What is the anchor bolt spacing for a sill plate on a foundation?
Minimum ½-inch anchor bolts no more than 6 feet apart, embedded 7 inches, with two per plate section and one within 12 inches of each end (IRC R403.1.6).
Wood sill and sole plates must be anchored to the foundation with anchor bolts at least ½ inch (12.7 mm) in diameter, spaced no more than 6 feet (1829 mm) on center. Each bolt must embed a minimum of 7 inches (178 mm) into the concrete or grouted masonry cells.
Every plate section needs at least two bolts. One bolt must be located within 12 inches of each end of the plate, but no closer than seven bolt diameters from the end.
Higher seismic design categories tighten the maximum spacing to 4 feet on center for taller buildings, so confirm your seismic category before laying out bolts.
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Ask Donnie →General information based on the International Residential Code (a model code). This is AI assistance to verify — not legal advice. Confirm the adopted edition and any local amendments with your local building department (AHJ) and a licensed professional before you build.