SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: http://read.dmtmag.com/i/338693
14 SportsTurf | July 2014 www.sportsturfonline.com Field Science depth (each company's recommendations are different), monitor the field and when your average infill depth gets below recommended threshold, call your manufacturer for their recommendation. If it is recommended to install more infill, have a professional infill installer apply the infill. One thing I have learned, you don't need to apply much rubber to bring your numbers back into spec. Installers have methods of getting the infill down into the system for a safe and playable field more quickly. Hollis: The infill material provides a cushioning effect; the more infill, the more cushioning. Playing surface hardness levels, or Gmax ratings, are almost always associated with low infill levels. It is not that the infill material is compacting like the soil does on natural turf fields. Instead, the infill is actually being removed or displaced on fields over time, in a variety of ways. The result is less infill in the field and increased surface hardness. In order to prevent this, infill levels should be measured regu- larly and compared to the infill depth recommendations provided by the field manufacturer. When infill levels drop below the manufacturer's recommended range, additional rubber should be added. Mueller: Our field is about 4 years old, and we monitor it regularly with an infill depth gauge. We have not had noticed a decrease in our infill depth, and the depth is consistent throughout the field. This is probably due to our regular grooming schedule. Also, our turf is Astroturf 3Di, and has a thatch layer incorporated into the fibers that reduces the movement of the infill. McNeal: As often as the field needs it per your observation and manufacturer's recommendation. Sports turf managers have to be diligent about monitoring the infill levels as the field is used; higher use fields may require more frequent additions of rubber infill mix. On our baseball field we add material in our higher traffic areas (batters boxes and base areas) almost every other day during our season. If we do not monitor these areas closely then we can have fiber wear sooner then anticipated. Lober: The end user should have a system to chart the areas that tend to have infill movement due to high activity. For example the penalty kick line in soccer gets used heavily during practice where several kids will line up and go one after another. Corner kicks, goal mouth areas for soccer and lacrosse, and extra-point kicks for football are also critical areas. The growing application of turf for baseball fields makes sliding into second, third and home the areas that get infill movement more than any other application. How do you check the infill depth? This is easy and can be done by using a depth meter that can be purchased for as much as $250 or there are other companies that make depth testers for rubber track sur- faces that are around $20. These tools are reasonably accurate because testing a rubber track surface requires a fine tolerance. The infill should be ~1/2"-3/4" below the tips of the blade so a 2-1/2" system should have a minimum of 1-3/4" of infill. Not sure what height system you have? Go along the edge of the field and pull a bundle of blades and measure them. Charting the areas that require regular maintenance is some- thing that should be done often but adding large amounts of infill should generally not be necessary for the first 3-5 years. Spreading bags of rubber and brushing the field to distribute it should be done by professional turf installers but can be done by facility maintenance staff if they are up to han- dling the task of moving and spreading supersacks of rubber. For example each pound of rubber equals about 1/2" of infill per square foot. If an 80,000 square foot field is low by an average of 1/4" then it would take approxi- mately 1/2 pound of rubber per square foot or 40,000 pounds, which is 20 supersacks. I generally don't recommend trying to put more then 6-10 sacks of rubber in at any one time unless the field is extremely low and requires more infill. A good practice would be to add 3-4 bags in years 4, 6 & 8. Dewitt: Never have had to; on my old rug the fibers were completely worn away and existing crumb was right on the surface! My new rug doesn't get used a whole lot and it's indoors so I haven't had to add anything since it was installed in summer 2010. Vescio: First and foremost the field should be filled to appropriate levels (according to specifications). The field should be checked in its entirety at least once per year. Typically a Gmax report will indicate the levels of infill. Through the Gmax report or at a minimum a yearly check will help establish the need for additional infill. More attention Courtesy of Kromer Company