Types of Tile
ANSI A137.1 (the industry-recognized resource when it comes to tile) defines tile as: “A ceramic surfacing unit, usually relatively thin in relation to facial area, having either a glazed or unglazed face and fired above red heat in the course of manufacture to a temperature sufficiently high to produce specific properties and characteristics.”
The specific “properties and characteristics” that sets porcelain tile apart from other types of tile (ceramic tile and wall tile) include:
- Very low water absorption rate of < 0.50% makes it frost resistant
- High firing temperatures (2200° F as opposed to 2050° F for ceramic tile) and higher psi during pressing makes it compact and dense
- Highly refined, purified clays make it durable and an ideal palette for broadly ranging surface designs
The combination of these elements make porcelain tile an outstanding choice for residential and commercial applications, walls and floors, interior and exterior – there’s a porcelain product suitable for every installation.
Both products are porcelain that must meet the ANSI A137.1 requirement of < 0.50% water absorption and possess the density and durability associated with porcelain products.
Through body porcelain (sometimes referred to as unglazed porcelain) tiles are produced using colored raw materials that permeate the entire tile, incorporating uninterrupted color and pattern features seen on the surface all the way through the tile body. The surface design is evident in a cross-section of the tile body, providing outstanding abrasion resistance and durability.
Color body porcelain tiles are created with continuous colored stains from the glaze surface throughout the body of the tile. Synchronizing the color of both the glaze and body lessens the visibility of any impact chips which may occur. The color remains consistent throughout the tile, but any surface design does not continue through the tile body.
Generally speaking, any tile designated by the manufacturer as floor tile can be installed on vertical surfaces and countertops. The durability required for floors is necessarily greater than for walls (which receive no foot traffic), so floor tile with Abrasion Resistance values from I – V is sufficiently durable for a typical wall installation. Exterior wall applications must use tile that is Frost Resistant. (See What Tile Should I Use Outdoors? FAQ)
The reverse is not true, however. Wall tile (identified by Abrasion Resistance 0) is not suitable for use on floors. It is usually non-vitreous, i.e. not manufactured to withstand excessive impact, abrasion or freeze/thaw cycling.
One caveat when considering floor tile for wall or countertop installation is the abrasiveness of the tile. A highly abrasive product would be more difficult to clean on a wall or countertop since commercial floor scrubbers could not realistically be used for maintenance. Otherwise, continuing the chosen floor tile on walls adds great cohesion to an installation and continuity of design flow.
A tile that has been “rectified” has had all its edges mechanically finished in order to achieve a more precise facial dimension. The process involves cutting or grinding a tile to a specific size.
Both large format tiles and narrower grout joints have recently gained in popularity. A rectified tile is a great candidate for use in these circumstances; however, several installation guidelines must be followed to assure a pleasing result on tile larger than 15”:
- As the size of the tile increases, the flatness of the substrate becomes even more critical.
- Setting materials specifically designed to support large sizes must be used.
- Running bond or brick joint patterns (square or rectangular) require a maximum offset of 33%; do not align on-center; always check lippage at T-joints before installing.
- Grout joint widths must be at least 1/8” for rectified tile.
- Use a contractor experienced in installing large-sized tile.
Marazzi’s state-of-the-art 3d printing technique uses the latest in digital print technology, allowing for infinite design capabilities at maximum resolution.
Installation Related Questions
Due to the extensive range of variables inherent to tile installation – tile types, setting materials, underlayments and substrates – Marazzi USA stipulates the installation recommendations published in the TCNA (Tile Council of North America) Handbook for Ceramic Tile Installations as recognized industry guidelines for proper installation techniques.
When choosing setting materials and grouts it is best to maintain a monolithic system, i.e. choosing all materials from one manufacturer. All reputable installation systems manufacturers will have a technical support team to assist with questions related to these choices.
A tile’s shade (dye lot) refers to the coloration and reflectivity of a tile. A tile’s caliber refers to its facial dimension (size) and is measured with a tool called a caliper (often the terms are confused). Marazzi carefully selects its tile and indicates on every box the particular shade (dye lot) and caliber to offer customers consistency throughout an installation. Since natural materials are used in both the body and glazes of the tile, slight variations in shade and caliber are normally inherent from one production run to the next. Typically, Marazzi shades (dye lots) are indicated by either an alpha/numeric combination or a three or four-digit numeral (i.e. A16, 3408, 250, etc.) while caliber sizes are normally shown as 07, 08, 09, 00, 01, 02, etc.
It is important to purchase tile that has the same shade (dye lot) and caliber, if at all possible, to ensure a pleasing aesthetic appearance as well as consistent grout joints. Using different caliber sizes result in a variation in grout joint widths, exaggerated as the size of the tile increases. Normally, with Marazzi products, two adjacent calibers (i.e. 07 with 08 or 08 with 09 - not 07 with 09) can be used in an installation if the installer is aware of the variation before the installation is begun because the slight difference can be adjusted within the grout joint. It is generally not acceptable to begin an installation with one size and abruptly change to another at some point.
Both Frost Resistance and Coefficient of Friction are criteria that must be considered when selecting tile that will be installed horizontally outdoors in freeze-thaw areas or in areas with similar environments such as walk-in freezers.
Frost resistance is determined by the water absorption rating of a tile. To be recognized as porcelain, a tile must be impervious with < 0.5% water absorption. This results in a frost resistant body capable of withstanding the rigors presented by freeze-thaw conditions.
The second factor to note when selecting a tile for outdoor usage is Coefficient of Friction, i.e. how slip-resistant is the tile? The ADA (Americans with Disabilities Act) recommendation for slip-resistant accessible routes is a Wet COF >0.6 (> 0.8 for ramps).
So, for freeze-thaw areas, choose Porcelain tile with a Wet Coefficient of Friction>0.6 and verify that any trims selected meet the same criteria.
These combined guidelines are critical when selecting tile for exterior horizontal installations. For vertical exterior installations, Frost Resistance is the primary factor.
Maintenance Related Questions
Most Marazzi porcelain and ceramic tiles require minimal maintenance. They can generally be cleaned with clear water and/or a neutral pH liquid cleaner (soapless). Follow with a clear water rinse and wipe dry to prevent film formation. As with most porcelains, spilled liquids may stain the light-colored products if not promptly removed. Neither sealing nor acid cleaning is recommended for any of Marazzi porcelain or ceramic tiles.
The tile should be thoroughly cleaned of grout after installation (following the grout manufacturer’s instructions) to assure ease of maintenance in the future. Tile, whether glazed ceramic or porcelain, should be maintained on a regular and frequent basis to prevent build up of soil, grease, residue, soap detergents, sealers, dampness, liquids, etc., to keep the surface clean and lessen slippery conditions.
For heavily abrasive tile, i.e. tile with a wet C.O.F. of ≥ 0.70, the following maintenance equipment and procedures may be required:
Wash Group: One five gallon plastic pail, one deck brush (10 inches wide with two inch bristles) and one mop (rayon).
Rinse Group: A standard mop bucket with a mop wringer and one mop (rayon).
Procedure: Fill the five gallon Wash Group pail with hot water and p.H. neutral liquid cleaner (soapless) in concentrations according to manufacturer’s recommendations. Half-fill the Rinse Group mop bucket with clear hot water.
Immerse the Wash Group mop in the five gallon pail of cleaner solution. Working in ten foot by ten foot sections, spread the cleaner solution to cover the ten square foot section. Scrub well with the deck brush.
Following the scrubbing, rinse the area with the mop and water from the Rinse Group. Proceed to the next ten square foot area and repeat these procedures until the floor is cleaned, changing both the wash solution and rinse water frequently as they become dirty.
These questions are often interrelated. If the surface appearance of the tile differs significantly from uninstalled pieces left from the installation there are several possible explanations.
The tile may appear dull if a grout haze remains on the surface of the tile. This often happens when the grout is not thoroughly cleaned from the tile surface immediately following installation. Since grout is a form of cement, it becomes very difficult to remove after drying completely. This can be avoided by grouting only manageable sections at one time and cleaning each well before moving on to other areas. This step is particularly important when working with textured, natural stone-like tile that feature crevices or clefts.
When grout remains on the surface, it attracts and holds dirt, thus making it impossible to restore the original sheen to the tile. Products exist in the marketplace to remove grout haze; these products often contain acids that can damage the surface of the tile. Since the surface of tile is essentially a layer of glass, it can be easily etched by acid. Marazzi does not recommend acid cleaning for any of our glazed products. Any effort to remove grout haze with an acid-based product should be cautiously undertaken by a professional contractor and utilized with extreme caution. Improper use of acids that etch the glaze also results in loss of light reflection and dirt retention that diminishes the sheen of a tile.
Additionally, normal wear and tear can result in scratches that, over time, retain dirt and reduce sheen. Culprits can be sand or gravel adhered to shoe soles, chairs or bar stools that are repetitively moved across a tile surface, children’s toys with abrasive finishes, loaded carts or other conveyances, etc. Always consider a tile’s durability classification when choosing a product for specific areas.
Characteristics of Tile
A tile’s ability to withstand wear is determined by many factors, i.e. glaze composition, surface texture, traffic levels, maintenance procedures, etc. Marazzi’s standard limited warranty addresses the issue of a tile’s conformance to industry standards regulating First Choice products. Any variation from those standards would be evident within a one-year period.
You can bet that the tile in those ancient installations looks much different now than it did when it was installed. More than likely, the edges are chipped; the surface is scratched and worn (in many cases through to the body); there are impact chips and structural cracks - all of which may seem acceptable in an historic site but less so on your kitchen floor!
This situation is generally the result of receiving two different shades (dye lots) of tile that were produced at different times, possibly fired in different kilns, with slightly different glaze components. Many natural components are used to produce both the body and glaze of Marazzi products.
Each time raw materials for a glaze are obtained from a supplier, each time the components of the tile body are mixed, each time a tile is pressed and fired slight variations may result. Generally, this presents no problem because a customer receives the same shade (dye lot) for each purchase; however, in an installation that evolves over a period of time, it may not be possible to obtain the same shade as originally installed. In such an instance, be sure to request the original shade (dye lot). If not available, request a sample of current shades for comparison before purchase or installation.
Firing temperatures for ceramic tile products in general are 1800° F. Marazzi products are fired at temperatures greater than 2000° F.
There is no relevant test that relates ASTM E84.75, i.e. Steiner Tunnel Test, to measurement of performance of ceramic products for combustion, flame spread or toxicity. Maximum temperatures for conducting this test range only from 1202° F to 1562° F. It was developed to evaluate softer construction materials ranging from carpet to lumber because these products to ignite and may release deadly chemicals when burning. The fact that ceramic products actually originate at much higher temperatures renders such a test in the 1472° F range useless.
Tests conducted within the industry have shown bathrooms with tile tub surrounds that are left standing after the entire room has been burned.
More economical than natural stones like marble, granite, slate, hardwood, and solid surfacing, porcelain tile can capture the look of these products without the maintenance headaches. Porcelain doesn’t require sealing, stripping or waxing; it doesn’t flake or stain; it requires no special cleaning agents (generally only hot water and a pH-neutral cleaner are necessary unless it is installed in a heavily-trafficked, commercial environment).
While the initial cost for other flooring products such as laminate or vinyl may be lower, the lifecycle costs are significantly higher because the laminate or vinyl will not wear as well and will require more frequent replacement.