To prove ceramic tile's green credentials. simply walk into any history museum and marvel at mosaics that often are the only remains of a past civilization. Ceramic tiles installed thousands of years ago still are being walked upon and admired for their beauty and longevity today. They may be considered among the most durable of all building materials and, consequently, very green.
But tiles owe their longevity to the installation materials that support them. Although there are many high-performance tiles available today, poor installation may make them short lived. When this happens, the ruined tiles and installation materials are anything but green. Fortunately, through the Washington, D.C.-based American National Standards Institute, the tile industry publishes manufacturing, material and installation standards for ceramic tiles. The industry always is working on improving material and installation standards.
REDUCE AND REUSE
Ongoing research about ceramic tiles and their installation is essential because the building industry is faced with increased demand for buildings amidst a diminishing supply of materials. The result is a movement toward buildings that are thinner and more flexible. Unfortunately, a decrease in the amount of material required for the building leads to an increase in the amount of materials required for the tile portion of the construction.
For example, when buildings were made primarily from masses of masonry or concrete, tiles simply could be applied directly to the concrete or masonry surfaces because they were so strong. Now that buildings are designed to be flexible, tile installations require new setting-bed materials and protective-membrane systems. The cost of installing protective membranes has led to the development of lightweight tile backer boards. Made completely from recycled and melted nylon, the backer boards do not require special construction or membranes. They simplify tile installation and eliminate the need for extra layers of flooring, membrane systems and other special materials.
An added bonus is that the backer boards simultaneously help rid landfills of discarded nylon carpet. The nylon fibers in carpet we began throwing away in the mid 1950s still are fresh, flexible and can be turned into durable materials rather than useless scrap. Independent studies have proven the reliability of re-melted, recycled nylon building materials when they are exposed to UV. When covered with tile, adhesive and grout, nylon backer boards easily should outlast the life of any building in which they are installed.
Testing conducted under the West Conshohocken, Pa.-based ASTM International’s standard C627, “Test Method for Evaluating Ceramic Floor Tile Installation Systems Using the Robinson-type Floor Tester,” indicates that on some applications, the layer of thinset mortar normally installed to support tile backers may be eliminated. This further reduces the amount of material needed. When applied to large-scale construction, the weight-saving potential alone could be considerable.
Another innovation for tile installation is the use of lightweight aggregates for tile adhesives and grouts. Reduced weight translates into lower shipping costs and a smaller load for the installer to transport. One such lightweight product occupiesthe same sack traditionally containing 50 pounds (23 kg) of sand and cement-based thinset but weighs only 30 pounds (14 kg).
Because of its lighter weight, this particular adhesive mix is easier to spread than traditional thinset mortars, and like other high-performance tile installation products, has more than just an adhesion function. In addition to being rated for use with porcelain and glass tiles, the extra-sticky mix provides crack-isolation protection for floors with cracks up to 1/8-inch (3.2-mm) wide, thus eliminating the need for additional materials or a membrane.
Traditional cement-based tile backer boards cannot be cut with a carpenter’s blade; dust-generating dry-cutting diamond blades are required for the task. There are traditional tools that can cut the backer boards without generating dust, but they are considered slower than power tools and are ignored by most contractors. Fortunately, many building zones are prohibiting the use of dust-generating methods to cut cement-based backers.
Dust has an impact on the world at large, as well as on installers who typically shun the use of filter masks. With this in mind, the developers of the nylon board wanted a material that could be cut with a cheap, carbide-tipped blade used by many pro and amateur carpenters. The result is a board or shingle that easily is cut with a regular blade, leaving a pile of chips instead of a cloud of dust.
The task of mixing the adhesive mortar and grout powders with water or latex also can generate large clouds of dust that affect the installer and building occupants. This has been a problem for thousands of years; early installers mixed volcanic ash with powdered marble dust and were told to take their mixing outside. Volcanic ash still can be found among the ingredients of some tile adhesive, and installers still are requested to take mixing outside.
Having acknowledged a problem existed, a low-dust process has been developed for manufacturing grouts and adhesive mortars. The new process results in a 90 percent reduction in airborne particles released during the powder stage. (Once prepared and thoroughly mixed, thinset mortars and grouts should emit no airborne dust particles.) The process borrows from pharmaceutical companies, who have learned how to encapsulate powders, and has no apparent negative effects on performance properties, like compressive and bond strengths.
Tiles can be durable and green, but that pedigree goes flying out the window if they are not accompanied by careful and appropriate installation. The tile industry is eager to provide installation specifications to ensure long-term performance. Many manufacturers offer lifetime warranties on projects with proper installations. On the other hand, it is a mistake to assume the installer will do things correctly, especially if the budget precludes the use of important materials and features, such as latex thinsets and grouts, membrane systems, movement joints and other elements that contribute to the long life expectancy of tile.
The best approach for anyone seeking long-term performance from a tile installation is to take advantage of the technical support offered by most reputable manufacturers. When possible, obtain all the installation materials from one manufacturer. Request a printed specification for your particular installation and base your design, bid and installation decisions on the manufacturer’s printed recommendations.
Have copies of printed installation instructions for all materials available on-site at all times. For most high-end installations, it is a good idea to specify a certain level of third-party inspection; this may vary depending on the level of complexity, size and other factors. Reasonable oversight of the installation process is a great way to ensure your tile installation remains green.
Materials and Sources
--Low-Dust Grouts and Adhesiver Mortars / MAPEI, Deerfield Beach, FLa., www.mapei.us
--Lightweight Mortar / MegaLite from Custom Building Products, Seal Beach, Calif., www.custombuildingproducts.com