Wood chips are among the best shock absorbing materials for a playground. They shed rain quickly and provide better shock absorption than sand or gravel. A 9-inch layer of wood chips, for instance, protects children from serious head injury to a fall height of 10 feet, according to the Public Playground Safety Handbook published by the U.S.Consumer Product Safety Commission. A 9-inch layer of sand protects children from a fall of 5 feet. When choosing wood chips, consider durability, as well as safety factors.
Types of Wood Chips
All playground mulches require annual replacement because they break down, become compacted or blow away. Cedar mulches are naturally rot resistant and last longer than softwood mulches. Hardwood mulches are more durable than softwood mulches but may cost more than cedar.
When selecting wood chips for a playground, look for wood chip pieces that are smooth, uniform and flat and no larger than 2 inches. Avoid bulky bark pieces that may cause children to trip or wood chips that haven't been screened. These chips may contain sharp sticks or debris. Avoid wood treated with preservatives for playground mulch, warns the U.S.Consumer Product Safety Commission.
To determine how much mulch to use, measure the highest point a child could fall from. Use charts available from the U.S. Consumer Product Safety Commission to determine how much mulch to add, based on the height of the equipment, but add 3 inches to that amount because the wood chips will become compacted over time. For example, if the playground equipment is 10 feet from the ground, you'll need 9 inches of mulch, plus 3 inches for compaction, making a total of 12 inches.
Rake the mulch occasionally to reduce compaction and cover exposed areas, such as under swings and slides. Replace it annually or as needed to maintain the proper level of shock absorbency. Buy wood chip mulch in bulk through landscape companies and have it delivered if you have a large area to cover.