Second Story Floor Framing Jost Spacing

Maximum floor joist span for no.

Second story floor framing jost spacing.

Given that 2x8s are actually 1 inches wide it works out to be 14 inches between each joist. Some builders reduce joist spacing to 12 on center to strengthen the deck frame or to increase maximum allowable joist spans. See the image below for an example of joists spaced 16 on center 16 o c. Section r502 10 of the international residential code states that header joists can be the same size as the floor joists when the header joist span isn t greater than 4 feet but if the header joist span is more than 4 feet you ll need to double the header joist and ensure that it s capable of supporting the floor joist framing.

The floor joist spacing is the distance between the centers of any two installed joists. Joist spacing for composite decking. Live load is weight of furniture wind snow and more. Joist span and spacing is set by your local building code.

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. 2 grade of douglas fir are indicated below. Most decking is not strong enough to support longer spans than 16. Normally floor joists are spaced 16 inches apart on center.

This means from the center of one upright joist to the center of the next. As well as human traffic. I have a 20 x 40 x 18 ft rv building basically 800sq ft which i want to add a second floor. 1 ft 0 3048 m.

For 7 8 inch panels joists can be up to 32 inches on center and for 1 3 32 and 1 1 8 inch thick panels the joists can be spaced 48 inches on center. 1 psf lb f ft 2 47 88 n m 2. With some structures floor joists are required to be 12 or 24 inches apart on center. Dead load weight of structure and fixed loads 10 lbs ft 2.

The walls are std concrete block. 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. Looking at this table you will see there is a choice in the size of floor joist 2 x 6 2 x 8 2 x 10 or 2 x 12 and there is a choice in the joist spacing 12 16 or 14. I want this added floor space 2nd floor to support 23000 lbs of house hold furniture no water fixtures.

You should check with your local building department for construction requirements in your area.