by Erik Spring, PLA
Synthetic turf fields are everywhere from the NFL to peewee soccer fields. I have designed many synthetic turf athletic fields for school districts and public parks (see some projects here). After working with great turf manufacturers, athletic directors, and student and recreational athletes, I have a good idea of the pros and cons of the most common synthetic turf options.
Lace up your cleats and I'll help you understand synthetic turf and which turf will work best for your field. To keep this simple I'll focus on multi-use athletic turf. That's the turf that looks like a lush green lawn, not the thin green rug-burn inducing carpet.
If you need more detailed information, I've included some resource links at the end, and you can leave a comment below and I'll contact to you.
The Green Stuff
Most synthetic turf is made of one of the following three fiber types:
Monofilament. Single blades of fiber that stand up straight, sometimes with a thickened spine or edges to help them stand on end. Monofilament turf is the best looking turf because the blades stay upright longer, but it's not the most durable. It can be great for soccer because the upright fibers lend themselves to a slower ball roll, but the nature of individual fibers means there is usually more infill splash.
My assessment: ideal for football or lacrosse.
Slit Film. Extruded tape-like flat strands that are sliced (slit) forming a honeycomb-like fiber. Once the turf system is in use, the strands break apart, or filibrate, at the slits. Slit film turf holds up to high use activity better than monofilament . It tends to provide a faster ball roll and less infill splash.
My assessment: ideal for baseball/softball and multi-use fields.
Hybrid. The best of both worlds: hybrid systems include a combination of monofilament and slit film turf fibers.
My assessment: great playability for soccer and most multi-use athletic fields.
Backing is the Unsung Hero of Synthetic Turf
Fibers are punched, or tufted, through a woven sheet of fabric and urethane is applied on their underside to help hold the fibers in place. Then the backing is perforated to allow for drainage. The finished product is supplied in rolls typically 10-15 feet wide. During installation the rolls are sewn or joined with glue, or both.
One exception is woven turf. With woven products, the fibers are woven into the backing rather. The fibers are more fully integrated into the backing, increasing holding strength (called tuft bind). Woven products are stronger than tufted products and tend to stand up on their own. Woven turf is a new technology; I suspect it will quickly become the norm.
What Makes Synthetic Turf Soft
If you took a sheet of synthetic turf off the manufacturing line and laid it on the ground, the fibers would fall over and lay flat. Enter the infill. Infill material fills the gaps between the fibers. It also weighs down the turf, helps the fibers stand up, and provides impact attenuation (meaning: the turf is softer when you fall on it).
Infill also provides a surface for cleats to dig into. Silica sand and crumb rubber make up the infill for most synthetic turf, however synthetic turf technology evolves quickly; this could change at any time.
Major Benefit of Synthetic Turf #1: No More Rain-Outs
Games can be played on synthetic turf in almost any kind of weather. The perforations in the backing allow a tremendous amount of water to quickly exit the field. Fields with synthetic turf have below-ground drainage systems, usually made of gravel and perforated drain pipes.
Turf systems typically drain up to 20 inches of water per hour. To put that into perspective, the average rainfall here in Colorado is around 15 inches--for the year!
Bottom line: within minutes of even a torrential downpour, play can resume on a synthetic turf field. A natural grass field may take hours or even days to dry out enough for play.
Major Benefit of Synthetic Turf #2: Sell The Mower
Synthetic turf is easy to maintain. There is no need for watering, mowing, aerating, or fertilizing. Synthetic fields mostly need to be groomed (brushed) regularly. Grooming keeps the fibers standing up and the infill materials evenly spread. Specialized equipment is available to make the task even easier.
This is part of a four-part series on athletic field design. See Dave Peterson's blog for an amazing look at the science behind athletic field design in a post on GIS field analysis. Check back throughout August to see blogs on the changes new soccer standards mean for athletic fields and the ins-and-outs of replacing tennis courts, and an amazing