Four-inch sand base, laser leveled to 1% pitch side to side. No gravel or drainage required with post-tensioned slab.
The vapor barrier prevents moisture from coming up through the slab and also reduces the coefficient of friction to allow concrete to move when it shrinks, reducing shrinkage cracks in the first few hours after concrete placement.
Cables are place according to PTI specifications and checked for accuracy by two seperate engineers. Basketball goals are also set in their own concrete footings.