As per IS 456-2000
Tolerance on Formwork: (page no:25)
a) Deviation from specified
dimensions of cross-section
of columns and beams +12mm & -6mm.
b) Deviation from dimensions of footings
1. Dimension in plan +50mm & -12mm
2. Eccentricity 0.02 times the width of the footing in the
direction of deviation but not more than 50mm
3. Thickness ± 0.05 times the specified thickness.
Tolerances on Placing of reinforcement: (page no:26)
Unless otherwise specified by engineer-in-charge,the reinforcement shall he placed within the following tolerances:
a) for effective depth 200 mm or less ±10mm
b) for effective depth more than 200 mm ± 15mm
Tolerances for cover: (page no:26)
Unless specified otherwise, actual concrete cover should not deviate from the required nominal cover +10mm & -0 mm.