A waste pipe between the floor waste and the drainage system. During our standard seal we create and impenetrable DiaoSeal epoxy sleeve which act as a capillary barrier to prevent waste water wicking through any exposed tile bed.
The tile biscuit delaminates and separates from the substrate to become drummy. Note: Drummy or hollow sounding tiles can easily be detected by tapping or running over tile surface with a small metal object such as a key, coin or the plastic handle of your screwdriver. If you hear a dense sound, the tiles and screed or bed are generally solid. However, if the sound is hollow this is due to the adhesive bond between tiles and the substrate breaking down.