November 9/16; Volume 30/Number 11
By Ken Ryan
(Editor’s note: This is the ninth in a 10-part series familiarizing flooring retailers with merchandising and installing tile and natural stone.)
In many flooring applications tile is used because the installation area is likely to be exposed to excessive water. However, a ceramic tile surface is not necessarily the waterproof solution, which is why a waterproof membrane must be incorporated into the installation.
Liquid-applied membranes have been utilized in the tile industry for some time, evolving accordingly over the years. This subfloor application can provide waterproofing or crack isolation, some products offer both features depending upon the manufacturer. Liquid membranes are typically installed using conventional paint brushes, paint rollers, small-notched trowels or paint sprayers.
Bob Baldocchi, vice president of marketing and sales support for Emser Tile, said flooring dealers and their installers need to be aware of the application of liquid membranes and the importance of using them properly. Take crack isolation, for example. There are products on the market today that offer maximum protection by inhibiting the transfer of cracks to a specific area.
“To be able to isolate a problem and spot repair it, as opposed to ripping out the entire floor, can save consumers a tremendous headache,” Baldocchi said. “We are trying to educate all of our retail customers. We take very little for granted in what they may or may not know.”
Moisture proofing is another key element of liquid-applied membranes. Moisture migration can contribute to the deterioration of stone tile surfaces when they are directly bonded to the concrete slab. On products that provide both waterproofing and crack prevention for tile and stone installations, one coat is recommended for crack prevention and two coats for waterproofing.
Today’s pressure of completing projects in a specific time frame often leads to tile/stone installations being rushed and installed incorrectly. However, the advanced technology that goes into today’s waterproofing membranes allows for faster curing times, which means quicker flood testing, ultimately allowing the installation to move forward in a timely fashion.
Curing of concrete is defined as providing adequate moisture, temperature and time to allow the concrete to achieve the desired properties for its intended use. The liquid cures in the air to form a seamless, joint-free membrane. Applying more of the liquid chemical per unit area can control the thickness, experts say. Cure times vary depending upon the manufacturer’s requirements and job site conditions.
When properly applied, liquid membranes can be used in both interior and exterior applications and are effective for both horizontal and vertical crack suppression. Suitable substrates typically include concrete, masonry, cement plaster and cement backer board. The membrane, however, must cure before proceeding with the stone or tile installation. Once the membrane has cured, the appropriate thinset or mortar can be applied directly over the membrane and the stone or tile installed. For a shower installation, it is advisable to conduct a flood test of the shower once the membrane has cured (normally after 72 hours) and before the tiling begins. Liquid-applied membranes are generally cost effective and can be the best choice for projects with many angles and/or shapes.
While excellent for waterproofing, professionals advise that liquid membranes are not necessarily complete vapor barriers. If vapor is a concern, such as in a steam room, then a suitable vapor barrier may need to be used in conjunction with the liquid membrane. Liquid-applied membranes are designed to meet the waterproofing requirements of ANSI A118.10.