Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
Roof joist span table.
If this is the case with your structure use the floor joist table to determine maximum joist length load.
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.
Joist and rafter span tables.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
1 inch 25 4 mm 1 foot 304 8 mm 1 pound per square foot 0 0479kpa.
Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.
These 46 tables are based upon design values for visually graded southern pine dimension lumber that became effective june 1 2013.
Tables listing maximum spans for southern pine joists and rafters are detailed below.
View joist rafter tables.
For each application a pdf download is available.
Also available for the android os.