What Is Floor Joist Spacing

Joist span and spacing is set by your local building code.

What is floor joist spacing.

You should check with your local building department for construction requirements in your area. Normally floor joists are spaced 16 inches apart on center. True floor joist span calculations can only be made by a structural engineer or contractor. The floor joist spacing is the distance between the centers of any two installed joists.

A 2x8 up to 12 feet. 2x10 to 15 feet and 2x12 to 18 feet. In general terms joists spaced 16 inches on center can span 1 5 times in feet their depth in inches. See the image below for an example of joists spaced 16 on center 16 o c.

With some structures floor joists are required to be 12 or 24 inches apart on center. 1 ft 0 3048 m. This means from the center of one upright joist to the center of the next. Maximum floor joist span for no.

Two options that arise could be your wider 24 and your narrower 12 options for spacing. Live load is weight of furniture wind snow and more. 1 psf lb f ft 2 47 88 n m 2. 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.

2 8 s come standard at 1 inch thick. In many circumstances 16 inches would be your standard spacing for shed floor joist but this is just a rough guideline. The larger the deck the larger the joists. 2x8s are used frequently for these projects.

While most residential construction uses 2x8 joists with 16 inch spacing there are many other factors you need to consider when determining the proper joist span length. 2 grade of douglas fir are indicated below.