Reinforced Concrete Drill Pattern
Hole Diameter 1⅜"
Hole Diameter 1½" - 1¾"
If removal is by hand, consider grid that makes drilling through rebar easiest. Since most rebar is placed on 6" increments, hole pattern should reflect this. Best is
usually 1 foot centers. Drill starter hole in concrete 6 to 8" in from edge, once you establish rebar location, lay out holes in increments to miss rebar. Much more
effective than laying out a pattern, having driller hit steel and then compensating for rebar.
Hole diameter and spacing depend on both quality and shape of the reinforced steel.