Sill-Plate Anchor Bolt Count (IRC R403.1.6)
Lays out sill-plate anchor bolts at the IRC max spacing with a bolt near each end: bolts = max(2, ceil((wall - 2 x end distance) / max spacing) + 1). A 40 ft wall at 6 ft spacing with 9 in end distances takes 8 bolts; a short 8 ft wall still needs 3 because the 6.5 ft between end bolts exceeds the 6 ft spacing - a mid bolt the two-bolt minimum alone would miss. IRC R403.1.6 caps spacing at 6 ft; the code and engineered plan govern. Distinct from anchor-embedment capacity.
Formula and source
effective_len_ft = wall_length_ft - 2 x (end_distance_in/12); bolts = max(2, ceil(effective_len_ft / max_spacing_ft) + 1).
Sill-plate anchor-count rule by name (bolts from the span between end bolts over the max spacing, min two); IRC R403.1.6.
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