Tile Tap Method: Human and Auditory Scientific Analysis

This study examined the scientific basis for the tile tap method by comparing the results obtained using the human ear to sensitive auditory equipment. The study was composed of six tasks: (1) create a representative non-bonded tile, (2) identify the best tapping instrument, (3) evaluate tapping on different tiles, (4) identify the predominant sound frequencies from bonded and non-bonded tiles, (5) determine whether distinct frequencies could characterize non-bonded areas of tile above and below the thin set, and (6) determine the detection limit for increasingly smaller portion of non-bonded tiles. This study examined six types of floor tile (ceramic, travertine, marble, porcelain, limestone, and sandstone) and used wax paper beneath the tile to provide the best non-bonded sound. Among these tile types, marble exhibited the most modest difference between bonded and non-bonded areas. In general, the sound frequencies were lower and louder among portions for non-bonded tiles when tapped. Among the 18 different tapping instruments tested, a 2-inch steel ring produced the most distinctive sound for human ear perception to both bonded and non-bonded tiles. Microphonic analysis, unlike the human ear, was capable of distinguishing the difference in sound frequency produced between the non-bonded areas above and below the thinset. Finally, the detection limit for the tapping could distinguish area separations of approximately 9 in². The study concluded that the tapping method supported the non-bonded versus bonded distinction by the scientific method though some tapping instruments were shown to be better than others.