What Is Floor Joist Spacing

Normally floor joists are spaced 16 inches apart on center.

What is floor joist spacing. 1 ft 0 3048 m. Dead load weight of structure and fixed loads 10 lbs ft 2. True floor joist span calculations can only be made by a structural engineer or contractor. 1 psf lb f ft 2 47 88 n m 2.

Since the example house we are designing for is 12 feet wide we need to find in the floor joist span table a joist size and centering that can span 12 or wider. 2x8s are used frequently for these projects. In many circumstances 16 inches would be your standard spacing for shed floor joist but this is just a rough guideline. The floor joist spacing is the distance between the centers of any two installed joists.

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. This means from the center of one upright joist to the center of the next. See the image below for an example of joists spaced 16 on center 16 o c.

A 2x8 up to 12 feet. The larger the deck the larger the joists. You should check with your local building department for construction requirements in your area. With some structures floor joists are required to be 12 or 24 inches apart on center.

In general terms joists spaced 16 inches on center can span 1 5 times in feet their depth in inches. Maximum floor joist span for no. 2x10 to 15 feet and 2x12 to 18 feet. 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.

Joist span and spacing is set by your local building code. Given that 2x8s are actually 1 inches wide it works out to be 14 inches between each joist.