Floor Joist Sizing Chart

Floor joist span tables for various sizes and species of wood.

Floor joist sizing chart.

When building a house or even a deck it is important to confirm you have the correct joist sizes spans and spacing before you get started. 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. What is the proper placement.

Joist span table use these tables to determine floor joist spans based on grade of lumber size of joist floor joist spacing and a live load of 30 lbs ft 2 or 40 lbs ft 2 these tables can also be used to determine deck joist span. Live load is weight of furniture wind snow and more. Maximum floor joist span for no. 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.

See the image below for an example of joists spaced 16 on center 16 o c. 1 ft 0 3048 m. A lot of questions revolve around joists when it comes to building a deck. 1 psf lb f ft 2 47 88 n m 2.

How far apart are floor joists placed. A 2x8 up to 12 feet. 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.

In general terms joists spaced 16 inches on center can span 1 5 times in feet their depth in inches. Joist span and spacing is set by your local building code. 2x10 to 15 feet and 2x12 to 18 feet.