Part 3–Execution
- The specific installation method and detail from TCNA Handbook for ceramic, glass, and stone tiles must be specified.
- It must be noted in Division 03–Concrete that concrete substrates are to meet ANSI A108.01 tolerances and surface textures in preparation for tile work.
- Substrates for exterior decks and balconies, and interior showers, must be sloped to drain at 6 per 305 mm (1/4 per 12 in.). The type and location of drains need to be specified.
- Installers must be required to inspect substrate conditions before commencing with the installation. When there are any obvious defects or conditions preventing a satisfactory tile installation, the installer is to notify (per ANSI A108.02) the architect, general contractor, or other designated authority in writing, and is not to proceed until satisfactory conditions are provided.
- When concrete surfaces do not readily absorb water or have any type of contaminate, they must be scarified until the surface is acceptable. When the concrete surfaces in wet areas do not meet the required 6 per 305-mm slope-to-drain or the ANSI A108.02 tolerances, they must be corrected by the concrete subcontractor.
- A movement joint layout plan needs to be provided, and the architect must specify types of movement joints as referenced in TCNA EJ171 Movement Joint Guidelines. The tile installer should be instructed to submit Requests for Information (RFIs) if he or she is not clear with the requirements.
- It should be specified that substrates are to be cleaned with no contaminates and must readily absorb water. It should also be specified that the backs of the tiles and stones must be cleaned.
- The specifier should state waterproof membranes are installed per manufacturers’ directions and must be continued up walls over any horizontal surfaces, and over any dam. Flashing should be detailed in the plans shown at all appropriate transitions. Waterproofed areas should be flood-tested per ASTM D5957, Standard Guide for Flood Testing Horizontal Waterproofing Installations.
- In the specifications, it should state drain weep holes must remain open and protected with an appropriate amount of pea gravel or with a weep hole protector cover.
- It should be specified that tile and installation products must be installed per manufacturers’ instructions and industry standards. Products should also be mixed per manufacturers’ instructions. Temperature limitations must not be exceeded, and shading or heat must be provided as required. Also, work is to be protected from both weather and other trades.
- For exterior and wet interior areas, it must be specified the adhesive contact between the tile and its substrate is to be 95 percent with no voids at corners or edges (and with no voids larger than 50 x 50 mm [2 x 2 in.]). Voids in wet areas will collect water and can result in efflorescence and spalling problems.
- A detailed quality control plan, to be implemented by a third party, must also be provided.
Conclusion
Exterior decks and balconies, and interior wet areas, are more prone to problems because of their exposure to large volumes of water. Failures of these areas are typically due to a combination of installer error, improper material use, and not having thorough specifications and details. Three common deficiencies found are the lack of an adequate slope-to-drain at the waterproof membrane surface, plugged drain weep holes, and the lack of adequate waterproof flashing to keep moisture from migrating into the substrate and tile or into adjacent materials causing expensive collateral damages.
To avoid these problems, architects must write detailed specifications that are specific, complete, and clear. Installers must be current with industry standards, and follow those standards and the manufacturers’ directions while installing the tile. Installers are mechanics with the skill to provide quality workmanship, but they should not be expected to make architectural decisions—architects must give the installers the details they need to do their job correctly.
Most installers learn their skill on the job and do not have the opportunity to learn the industry standards. So it should be specified and verified the tile-installers are up to date with the current industry standards.
This author has never investigated a tile or stone failure and found all the industry standards and manufacturers’ instructions were followed. It is always the opposite. The failure is never due to one deficiency, but is always because of many compounding problems. Simply put, the key to a successful tile and stone installation is to follow industry standards and write good specifications.
MasterFormat and SectionFormat provide the structure for good-quality specifications, which if used correctly and thoroughly, will limit risk and liability when specifying ceramic tile, glass tile, and stone applications.
Donato Pompo, CTC, CSI, CDT, MBA, is the founder of Ceramic Tile and Stone Consultants (CTaSC), and of the University of Ceramic Tile and Stone (UofCTS). He has more than 35 years of experience in the ceramic tile and stone industry from installation to distribution to manufacturing of installation products. Pompo provides services in forensic investigations, quality control (QC) services for products and installation methods, training programs, testing, and onsite quality control inspection services. He received CSI’s 2012 Construction Specifier Magazine Article of the Year Award. Pompo can be reached at donato@ctasc.com.
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