The spacing between bars is limited to a maximum of 2 times the slab thickness.

This provision is applied to slabs only.

If the member is designated as post-tensioned, bonded (grouted) post-tensioning ducts that are on the tension side of the cross section centroid, or are within 10% of the cross section depth of the centroid elevation are considered as equivalent to an un-tensioned bar. These ducts are assumed to be optimally placed for spacing purposes - their plan locations are ignored. This implementation is somewhat more conservative than a literal reading of the code requirements.

User defined bars are counted toward satisfying the maximum spacing requirements. Bars at an angle to the cross section consider the sum of their vector components divided by the gross area of one bar as the total number of provided bars for spacing calculations.