Floor Joist Span Sizes

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.

Floor joist span sizes.

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. 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. 2 grade of douglas fir are indicated below. Floor joist span tables for various sizes and species of wood.

Floor joist span tables for surveyors floor construction. The floor joist spacing is the distance between the centers of any two installed joists. Maximum floor joist span for no. See the image below for an example of joists spaced 16 on center 16 o c.

1 ft 0 3048 m. 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. Live load is weight of furniture wind snow and more. 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. Joist span and spacing is set by your local building code.