Floor Joists Capacity

Dead load weight of structure and fixed loads 10 lbs ft 2.

Floor joists capacity. The heaviest joist along with the above factors will span a maximum of 23 feet 8 inches. Maximum floor joist span for no. The floor joist spacing is the distance between the centers of any two installed joists. 1 psf lb f ft 2 47 88 n m 2.

So our house would look like the picture below with all floor joists 2 x 8. Live load is weight of furniture wind snow and more. Live load 30 lbs ft 2 1436 n m 2. 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 capacity max working load 3 0 kn m 2 as pdf file. You should check with your local building department for construction requirements in your area. The span table for a 30 psf live load 10psf dead load floor indicates a required fb value of 1 315 and a minimum e value of 1 800 000. 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.

Bci joist span and size charts available for download. In this case your joists are adequate to support a 30 psf live load and 10 psf dead load. 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. Joist span and spacing is set by your local building code.

See the image below for an example of joists spaced 16 on center 16 o c. This is the most common as the typical span is 15 feet. Span calculator for wood joists and rafters also available for the android os. With these factors the lightest joist will have a maximum span of 17 feet 8 inches.

Also available for the android os. Bci joists are specially constructed floor i joists with flanges made from strong versa lam lvl. 1 in 25 4 mm. True floor joist span calculations can only be made by a structural engineer or contractor.

Floor joist capacities max working load 3 0 kn m 2 floor joist capacities for timber grade c 18 c 24 and c 30 joist center space ranging 300 to 600 mm are indicated in the diagram below. Reading the table you ll see that 2 x 8s installed 16 apart on center can span 12 4. 2 grade of douglas fir are indicated below. In the example the joists have a spacing of 16 inches and a span of 11 feet 2 inches.