Sixteen inch oc spacing of ceiling joists made from 2 southern pine allows for a maximum 13 inch span length.
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.
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.
Although 2 x 4 s are included in the official table they are not listed because it is never advised to use them.
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.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.
Large room joist spacing.
Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.