Ceiling Joist Support Beam Span

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

Ceiling joist support beam span.

Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. While every effort has been made to insure the accuracy of the information presented and special effort has been made to assure that the information reflects the state of the art neither the west coast lumber inspection bureau the american wood council nor its members assume any responsibility for any particular design prepared from this online span calculator. Large room joist spacing. View joist rafter tables.

Although 2 x 4 s are included in the official table they are not listed because it is never advised to use them. 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. This will support a room ceiling that is 10 feet long on one side as in 10 foot by 15 foot or 10 foot by 17 foot rooms which is a standard dimension for many rooms in residential construction. Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.

This ceiling joist span table is based on the 2012 irc for uninhabitable attics with limited storage. It covers 2 common lumber species and sizes at 20 pounds per square foot load.