Ceiling Joist Support Beam Span

Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.

Ceiling joist support beam span.

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. View joist rafter tables. 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. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.

Although 2 x 4 s are included in the official table they are not listed because it is never advised to use them. Large room joist spacing. Sixteen inch oc spacing of ceiling joists made from 2 southern pine allows for a maximum 13 inch span length. 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. 2 x 12 s are not listed because you can span pretty much whatever you want.