Feature Article - November 2018
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Play It Safe

The Key Elements of Playground Safety Surfaces

By Rick Dandes

Loose Fill

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.

Unitary Surfaces

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."