In their excitement over the wide array of home furnishing colors, styles and designs available, homeowners tend to overlook some of the fundamental aspects of building or remodeling. One aspect that every ceramic tile customer should be aware of is underlayment.

Hardibacker 500 Ceramic Tile Backerboard is an example of a fiber-cement underlayment designed for tile installations. Photo courtesy James Hardie Building Products.


Bonsal's Util-A-Crete underlayment features a fiber-cement core with a fiberglass mesh covering its surfaces.
Whether they are building a new home or simply remodeling their existing dwelling, today¿s homeowners are enthusiastically taking control of their living space. Naturally, they are most excited about choosing the design elements ¿ such as decorative tile, wall treatments and interior furnishings ¿ that will help create a harmonious, comfortable and attractive home.

But in their excitement over the wide array of colors, styles and designs available, homeowners tend to overlook some of the fundamental aspects of building or remodeling. One that every ceramic tile customer should be aware of is underlayment.

What is ceramic tile underlayment? In the simplest terms, it is a product manufactured for use as a substrate for ceramic tile. Available in a wide variety of compositions, it is most frequently used in floor, wall and countertop applications.

In high-traffic, moisture-prone areas of the home ¿ such as bathrooms, kitchens and laundry rooms ¿ use of a reliable underlayment is crucial because it provides a solid foundation for the tile, and prevents the underlying deterioration often caused by water and steam.

Typically, this deterioration occurs when water and steam penetrate a ceramic tile application through grout joints, which are porous. As a result of this frequent exposure to moisture, many underlayments rot, warp and swell over time This causes failure of the adhesive bond, and the tiles become raised and loose as a result.

Therefore, even as homeowners explore the myriad of ceramic tile options, it¿s important that they carefully consider to the underlayment product they, or their contractor, will use.

Due to the deleterious effects of prolonged expose to moisture, direct application of tile to plywood may open the door to significant problems over time, because wood-based substrates are extremely vulnerable to warping, rotting and other damage.

One commonly used alternative product consists of a cement core faced with fiberglass mesh on both sides. Another alternative is based on fiber-cement technology, a durable, lightweight option. Gypsum panels are sometimes used as an underlayment material as well.

Many factors must be considered when selecting an acceptable underlayment, one of the most important being the environment surrounding the installation. Careful consideration of factors such as moisture, heat and humidity helps ensure a superior bonding system for the tile.

Just as in any step of building or remodeling, selecting tile treatments can be an emotional, costly and time-consuming process. The worst thing homeowners can do is disregard the critical role that the underlying foundation plays in the longevity and durability of their new tile investments. Making an informed decision can be the difference between a ceramic tile surface that looks great just over the short term vs. one that will perform beautifully for years to come.