoes. Synthetic material choices are generally reserved for elementary and middle school facilities. These floors are usually more cost effective than hardwood installations.

Vinyl flooring for sports and athletic applications is available in both solid colors and wood looks, and it comes in both sheet and rolled formats. The flooring is used in gyms, aerobic rooms, locker rooms and common areas. Some vinyl is suitable for wet areas like pools. Like poured in place flooring, vinyl has good shock absorption, coefficient of friction and ball rebound qualities.

Though sustainability isn’t yet a driving concern in the field of sports, Sayers clients are realizing that it is a smart tool to utilize in marketing. Two of her projects—the University of Oregon’s Matthew Knight Arena and Brooklyn’s Barclays Center, future home of the New Jersey Nets—are seeking LEED certification.

Currently, many rubber flooring manufacturers offer products that contain recycled rubber chips. There are even some manufacturers who have flooring made of 100% recycled rubber. Ecore International, maker of EcoSurfaces commercial flooring, now has a material reclamation program called Redeux that accepts and recycles some rubber flooring. Mondo, Gerflor, Ecore International, Roppe, Flexco, Nora and Tarkett all sell resilient flooring for sports applications.