Synthetic-Turf Maintenance Basics
Let’s begin with the knowledge that synthetic-turf fields are NOT maintenance-free. With that aside, let’s look at what it takes to properly maintain a synthetic-turf field to ensure the longest life possible. After all, it’s hard enough to come by budget dollars. Don’t you want to stretch them as far as you can?
For starters, be aware that whatever comes off of the fields must be replaced. Whether all crumb rubber or a rubber/sand mix, the infill material that disappears as it is carried off by players, wind, rain, snow, snow removal, routine maintenance, etc., needs to be replenished because it is the supporting substance of these fields. And when turf fibers are laid over with minimal support—causing them to prematurely break off—this is a lethal combination. The worst enemy to the fibers of the synthetic-turf field is the sun’s ultraviolet rays day after day. Maintaining a proper amount of crumb rubber and allowing only approximately a ½ to ¾ of an inch of fiber exposed prevents the fibers from folding over, and minimizes the ultraviolet rays breaking down the materials. On average, an athlete or end-user will carry off 3 to 4 pounds of infill material during a playing season. To calculate your needs, measure the amount of crumb rubber in a variety of locations within the synthetic field boundaries to determine what is already there. Measure 10 locations using the ASTM 1936-10 guidelines for Gmax testing as the test points. If the turf is 2¼ inches tall and there is less than 1½ to 1¾ inches of infill, you need to add more. Most crumb-rubber infill calculates to 0.55 pounds per square foot for a ¼-inch lift. Most rubber/sand infill systems will not need additional sand as they tend to stay stable within the turf. There are rare occasions when the sand is removed due to operations (snow plowing) or torrential downpours that cause flooding and must be added to the mix.
Using a groomer designed for synthetic turf, such as the Greens Groomer or the Wiedenmann units, is highly recommended. Adjust the groomer so that it lightly touches the fibers to provide the best results; do not lower the entire weight of the groomer onto the turf unless you are trying to level out or move crumb rubber to fill an area, such as a lacrosse goal crease. When tickling the fibers with the groomer’s brushes, the intent is to stand the fibers up to minimize the lay-over from use.
How often should a field be groomed? While there is no exact answer, a good rule of thumb is after 300 to 350 hours of use; some might say 400 to 500 or more, but much depends on the manpower available. At minimum, the field should be groomed several times during the highest use periods and less during the downtimes (if there are such things).
Sunflower seeds, chewing gum, candy wrappers, cigarette butts, wire ties from nets, broken sand bags, or stone bags used for weighting down goals are some of the typical items one can expect to clean up off of turf. Timely removal is important to keep the trash and debris from being ground into the infill material, causing removal problems in the future. Water, Gatorade, juice, and soda bottles are unsightly and also need to be removed.
Removal of chewing gum is largely overlooked and needs to be addressed as soon as possible. Since most chewing gums today never harden, they become a gooey mess with the intense heat on the field and eventually are carried across the turf surface. To remove, use either ice cubes or a freezing-spray agent to harden the gum, chip it off, and remove it.
Weeds And Creeping Grass
If the turf is surrounded by Bermuda grass or other creeping grass, be prepared—these grasses tend to seek their way into and under the synthetic turf, and since temperatures on these fields reach optimal growing peaks before the surrounding turf, it provides the perfect greenhouse-effect for these varieties to spread. Once they start spreading beneath the turf, they will find the drainage holes and send shoots upwards for the sunlight. These plants become very hard to remove due to their sewing-machine effect, and in most cases will need to be treated chemically (as approved by the turf manufacturer) in order to kill them. The easiest way to combat this problem is to understand it, look for it, and act quickly when it is discovered.
Wear And Tear
Synthetic-turf fields wear just like natural turf with the exception that it can’t grow back once it is gone, so pay attention to heavy wear areas. For example:
- Football—the center of the field between the hash marks
- Soccer—the penalty-kick and corner-kick areas, and goal crease
- Field hockey—the goal crease and penalty arc
- Lacrosse—the goal-crease areas and center of the field where face-offs take place.
Lacrosse play—men’s or women’s—has the ability to destroy a goal crease in as little as one year if not properly maintained because the infill material gets kicked or shuffled out, so the fibers take a beating and break off quickly. Before you know it, a large black area, that is the backing of the turf, appears; then it’s time to patch or replace the area with either the pieces saved from installation or maybe cut out from outside the playing area so that the piece matches the color and type. Even after one year, it won’t be a perfect match (even if left on a rooftop to sunburn like the turf on the field) because the surrounding fibers in the field will have been used and have started to mat out or break down. Or contact the manufacturer or a reputable service company to deal with the patch. There are special materials needed and the local home-improvement or hardware store does not carry them. Don’t use Gorilla Glue, LIQUID NAILS, styrene bonding agents, drywall screws, or framing nails for repairs, as they are not designed for synthetic turf and may become a liability nightmare later.
Painting may or may not be part of regular maintenance, depending on whether it was inlaid during installation. For those who have to paint, use only paint that is approved for synthetic-turf fields. Almost every year some company announces that it has synthetic-turf paint; do your homework, look at the company’s history, and get recommendations. If you need to remove the paint, ask the supplier whether it can be done, how this is done, the cost associated with it, any special equipment and chemicals needed, whether the product has been endorsed by any manufacturers, and whether your turf manufacturer is one of them. If you have to paint, try to do it at times other than in the heat of the day; if removing lines, do this at night or early in the morning when the turf is the coolest. Chemicals used in the heat will evaporate long before they start to work, and this will only cost more time and materials.
Dust, dirt, pollen, body-skin cells, screws, nails, track spikes, bobby pins, and human hair do not break down on these fields; they remain for much of the life of the field, and it is truly amazing how much accumulates. Special equipment with HEPA-filter vacuums will clear out and remove this debris from within the turf. Rain, snow, sleet, and hosing do not help.
Static is common and can increase with humidity and sometimes age; to combat this, use several household products. Liquid Tide washing-machine soap and/or a fabric softener both work well when sprayed on the turf.
Eventually, someone will inquire whether these fields need to be disinfected. For the best answer, review Andrew McNitt’s research pages at http://cropsoil.psu.edu/ssrc/sportsturf-scoop. Information also can be found on the Synthetic Turf Council’s website at http://syntheticturfcouncil.org.
Lastly, unlike with natural turf, you can’t see what is going on beneath synthetic-turf fields. ASTM has recommended that synthetic-turf fields be tested annually to determine their hardness in G force (also known as Gmax). Some people do not believe this is necessary, but testing is an important tool, much like soil tests. If this is not done, you have no history data of what went on before. I have tested both 2-year-old fields and 11-year-old fields with less than ¾ of an inch of fibers remaining and with almost no infill, yet the newer one tests harder than the older one. Does this mean that the turf is not being tested but only the stone base beneath? This is a good question, and since there aren’t data for 11 years of historic Gmax testing, one can assume that people are now testing the Gmax of the stone base.
Synthetic-turf fields are a great tool, and if properly maintained will provide years of use and play. There is obviously much more to learn about these fields. Don’t be afraid to ask your peers or contactor because that may prevent you from making a huge mistake.
Jim Cornelius, CSFM, manages the Fisher and Son Company’s Pro Services division in Exton, Penn. His commitment to educating the owner of these fields will ensure playability, safety, and performance for users, which will eventually create longevity for the ever-evolving synthetic-turf industry and the fields they service.