Tile underlayment is something a lot of customers ask about when they want to install new tile flooring. The typical idea is that because it’s tile and therefore not carpeting or wood, underlayment isn’t necessary. Nothing could be further from the truth. There are valid reasons why tile underlayment is used.
To Dampen Sound
It doesn’t matter what kind of flooring you install. Sound that is not absorbed is sound that carries, bounces, and echoes. Tile doesn’t asborb sound any more or any better than any other flooring material, which is why an underlayment is needed.
To Provide a Surface for the Mortar
In case you have never seen tile installed, you should watch a short video on the subject. The underlayment goes down and then a layer of mortar goes over that. The underlayment acts as a moisture barrier and as a surface to which the mortar can be applied smoothly. Then the tiles are placed over the mortar and smoothed into position. The underlayment helps keep the mortar from being applied unevenly and subsequently provides a level surface for the tiles.
To Keep Tiles From Shifting and/or Breaking
The underlayment prevents tiles from shifting and/or breaking. If no underlayment is used, the tiles can shift just enough over time to snap and crack, creating hairline crevices where dirt, debris and even mold can collect. This becomes a major problem because nothing can get into these crevices to clean them, leaving unsightly eyesores in your tile and smells that won’t go away.