Rafter Span Roof Joist Span Table

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.

Rafter span roof joist span table.

Keep in mind that these are maximums in other words shortening spans slightly will result in a more solid structure. In making your choice consider how you will insulate your insulate your roof. 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. Strength live load of 30 psf plus dead load of 10 psf determines the required bending design value.

Limited to span in inches divided by 360. For lesser grades spans should be shorter. This rafter span calculator is species specific for douglas fir hemlock etc. These 46 tables are based upon design values for visually graded southern pine dimension lumber that became effective june 1 2013.

For each application a pdf download is available. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. This is based upon the span of the rafter horizontal span not total rafter length live and dead loads. Span calculator for wood joists and rafters also available for the android os.

Another option are 2 x 8 rafters spaced 24 inches o c. Also available for the android os. Tables listing maximum spans for southern pine joists and rafters are detailed below. Span tables for jois ts and rafters american wood council 4 span tables for joists and rafters american wood council design criteria.

The tables below give maximum spans for rafters and beams. Deflection for 30 psf live load. The figures are based on quality materials. Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.

View joist rafter tables. More roof calculators roof truss calculator how to cut rafters. 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.