The 2021 Span Tables for Joists and Rafters updates the 2015 edition and provides a simplified system for determining allowable joist and rafter spans for typical loads encountered in one- and two-family dwellings and is referenced in the 2021 International Building Code and 2021 International Residential Code.
A tutorial for using the span tables is also available.
A companion Supplement to Span Tables for Joists and Rafters, Design Values for Joists and Rafters tabulates allowable bending (Fb) and modulus of elasticity (E) design values for visually graded and mechanically graded dimension lumber.
This edition has been updated to the 2018 NDS Design Values Supplement. Changes include new design values for Southern Pine and Mixed Southern Pine design values.