Roof Joist Span Table

Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.

Roof joist span table.

Table r802 4 1 ceiling joist spans for common lumber species uninhabitable attics without storage live load 10 psf l δ 240 check sources for availability of lumber in lengths greater than 20 feet. View joist rafter tables. These 46 tables are based upon design values for visually graded southern pine dimension lumber that became effective june 1 2013. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.

Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. If this is the case with your structure use the floor joist table to determine maximum joist length load. Span calculator for wood joists and rafters also available for the android os.

For each application a pdf download is available. For example the highlighted cell below shows that a 2 x 6 southern yellow pine joist with a grade of 2 and spaced 24 apart can have a maximum span of 10 feet 0 inches 10 0 if you are designing your structure to support a plaster ceiling. Joist and rafter span tables.