Tile Frequently Asked Questions (FAQs)
- What is a tile?
- What is a Backsplash
- Why should I use tile in my home or remodeling project?
- What are the different types of tile available?
- Glass Tile Questions
- Porcelain Tile Questions
- Ceramic Tile Questions
- What are common tile terms and terminology?
- How is slipperiness measured?
- What is meant by water absorption?
- What is meant by calibre?
- What is meant by Tone?
- What is PEI Rating (how is durability measured)?
- How are tiles made?
Concerning the safety of the final user, the slipperiness of a floor, directly linked to the coefficient of friction, is particularly important. The En ISO 10545-17 standard describes various possible methods for measuring the coefficient of friction, each one of which is specific for a different country.
The "ASTM" coefficient (U.S.A.)The ASTM C 1028 standard (Measurement of the static friction coefficient) is used in the U.S.A. for classifying tiles on the basis of their slipperiness. The Ceramic Tile Institute classifies the tiles in three categories: anti-slip (>0,60), not anti-slip (0,50 – 0,60), and questionable friction (< 0,50).
Among the manufacturers of ceramic tile there are certain standards that are universal. ISO Standards have been established by the International Standards Organization to unify product standards and testing methods for ceramic tiles worldwide. One of the most important of these standards is the PEI rating. The P.E.I. (Porcelain Enamel Institute) rating is a measurement of how well a ceramic tile will wear. Generally, ceramic tile manufacturers classify their products in 5 categories. They are as follows:
In addition, there is a classification, U, which is given to products specifically designed for industrial applications.
The manufacture of ceramic floor and wall tiles has undergone considerable and continuous changes over the past years. Ceramic wall tiles are normally porous, which favors their adhesion to walls. On the contrary, floor tiles have low porosity, with low-medium water absorption, which gives them better technical characteristics.
Traditionally, tiles were manufactured following different methods and by means of a practically manual process. As from the seventies, the process has gradually been automated and methods have been unified considerably, with dry pressing being the most common and allowing the product to be manufactured in two different ways:
Double firing process
In this process, the pressed body is fired to form a bisque and subsequently a glaze is applied on top of this and the body is once again fired to obtain the final finish.
Single firing process
In the single firing process, the glaze is applied directly on to the pressed and raw body; both are fired simultaneously to obtain the final finish.
For many years there has been a controversy with regard to which of the two methods is better. In fact, having the correct formulation of both the body and the glaze, and keeping strict control of all the manufacturing stages, it is possible to produce good tiles using any of the methods.
Traditionally the double firing process was used more, with firing cycles of forty and twenty hours for the first and second firing respectively (firing of the body and of the glaze). It is currently more convenient to follow the single firing process, with cycles that last only forty-five minutes.
Moreover, in addition to the economy of the single firing process, it is very easy to automate the different manufacturing processes, which in turn results in cost reductions.
Ceramic floor and wall tiles are obtained by preparing a composition of purified raw materials comprising aluminous silicates, with different compositions in the case of floor and wall tiles in red body or in white body.
These compositions undergo dry or wet grinding until a fine grain size is obtained, after which they undergo granulation or drying by subsequent atomization in order to obtain granules with defined characteristics (size, shape, apparent density, fluidity, etc.).
The granulated powder is the base for the obtention of the ceramic product and its homogeneity guarantees the constancy of the physical properties of these materials. The granules feeds a oleodynamic press with a force of 600 to 1400 MT, that forms the tile into the shape and thickness chosen, for which metallic moulds with the exact dimensions are available.
Subsequently, the shaped tiles are dried and glazed with several layers of glazes of different compositions and with optional decorations in accordance with the models available.
Once the tiles have been glazed and decorated, they are placed in an oven for firing in more or less quick cycles and high temperatures, depending on the type of product being manufactured. Maximum temperatures depend on the type of product to be obtained.
The ceramic glaze and decoration embellish the tiles and give them the technical superficial characteristics desired. In the case of ceramic wall tiles, these are impermeability, resistance to detergents, etc, and in the case of floor tiles, they are resistance to abrasion, acids and scratching, etc.
The techniques, process control requirements, careful design that meets the needs of each atmosphere and the care taken in classification, give the product homogeneous characteristics that are in accordance with the requirements of its use.
The space above the counter top is referred to as the backsplash. Sometimes a 4" piece of counter material is used as the only backsplash. This look is commonly used in bathrooms while more decorative tile is used in kitchens. Varying in size and design, backsplashes typically require lots of planning.
In kitchens, the standard backsplash runs from the counter to the bottom of the upper cabinets in a space that averages about 18" high. Many times there is a larger space above the cooktop or sink. The kitchen,called the heart of the home, can showcase the backsplash as art.
More modern designs may run a single tile throughout the entire space. Whereas, a more traditional look may use the larger space above the cooktop as a focal point by adding more decorative elements. With the smaller scale of this project, one may choose to spend more per square foot on tiles.
With backsplash design the possibilities are endless. Shopping for tile after your counter is selected may also help to speed up the process.