Rubber Mats

• Rubber mats for under swing sets are semi-soft and will not compress after years of use. Some mats have interlocking pieces so you can make the cushioned area as large as you need it, but some mats lay next to each other and may move away from each other over time. Rubber mats come in many different colors, which will define the play area.
  
  

Mulch

• Mulch can cushion the ground under a swing set. The depth of the mulch should be about 7 to 11 inches. Depending on where you live or what type of mulch your local nursery carries, you may have a choice between wood chips, shredded bark mulch and rubber mulch. If the nursery doesn't carry rubber mulch, you can find it at a home improvement store.
  
  

Sand

• Sand offers a soft cushion if children jump or fall on the ground. You can use fine or coarse sand, but it should be between 5 and 9 inches deep. The only problem with sand is that it can blow around and kids will get dirty if they fall or play in the sand. You will need to contain the sand using a border such as timbers or lawn edging. Sand will need to be sifted or raked periodically to remove debris.
  
  

Pea Gravel

• Pea gravel in an option for under swing sets if you don't have little ones who will pick up small objects and put it in their mouth or ears. The gravel will allow the water to drain away from the play area and will not attract bugs. You should use at least 4 inches of pea gravel to cover the play area.