How far apart must rebars normally be spaced?
There should be a clear distance at least equal to the bar diameter between parallel bars but never less than one inch. This assumes that the concrete will contain aggregate that is no more than three-fourths of these distances; otherwise the aggregate size or bar spacing must be changed. If there is more than one layer of rebars the bars in the upper layers must be directly over those below them and no closer to them than one inch.