Use the span tables in the links below to determine the maximum allowable lengths of joists and rafters. These tables provide maximum spans for the #2 grades of four common species of …

115% load duration for snow loads. 125% load duration for construction loads.

Using span tables to size joists and rafters is a straight-forward process when you understand the structural principles that govern their use.

Joist and rafter span tables show the maximum distance these framing members can safely cover. The spans listed are based on the specific properties of the wood being used.

The 46 span tables below are for three types of framing members: floor joists, ceiling joists, and rafters. Spans in the tables are listed in feet and inches and are the maximum allowable …

In these Western Lumber Span Tables, Western lumber Fb base values have been adjusted for size by appropriate size factors (CF); no further size-adjustment is necessary.

Links to span tables and associated design values offered by industry organizations for various wood species and products.

Visit the roof framing page for more information on cutting roof rafters, and visit the roof pitch calculator for determining rafter lengths based on rise and run.

Jan 3, 2005 · Size your deck beams and headers with our easy-to-use span table, which allows you to cross reference the post spacing and joist length to determine the right deck beam size.

Joists and rafter spans for common loading conditions can be determined. A “span options” calculator allows selection of multiple species and grades for comparison purposes.