Bars must be placed carefully and accurately to conform to the requirements of placing drawings, schedules, typical details, and notes. Placing drawings should clearly identify such items as top and bottom bars, bars hooked around other bars, and on which side or face of the member the bar is to be located. Bars must be fitted around sleeves, inserts, holes, and openings as shown on the contract drawings. The ironworker, ironworker foreman, contractor, and inspector all have the responsibility to see that reinforcing bars are properly placed.
Proper embedment of bars in the concrete is very important. To determine the amount of concrete protection required, the engineer takes into consideration the requirements of building codes, fire hazards, possibility of corrosion, and exposure to weather. The strength of any concrete member can be affected by the improper positioning of the reinforcing bars. The exact positioning of longitudinal bars is generally not critical to the strength of the structure; therefore, the placing tolerances are not as close as those for cover.
In long runs of slabs or walls, the exact spacing of bars specified on the contract drawings is not critical. It is satisfactory to place the number of bars called for in any given length or panel at approximately the spacing required; no exact spacing measurement is necessary for each bar.
For buildings, the ACI Building Code specifies the minimum amount of cover over stirrups, ties and other bars, as well as the minimum clear space between bars.