AWC - STJR
DESIGN VALUES FOR JOISTS AND RAFTERS - SUPPLEMENT TO SPAN TABLES FOR JOISTS AND RAFTERS
|Publication Date:||1 January 2012|
These span tables for joists and rafters are calculated on the basis of a series of modulus of elasticity (E) and bending design values (Fb). Additionally, compression perpendicular to grain design values (Fc) are included as a consideration for selection of joists and rafters. The range of values in the tables provides allowable spans for all species and grades of nominal 2-inch framing lumber customarily used in construction. These span tables assume installation of at least three joists or rafters that are spaced not more than 24" on center. The calculated spans assume fully supported members, properly sheathed and nailed on the top edge of the joist or rafter. Straight-line interpolation shall be permitted for intermediate spans and design values.