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.    

This report will explore some special floor loading issues that are not specifically mentioned in the building codes and require special attention to ensure that the floor system is properly designed with no serviceability issues. The following are the major issues that will be discussed: 

Stone/Ceramic Tiles – The use of brittle flooring surfaces such as stone, ceramic, or glass tiles require more strict deflection limits than the building codes suggest. 

Large Concentrated Loads – Loads from sources such as aquariums, fireplaces, and granite countertops can be large and require consideration beyond the standard floor truss design. 

Floor Vibrations – Although usually not a structural issue, vibrations caused by typical service conditions can be annoying to homeowner/occupants and can be reduced or eliminated by stiffening the floor system.