Rafter Span Roof Joist Span Table

This is based upon the span of the rafter horizontal span not total rafter length live and dead loads.

Rafter span roof joist span table.

Another option are 2 x 8 rafters spaced 24 inches o c. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Limited to span in inches divided by 360. Span calculator for wood joists and rafters also available for the android os.

Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. Span tables for joists and rafters 3 american forest paper association table 9 1 required compression perpendicular to grain design values f c in pounds per square inch for simple span joists and rafters with uniform load. For each application a pdf download is available. Tables listing maximum spans for southern pine joists and rafters are detailed below.

This rafter span calculator is species specific for douglas fir hemlock etc. Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Span tables for jois ts and rafters american wood council 4 span tables for joists and rafters american wood council design criteria.

Strength live load of 30 psf plus dead load of 10 psf determines the required bending design value. Keep in mind that these are maximums in other words shortening spans slightly will result in a more solid structure. More roof calculators roof truss calculator how to cut rafters. View joist rafter tables.

Span ft 1 5 2 0 2 5 3 0 3 5 2 30 22181513 4 59 44363025 6 89 67534438 8 119 89 71 59 51. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. The table states that 2 x 6 rafters spaced 16 inches on center o c can span a maximum distance of 13 feet 5 inches. To size joists and rafters use the maximum span tables for southern yellow pine.

Deflection for 30 psf live load. For lesser grades spans should be shorter. These 46 tables are based upon design values for visually graded southern pine dimension lumber that became effective june 1 2013. The figures are based on quality materials.