In Safe Keeping
The Right Surface Is Crucial to Playground Safety
No matter what precautions parents, caregivers or teachers take, falls and accidents on playgrounds are inevitable. Each year, more than 200,000 children ages 14 and younger are treated in emergency departments for playground-related injuries, according to the Centers for Disease Control and Prevention (CDC). More than 20,000 of these result in Traumatic Brain Injury—including concussion—and nearly 70 percent of these accidents are due to falls.
But there are certain measures that playground managers can take to at least lessen the risks for children. These include addressing any rusty or broken equipment, making sure guardrails are in good condition to help prevent falls and keeping trip hazards such as tree stumps or rocks out of playground areas. And one of the biggest considerations is providing an effective safety surface—something soft and thick enough to absorb impact and help to keep a minor injury from turning into a severe one.
The days of dirt, grass, concrete or asphalt playground surfaces are (mostly) gone. These days, there are two categories of safety surfaces that we'll look at: loose fill and unitary.
Loose-fill surfaces include engineered wood fiber (EWF), loose fill rubber (LFR), sand and pea gravel.
Unitary surfaces are bound elements formed into tiles or rolled products. These surfaces include rubber tiles, artificial turf, poured-in-place rubber (PIP) or carpeting products.
Before retiring, Kenneth Kutska was the director of parks and planning for the Wheaton, Ill., park district. He's also a Certified Playground Safety
Inspector (CPSI) and has been involved with the National Recreation and Park Association (NRPA), AS™ International (formerly the American Society for Testing and Materials) and the International Play Equipment Manufacturers Association (IPEMA). He is currently the executive director of the International Playground Safety Institute (IPSI), traveling the world to teach and lecture about playground safety.
One training program that IPSI offers is called "Playground Surfacing: Putting Theory into Practice." Kutska said the objective of this program is to make sure the playground owner and designer's eyes are open to all issues related to each surface type.
"There is no perfect surface," he said. "Of course, price comes into play every time, but so does maintenance, repair and inspection to ensure compliance to current standards. A term we like to use when one considers what surface to purchase is 'Functional Longevity.' The amount of use and the local environmental conditions are critical to longevity and performance. Can the owner make repairs, or do they have to bring in a contractor? How expensive are the repairs? What are the purchasing specifications for length of warranty?"
No matter what precautions parents, caregivers or teachers take, falls and accidents on playgrounds are inevitable.
Indeed, playground managers and designers have many factors to look at when determining the best fit for their playground, as each site and situation is unique. Budget, accessibility, size of playground, types of playground equipment, climate and maintenance requirements all come into play. Safety standards and requirements need to be considered.
Loose-fill and unitary surfaces can both be a safe choice, and they both have pros and cons. The loose-fill surfaces are generally more affordable than unitary surfaces, and they're easier to install. When installed correctly, they offer good drainage and typically provide exceptional protection for falls. Loose-fill materials like EWF blend well with natural surroundings and complement eco-friendly playgrounds.
"Most loose-fill products are made from natural materials like wood, whereas unitary are usually synthetic," said Jeff Mrakovich, research and development manager for a Pennsylvania-based manufacturer of recreation surfaces offering EWF and synthetic grass. "Synthetic products tend to get harder over time due to UV rays from the sun, so getting unitary surfaces impact tested periodically is recommended."
EWF is not a landscape mulch, and has been manufactured or engineered specifically for use as a playground safety surface. It is ground more finely than ordinary landscape mulch, is from virgin wood and has had the sawdust removed. EWF meets Consumer Product Safety Commission (CPSC), ATSM, IPEMA and Americans with Disabilities Act (ADA) safety standards.
Mrakovich said that EWF offers excellent fall attenuation when properly maintained, but it's important to learn the origin of the product. "Recycled materials such as pallets have a greater risk of having dangerous elements in them. Pre-consumer woods have less exposure, which reduces the risk."
The higher the fall heights are at a playground, the thicker the surface must be, no matter the type of surface. If fall heights are above 10 feet, then loose-fill surfaces are more commonly utilized. Generally it's recommended to install and maintain a 12-inch thickness with all loose-fill surface materials because of natural compaction and scattering.
In fact, a disadvantage of loose-fill surfaces is that the product can get kicked away or displaced from frequently used areas. As a result, EWF and other loose-fill surfaces must be raked, replenished and compacted regularly to ensure safety and accessibility. "More maintenance is required with loose-fill, but there are accessory items like wear mats that help to maintain performance in high-wear areas," said Mrakovich.
Wear mats are designed to hold fill in place, particularly under swings, and at entrances and exits of slides, spinners and other high-traffic areas. Mrakovich's company also offers a wear mat requiring no fill under or above the mat—the mats provide the impact absorption needed. He said the mats are extremely helpful in maintaining performance in loose-fill surfaces. "The wear mats will keep the area level and retain fall attenuation. If theft is a concern, we recommend using a safe anchoring system that we developed."
Sand and pea gravel are still used as playground surfaces, and affordability is one big factor why. Again, they should have at least a 12-inch depth. Some sand can contain harmful materials, so it's recommended to use only sand or pea gravel specifically made for playgrounds. Additionally, these surfaces can conceal sharp objects, animal waste or pests, and small children might stick them in mouths or eyes.
Rubber mulch—whether shredded or nuggets—is also inexpensive, offers good drainage and minimizes dust. It won't float or absorb water in heavy rains and doesn't attract harmful insects. However, like sand and pea gravel, it doesn't provide good ADA accessibility.
"These choices offer good fall attenuation when properly maintained," Mrakovich said, "but can be challenging when dealing with accessibility. These loose-fill surfaces do not offer the same knitting quality as EWF. Some rubber mulch products will knit together, but some are shaped into nuggets and do not typically form a firm, stable surface. Ask the manufacturer for samples."
Kutska said that while sand and gravel do have accessibility issues, both do have benefits as playground surfacing under certain conditions, as long as the proper type of sand is used. "Once you start with pea gravel and sand and have a good source for what will comply with impact attenuation requirements, the owner must commit to continue to purchase any future additions needed to maintain the proper depth from the same provider and in most cases the same quarry."
"Rubber mulch has issues with metal from tire shredding operations that cannot completely be removed," said Kutska. "The standard is that loose rubber must be 99.9 percent metal-free. In a ton of loose rubber, how much metal equals one-tenth of one percent? You do the math."
He added that rubber can oxidize from UV degradation and some claim it's dirty, but it can give good impact attenuation if maintained according to the requirements of the CPSC Handbook. "It likes to migrate out of its intended home and can get into everything, just as all loose-fill surface systems."
Unitary surfaces don't require a lot of maintenance, and they typically offer longer warranties. They're available in an array of colors and designs so you can create original themes in your playground. They are slip-resistant, won't conceal foreign objects and offer excellent accessibility for mobility devices, wheelchairs and strollers. They generally offer a high level of firmness, stability and durability.
Downsides include cost—they are a much more expensive option and require professional installation. Unitary surfaces can get hot in the summer and can harden over time with exposure to UV light or extreme temperatures. Some experts suggest that long bone fractures like wrist or ankle injuries might occur more frequently on a unitary product versus a loose-fill product. And while PIP surfaces are relatively maintenance-free, cracking or flaking can occur after years of use.
The poured-in-place surface is poured over a sub-base, and the end product is a smooth, seamless and cushioned rubber surface. PIP is installed at different thicknesses for different deck heights. It offers excellent shock absorption, and is available in a range of colors and designs. "Any creative person can design amazing patterns and elements with PIP. Cool designs are definitely on the rise compared to five years ago," said Darren Toomey, CEO of a Texas-based safety surfacing company offering PIP, synthetic turf and shredded rubber mulch. "Loose-fill needs at least weekly maintenance in order to stay compliant. Turf needs to have the sand infill redone annually to keep the impact attenuation in check and to avoid wrinkling. PIP is a maintenance-free system," said Toomey.
Rubber tiles are made of bonded rubber and formed into squares with interlocking sides. They're highly durable and impact resistant, and another great choice for accessibility. Like PIP, they are more expensive than loose-fill surfaces and require professional installation. Tiles can curl at the edges over time, causing a tripping hazard, and dirt and debris can accumulate between the joined pieces. But worn tiles are easily repaired, and maintenance consists of simple sweeping or cleaning, like PIP. Various colors and designs are available.
Synthetic grass has evolved over the years, and these days there are softer, more realistic grass-texture options. Grasses can be nylon, polyethylene or polypropylene. "Nylon is a more durable material, but polyethylene and polypropylene are softer to the touch," said Mrakovich. It's less costly then solid rubber, but does require professional installation. It offers good impact attenuation, is easy to maintain, won't conceal objects and offers good accessibility. Static electricity may build up on the turf, so the surface might require an anti-static solution, and it can absorb heat.
Sometimes playground sites incorporate a combination of loose-fill and unitary surfaces, installing a unitary surface where more accessibility is desired and loose fill under and around taller play equipment. "We install some ramps of PIP into mulch pits for ADA purposes," said Toomey.
Kutska said local weather conditions are critical to the performance and life cycle of any surface. Water will freeze in northern climates, and standing water can rot organic surfaces and synthetic surfaces using binders. "I've seen too many brand new surfaces fall apart in a year when they did not have a good drainage system."
He explained how drainage issues can result from both surface runoff and poor subsurface drainage and high water tables, saying this is true for both loose-fill and unitary surfaces. For instance, EWF or sand can freeze as hard as a rock, or freeze/thaw cycles might cause subgrade stone and soil to affect the raised feet on the bottom of rubber tiles that function as shock absorbers, lowering impact attenuation. "Do it right the first time. Provide good surface and subsurface drainage," Kutska said
Naperville, Ill., is a large suburb of Chicago, with 74 playgrounds throughout its park system. Jessica Burgdorf is the project manager for the park district's planning department, overseeing playground construction and development. She said the most common surface type for their playgrounds is EWF. Four sites have a PIP surface—which are one or two solid colors—and three sites utilize a combination of EWF and PIP. "Buttonwood Park is located within a neighborhood's detention area, and poor drainage and difficulty with maintenance led us to switch from EWF to PIP during a 2014 renovation," said Burgdorf.
"The common theme with our sites that have PIP is that they're larger community parks that include a parking lot among other amenities," according to Burgdorf. She added that they're planning to use synthetic grass at a future development and are considering switching to it at another renovation. They also have separate sand areas with ground-level components at seven sites.
So what are some factors they consider when choosing a surface? "Each surfacing type must be ADA-compliant," said Burgdorf. "Other factors include overall volume of anticipated use, cost and required maintenance."
Regarding maintenance, Burgdorf said the EWF is raked at least twice a month and refilled every one to three years as needed, to ensure proper safety depth. "For maintenance with PIP, patching is typically required after five to seven years, mainly under swings. All surfacing maintenance is completed by Naperville Park District staff." She said that they do have two staff members who are CPSI-certified.
IPEMA provides a third-party certification service for playground safety surfaces, which validates a manufacturer's conformance to impact attenuation standards, as well as validating EWF and LFR products. "More and more playground owners are specifying IPEMA-certified products for their playgrounds, and thus it's a must for manufacturers to have their products third-party-certified," said Mrakovich. "I think it puts owners' minds at rest that another entity besides the manufacturer is making sure products are up to spec and safe for them to use."
Kutska explained how impact attenuation standards have recently been revised and updated. The AS™ F1292 standard has been split into two different standards, and another new one is in the making. These surface tests are conducted at three different temperatures and from different heights—including above and below the certified critical height.
And while Kutska is seeing some progress when it comes to playground managers maintaining and testing their surfaces regularly, he feels there's still a long way to go. "This includes the manufacturers and designers of playgrounds. The owner needs to step up their game and get knowledgeable in all factors related to their local environment and the reality of their agency's ability to do a good job in the design and execution of their plan. And they then need to understand their role in supplying the necessary resources to inspect and maintain the play area in compliance with today's best industry practices."
He also said they shouldn't settle for "bottom basement" requirements. "Why design to the minimum requirements of the standard and have the surface fail in one or two years?"
Current AS™ surfacing standards state that if a surface is not performing to the minimum requirements, the owner is to take the play area out of service until it can be brought into compliance. "This is an important fact and consideration in selecting your surface system that nobody seems to care about or try to inform the customer," said Kutska.
Kutska feels municipalities and elected officials aren't always recognizing their responsibility to create a good maintenance budget for each playground, and Toomey agrees, believing that playground managers aren't diligent enough when it comes to performing regular testing on their surfaces. He said that if money were not an issue, everyone would check their playgrounds on a regular basis. "The bottom line is if people don't have money to fix the problem, they don't want to know about it. Once they know their playground is non-compliant, they must do something about it."
Playground managers have a lot of considerations when it comes to selecting safety surfaces. And while playground accidents will never be eradicated, much progress has been made in terms of making our play spaces safer for our kids. But there is still work to be done.