Play It Safe
The Key Elements of Playground Safety Surfaces
Playgrounds provide a place for children to not only expend their energy, have fun and physically interact with their peers, but also to offer a diverse, inclusive environment, whether in an urban or rural setting, where children of all ages can develop their emotional, social, emotional and cognitive skills.
But the public municipalities, school districts, and privately owned recreational facilities that provide playgrounds also carry with them the responsibility of keeping users safe.
ATSM, an international standards organization based just outside of Philadelphia, has written playground surface specifications that mandate a strict adherence to safety standards. And, because it is not only the right thing to do, but also because of liability issues, surface manufacturers adhere to the code, and sometimes even exceed the requirements.
How often do children use play equipment in a manner inconsistent with its original design intent? asked Brennan Prins, director of a Petrolia, Ontario, Canada-based company that manufactures playground safety surfaces. "A well-designed guardrail can become a high-wire act, or a slide can turn into a giant wave to be surfed down," he said. "Despite our best efforts, the nature of children's play makes falls to the surface inevitable."
The facts bear him out. The Centers for Disease Control and Prevention, estimates that more than 70 percent of playground injuries are due to falls to the surface.
"Because of this," Prins said, "it is a wonder that protective surfacing options remain one of the most overlooked and under-evaluated aspects of playground design."
So, let's say your facility needs a new playground.
"Don't forget about the surfacing," said Darren Toomey, CEO, of a Driftwood, Texas-based turnkey safety surfacing company. "Realistically," he explained, "the surfacing you choose is one of the most important choices you will make in the process, because your ability to decrease the risk and liability of serious injuries related to falls depends on the kind of safety surface material you choose. Determining the best playground safety surface to meet your needs means taking many factors into account, from the playground equipment you choose to your budget and maintenance capabilities."
After 30 years in the business, said Richard Hawley, vice president of sales for a Chattanooga, Tenn.-based playground systems manufacturer, "I've come to the conclusion that there is no perfect surface. They all have their pros and cons, based on how someone sees them used."
There is a difference between the usage patterns at a playground in a regional park out in the middle of the woods vs. an urban playground that sees daily use, he said. "A remote playground basically will be busy on Saturdays and Sundays. An inner-city school playground is getting used almost every minute of the day."
Remember the old days when a playground was often stationed on an asphalt surface and had just traditional monkey bars and swings? Hawley reminisced. "It is a whole new game these days—what we see now coming into surfacing," he said.
The Centers for Disease Control and Prevention estimates that more than 70 percent of playground injuries are due to falls to the surface.
As playgrounds become more sophisticated, there is a lot of learning that can be incorporated into the surface design, he said. "Games and activities will be designed into the surfaces to give the children play value. We are incorporating sound into the surfaces. One of the trends I like very much is called inclusion, where someone can design a playground with different types of surfaces and add playground equipment to ensure that children with all types of abilities can play. What a change from when we grew up."
The importance of the surface beneath the play equipment is important, in terms of inclusiveness, but don't forget the need for an accessible route to and from the play area, as well as outdoor fitness areas and other amenities. "More emphasis on accessibility and routes of travel for ADA is a must," Hawley noted. "You'll need different surfaces to get there. Customers have to decide on their budget, maintenance and durability, and determine what they want to get out of the surface as they begin their due diligence."
The functionality of the different types of materials used in a playground safety surface is the most significant concern for a school or public entity that is installing or upgrading a playground. There are two basic types of playground safety surfaces: loose fill, which includes sand, pea gravel and the commonly seen wood mulch, engineered wood fiber and rubber mulch; and unitary surfacing, which includes rubber tiles, poured-in-place surfacing, bonded rubber mulch and artificial turf.
Surfacing options remain one of the most overlooked aspects of playground design
Although loose-fill varieties are easier on the pocketbook and usually easily sourced and installed, Toomey noted, their downside is that they require continual maintenance and replenishment, which requires more labor and effort over time. All loose-fill surfacing requires daily raking to maintain the required depth of the material to ensure the safety of children. Replenishment is also required as loose fill gets packed down or kicked away. Often this type of maintenance does not take place, creating unsafe playgrounds. In addition, loose fill can be tracked into buildings, requiring additional maintenance indoors.
These are the most common types of loose fill, experts say:
- Pea gravel is quite cheap and easy to maintain. It allows for good drainage and does not attract animals, but it can be a hazard if thrown. It also creates a problem for maintenance of the grass and surfaces surrounding the playgrounds.
- Sand is one of the easiest products to maintain. You just need to level out the sand if it gets windswept. But beware: cats often use the sand as a liter box.
- Wood chips or mulch is inexpensive material, easy to find and easy to move. It is, the ATSM reports, "a good fall attenuating surface material." It does, however, require maintenance to ensure the depth remains constant, especially at slide runouts and underneath swings.
- Engineered wood fiber (EWF) generally consists of new wood that has been debarked and ground into a fibrous consistency, Prins explained. It is ADA-approved for mobility.
- Shredded rubber mulch provides another option that makes use of recycled rubber.
"Engineered wood fiber offers the user a number of advantages," Prins said. "The primary advantages are cost and impact attenuation ratings. EWF offers one of the lowest initial purchase costs. EWF also provides one of the most favorable initial impact attenuating ratings when tested in laboratory conditions. Additional advantages include ease of installation, conformance to AS™ F1951 (wheelchair accessibility) and adequate resistance to flammability (rate of flame spread).
Most loose-fill surfacing will require a regular maintenance program in order to maintain compliance with ASTM1292 (which measures impact attenuation), as well as AS™ F1951 (in the case of engineered wood fiber and other surfaces approved for accessibility). "A typical maintenance program would involve regular raking, leveling and sifting of the loose material to counter the effects of decomposition, compaction and material displacement," Prins said. "In the absence of a maintenance program, consistency in fall protection and wheelchair mobility can be compromised."
Detailed inspections, Prins said, will also be required to detect and remove embedded objects that can be dangerous and unhealthy. Replenishment of the material can be a regular requirement to accommodate for decomposition, compaction and displacement of the loose particles.
"Pay attention next time you see a playground with loose-fill surfacing," Prins said. "Nine times out of 10 there are hollows under the swings and slides. This is just one problem resulting from improper maintenance. If the overall thickness decreases from displacement, then the children playing on the playground are not protected to the level required by government standards."
For these higher-wear areas, safety mats can be installed that help maintain an even level of protection.
The second category of playground surfaces, unitary surfacing, consists of two major types of products including poured-in-place (PIP) and prefabricated mats or tiles. Synthetic turf surfaces are also becoming more common on the playground, and are sometimes classified in this category.
Unitary surfacing has a higher upfront cost than loose fill, but requires much less maintenance over the life of the playground, Toomey said.
If you're on a tight budget, bonded rubber mulch is the least expensive unitary option. It is a one-layered system, made from shredded recycled rubber, which is bonded together with polyurethane binder.
"The common belief is that bonded rubber is a lot less expensive than poured-in-place rubber," Toomey said, "but when you run the numbers, this is only true for 3-inch thicknesses and less. When you compare the two systems at 3.5 inches thick, the cost is the same."
Rubber tiles are another option. Tiles have been a mainstay in surfaces for many years, Prins said. "Its main asset is durability because it is manufactured. It is very dense. And can take an awful lot of wear and tear. It's a 20-year surface that you don't have to think or worry about, and that's the beauty of the rubber tile. As durable as it is, it is also safe in terms of compliance to AS™ F1292, in cold weather, rain or snow."
Prins noted that AS™ F1292 says that when playgrounds are in use, any time, not just year one, but year two, 10 or 12, the surface has to be compliant to the standard. "That's how we design our playground," he said. "As a manufacturer, how do we build a product today that in year 10 needs the lowest amount of maintenance and is still compliant? Because the reality is with playgrounds, it is not about day one, as much as everyone loves to see a beautiful shiny playground. It is about year five, 10 and 15."
When it comes to maintenance, a tile surface may need to be cleared of debris from time to time. One of the benefits of this type of unitary surface is that damage can be simple to repair by swapping out damaged tiles.
Poured-in-place (PIP) is a two-layer system that is mixed and installed onsite over a stable surface such as concrete, asphalt or highly compacted stone, Toomey explained. "The first layer is made from recycled rubber mesh, or in some cases crumb rubber, and the top layer is manmade colored granules, both mixed with moisture-curing polyurethane binder at different content percentages. The base layer varies in thickness corresponding to the different fall heights of the equipment. Since the surface is hand-troweled, there is margin for human error, and since most playgrounds are outside, the weather plays a big part as well."
Poured-in-place has been sort of the granddaddy of surfacing for a long time, Hawley said. "It is very architectural, and it is free-forming. There are different colors and designs that can go into the poured-in-place to complement the play value of the playground equipment. It could be themed. We see poured-in-place used almost exclusively when you have a capital project where an agency has budgeted X-amount of millions of dollars for a new park and it is being created by the architectural and design folks. They love poured-in-place because they can do so much with it."
"To get a good quality PIP surface that lasts," Tommey said, "using an experienced install crew is just as important as using quality materials. The crew must be able to handle different atmospheric conditions, as well as other job-site challenges. We are often the last contractor on the job, so our crews must be knowledgeable about AS™ standards and all aspects of playground construction. It's a technical and time-sensitive install process using expensive raw materials. So, it must be done right the first time."
Like any other surface, PIP needs to be maintained. And there are programs where the rubber surfacing is regularly recoated with urethane to help it from wearing out, Hawley said. "It also revitalizes the colors and helps it come back to the original reason they bought it in the first place. Yes, it needs to be maintained. It needs to be cleaned and use zones need to be patched if they wear out and then the overall durability can be improved if it is maintained with the top coatings."
Artificial turf is another up-and-coming option, Hawley noted. "The turf comes with recycled foam pad beneath for resiliency. Artificial turf is a natural-looking option and is considered environmentally friendly because it eliminates the need for watering, fertilizers and other harmful chemicals."
The downside to artificial turf is that it can get very hot. For example, on a 98-degree day, the temperature on the turf could rise to more than 180 degrees, Hawley said. Turf also requires some maintenance to keep it looking good; however, it does provide consistent fall protection.
"There are some maintenance requirements with turf," Hawley said, "because if you don't brush it and maintain the infill required the fibers can lay down. Look at normal grass and most of the time it is standing up, so you have to do some brushing and raking, as far as maintenance goes."
All the varieties of unitary surfaces are relatively low-maintenance, while providing ADA compliance and consistent fall protection. But they all require a greater initial expense and need to be professionally installed. Loose-fill varieties are less expensive but require more maintenance, and they do not provide consistent fall protection unless properly maintained.
The playground, as an environment to get everyone involved and keep them safe is at an all-time high, Hawley said. "It's a fun business to be part of when you get a chance to play a role in the planning of all that."