Psi Load For Floor Joists

Table 9 2 adjustment factors for alternate loading and spacing conditions for determining required com pression perpendicular to grain design values f c for joists and rafters.

Psi load for floor joists. Bc calc performs engineering analysis to help our customers size beams joists columns studs and tall walls for their building projects. Loads psf on center spacing in. Joist spacing common joist spacings for 2 by 10 joists and other dimensional lumber sizes are 12 16 and 24 inches. For this example i ll use the icc which serves as the model for many state and local codes.

A floor joist appropriately selected to span 10 feet with an l 360 limit will deflect no more than 120 360 1 3 inches under maximum design loads. When sizing joists use the clear span the length from support to support not the full length of the joist. 1 psf lb f ft 2 47 88 n m 2. Next consult a span table to cross reference the spacing and span to find the required fb value for that table s load limits.

Joists that are closer together can support. 4 see a 1 3 for 2 span floor joist requirements. 1 ft 0 3048 m. Two species used for structural lumber include douglas fir and southern yellow pine.

It is simple to use yet flexible enough to analyze a variety of common applications. 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. Step 1 check the code. The user enters the member geometry adds loads holes and other relevant data and then selects a product for analysis.

A uniform load rating on a beam can easily be translated into what an equivalent maximum point load can be. Maximum floor joist span for no. Drywall attached to the underside of this system is not expected to crack when the floor joist system deflects 1 3. But larger is not always better when builders are constructing a home or adding a room addition.

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. For example a floor joist at 16 spacing s that can carry 53 pounds per linear foot would translate into a 318 pound single point load at its center. Live load is weight of furniture wind snow and more. 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.

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. Dead load weight of structure and fixed loads 10 lbs ft 2. Live dead 12 16 19 2 24 10 5 0 23 0 30 0 36 0 45 20 10 0 45 0 60 0 72 0 90. In the example the joists have a spacing of 16 inches and a span of 11 feet 2 inches.

First check the local code for allowable live load dead load and deflection see figure 2.