Drummy tiles are loose tiles, which, if tapped with a resonance-testing tool (a metal bar or rod), will produce a drummy type of sound. They are typically detected with ease on floor surfaces, as the latter are subjected to frequent foot traffic. Still, you can get drummy tiles on walls, too. Broadly speaking, the tiles have not been glued correctly during installation but there may be, in effect, various more specific reasons behind the flawed function of the flooring, be it ceramic, porcelain, terracotta, etc. Let’s look at these in more detail.