Span Stress Floor System Definition

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.

Span stress floor system definition. If that same joist had gypsum ceiling l 240 the allowable deflection is 0 6. One way joist floor system lateral space frame floor joists type rib joist slab with beams. Drywall attached to the underside of this system is not expected to crack when the floor joist system deflects 1 3. The depth of a floor system is directly related to the size and proportion of the structural bays it must span and the strength of the materials used.

In the example the joists have a spacing of 16 inches and a span of 11 feet 2 inches. Rather the reader is referred to the aisi standard for cold formed steel framing prescriptive method for one and two family dwellings aisi 2001 for guidance. One way joist floor system 2d lateral frames floor joists type rib joist slab. 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.

Although cold formed steel framing for floor systems also is permitted by the irc it is not covered here. A floor system may be composed of a series of linear beams and joints overlaid with a plane of sheathing or decking or consist of a nearly homogeneous slab of reinforced concrete. The range of steel based floor systems is presented in general terms with the advantages and disadvantages of each system identified so that these can be compared against the requirements of a given project. The article does not go into technical detail about the different types of composite long span and shallow floor solutions.

69 chapter 4 floor construction woodframe floor systems and concrete slab on grade floors are discussed in this chapter. True floor joist span calculations can only be made by a structural engineer or contractor. Cast in place and pre cast slab types and floor systems for mixed use building project. For example the allowable deflection of a 12ft span floor joist with plaster l 360 is 0 4 12ft divided by 360.

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. Together the concrete form and working platform are raised by means of hydraulic jacks. See the table below. In vertical slip forming the concrete form may be surrounded by a platform on which workers stand placing steel reinforcing rods into the concrete and ensuring a smooth pour.