which are different from other floor coverings like engineered wood or vinyl. An ANSI specification was developed to qualify sound con- trol membranes for use under tile. ANSI A118.13 includes various requirements for bonded sound membranes, such as bond strength, Robinson floor test performance, and impact sound reduction per- formance. One key feature of the specifi- cation is that the Robinson floor test and impact sound transmission tests are specified to use the same materials so owners and design professionals won’t be misled by the use of different assemblies to maximize performance in each test. Only one assembly can be installed on a particular job and the owner must be assured that the assembly will provide the expected sound control and still support the tile covering. Another key feature is that the contribution of the floor covering itself to impact sound control over a standard concrete slab is tested and quantified with a value denoted ΔIIC (delta IIC). This value can’t be added to any floor/ceiling assemblies other than concrete with no ceiling below. However, it allows design profes- sionals to compare sound con- trol membrane assemblies directly, without the potential to be misled by other elements in the floor/ ceiling assembly tested, such as a sound-rated ceiling. Still, the design professional will require full floor/ceiling assembly testing to validate specific assemblies will satisfy building code or housing authority requirements. Warm tiles for comfort Tile coverings can be cold under- foot, but there are various floor warming systems available to improve comfort and add a touch of affordable luxury. The heat source for most electric floor warming is a cable system where resistance of the wire causes electrical energy to be converted to heat energy. Originally, cables were purchased FEATURE: Schluter Systems L.P. - the evolution of the tile membrane Mike Gwizdala of Mike’s Custom Tile Company in Bay City, Mich., always takes photos of the placement of items like thermostat wires for heating cables so he knows where things are after the tiles are installed. 38 TileLetter | May 2017