Total Load Deflection Floor

Question 8 a floor beam with a total load dl ll 2000 ft spans 15 feet.

Total load deflection floor. These tolerances generally are expressed in terms as a maximum deflection value and must be considered in design. Any non structural partition under the beam must be able to accommodate this deflection. 40 psf x 12 ft 480 pounds per lineal foot. 80 pounds per lineal foot.

10 psf x 12 ft 120 pounds per lineal foot. Step 1 check the code. 30 psf x 12 ft 360 pounds per lineal foot. First check the local code for allowable live load dead load and deflection see figure 2.

Chapter 3 of the international residential code irc provides the maximum allowable deflection for a given structural member floor roof wall etc. Increasing the total weight on the floor to 4 480 pounds however results in a live load of 40 psf which is beyond the floor s load capacity. The dead load in the tiled area will be higher than the typical 10 psf associated with carpet or vinyl finishes tile industry associations recommend special total load deflection limits the following tables list the components and weights of typical floor systems along with the deflection limits that apply. Typically for better performing floors minimal defection is desired.

This sets an allowable first floor live load of 40 psf a dead load of 10 psf and a deflection of l 360. For example if the span live load deflection limit is l 360 the cantilever live load deflection is limited to l 180. 2nd floor live load. Question 9 a steel floor beam with a total load dl ll 2000 ft and a span of 16 feet uses.

A wide flange section whose moment of inertia. For this example i ll use the icc which serves as the model for many state and local codes. 2nd floor dead load. 1st floor dead load.

Larger of twice the span deflection criteria or 0 2. 1 199in4 made of a992 steel whose young s modulus. Cantilever deflection limits are twice the span deflection criteria for both live load and total load deflection. 10 psf x 12 ft 120 pounds per lineal foot.

The amount of flex depends on the magnitude of the load applied span of the member and stiffness of the member. 1160 pounds per. 1st floor live load. For example a floor girder spanning 36 ft may deflect up to 1 2 inches under a live load only deflection limit of l 360.