Changes and confusion in the marketplace
Known widely in the tile industry as “Thin Porcelain Tile” or “TPT,” a material standard is in the process of being established to define what this category includes and does not include
One thing in life is certain and that is change. Change is inevitable and this is certainly true in the tile world with the advent of the new thinner tile products. The evolution of this type of tile technology started recently and it continues to grow as time progresses.
When we consider this “new kid on the block” category, we may see change turning into confusion in the marketplace. New entries on the horizon may or may not fit into the existing model that we have come to acknowledge in the short term — at least until a national standard is established. By developing a product standard for these new types of tiles, it will help to clearly define what category products fall underneath and which ones they don’t.
The product name is…
It is really interesting that this new technology landed on the shores of the U.S. without consensus on its name. It has been given a host of different names, some of which include “thin tile,” “thinner tile,” “thin porcelain tile,” “thin panel tile,” “thin porcelain panel tile,” “thin panel porcelain tile,” “tile slabs,” “thin tile slabs,” and the list continues to grow. The 2015 TCNA Handbook describes it as “Reduced Thickness Porcelain Tile,” but to eliminate confusion in this article, we will call it thin porcelain tile, or “TPT,” as its been widely referred to within the industry.
With the growing number of manufacturers adding products with differing properties from traditional ceramic tile, it becomes more difficult to keep score. Presently, many manufacturers define TPT as being between 3 and 6 mm in thickness. However, some are talking about tiles up to 10 mm thick.
To aid in understanding TPT as we know it today, we will use the TCNA Handbook statement on Reduced Thickness Porcelain Tiles.
Reduced Thickness Porcelain Tiles
Reduced Thickness Porcelain Tiles, or thin tiles, are now in the marketplace with properties different from traditional ceramic tiles. Several manufacturing technologies exist, producing tiles in traditional sizes up to tiles — or “panels” — as large as 5 x 10 feet and less than 1/4-inch-thick (nominally).
Depending on the thickness, while typically meeting ISO 13006 modulus of rupture requirements (one measurement of strength), many of these thinner tiles do not meet ANSI A137.1 breaking strength requirements and require handling and installation that take the lower breaking strength into consideration. Not all manufacturers recommend their tiles for all substrates. Check with the manufacturer for recommended applications, and whether flooring applications are supported.
Some Reduced Thickness Porcelain Tiles employ reinforcement on the back, changing the physical properties of the tiles, adding impact resistance, raising the breaking strength (although in this category, the breaking strength after reinforcement can still be below the ANSI A137.1 threshold), and reducing crack propagation. There are a variety of technologies employed and such reinforcement requires additional consideration when selecting appropriate setting materials.
In general, specialized tools, equipment, thin-bed mortar and training are required for the successful installation of reduced thickness tiles. With larger tiles, flattening the substrate before installation may be required as stringent substrate and installation requirements apply, especially in flooring applications. Special care may be required to achieve sufficient mortar contact between the tile and substrate, especially near the grout joints.
These products are not characterized by ASTM, ANSI or ISO product performance or installation standards. Consult the manufacturer for all substrate, performance and installation criteria. Some manufacturers may require the use of pre-qualified installers (as noted at the end of TCNA Handbook statement).
Presently, the two predominant sizes of TPT seen here in the U.S. are 1 x 3 meters (approximately 39 3/8 x 118 1/8 inches) and 11/2 x 3 meters (approximately 59 1/16 x 118 1/8 inches). Although technology advancements continue to challenge these sizes, only the future will provide meaningful updates.
Developing a new product standard
The need for a product standard for TPT is reinforced in the statement where TPT meets the ISO 13006 modulus of rupture requirement (one measurement of strength), while many do not meet the existing ANSI A137.1 breaking strength requirement of conventional ceramic tiles. These strength differentials will be addressed in the new TPT standard, but extensive testing is required to establish a base line to which the committee can agree. Once this minimum criterion is established regarding strength, as well as many other necessary testing requirements, the creation of a product standard will move forward.
To further reinforce the statement in the TCNA Handbook, it is critical that the TPT manufacturer be consulted on which of their products can be used on which substrates. This may sound confusing, but some manufacturers recommend their 3 or 3.5 mm product’s use on floors while others do not. Similarly, not all manufacturers are recommending their products for use over substrates such as wood or various membranes, including waterproofing, crack isolation, sound reduction and other membranes. This is not to say that the TPT will not function properly over these materials, but it emphasizes the need to consult the TPT manufacturer being considered, and explicitly follow their guidelines and those of the mortar manufacturer.
The placement of a reinforcing fabric — often seen as a glass fiber — on the back side of the TPT has raised some challenges. Not all bonding products currently on the market will provide adequate adhesion between the substrate and the backing material. The mortar manufacturers have been diligently working on this issue and new mortars are already appearing on the shelf to address these challenges.
The last paragraph in the Handbook statement, although brief, is vital to the success of any TPT installation. Handled properly, the TPT will function well. If mishandled, consequences installers could face include a hairline fracture which may not appear until a contrasting grout is applied. Racking systems and cutting rails will help ensure a quality installation. Obtaining hands-on training from the TPT and the mortar manufacturer, sometimes obtained jointly, are crucial to obtaining a successful installation. Using the experience of these trainers in handling, cutting, spreading mortar, panel placement and bedding will provide the confidence needed to remove the fear factor of TPT installations.
As with any tile installation, a flat substrate is paramount. However, with TPT it is necessary. Realize that the installer can’t pick up the TPT and add a little bit more mortar to eliminate a low spot or lippage. This must be done beforehand and will aid in a better finished product.
The product and installation standard
As we speak, a committee is diligently working on the establishment of a material standard which will define what this category includes and what it does not include. Once the material standard is established, the installation methods will be tested and approved by the committee completing the TPT standard. It takes time to create a solid standard. Extensive testing and retesting is required until a baseline is found. The word here is patience; it is coming.
For now, the trend seems to be leading toward a more descriptive term for this product. One that better describes what the consumer is receiving. So, what will it be? Possibly “thin panel tile.” If so, the now popular TPT acronym would hold constant.
The bottom line in all of this discussion is that in the absence of both a product standard and an installation standard, heavy reliance must be placed on the manufacturers’ recommendations. This includes both the TPT manufacturer as well as the mortar (adhesive) manufacturer. If you take nothing further from this article, take this one recommendation: ask questions — a lot of questions.
TPT is a great product with a bright and expanding future. We need to work with it in the interim, using the knowledge gained to provide the consumer with a pleasing and long-lasting finish.