What type of membrane is recommended by the Tile Council of America when installing ceramic tile over gypsum board on wood studs using the "one coat" method?

The Tile Council of America recommends using 15-pound roofing felt when installing ceramic tile over gypsum board on wood studs using the "one coat" method. This specific type of membrane serves a crucial role in providing a moisture barrier, which is essential in preventing potential water damage or moisture-related issues that could compromise both the integrity of the gypsum board and the tile installation.

Using 15-pound roofing felt creates a reliable barrier between the tile and the substrate, contributing to the overall durability of the installation. The felt is lightweight, easy to work with, and cost-effective. It effectively allows for the movement of moisture away from the adhesive and tile layer, reducing the risk of mold growth or deterioration, which can occur if moisture accumulates behind the tile.

The other membrane options, while useful in certain contexts, do not align with the specific recommendation for this method of installation. For example, 4 mil polyethylene, while a decent vapor barrier, may not provide the same level of support or durability when adhering tiles directly onto gypsum board. Rubber and PVC membranes serve different applications in flooring and are not specifically intended for this type of installation scenario.