FEATURE: Schluter Systems L.P. - the evolution of the tile membrane Preventing cracked tiles and grout Crack-isolation and uncoupling membranes soon followed, with the primary benefit being preven- tion of tile and grout damage due to substrate movement. Crack- isolation membranes are depen- dent on flexibility from the elas- tomeric properties within a flat sheet, whereas uncoupling mem- branes are geometrically config- ured to limit stress transfer from the substrate to the tile covering. Applications include tile floors in nearly every environment in both residential and commercial set- tings. Sound control In multi-story construction like apartments and condomini- ums, controlling sound trans- fer through the floor/ceiling assembly is essential. There are requirements for sound control in building codes, and housing authorities may impose strict- er requirements. Both airborne sound (conversation, music, etc.) and impact sound (foot- steps, dropped items, etc.) are of concern, but in general the tile assembly has the greatest effect on impact sound. There are ASTM standard methods for testing and calculating impact sound transmission through a floor/ceiling assembly, with the result being a single-number rat- ing – this is called impact insula- tion class (IIC for short). A new ANSI specification Tile can actually increase impact sound transfer through floors so the sound management challenge is significant. In general, impact sound control is best achieved with floating systems such as mortar beds, poured gypsum, or lightweight concrete toppings that incorporate resilient materi- als underneath. However, progress has been made in developing rela- tively thin assemblies to help con- trol impact sound. The first such products came from manufactur- ers outside the tile industry and didn’t necessarily accommodate the requirements of tile coverings, Tiles are installed over the waterproof membrane in one of the showers. 36 TileLetter | May 2017