Special Floor Loading Considerations in Typical Residential Construction

The design of a typical residential flooring system is usually a simple process: estimate the appropriate dead loads based on floor surface and subfloor materials, select the appropriate live load based on the intended purpose of the room, and then design the floor trusses composed of the necessary material and required spacing to support the given loads at a particular span. If designing with engineered wood products (EWP), one would simply select the required joist size and spacing from established tables. The simplicity of this approach originates from the fact that loads are unpredictable. It is impossible to determine how a particular room will be used or what loads it will be subjected to and where those loads will be located, so it is simply assumed that a uniform load is distributed over the entire floor surface. This approach is very simple and, although it works and is even conservative a majority of the time, it does not account for every situation.