Ceiling Joist Spans

This ceiling joist span table is based on the 2012 irc for uninhabitable attics with limited storage.

Ceiling joist spans. This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction. True floor joist span calculations can only be made by a structural engineer or contractor. Also available for the android os.

Calculating ceiling joist spacing. Ceiling joist spans for southern yellow pine douglas fir and eastern spruce. How far apart can you span a ceiling joist.

It covers 2 common lumber species and sizes at 20 pounds per square foot load. These span tables are for 16 o c. This will be slightly less than the length of the board.

Span exceeds 26 feet in length. Span calculator for wood joists and rafters also available for the android os. Basic ceiling joist spacing.

Although 2 x 4 s are included in the official table they are not listed because it is never advised to use them. Plain ceilings are sized at 10 lb loads while the ceilings with storage are sized for 20 lb loads. If a room is 10 inside to inside and the joists are cut 10 7 so they will bear fully on both walls then the span will be 10.

The standard construction of interior framing in a home uses 16 inch on center oc spacing. Ceiling joists of the first floor of a two story structure often serve as floor joists for the second floor. Find the maximum spans for ceiling joists according to the 2018 international residential code using the most common types of lumber with these simplified span tables.