GYNASTICS PIT CONSTRUCTION

Vibrated poured concrete floor and walls is the best method for pit construction. The poured concrete floor and walls need to be steel reinforced with #4 Rebar on 16" centers grid to prevent a crack from opening up. Concrete blocks can be used, but can cause problems. Blocks have mortar joints that crack. The blocks are porous and allow ground water to get into the pit.

The earth needs to be excavated 18" deeper than the elevation of the finish floor. This will allow 10" of clean stone base for the 8" concrete floor. The 8" concrete floor will support the poured concrete or block walls. When the floor is poured, the #4 Rebar needs to be turned up 90 degrees to reinforce the connection of the walls. Plastic water stop 6" wide x 1/2" thick should be attached to the rebar so that it will embed in the floor and walls equally to seal the joint and prevent water seepage.

Once the concrete floor is cured properly the walls can be formed and poured. The walls also need to be steel reinforced with #4 Rebar on a 16" grid vertically and horizontally. The concrete needs to be vibrated during the pouring process to insure density and to prevent honeycombing. After concrete walls have cured, coat with two coats of basement sealer for added moisture protection. The drain tile needs to be covered with a minimum of two feet of clean gravel or crushed stone to prevent soil from filtering into the drainage system.