This is the third of four articles featuring the assessments involved in the Advanced Certifications for Tile Installers (ACT) program, with today’s topic being Mortar (Mud) Floors and Walls. The purpose of highlighting the features and benefits of the new, and recently launched, ACT program is to spread the awareness that the tile industry is providing tile installers who meet and exceed the industry standards and best practices of quality tile installations. This tile installer testing program was developed with a two-fold purpose: to allow the ACT installer to be differentiated from those who do not have this distinction and to provide the consumer, whether commercial or residential, with a choice of a better and more qualified tile installer.

The ACT program committee was formed in October of 2012, and it included five of the leading tile industry labor organizations, including the Ceramic Tile Education Foundation (CTEF), the International Masonry Institute (IMI), the International Union of Bricklayers and Allied Craftworkers (IUBAC), the National Tile Contractors Association (NTCA) and the Tile Contractors Association of America (TCAA). The Tile Council of North America (TCNA) was subsequently added to the committee — bringing the support of its manufacturing members, which was pivotal in the development of the ACT curriculum. The formation of this committee was an unprecedented event, in that it joined the open shop (CTEF and NTCA) and union (IMI, IUBAC and TCAA) tile installer organizations together with a common goal of creating a pool of qualified tile installers without regard to their labor affiliation. 

Over the course of just under one year, the committees drafted, edited and published all the documents necessary to construct the wood test modules, conduct the actual hands-on test, establish evaluation criteria for the hands-on test and administer the online written test. The ACT program originally contained four skills tests, including Large Format Tile and Surface Prep, Membranes, Mortar Bed (Mud) Floors and Walls, and Shower Receptors. Subsequently, the Mud testing was divided, yielding a separate Mud Floor and Mud Wall test for a total of five skills tests.

One key component and strictly enforced requirement of the ACT tests is that the applying installer (applying to take one or more of the tests) must have first successfully passed the Certified Tile Installer (CTI) tests, which are conducted by the CTEF, or he or she must have successfully completed the studies and practices of the IUBAC and received the designation of Journeyman. The installer successfully completing either of these programs has already proven his or her basic installation abilities and now moves on to elevate and document their advanced installation skills and knowledge.

The ACT tests are a combination of an open book written test, which is administered online and taken at home, or in the office per the installer’s schedule, while the hands-on test is provided at regional locations around the country. Upon registration, the installer receives a packet consisting of the ACT Statement of Intent, Study Guide, Instructions to the Installer (hands-on test guidelines), Installer Critical Points (items that if not completed according to industry accepted methods and standards, constitutes a failed test), the TCNA Handbook and the ANSI Specifications. These documents provide the installer with all the study materials necessary to take both the written and hands-on tests. 

The program is designed to have the installer take the written test first, followed by the hands-on testing. The scores of each test must be a minimum of 85%. While this may seem to be a high requirement, it speaks to the high integrity of the program — along with the above average skills and knowledge needed to achieve the ACT designation. Realize that ACT certified installers are the pinnacle of their trade. With the addition of new products and new installation techniques emerging on a more frequent basis, only the highly trained craftsmen and women have the knowledge and skill sets required to meet the challenges of today and tomorrow.

The use of mortar as a setting base for tile installations, whether floor or wall, has been known as the premiere installation system for many years. The beauty of the mortar bed is multi-faceted. Mortar can be placed in a variety of thicknesses that may be necessary to overcome subsurface irregularities while yielding a tile-ready surface that, for floors, is both flat and level. For walls, the surface can be trued to produce a surface that is flat, plumb and square. These mortar systems also allow the installer to produce surface areas that meet exacting size tolerances, allowing many tile installations to be completed in full tile rather than small unsightly cuts.

The very recent introduction of a new product known, at least for now, as “thin panel porcelain tile” (TPPT) to the U.S., has sparked renewed interest in mortar beds. These products range from 3 to 6 mm thick, or thin if you will, and come in sizes up to 1.5 x 3 meters, or approximately 5 x 10 feet. They require full coverage of the setting material and an extremely flat substrate. Utilizing an old method, such as a mortar bed, to provide a surface that will meet these exacting requirements may be a future marriage. We will see.  Currently, there are no industry standards for either the TPPT product or an approved installation method. However, extensive testing is proceeding toward this goal. 

Mortar (Mud) Floors

The ACT Mortar Bed Floors test is based on TCNA Handbook method F111, On-Ground or Above-Ground Concrete Unbonded Mortar Bed. The test requires the installer to begin work in an 8- x 8-foot wood test module configured in a “U” shape. The installer starts by checking the given surface to determine if it is within the industry guidelines of 1/4-inch in 10 feet (6 mm in 3 meters). If the surface is within these allowances, the installer places a cleavage membrane on the module floor, which prevents the mortar from bonding to the substrate. Wire reinforcing is cut to size and placed at approximately the center of the mortar bed that is compacted and smoothed.  At a given point, the installer must provide the mortar bed to a specified thickness of 1 1/2 inches, while supplying a flat and level surface, which meets industry tolerances, and be completed in three hours. 

When the installer’s work is completed, the Evaluator verifies the quality of the work using a long straight edge and level. The requirement of this test is based on using a large-format tile, which has one side that is 15 inches or longer. In this case, the mortar bed must be level within 1/8 inches in 10 inches. The Evaluator will base his or her assessment on the Critical Points document mentioned above that includes two areas within this test that if not provided, constitute a failure. They are: level within 7/64 inches in 8 feet and a mortar bed thickness of 1 1/4 inches to 2 inches. If the installation is not level within 7/64 inches, which is just less than 1/8 inches in 8 feet, or if the mortar bed is not between 1 1/4 inches and 2 inches thick, the test fails. You can see that the allowance for error is very small, and if not provided, the test fails.

Mortar (Mud) Walls

The ACT Mortar Bed Walls test is based on TCNA Handbook method W222, Mortar Bed (One Coat Method) over Solid Backing. Here, the installer is given a wall module that includes a tall back wall, an intersecting shorter knee or pony wall, which turns to create an outside corner.

The Mortar (Mud) Walls test, while based on a similar criterion as the Mortar Floors, contains a significantly larger number of Critical Points that are divided into three categories.

In the first category of cleavage membrane, there are three fail points. The cleavage membrane must be installed in a shingle fashion, which means the starting row of paper at the floor must be overlapped by the subsequent row of paper in order to shed water to the shower side rather than into the wall cavity, which must be kept dry. In the second fail point, the cleavage membrane must include a minimum 2-inch overlap at all seams.  The third fail point occurs if the paper is damaged during installation. The paper must be free of any holes or tears, since these areas would also allow moisture to enter the space behind the shower assembly — causing a failure.

The second category covers the application of the metal lath to the wall, which must be continuous on all outside corners. However, when an inside corner is encountered, the metal lath must be cut (stopped) and allow a 1/8-inch vertical space for movement as noted in ANSI A108.01.3.7.  If this space is not provided, the test fails.

The third category covers that same inside corner joint after the mortar has been applied.  The 1/8- to 1/4- inch movement joint must be free and clear of both mesh and mortar. If either is present, the test fails.

The installer now applies the properly mixed wall mortar to the wire lath, creating a reasonably flat surface. Within the W222 method, the installer may vary the mortar thickness from 3/8 to 3/4 inches to obtain a plumb wall. Wood float sticks are pressed into the fresh mortar and adjusted to make them perfectly plumb by using a 6-foot level. A straightedge is then moved across the float sticks in a left to right motion, while also moving vertically. When completed, the float sticks are removed and the gap left is filled with mortar.

The application of the mortar must be completed so that very exacting measurements are achieved to accommodate a full-tile installation of 4 1/4- x 4 1/4-inch wall tile. Although no tile is set in this test, the finished wall must meet these specifications.

All the work that has been explained here — and many details that were not due to article length constraints — must be completed in five hours. The installer is also required to maintain a neat and clean workspace throughout the installation process.

The test requirements outlined here may seem overly stringent, but to obtain high-quality workmanship, it is absolutely necessary. The focus of the ACT tests is to differentiate ACT certified installers from others in the field, especially those who obtain a certificate of attendance after attending a coached seminar and call it tile certification.

No matter which of the ACT-related tasks are involved on the job, the use of truly qualified labor makes perfect sense. Saving money by hiring the cheaper “l got a piece of paper somewhere that says I can do it” amateur can be extremely expensive. Think about it.