Equipment with asphalt or concrete underneath can lead to serious head injuries if a child falls. Grass or dirt, while a little softer, can become hard-packed and dangerous, too. The safest alternates are loose-fill materials or cushioning mats. While these surfaces can’t totally protect a child from getting hurt, they can reduce the severity of the injury. The height of the play equipment determines how deep the loose fill underneath should be. Children falling from greater heights need more cushion in a fall. The CPSC-recommended depth is at least 12 inches for equipment in typical public playgrounds. If your backyard equipment is not as tall, you won’t need it quite as deep. Detailed information on depth needed for the height of specific equipment is available from CPSC. Some playgrounds have soft surfaces but they don’t cover a wide enough area. The soft surface, or “fall zone,” under a swing, for example, should extend out twice as far as the height of the swing in both the front and the back. The “fall zone” under stationary equipment should extend at least six feet in all directions from the edges of the equipment. If loose fill material is used, it must be maintained. This includes replacing the material as needed and raking, leveling, and sifting to maintain an adequate depth and to remove foreign matter. Good drainage underneath the fill is necessary to maintain the surface.
Mulch and Chips
Shredded mulch and wood chips are popular loose fill surface materials because they are easy to obtain, easy to install, and inexpensive. A retaining barrier is required to contain the material, and the loose fill has to be replenished often because it decomposes and compacts. The disadvantage is that it is subject to microbial growth when it’s wet. It also can conceal sharp objects such as broken glass.
Sand and Pea Gravel
Sand and pea gravel also are inexpensive and easy to install. Maintenance is required similar to mulch and wood chips. Disadvantages of sand are that it can blow into children’s eyes and can become hard-packed when wet. Kids also can track it out of the intended area, making regular replacement necessary, and of course there’s the danger of it being used as a litter box by cats and other animals. Gravel can be hard to walk on. If it gets thrown onto walkways, it can cause falls.
Mats and Tiles
Rubbery mats and tiles come in a variety of synthetic materials and require little maintenance. They don’t hide sharp objects or animal waste as loose fill can. The disadvantage is that mats cost a lot more initially and require professional installation.