Strength live load of 30 psf plus dead load of 10 psf determines the required bending design value.
Rafter span roof joist span table.
This rafter span calculator is species specific for douglas fir hemlock etc.
More roof calculators roof truss calculator how to cut rafters.
For lesser grades spans should be shorter.
The tables below give maximum spans for rafters and beams.
Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.
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.
Limited to span in inches divided by 360.
Another option are 2 x 8 rafters spaced 24 inches o c.
This is based upon the span of the rafter horizontal span not total rafter length live and dead loads.
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.
These 46 tables are based upon design values for visually graded southern pine dimension lumber that became effective june 1 2013.
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.
Also available for the android os.
The figures are based on quality materials.
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.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.
Span calculator for wood joists and rafters also available for the android os.
In making your choice consider how you will insulate your insulate your roof.
Keep in mind that these are maximums in other words shortening spans slightly will result in a more solid structure.
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.
Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.
