Floor Joist And Cross Beam Design

The minimum size joist to be used in deck construction depends on the number of footings and beams that will be installed.

Floor joist and cross beam design. W l 40 psf. Continuing on from part 3. Our floor joist beam can span a maximum of 13. Design of 3 3x12 beam with southern pine.

Superimposed dead load including mechanical and electric load w sd 8 psf. In the table above the widest floor beam span for 12 of supported floor joists is 14 7 if using a 5 ply 2 x 12. What is a beam. Let s consider a basic gable wood roof framing design.

In this video we discuss design and analysis procedures for joists beams and girders. True floor joist span calculations can only be made by a structural engineer or contractor. That means these joists can span the 12 foot depth of the deck and the beam can be located at the perimeter. So we now have adequately sized floor joists and an adequately sized floor joist beam for our 24 x 13 house.

A beam is the main load bearing element for the structural soundness of your deck s roof. For structural engineering services in massachusetts and new hampshire. S 8 ft. Floor beam span tables of residential structural design we will now look at roof rafter and beam design.

Nine joists will be needed for the 16 foot width. 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. Though joists may be any size that you desire using typical floor joist and beam specifications ensures that you can find hardware to fit the joists and that the floor provides adequate support for furniture and other items in a room. Joists are the repeated structural members that are used to build a deck frame.

Floor joists or beams provide the below surface support for the wood subfloor of a room. W d 10 psf. Cross sectional area nominal adjusted wood education institute reference value. L 16 ft.

Wood member design asd or lrfd compares demand to capacity. Pier and beam foundations offer a high level of versatility specific not only to the dead live seismic and wind loads to be supported and or restrained but also to the girders or sill beams and floor joists and their respective span capabilities. Both the 2009 irc and the dca6 09 allow 2 southern pine 2x10s to span 13 feet 1 inch at 24 inches on center at a design load of 50 psf. Beam design example.

Here we have a wood framed gable roof. Top of beam supported by floor joists at 16 in o c.