This method is developed to determine the vibration controlled spans for wood joisted floors built with joists, subfloor, topping, and lateral reinforcements such as strong backs, straps, bridging or blocking. The floors may have a ceiling. The joists can be solid sawn lumbers, wood I-joists, or wood trusses. This method is also applicable to the floors built with the light-gauge steel joists with a wooden deck.
The method accounts for subfloor, nail, or nail and glue connections between the joists and the subfloor, the topping, and the lateral reinforcements, and their effects on the vibration controlled spans of the floors. The effect of the ceiling is not taken into account since it was found to be insignificant (Hu 2005). The effect of the continuity of the joists over multiple spans was also found to be insignificant (Hu 2005), and is therefore, also not taken into account. This means that when we determine the vibration controlled spans for multiple span continued joists, we treat each span as a single span joisted floor and use this method to determine its vibration controlled span.
This method is only applied to lightweight joisted floors that present fundamental natural frequencies larger than 9 Hz.
The floor should be well-supported and built without construction defects as specified in the building code.