Two related areas of research are presented in this thesis. In one area, 106 in-situ wood floor systems were subjectively rated and tested to determine fundamental frequency values. This database of wood floor systems was used to provide further validation of a recently proposed design criterion which uses fundamental frequency to predict acceptability of wood floor systems to vibrations resulting from human footfall impacts. Included in the database are floors tested previously unoccupied which were tested again with occupancy loading. Additional occupied and unoccupied wood floor systems not included in the original study were tested. A second area of research was conducted to quantify the changes in frequency content and modal damping values through construction of six typical wood residences. The data from these floors provided insight into the dynamic behavior of wood floor systems and provided further data to validate the above design criterion. / Master of Science