Floor Joist Design Example

Drywall attached to the underside of this system is not expected to crack when the floor joist system deflects 1 3.

Floor joist design example.

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. The floor joist spacing is the distance between the centers of any two installed joists. Draw the shape of the moment diagram below. Calculate the dead load on a typical purlin.

Calculate the moment due to dead load. Since the example house we are designing for is 12 feet wide we need to find in the floor joist span table a joist size and centering that can span 12 or wider. Design of 3 3x12 timber beam with southern pine solved example. Ce 331 spring 2002 joist and frame design example 1 2 1.

But larger is not always better when builders are constructing a home or adding a room addition. Draw the purlin and show the dead loading. Design a typical floor joist for the two story office building indicated below. 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.