Floor Joist Spacing

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.
Floor joist spacing. Given that 2x8s are actually 1 inches wide it works out to be 14 inches between each joist. This means from the center of one upright joist to the center of the next. 1 ft 0 3048 m. True floor joist span calculations can only be made by a structural engineer or contractor.
2 grade of douglas fir are indicated below. Live load is weight of furniture wind snow and more. 1 psf lb f ft 2 47 88 n m 2. Normally floor joists are spaced 16 inches apart on center.
In this situation your floor joist will be required to be 12 or 24 inches apart on center. Joist span and spacing is set by your local building code. You should check with your local building department for construction requirements in your area. 2x8s are used frequently for these projects.
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. Maximum floor joist span for no. Dead load weight of structure and fixed loads 10 lbs ft 2.