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IRC Section R502 — Floor Systems

Updated Apr 3, 2026

Provides prescriptive sizing tables for floor joists and sheathing.

Section R502 includes tables for selecting joist size based on span, spacing, load, and species. 2x10 joists at 16 inches spacing can span 16-18 feet depending on load. Joist spacing typically 16 inches is standard, with 24-inch spacing used for stronger members. Rim joists must be same size as floor joists. Floor sheathing must be nailed per requirements with spacing based on sheathing thickness.

TAGS

irc floor-framing joists

DETAILS

section

R502

category

Wood Construction

code body

IRC

code year

2021

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