Building the Pit

• 1). Place the scrap dowels at the four corners of your pit location, 20 feet apart. Run the string around the dowels to mark off the parameters of your pit.
  
  
• 2). Using the shovel and hoe, dig out the pit inside your marked area to a level depth of 13 inches. Check your flatness and level by laying one of the 4 by 4 boards down, if it touches the bottom across its entire length than that section is flat. Placing the level on the board will tell you if the section is level.
  
  
• 3). Dig out a shelf around the top of your pit 4 inches wide and 4 inches deep.
  
  
• 4). Mark a point on each 4 by 4 board two feet in from both ends. It is important for the longevity of the pit that the boards be pressure-treated to prevent rot. The boards can also be stained or painted if desired; if you are using non-pressure-treated boards, staining or painting is highly recommended.
  
  
• 5). Drill a hole at each marked point on the 4 by 4 boards. The holes should be just large enough to allow the rebar to pass through.
  
  
• 6). Place the boards around the lip at the edge of the pit.
  
  
• 7). Use the sledgehammer to hammer the rebar sections through the holes in the boards until the tops of the rebar sections are flush with the top of the top board. This will help secure the board edges in place and prevent erosion of your pit's edge.
  
  
• 8). Spread the gravel evenly through the bottom of the pit, making a layer two inches deep. This is to assist in drainage and prevent the wood chips from rotting.
  
  
• 9). Spread the wood chips evenly over the gravel, making a layer nine inches deep. Nine inches is the minimum depth recommended by the United States Consumer Product Safety Commission for public playgrounds and is a good measurement for your training pit. This will use 300 cubic feet of wood chips. The other 75 cubic feet is to replace an expected 25% loss due to compacting, as outlined by the U.S. Consumer Product Safety Commission.