Is adding a synthetic field the answer?
Many factors impact the capacity of a sports field to handle high usage including: the soil type, grass species, weather conditions, kind of sport, amount of usage, management program, etc.
Most school sports fields are also used for gym class, band practice, community activities as well as practices and games. Native soil fields can take just so much use before the turf thins and compaction becomes severe. Overuse does impact the function and aesthetic expectations of sports fields.
Some managers have considered adding a synthetic turf field which can be played on essentially 24 hours a day, seven days a week. Having and using a synthetic turf field would allow native soil fields to be rested and have time to recuperate. These fields are especially useful in the spring and fall when temperatures are more moderate than in the heat of the summer.
What are they made of?
Today’s artificial or synthetic infill turf fields typically include nylon fibers attached to a porous polyethylene backing, 2 inch infill of crumb rubber placed within the fibers, and often a polyurethane pad placed just under the backing for extra cushioning. For drainage, most use a 8-12 inch gravel/sand sub-base and sideline drains. These fields can take incredible amount of use compared to native soils fields.
The below subjective comparison of both natural grass fields and synthetic fields is a summary of collected input provided by a wide-range of users. See also the complete Natural Grass vs Synthetic Turf Decision Making Guide.
|Natural turfgrass||Synthetic turf|
Any drawbacks or issues with synthetic fields?
Cost of construction and maintenance
Synthetic infill fields are very costly to install and maintain in comparison to a native soil field. They must be installed by experienced companies that specialize in this new technology.
Many factors influence field construction costs including field size, geographic location, site work required, labor costs, irrigation system, etc.
Comparison of Construction Costs of Several Sports Field Types
Field size: approximately 2 acres
|Estimates||Natural Turfgrass on Native Soil||Natural Turfgrass on Sand-based Field||Sand-Capped Field||Synthetic field|
|Source A||$50,000 - $150,000||$250,000 - $350,000||$850,000 – $1,000,000
(8-10 years of use before replacement)
|Source B||$400,000 – $600,000||$200,000 - $300,000
$60,000 - $100,000
Spartan Cap System
|$600,000 - $1,000,000|
|Annual Maintenance Costs|
250 hours of labor
375 hours of labor**
(not including equipment)
|Source B||$5,000 – $22,000|
*Source A: Estimates are derived from 2008 average costs cited: A Guide to Synthetic and Natural Turfgrass for Sports Fields, STMA, and included annual inflation of 3%.
Source B: Information provided by David Minner, Extension Specialist, Iowa State University
** The cost can even be higher if field markings must be painted and cleaned often, or if frequent repairs are necessary.
Although your maintenance program will depend on the amount of use, level of play, kind of sports played, type and quality of construction some basic practices must be made on a routine basis to protect your investment including:
- Measuring field hardness periodically to ensure the level of hardness is lower than the 200 Gmax level. At least once a year.
- Sweeping and dragging to keep the carpet fibers in an upright position. Once a week or once a month depending on use.
- Loosening and redistributing of infill (to improve footing, reduce static electricity and improve the look of the field). Groom fields before each game.
- Checking and replenishing the infill level especially in high use areas. The infill creates the padding and shock-absorption for the synthetic turf system and restores the field’s resiliency. At least once a year. It takes about 20 tons of crumb rubber to provide ¼ inch layer.
- Using a vacuum or leaf blower to remove debris like sunflower seeds. After each game.
- Cleaning with special solvents and cleansers with difficult to remove items. After each game.
- Treating with anti-microbial products to remove bacterial growth. Weekly to monthly.
- Troubleshooting for common problems and minor repairs, such as seam repair. Frequently.
- Removing snow during winter months.
Prevent problems and extra work by:
- Establishing policies that prohibit the use of chewing gum, sunflower seeds, chewing tobacco while on the field surface.
- Providing trash containers in strategic places so trash is not place on or around the field
- Providing scraper mats where players and coaches enter the field so debris can be removed from shoes.
- Involving athletes to help remove debris after reach game
|Concerns||Natural Turfgrass Field||Synthetic field|
|Heat||Grass dissipates heat and naturally cools the environment. Heat related injuries are rare.||Can reach extremely high temperatures even at head level.**|
|Abrasions, burns, grazes||Generally soft and not abrasive. Only a problem when ground has become bare and dry.||Most fibers are relatively non-abrasive. Choice of infill critical. Sand more abrasive. Rubber can cause friction burns if sliding.|
|Traction: knee and ankle sprains and muscle strains||Choice of grass type is important for traction. Too much traction has been linked to an increased risk of severe knee injuries and too little traction to muscle strains and facial fractures.||Footwear plays a major role in the amount of traction a player experiences, so you need to consider if you are going to impose footwear rules on users to reduce the injury risk.|
|Bacteria||Less potential for abrasions.||Greater potential for abrasions, opening up wounds to possible entry point for bacteria.|
* Natural Grass vs Synthetic Turf Decision Making Guide, Government of Western Australia, Department of Sport and Recreation. 2011.
** “Synthetic Turf Playing Fields, Present Unique Danger”, Applied Turfgrass Science, November 3, 2005, Brad Fresenburg, University of Missouri.
More safety information:
When considering adding a synthetic field, follow the steps for success:
- Read resources published that contain the benefits and issues of both natural turfgrass fields and synthetic turf to aid in decision-making.
- Visit the synthetic fields of your colleagues to see how they are performing and the level of care they require.
- Only work with reputable companies that have the experience with construction and maintenance of synthetic fields.
- Attend dealer sponsored training programs to learn recommended maintenance practices.
- Read and follow manufacturer guidelines carefully to avoid having the warranty voided.
- Develop policies that prevent or reduce the likelihood of increased maintenance or repair to the field.
Remember, before making any decisions, review the information found in the following publications. Also take the time to visit and learn from other sports turf managers who have put in synthetic fields.
- Natural Grass Athletic Fields
- A Guide to Synthetic and Natural Turfgrass for Sports Fields: Selection, Construction and Maintenance Considerations
Construction and Maintenance Resources:
Current Research Findings on Health Issues