Not all cork is created equal! But, many can provide a suitable backing for ceramic tile. Widely popular for its sound deadening properties, cork installation guidelines can be found in the Tile Council of America Installation handbook. Photo courtesy of Amorim Cork Composites.

Rare is the occasion an installer does not have to deal with concrete control joints. Many but not all crack isolation systems allow movement joint relocation to the next closest grout joint. Recommendations vary widely even in seemingly “like” products. Photo courtesy of MAPEI.

One area of ceramic tile that continues to bode well, even in a tight market, is membranes. Use of various types of membrane systems continues to grow as people seek increased performance features from their ceramic tile installations.  Specifiers and increasingly educated consumers are looking for waterproof, crack free, and quiet ceramic tile floors, sometimes all three. That has received increased attention from both traditional manufactures of setting materials and installation systems and some not-so-familiar sources outside the tile industry. With today’s building practices calling for faster construction and at the same time, end users wanting higher performance, all in a tighter economy, there seem to be some increasingly opportunist products and strategies being deployed. This is especially true with sound attenuation in multi-unit buildings, which is being mandated under building code compliance. Then there are the ongoing fears, both founded and unfounded, about mold contamination, which continue to do their part in driving increased sales and use of waterproofing. Add to that the rightful desire for long-lasting, crack-free floors. These concerns have all contributed to the sales growth of existing traditional products and served as cause for many new products to be developed.

There is a long history of failure when using products that don’t meet appropriate standards, such as roofing felt, sheet vinyl, scribing paper, and plain or scrim reinforced Kraft paper, for crack suppression and/or waterproofing. In the sound reduction market, it is probably much worse when it comes to use of products that do not deliver. This is primarily due to lack of a cohesive standard for sound reduction products and applications related to ceramic tile. There are published standards for ceramic tile and most tile-related products that help assure a level playing field. The product standard for waterproofing is the American National Standard Specifications for Load Bearing, Bonded, Waterproof Membranes for Thin-set Ceramic Tile and Dimension Stone Installation A118.10. This standard was developed to provide specifiers and installers with the minimum criteria necessary for a material to function as a barrier to positive liquid water migration in a load bearing, bonded, thin-set installation of ceramic tile and dimensional stone. This standard applies to trowel-applied, liquid, and sheet membranes. Waterproof membranes for thin-set ceramic tile and dimension stone installations function as barriers to positive liquid water migration. Products meeting this standard are not designed for moisture reduction such as a slab under hydrostatic pressure. The intention of waterproof membranes meeting tile standards is to stop liquid water from going into the substrate or entering the wall cavity. There is currently no requirement relative to the passage of moisture vapor which can be a concern in applications such as a steam shower with heavy use or other specific building conditions.

  For crack isolation there is the American National Standard Specification for Crack Isolation Membranes for Thin-set Ceramic Tile and Dimension Stone Installation ANSI A118.12. This standard was also developed to provide specifiers and installers with the minimum criteria necessary for a material to function as a deterrent to crack propagation from the substrate through the finished thin-set tile or stone installation. Additional tests, which are not a requirement of this specification, may be run when requested for a particular project. Dependent on the scope of the job, there may be additional testing using the exact materials for that project, which can be a very prudent decision.  The standard test method under this specification uses 4”x8” quarry tile to check for a membrane’s crack-bridging abilities. Anyone who has installed quarry tile knows it is a very elastic product as far as tile goes. It also has a much higher breaking strength than the porcelain tile more commonly used over membranes. Crack isolation membranes for thin-set ceramic tile and dimension stone installations are intended to isolate the tile or stone from minor in-plane substrate cracking. Membranes covered by this specification can be bonded to a variety of manufacturer-approved substrates under ANSI specifications. In some cases the trowel-applied products may also be used as the adhesive for the ceramic tile or dimensional stone. Other products used within the scope of this specification are allowed to cure or are applied as sheet goods and are then used as the substrate for the application of ceramic tiles and dimension stone by traditional methods and materials. Work is currently in progress on establishing similar standards for sound reduction materials. As with all products, consult individual manufacturers for specific instructions, applications, performance levels, and limitations concerning their materials, and always follow the individual manufacturer’s written instructions precisely.

Soon to be a focal point, a liquid waterproofing product is applied prior to tile application in this concrete tank. Liquid waterproofing products work well in many areas requiring waterproofing applications. Special attention must be given to the required thickness and any corner treatments if recommended. Photo courtesy of LATICRETE International.

So why do standards matter? Quite simply, if there is no standard for any given product or installation then there is no expectation of performance other than that implied by the installer or manufacturer.  While 95 percent of product manufacturers and installers are both legitimate and very conscientious about their work, I don’t believe a single person reading this would claim that all share these admirable traits. Standards provide an expectation of performance in both product and installation for all affected parties. Then there are also the competitive pressures being seen in the current market.  We are noticing an upward trend in customers to wring every penny out of a job, and installers using sub-par materials and methods to accommodate them. We also see more people entering the tile industry with little or no education in an effort to secure more work in an attempt to generate income. Consider the following recent email I received: “I am sending you this email with my inquiry on the “accepted standard” of ceramic tile installation on a concrete slab. My 1,700-square-foot tile floor has failed!  It was installed in 2004 when my new home was built.  The tile company used an anti-cracking material between the tile and the concrete floor because most builders in this area believe that it will save them money because they will have to deal with less cracked tiles.  The paper separated from the concrete floor leaving my tile floor free floating on the concrete.  About two months ago a complete row of tiles going across the middle of my living room tented up from the pressure and the tiles being loose.  This is how I discovered the installation materials used. The anti-cracking material appears to be made out of paper with a waxed coating.  I have seen the term “craft paper” and it may be this product.  The paper was stuck to the tile but completely loose from the concrete floor.  Between the tile and the paper was thinset.  The material that was used to attach the paper to the concrete was a mastic glue, which dissolves with water. I put water on the glue to remove it from the concrete.  Some of the glue was left on the concrete and some was transferred to the paper on the back of the tile. I believe the floor failed because of the cheap paper used and the fact that it was attached to the concrete with a water-soluble mastic glue. The contractor told me that this method was acceptable by the Tile Council of America.”

This is another case of a paper product never designed for crack isolation but commonly used gone bad. A little further correspondence produced an attachment copy of an invoice from the tile materials supplier which labeled the product a “crack suppression membrane” under materials purchased followed by a big red stamp that says “not an approved crack isolation membrane under industry standards.”  So much for being acceptable under recommendations from the Tile Council of North America. 

There are numerous products available that could have provided this tile customer with a tile installation that would have lasted the life of the structure. Instead this relatively new home owner indicated he will probably switch to a competitive flooring product that can be installed by someone with less knowledge and skill, as is often the case due to the desire of avoiding the expensive nature of tile troubles again in the future.  As structures grow more complex in design and performance, we are certain to see an increased usage of membranes for their various attributes, be it for waterproofing, crack suppression, or sound reduction. I don’t think there is one company or one membrane that serves all conceivable situations. I suggest you align yourself with several manufacturers that make products meeting standards and offer responsive technical support. Take the time to learn all about their products‘ benefits and limitations. Most distributors will happily sponsor a contractor night if enough interest warrants. If not, do not be afraid to ask the manufacturer if a technical representative is available for assistance in your area. Presenting your chosen professional products with high confidence often eliminates the price sensitivities, making for a more profitable job and happy end user.