If the tensile stress in the concrete does not exceed $0.25\sqrt{{f^{\prime }}_c}$ then there is no need for crack control reinforcement and none of the following applies.

For beams, reinforcement is added on each face in tension to limit maximum spacing to 300 mm. For one-way and two-way slabs, reinforcement is added to limit maximum spacing to 300 mm or two times the cross section depth, whichever is smaller.

• All bars on the appropriate face (including fractional components for bars at an angle to the cross section) are considered for spacing requirements. A fractional number of bars and spaces may be used.
• User-defined reinforcement that is at an angle to the cross section will only have the component perpendicular to the cross section considered.
• Bars with a diameter of less than half the diameter of the maximum bar diameter on the face being considered are converted to an equivalent number of hypothetical bars with a diameter of half the maximum bar diameter. This conversion is based upon area.
• Each bonded tendon duct (that is in the tension zone based on gross section stresses) is considered to be equivalent to a single mild steel bar (even if it is far from the tension face). In the spacing calculation, all bonded tendon ducts are assumed to be optimally positioned to minimize the number of mild steel bars required. A fractional number of bars and number of spaces may be specified to meet the spacing requirement.

Section (a) with the $0.6\sqrt{{f^{\prime }}_c}$ limit is ignored because it does not give any guidance on how much reinforcement is necessary. Section (b) is always used instead.