Ceramic Tile Underlayments-The Basics

Ceramic tile material is rigid and relatively brittle, so a sturdy base is the most critical part of installing this type of tile. Unless you want to see cracked tiles, loose tiles, or loose grout, you need to select the proper underlayMent. UnderlayMent being what the construction trade calls the layer that goes between your wood subfloor and your tiles.

Ceramic Tile Underlayments-The Basics

Ceramic Tile Underlayments-The Basics

---

Ceramic Tile Underlayments-The Basics

Ceramic Tile Underlayments-The Basics

You have several alternate ways to accomplish the strong underlayMent required for ceramic tile installation.

Plywood-just a single layer of plywood isn't rigid enough to stop floor deflection. It needs to be covered over with an additional layer of exterior-grade plywood to achieve a total thickness of at least 1 1/8 inch. You can either (A) Cover the plywood with a cement backer board (more on these below) or (B)Cover the existing plywood with a second layer of exterior grade plywood. Under either of these, a thin-set mortar is applied to eliminate Air gaps. Additionally, in bathrooms, it's recommended to lay a "shower pan" over your wood subfloor. This refers to thin rubberized materials that protect the tile from floor expansion and contraction due to moisture, temperature and humidity.

Cement Backer Board-These are "prefabricated", lightweight concrete sheets used to cover wood subfloors. It has a dense Portland concrete core and fiberglass surfaces both sides and is able to withstand prolonged exposure to moisture. Brand names include DUROCK, UTILICRETE, WONDERBOARD and GLASCRETE. Joints of the backer board sheets should be sTAGgered such that they don't fall directlyover the wood subfloor joints.

Mortar Bed-Mud beds, or mortar beds, are used by professional tile contractors mostly. They're composed of a layer of thick roofing felt, then wire mesh, followed by a layer of mortar. The reason it is used mostly by the specialists is that it takes a high level of skill and practice to ensure the mortar bed produces a sufficiently level surface. The other reason is that it is the best foundation possible for a ceramic tile floor. Okay, but why? Because the mortar bed has a built-in reinforcement against floor deflections in the form of the wire mesh. Translation-less cracked tiles and loose grout, and longer-life flooring.

Ceramic Tile Underlayments-The Basics