Ceiling Joists Size

Most lay outs are on 16 so the field is pre selected.

Ceiling joists size. This is how far apart they will be. The highest is a fully loaded floor 70 pounds per square foot. It covers 2 common lumber species and sizes at 20 pounds per square foot load.

Enter a span for the joist. For a joist to have the most strength it should stretch all the way across a room from the top of one. Although 2 x 4 s are included in the official table they are not listed because it is never advised to use them.

To change it click on another option. Select the on center spacing for the joists. Though there is no standard joist size for the ceilings in all buildings most average homes.

Ceiling joist spacing in inches 12 16 19 2 24 species and grade of lumber various lumber size options 2 4 2 6 2 8 2 10 the maximum ceiling joist span based on the lumber size species grade and spacing used. You should check with your local building department for construction requirements in your area. This ceiling joist span table is based on the 2012 irc for uninhabitable attics with limited storage.

Typically span tables for joists used to frame ceilings are figured for a combination live and dead load of 20 pounds per square foot psf. 2 x 12 s are not listed because you can span pretty much whatever you want. The tables provide the following information.

Size length of ceiling joists standard size of joists. 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. The lowest is a plain ceiling joist with no storage 10 pounds per square foot.