Look Out Below!
Evaluating Your Playground Surface Options
Playgrounds are like workplaces for kids; they provide many important physical, social and cognitive benefits, besides being just plain fun. And while we certainly don't want to discourage our kids from visiting the playground, we also worry about the potential dangers. Close to 200,000 playground accidents occur each year that require emergency hospital visits, with almost half of those involving severe injuries, according to the U.S. Centers for Disease Control and Prevention (CDC). And nearly 70 percent of playground injuries come from falls. For this reason, providing a safe playground surface is critical.
Long gone are the days when a playground might pop up on any surface, whether it was asphalt, concrete, gravel, grass or packed dirt. Those are now all deemed to be inappropriate surface types by the Consumer Product Safety Commission (CPSC). These days, there are basically two types of playground surfaces: unitary and loose fill. Unitary surfaces include artificial turf and carpeting, rubber tiles and poured-in-place (PIP) rubber, while loose-fill surfaces include engineered wood fiber (EWF), pea gravel, sand, wood chips and rubber mulch.
Ken Kutska, executive director of the International Playground Safety Institute and a founding member of the US Play Coalition, is a Certified Playground Safety Inspector (CPSI), and has written extensively on playground safety. He points out that there is no perfect playground surface, a sentiment echoed by everyone we spoke with. But he believes that those in charge of choosing playground products need to do their homework and think in the long term. "Owners and designers need to become much more knowledgeable about the products that are out there. Complying with the standards is really easy at first, but maintaining that compliance over the projected/budgeted life of the play area is a whole different issue," Kutska said.
Environment, budgets, maintenance demands and the types of equipment at a playground can all be factors when selecting a surface. So, let's take a look at some of the different materials and surfaces, as they all have pros and cons.
Generally speaking, loose-fill surfaces are less expensive, drain well and give greater fall height protection, on average, than unitary surfaces. Plus, they don't require professional installation. Jeff Mrakovich works in research and development for a Middletown, Pa.-based manufacturer of EWF and artificial turf grass. He said that another plus of loose-fill products like EWF is that it is easy to maintain their fall protection qualities. "All that needs to be done is to mark your equipment post at the thickness that the manufacturer requires for the fall height of your equipment and top off as needed," he said. "A quick inspection is all you need to see the surface below a mark."
Playgrounds are like workplaces for kids; they provide many important physical, social and cognitive benefits, besides being just plain fun.
But not all EWF products are the same, and consumers should do their homework and ask questions before buying. For instance, is the product third-party certified? The International Play Equipment Manufacturers Association (IPEMA) certifies EWF for impact attenuation (standard test method AS™ F1292), and to be free of foreign metals and hazardous chemicals. Additionally, there are standard test methods for sieve analysis, which shows that the product will knit together properly to meet federal accessibility laws. Does the manufacturer offer any liability insurance or warranty programs? And what raw material does the EWF come from? This is critical to the quality and longevity of the product. EWF made from natural virgin wood byproducts means no negative health or environmental effects.
Since loose-fill systems are considerably less expensive than unitary surfaces, they're found in the majority of playgrounds throughout North America. But loose-fill systems are just that: loose. Therefore they do require more continual monitoring and maintenance. The material can be "easily displaced in high-wear areas, and requires frequent raking beneath swings, rotating structures and bottoms of slides," said Brennan Prins, sales manager for a Petrolia, Ontario-based manufacturer of rubber tile systems. Besides being more labor-intensive, Prins added that loose-fill products can settle over time, potentially increasing HIC (Head Injury Criteria) value.
Mrakovich said that the biggest drawback for loose-fill surfaces is maintaining them to ensure compliance with ADA guidelines. "Some things to keep in mind for EWF are to keep it firm, stable and level by raking, levelling and compacting as needed. Do this from the beginning installation, and you'll make your life a whole lot easier."
He advised focusing on the entrance to and from the outside of the play area to the play equipment, as well as the routes of travel from the entrance to exits of accessible equipment, such as transfer platforms and slide exits. "Wear mats at these locations help keep what the ADA calls a 'clear floor space,' which is required to be within 2 percent level in both directions and 30 inches by 48 inches."
Mrakovich added that ground-level components, which can be heavily used by kids with disabilities, also need to have a clear floor space that is level and compacted, and installing wear mats in these areas is also helpful.
Wear mats can assist in providing accessibility and fall protection, and are designed to be used in high-traffic areas. Some feature a concave shape and beveled edges to keep the loose-fill product underneath, and fastening mechanisms also help keep the surface products in place.
Mrakovich's company also offers a "full-depth" mat which, when installed properly, provides the impact absorption needed, requiring no fill under or above the mat. The mats come in various sizes and can be custom-sized as well. "Though wear mats are not a fix-all to the maintenance needed for loose-fill surfaces, they do help to limit the holes that are created in high-use areas like slide exits, swings and rotating equipment," Mrakovich said.
Poured-in-place surfaces are porous and consist of rubber materials that are typically mixed, poured and troweled on-site. Lisa Anderson is general manager, and Alex Stout is an estimator for a Corona, Calif.-based manufacturer of PIP, tile and artificial turf surfaces. They said that PIP surfaces are lower in overall cost than tile or artificial turf systems, and list some of the other pros as well, including the ease of day-to-day maintenance; the ability for owners to make minor repairs; and the many color choices available, with the ability to add designs to the playground surfacing. And they point out that many of their systems utilize recycled tires. "We're seeing an increase in the use of PIP systems on LEED projects," they said.
Anderson and Stout added that, compared to EWF or sand, PIP does not need constant monitoring and maintenance to ensure the material is at the proper thickness required for proper safety. They add that PIP is not prone to insect infestations, does not become a "litterbox" for area animals, and doesn't have kids coming home with splinters or sand-filled shoes. "Simply, PIP is a much cleaner overall safety surfacing environment than the wood fiber or sand options." Dirt can be removed with a light pressure-washing, and every two to three years it's recommended to apply a new coat of resin over the wear layer. "This can be done by the owner or by our crew," Anderson and Stout said.
Another thing that attracts customers to the PIP surfaces is the design factor, especially now when emerging playground trends might feature flowing hills and sloping grades. Facilities can choose from many color schemes, inset patterns and themes. Anderson and Stout said that their projects often may have a landscape architect or playground equipment supplier involved with design services. "But when needed, we work with the client to suggest color mixes and designs that work well with their areas or create the look they are trying to obtain."
Some facilities utilize PIP surfaces in only certain parts of their playground, sometimes to help provide better ADA accessibility.
One thing to consider with PIP surfaces is that they can become very hot to the touch, and color selection can affect this as well. Prins mentioned a few other potential drawbacks, such as premature surface breakdown in high-wear areas including beneath swings and at the bottom of slides. "Shrinkage around perimeter and seams requires unsightly repairs, and weeds may eventually start to grow through seam areas, and repairs are very noticeable," he said, adding that since the product is hand-troweled, inconsistent application and thickness can equal inconsistent fall protection. "Do your research! Challenge manufacturers on their warranties and truly understand what is covered and not covered within that surfacing warranty. PIP surfacing is porous. Over time, dirt and debris will begin to settle within the surface, hardening with each year that passes."
Prins explained that as a result, HIC values that meet required AS™ standards on day one may diminish rapidly, "rendering the surface unsafe within a few short years."
Rubber tiles are another popular unitary surface. Once again, these will involve higher upfront costs than loose-fill systems, but Prins believes that these costs can even out. "When you factor in the long-term maintenance and labor costs of a loose-fill system over the course of a playground structure's life, the costs often far exceed the initial investment of a unitary surface backed by a solid warranty."
Prins also pointed out that if a tile needs to be repaired or replaced, it can typically be done quickly and cheaply by someone with minimal training, and would not be noticeable.
Anderson and Stout agree that rubber tile repairs are simple, as is installation. "Tiles can be purchased and self-installed by the end consumer. When a repair is needed, it's as simple as removing a tile and replacing it with a new one."
And like PIP surfaces, design options are abundant. Prins said that as part of their quotation process, an entire site plan is designed. "This will include colors, pattern and design, right down to the amount of glue and tools required for the project."
The tiles can be lightly pressure-washed when dirt appears. Prins also pointed out that some of their products are up to 95 percent recycled, explaining the "circle economy" they're developing within their sphere of products: "Year one, we provide a playground tile to a client, and 18 years later we reprocess the old tile into a new roof paver, fitness tile, or even into a new playground tile."
But Prins also cautioned that since there are many different tile designs on the market, some come with disadvantages by design, including potential seam separation if they're not installed correctly. Anderson and Stout echo this: "Tiles can curl or shrink over time due to weather exposure, leaving trip hazard gaps between the tiles. Tiles are more difficult to install when dealing with going around posts or in curved areas due to the cutting required to do so."
In fact, some tiles are porous and some are impervious, so drainage issues may vary. Impervious systems don't contain air pockets that are susceptible to clogging, so the body of the system shouldn't become contaminated with fine particulate matter, therefore maintaining its intended safety performance.
Synthetic grass or artificial turf "… allows owners to keep the look of natural grass on the play areas that want to keep a more natural look without having to use wood fiber or sand," said Anderson and Stout, though they added that turf is not recommended for mounds or hills. As far as maintenance, they say the turf "requires some raking to redistribute the infill material and 'lift' the blades. It also requires some rinsing off from time to time with water, and new infill materials applied as required."
Mrakovich said that synthetic grass is "as close to the real thing as you're going to get and still be safe." He added that if infill is used, high-use areas should be maintained to proper infill depth, "especially to maintain impact attenuation qualities since infill tends to scatter after initial install or get compacted over time."
Mrakovich also pointed out that, while unitary surfaces might look fine from the top, as they age you can't really tell how well they'll absorb an impact from a fall unless you perform an impact test on them. "I've been on unitary surfaces that look great and even feel resilient, but once I tested them, they didn't perform nearly as well as I thought they would have from higher fall heights. It's surprising what a fall from eight feet will require to keep your child safe from traumatic brain injuries."
Lab vs. Field Results
Recently, there's been a push by the AS™ to separate the impact test standard F1292 into two separate standards, one for lab testing and one for field testing. Mrakovich believes this is because there's a sense by the consumer that lab test results may not always represent "real life scenarios" for a surface. "I think lab testing is always a good option to at least get a feel for how a surfacing will perform at various heights, but going out to a real live playground and performing an impact test is always the best option if you can afford to get it done, at least on a surface that has aged and is used a lot."
Playground safety expert Kutska explained that the field test process will not change from what is currently in test standard F1292. "It is not a mandatory test but it's slowly gaining acceptance for post-installation testing of unitary surfaces prior to final payout. That is a good thing and it's the only way for the owner or surface manufacturer to know the installer did what they were supposed to and that the owner got what they paid for. Often these surfaces are installed at just below the threshold limit, which likely will fail shortly after installation, if it would even pass a field test prior to payment."
Prins explained that they don't just manufacture to the standard, as many manufacturers do. "Our product has been engineered to comply with the safety ratings mandated for vehicle impact safety by the National Highway Traffic Safety Administration—performance that exceeds current playground regulations by nearly 50 percent."
Mrakovich suggested that owners make sure to get test data from the manufacturer showing test results in all three temperature ratings—25, 70 and 120 degrees Fahrenheit. "I've tested surfaces on-site that range from over 120 degrees to below freezing, and environment can
definitely play a role when it comes to how well the surface will absorb impact during not only freezing temps, but some can get too soft in hot temperatures, too." He added that since most results come from a lab, you should ask the manufacturer if they have any field test data showing how well their surface does in an actual playground in harsh temperatures if your location is prone to such. "You'd be surprised at how different it may be due to drainage, usage and, of course, temperature variations."
It's true that, besides environment, drainage is a key consideration. "Drainage is extremely important for all safety surfaces. The systems are porous, and long exposure to standing water can begin to break down the product, causing mold and other issues," Anderson and Stout explained.
Mrakovich said that loose-fill surfaces especially need good drainage to help keep the surface resilient and provide longevity. He said to imagine water sitting just below the surface when temperatures plummet: "The surface that was once safe and resilient will get harder and less safe as the temps go down." He added that unitary surfaces utilizing a foam base also require good drainage as the foam can retain water and will get less resilient as the water freezes.
Kutska explained that unitary surfaces like PIP are made with loose rubber held together by a urethane binder, adding that while there are two types of binders, only one holds up to UV radiation over time, which becomes an issue in some climates. Plus, he said, "Urethane hates water. It does not last long if not properly drained. That is not just surface drainage but subsurface drainage as well."
He suggested installing the surface level at plus or minus 2 percent to begin with. "That is the slope allowed on a playground platform and considered level but still has some drainage capability."
And Kutska agrees that loose-fill surfaces also require good subsurface drainage to perform as they're designed. "Likewise, diverting surface runoff away from the play area is something that is often overlooked. Stormwater runoff will carry solids and other contaminants into the playground surfacing that can negatively impact performance and longevity over time."
New playgrounds are not the only customers of surface manufacturers, as owners of existing playgrounds are also trying to keep up to date as innovations and trends occur. "Many of our customers with older playgrounds have tried a number of other surfacing options that did not live up to their expectations; this is often the reason for their call," Prins said.
Anderson and Stout agreed, adding, "We've recently seen quite a few older playgrounds removing the old wood fiber/sand surfacing and replacing it with PIP or artificial turf systems, or refurbishing/replacing the old PIP systems with new ones."
But as budgets get squeezed, more playground owners are forced to just upgrade the equipment and surfaces they already have, according to Mrakovich. He said his company has been asked to add accessible pathways with a bonded system, which "takes the top couple inches of the EWF surface and binds it with a urethane binder to create accessible pathways for a fraction of what it would take to remove everything and replace with a traditional bonded rubber surfacing such as PIP or tiles." He added that this, in combination with the use of wear mats in high-traffic areas, retrofits the current surfacing into a more accessible surfacing.
Manufacturers and designers continue to make strides when it comes to providing safer playground surfaces. And as a former playground operator, Kutska said he's seen how far many have come in inspecting, maintaining and repairing their facilities. But he feels there's still a lot of work to be done on all levels, especially with what we now know about concussions and traumatic brain injury, and he said there's a long way to go when it comes to complying with even the basic minimum thresholds. "We need to up our game when it comes to inspection and maintenance. Field testing surface systems would be a good start."