Floor Joist Span Sizes

1 ft 0 3048 m.

Floor joist span sizes.

Floor joist span tables for surveyors floor construction. 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. Surveyors and structural engineers use data from tables below to help calculate the size of timbers necessary to give adequate support to timber floors. True floor joist span calculations can only be made by a structural engineer or contractor.

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. See the image below for an example of joists spaced 16 on center 16 o c. 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. The floor joist spacing is the distance between the centers of any two installed joists.

Maximum floor joist span for no. Floor joist span tables for various sizes and species of wood. Dead load weight of structure and fixed loads 10 lbs ft 2. Live load is weight of furniture wind snow and more.

1 psf lb f ft 2 47 88 n m 2. Joist span and spacing is set by your local building code.