Floor Joist Spacing Chart

How far apart are floor joists placed.

Floor joist spacing 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. Floor joist span tables for various sizes and species of wood. But larger is not always better when builders are constructing a home or adding a room addition. This a rough guideline.

A lot of questions revolve around joists when it comes to building a deck. How do i keep them even. 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. 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.

See the image below for an example of joists spaced 16 on center 16 o c. The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important for example. Joist span and spacing is set by your local building code. Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor.

However when running spf 2 6 floor joists into the floor joist calculator referenced above you get a maximum span of 9 feet 8 inches with a minimum bearing length of 3 inches at each end on 12 centers. The floor joist spacing is the distance between the centers of any two installed joists. What is the proper placement. 2x10 to 15 feet and 2x12 to 18 feet.