There are many ways to define what is ceramic. We address in this “tips” the common use of ceramics in home architecture, shops, buildings, etc.
According to UNI, EN and ISO standards, today’s ceramic tiles are thin, generally used for walls and floors, made from mixtures of clays and other inorganic raw materials, which undergo a milling and/or kneading process, molding, then drying and finally kilned at high temperatures in order to acquire the required properties.
They can be classified in different ways: glazed or unglazed; low, medium and high water absorption; for walls only; light, medium, intense or very intense traffic; shaped by pressing or extrusion; among others.
Format wise, what matter most to the customers are the nominal or commercial sizes for which the products are known (32x32 cm., 45x45 cm., Etc.) and calibers.
The caliber is a digit (number) defined by the manufacturer to unify the tiles’ nominal size by the same width.
This is done due to the minimal differences in size always found in each production run. At the time to pack the tiles, these have already been sorted and grouped by the same caliber, so measures are homogeneous.
When we talk about the shade, we refer to the aspect that one tile has over another of the same model (more or less color intensity, the contrast in some part of the screening, etc.).
As in calibers, the shades are characteristic of the production process and are classified and grouped in a similar manner.
It is very important to correctly choose and install products under the same shade and caliber. This can be easily verified by reading the label in the tiles’ boxes.
The packaging not only provides the shade and caliber data, but also provides other information like the date and time of production, product specification, quality and class to which it belongs.
This information is found in a single line for easier identification and to facilitate product traceability.
The boxes not only serve the function of containing and protecting the tiles. Reading the labels is essential because it provides information about the product and installation recommendations for a proper job.
Within the endless designs offered by the ceramic market, it is also important to know whether the model chosen has a faded effect.
To achieve a particular visual effect (like natural stone) shade variations are designed on propose. Boxes are then packed with mixed shades to recreate such effect.
For that reason it is necessary to get correct information in order to avoid confusing a product that is assembled with different screens, with a production or packaging problem.
When it comes to quality, we are referring to a number of characteristics expected in a ceramic tile, such as the beauty of the design; manufacture and proper presentation; ease of care and maintenance; etc.
Some, like aesthetics, are typical of the personal appreciation of each person.
Others instead, as production techniques, respond to the fulfillment or not of the processes under which they are produced. Purchasing products from prestigious brands with market experience is a good way to be sure of the expected quality.
In general, a good brand is synonymous of good quality. However, ceramic manufacturing, as many other industries, may have some flaws, so in the control process, tiles are separated into different categories: first class, second, third and so on.
Regarding the finishing, top quality material is considered with less than 95% parts without defects. Quality is also classified by shade and caliber.
Second and third quality (second and third choice) have some shortcomings, such as chips, pinches in the glaze, texture variations, among other. As the quality decreases, the number of issues found will increase.
It is important to know that in both cases, the tiles are not classified by shade or caliber, so if we find these differences in such products, it is within the expectancy when purchasing.
It is worth remembering that the use of spacers is appropriate only in cases of monocaliber tiles (whether they be rectified or not).
The porcellanato, also called porcelain is a ceramic material characterized for a very low water absorption, obtained by single firing, generally manufactured by pressing (not so much extrusion) and it can either be glazed or not.
To avoid confusion that may lead to wrong decisions, it is good to clarify the types of porcelain (can be confusing because this is the most recent ceramic material that appeared in the market).
The usually called technical porcelain (also known as through body and full body) is a material in which the tile is fully formed from the same body, so that once installed, the visible side has the same appearance as the rest of the piece.
It can be a solid color or slightly decorated, and the surface appearance can be modified by a polishing process, which gives it its distinctive appearance and glossy texture (polished porcelain).
Sometimes a textured finish is incorporated to grant a certain degree of slip resistance.
Finally, there is the so called glazed porcelain, in which the surface is glazed, giving the product all kinds of variations and textures with rich designs and finishing.
It is common to hear that a product is rectified. In this process, the pieces go through a special machine, cutting the sides of the tiles, thus eliminating the production variations and having perfectly straight sides.
This process also allows to unify the caliber of the tiles so that they are all equal.
There is a very important trend when we talk about ceramic tiles, and it is not generally considered.
This aspect is understanding that the tile is only part of a construction (very visible as any finishing material) and that their performance is conditioned not only to its technical characteristics, but also how it fits the project, how it was installed, how they interact with other variables such as temperature (outside and inside), the elements that change the temperature (heated slabs), the transmission of motion and structural loads, and so on.
Construction process must be observed carefully in order to comply with the applicable regulations (such as IRAM or ISO) and the manufacturers’ specifications, which together with good professional practice and skilled updated workforce, will certainly guide the project to the best possible outcome.
Technical Standards exist for good reasons. There is a serious mistake when not applying criteria, which usually leads to unsatisfactory and expensive results.