Tolerance in the placing of reinforcement is very necessary because no work was to be done fully 100 per cent accurate. The strength of any structure can be achieved to construct and provide proper reinforcement in effective locations. If any type of error occurs, it may reduce the strength of the structure.
Example
The raising of bottom bars over the top bars. The specified limits are 15 cm in slabs, if the limit exceeds, it will reduce 20% of its load-carrying capacity.
The placement of cover reinforcement is another important. The tolerance in cover should be
1- Depth 20 cm or less: +- 10 mm depth
2- Depth greater than 20 cm: +- 15 mm depth
Reinforcement bars placing tolerances in the construction can be allowed in order to permit economical bar placing and do not apply to the fabrication of bars. There is not negative tolerance permitted for the cover.