The tile industry has talked about the market entrance and acceptance of an imported product which has had a myriad of names such as thin tiles, porcelain tile panels, and what the current Tile Council of North America (TCNA) Handbook refers to as “reduced thickness porcelain tiles.” Working through these titles, it has commonly become known as “Thin Porcelain Tile” or TPT for several years.

Without an established American National Standards Institute (ANSI) product standard, this or any other product for that matter, can be called by whatever term is most popular and accepted.  However, with a draft document for this product now in place and soon to be reviewed and balloted, TPT as we have known it is about to disappear. As currently proposed, the title of this category will soon be changing.

For the establishment of a new standard for TPT or any other product to take place, two components must be formed. The first is the creation of specifications describing the minimum physical properties for the product, including their basis for acceptance and methods of testing before and after installation; their marking and certification of the same and the definitions of terms relating to these products. Extensive testing and retesting is required to form a baseline or pattern of results. After the pattern is established and documented, work can begin on writing the new product standard, which many times take years to complete.

Within the ANSI specifications for ceramic tile, there are several designations, including A108, A118, A136 and A137. However, in this conversation, we will focus on just two of them: A137 and A108.

The A137 classifications include manufacturing specifications and testing procedures for tile products. A137.1 covers ceramic tile (American National Standard Specifications for Ceramic Tile) while A137.2 covers glass tile (American National Standard Specifications for Glass Tile).  This new category is proposed to be known as A137.3 and identified as Gauged Porcelain Tiles and Gauged Porcelain Panels/Slabs. Following the loosely established tradition of adopting acronyms, will the tile industry call this product “GPT and GPTPS?” We shall see.

The A137.3 specifications describe the minimum physical properties of Gauged Porcelain Tile and Gauged Porcelain Tile Panels/Slabs and back-layered (a reinforcing product, commonly mesh, adhered to the back) Gauged Porcelain Tiles and Gauged Porcelain Tile Panels/Slabs manufactured to a specific nominal thickness and includes three grades of material: Standard, Second and Specialty.

This specification is broken into two categories — tiles and panels/slabs — to differentiate the two. The panels/slabs are a ceramic tile of a size greater than or equal to one square meter. A product less than one square meter will be recognized simply as tile.

A137.3 is proposed to be divided into two thickness classifications: 3 1/2 to 4.9 mm and 5 to 6 1/2  mm. For installations on walls and countertops, whether it is 3 1/2  to 4.9 mm or 5 to 6 1/2  mm, the Gauged Porcelain Tile and Gauged Porcelain Tile Panels/Slabs must meet 16 testing requirements, including Thickness, Facial Dimensions, Wedging, Facial/Structural Defects, Color Uniformity, Shade Value, Water Absorption, Resistance to Freeze/Thaw, Crazing Resistance, Chemical Resistance, Stain Resistance, Thermal Shock Resistance, Thermal Expansion, Bond Strength, Breaking Strength and Modulus of Rupture.

When it is used on floors, the nominal thickness with or without back-layering must be 5 to 6 1/2 mm and meet the above mentioned test requirements. Additionally, floor installations must pass the Robinson Floor Test, as well as tests for abrasion resistance and Dynamic Coefficient of Friction (DCOF).

The A108 classifications include the approved installation methods of the designated products, which include using some of the existing A118 Material Specifications in their installation. This new category is proposed to be A108.19, Interior Installation of Gauged Porcelain Tiles and Gauged Porcelain Tile Panels/Slabs by the Thin-Bed Method bonded with Modified Dry-Set Cement Mortar or Improved Modified Dry-Set Mortar. You will notice that this specification is designed for interior applications and should not be assumed to encompass exterior installation methods. Additionally, this standard utilizes mortars in the A118.4 and A118.15 categories.

These installation methods are developed in a similar fashion to the product standards found in A137 where extensive testing is required to assure that the installed product will stand the test of time. Since these products differ from traditional ceramic tiles in the their physical characteristics and performances, along with the fact that many are manufactured using different methods than those used in the production of traditional ceramic tiles, which meet ANSI A137.1, unique installation techniques and workmanship must be developed.

Considering the size of these products, currently 1 x 3 m (approximately 40 x 118 inches) and 1 1/2 x 3 m (approximately 59 x 118 inches), the methods used to handle, transport, cut, apply mortar and install are quite different than those used with traditional ceramic and porcelain tiles. 

The use of aluminum frames equipped with suction cups which are attached to the panel/slabs allows for safe removal from the shipping crate to the work table and subsequently to the wall or floor substrate. The introduction of these panel/slabs has spurred a new generation of cutting tools that will score and snap the tile cleanly over its entire length. Prior to the creation of these new cutters, the only method of cutting slabs was a large wet saw. Applying mortar is likewise much different than conventional tile products. Rather than only keying in and spreading the mortar on the substrate, these slabs receive the same mortar application with the mortar on both surfaces being spread parallel to the short side of the tile. The two are then joined together meshing the trowel ridges in a zip lock fashion.

Due to the tremendous suction of the mortar, the panel/slabs cannot be lifted to determine if adequate coverage has been achieved. Therefore, the spreading technique needs to provide the acceptable coverage and allow for the air in the trowel ridges of the mortar to escape. If the tile is installed on the floor, walking carefully on the tile with clean, smooth-soled shoes from the center to the edges collapses the mortar and expels the air. On wall applications, the use of a vibrating sander with soft cloth pad or a slapping block, beginning in the center and working toward the edges, will lay the tile properly.

In order to minimize and/or eliminate lippage between two adjacent tiles being installed, where any one side is greater than or equal to one meter (39 inches), the use of a lippage control device or lippage control system is required.

This list of installation procedures is very brief in contrast to the A108.19 requirements. To be successful in the installation of Gauged Porcelain Tile and Gauged Porcelain Tile Panels/Slabs, proper tools and equipment along with acquiring sufficient product knowledge and installation experience through the completion of an Installer Qualification Program is strongly encouraged.  These programs include the Advanced Certifications for Tile Installers (ACT), completion of a comprehensive installation program provided by the manufacturer of the tile, the manufacturer of the setting materials, or other approved certification or installation programs.

The one caveat to this article is that until the ANSI committee unanimously votes to accept these new standards or makes mutually acceptable changes which the entire committee will approve, the consuming and installing public must maintain the status quo and await the arrival of these documents.