Faq

In this section you will find the most frequently asked questions, regarding the ceramic sector, followed by short and comprehensive answers.

WHAT IS THE PORCELAIN STONEWARE?

The porcelain stoneware is composed by a mixture of raw materials whose composition does not differ from that of vitreous china (used in manufacturing sanitaryware and crockery).
Therefore, it is a completely impervious material and with high mechanical features. The term porcelain, underlining stoneware's refined elegance, derives from the use of kaolin, a kind of white clay used also in the production of bone china.
Clays and valuable feldspars, undergoing a firing process at extremely high temperatures, turn into stoneware tiles with the following features: chemical- and frost-resistance, impact strength and scratch hardness.

WHAT IS A RECTIFIED TILE?

The tile rectifying process is a process of grinding the edges of fired tiles to allow for butt jointed installation; thus the grout lines are barely visible granting a uniform smoothness effect.

WHAT IS THE SURFACE FINISHING?

How to recognize a matt, semi-polished, bush-hammered or textured surface?
The surface finishing is the working processing of a tile in order to achieve certain surface roughness conditions and shape and size allowances.
The natural/matt finishing is very versatile and it has a universal application; the semi-polished effect enhances the aesthetic values of the material by increasing its brilliance and elegance to such degree as to overcome the natural marbles gloss; the bush-hammering processing is carried out with tools like chisel, cap, etc., in order to obtain a rustic, rough surface; the textured finishing solves the slipperiness problem, caused by water or particular environmental conditions.

WHAT IS THE SHADE?

The shade is the colour tone that features a particular batch of tiles.
In industrial manufacturing it almost impossible to accomplish tiles with the exact same colour shade, therefore, before packing, they are grouped together according to colour uniformity, that is to say colour shade.
The shade is often marked by a letter which is stamped onto the pack (Shade A, Shade B)

WHAT IS THE WORK SIZE?

The work size is the manufacturing dimension of tiles.
Due to manufacturing technology reasons, the tiles leaving the kiln may be of slightly different dimensions. Therefore, during the grade sorting stage, they are divided and grouped into batches of the same dimensions, according to the standards tolerance provided for by specific regulations. Like the colour shade, the work size is also displayed on the pack, as follows:
20 x 20 cm (W 198 mm x 198 mm)
where 198 mm stands for the manufacturing dimension.
Or:
20 x 20 cm - Size 01

WHAT IS THE SIZE?

The size identifies shapes and dimensions of the tile. The most common shapes are the quadrangular ones (square and rectangle), but polygonal shapes are also available (hexagons, octagons, etc) as well as complex shapes( Moorish, Provencal, etc).
Anyhow, current technology allows for the creation of any shape at least in theory.
Dimensions can also range from only a few centimetres (mosaic) up to a metre per side.

WHAT IS THE QUALITY GRADE?

The quality grade represents another parameter featuring a tiles supply.
Only the 1st/top quality is characterized by specific regulations. For example, no more than five tiles out of a hundred may present appearance defects. The other quality grades (the second, the third, commercial, kiln output, etc) are of lower quality and may contain a greater number of defects.

HOW MANY TILES SHOULD BE ORDERED?

Before ordering a certain number of tiles, it is necessary to know the extension of the surface to be tiled and have selected the installation technique and plan.

Being stated the above, it is necessary to know that:

  • even a batch of top quality tiles can contain some defective tiles (the standards allow for a 5% of defective tiles)
  • some tiles must be cut or drilled, therefore a certain number will be wasted.
  • some tiles should be kept aside for any future repairs, it is also important to spare a sample to show in case of any complaints.

All in all, about a 10% extra tiles should be ordered exceeding the actual extension of the surface to be tiled, moreover, a sole order is recommended, for the product of another lot might not be perfectly uniform with the one of the previous order.

CERAMIC AND OTHER CLADDINGS

The main classification criterion of the different materials available for flooring and cladding is based on their nature.

Therefore, they can be divided into:

  • ceramic materials, obtained with a mix of raw materials widely available in nature (clays, sands, etc). For example, tiles and bricks
  • stone materials, that is to say tiles or plates obtained by cutting blocks of particular stones available in nature. For example marbles, granites and travertines
  • Binding materials of various nature, non yet formed (concretes, limes, plasters, etc) that if combined with water and sand, can be shaped into any thickness and hardening bodies. For example concrete round coatings and plaster walls finishings.
  • composite materials, claddings obtained with rock fragments scattered in a concrete or polymeric binding matrix. For example sandstones with stone fragments in a concrete or polymeric binding matrix.
  • polymeric materials, generally called "plastic raw materials". For example vinyl, linoleum, rubber, carpet etc.
  • organic material of animal or vegetable origin, derived from materials directly available in nature within the animal and vegetable world. For example wood and cork, wallpaper, etc.

As for performances, the ceramic material proves to be superior to all the others in many circumstances:

  • abrasion resistance
  • chemical attack resistance
  • hygiene
  • fastness to light
  • fire resistance
  • decorability

HOW CAN I CHOOSE THE SUITABLE FLOOR OR CLADDING?

In order to choose the most suitable kind of tiles for your plan, it is necessary to take into consideration both technical and aesthetic aspects.

THE TECHNICAL FEATURES
The technical features are those necessary for the material's suitable and reliable performance.

They can be divided as follows:

  • uniformity features
  • structural features
  • massive mechanical features
  • surface mechanical features
  • thermo-hygrometric features
  • chemical features
  • safety features

Uniformity features determine the suitability of a batch of tiles to perform a "regular" tiled surface, or free of "irregularities" like bumps or dimples, steps between adjacent tiles, irregular joints course.

Structural features refer to the real structure of the material the tile is made of: in particular to its porous structure. The tile porosity provides an immediate indication of the water absorption, which reaches the lowest levels with porcelain stoneware. The products with higher levels of water absorption are mono-porous, majolica tiles, cottoforte and terracotta.

Massive mechanical features concern the load bearing strength (for example the weight of people and furniture on a floor) to which the tiled surface may be exposed. We call them "massive" since they refer to the tile's "mass" and in order to distinguish them from the "surface" features that concern its surface. The mechanical features are the bending strength and the breaking stress.
The first one concerns the material the tile is made of, and it is directly proportional to the water absorption.
The breaking stress is a property peculiar to a finished tile, with its own structure and size. Therefore, it is directly proportional to its thickness. Among these features we also find the impact strength.

Surface mechanical features
These features refer to the working surface of the tile and they can be associated with the resistance to scratches, wear and deterioration, due to the handling/moving of hard bodies on the surface and in contact with it.
These features are very significant in case of floors. The most important one is the abrasion resistance that provides a measurement of the propensity of a tile to wear down (if unglazed) or to alter its appearance (if glazed) as a result of the above mentioned conditions. As for unglazed tiles, this value tends to increase as water absorption decreases, therefore, porcelain stoneware will have the highest level and the best performance.
However, the resistance to abrasion can vary depending on the treatments the tiles can be submitted to: in case of terracotta, the impregnation with various substances, natural or synthetic; in case of porcelain stoneware, polishing and smoothing.
As for glazed tiles, the abrasion resistance depends exclusively on the glaze. Light glazes show a greater wear deterioration, also due to the fact that they are harder to clean.

Thermo-hygrometric features
These features describe the resistance to specific temperatures ("thermo") and dampness ("hygrometric") conditions, such as thermal shock and frost resistance and for glazed tiles only, crazing resistance. Sudden changes in temperature (for example, when a hot pot is placed on top of a kitchen tiled counter-top) and exposure to frost, should not cause any damage to the tile at all. The frost resistance highly depends on the porosity and on the water absorption: the lower the values are, the less the chances of damage by frost will be.
Crazing, in the form of thin cracks of the glaze, can be favoured by some building or environmental conditions. The crazing resistance depends on the glaze composition. Some types of glaze run higher crazing risks compared to others. Further thermo-hygrometric features are represented by thermal expansion and dampness expansion, that is to say the measurement of the tile dimensions increase, when submitted to higher temperature and dampness levels.
As regards to thermal expansion, no major differences exist between the various types of tiles, though a slight increase has been noticed in the presence of a great vitreous phase, which means in products with a more compact, vitrified body.
Dampness expansion is usually linked to water absorption, although considerable variations have been observed, likely due to the effects of other micro-structural features, like the type and distribution of the various existent phases.

Chemical features
The chemical features are the stain resistance, resistance to household products, acid and alkali resistance.
The lower the porosity, the higher the chemical resistance will be.
Contrariwise, the layer of glaze covering glazed products makes the working surface compact and non-absorbent. Such resistance decreases in presence of some colouring and decorations quite sensitive to aggressive agents, above all acids. Unglazed products like porcelain stoneware generally posses an excellent chemical resistance.

Safety features
These features particularly preside over the safety of tiled areas regarding accidental or sanitary risks.
The main safety feature, also very important for outdoor, public and industrial areas, is the slip resistance, which is inversely proportional to the surface friction coefficient.
Safety features also include lead and cadmium cession (metals sometimes contained in glazes), which must be checked when a contact with food substances is forecast, for example kitchen countertops.

THE AESTHETIC FEATURES

The aesthetic features of ceramic tiles are basically three:

  • size
  • colour
  • decoration.

Size
The size is a feature significantly affecting the visual appearance of the tiled surface. By varying the size, the frame of the grout lines varies accordingly, thus appearing increasingly thicker as the size diminishes and larger, so less visible, as the size increases.
The most common sizes are the square and the rectangle (though there are many other such as the hexagon, octagon, Provencal, Moorish, etc), very plain shapes, yet providing a wide range of different solutions. In fact, by simply altering the joints course (for example, by passing from continuous joints in both direction to offset joints), or by varying the orientation of the joints in relation to the sides or the axes of the surface to be tiled, the visual impact may be totally changed.
Further solutions can be achieved by combining tiles of different size.
Thanks to these two methods together with the design research and innovation developments, nowadays, the range of tiling solutions has become almost unlimited.

Colour
In case of glazed tiles, the colour is given by the glaze. Ceramic glazes offer a countless chromatic range, which includes every basic colour, tone or shade.
Within the same colour, tiled surfaces can vary in terms of glosss, glossy or non-reflective ("matt") and in terms of chromatic texture.
In case of unglazed tiles, the colour is basically that of the body and this obviously limits the range of solutions; a limitation that becomes a virtue in case of terracotta, beautiful, appreciated and sought after precisely because of its particular colour, a colour to be enhanced but not changed.
The same cannot be said for porcelain stoneware, since such "chromatic uniqueness" does not exist. From the original neutral tones of the past few decades, when it was a sole technical high-performing product, further developments have brought a wider range of solid colours and consequently granular colour textures and reproductions of some natural stones. Such objective can be achieved by working both on the composition of the initial powders and on the surface itself, by creating special effects like veining, nuances, colour blends, etc. The chromatic solutions are also enhanced by the opportunity to create glossy and reflective surfaces through polishing-smoothing.

Decoration
As for decoration, different considerations must be made depending on weather the tile is glazed or unglazed. Glazed tiles offer an almost unlimited range of decorations. Thanks to silk-screening, in fact, any design or picture, however complex and multi-coloured, can be reproduced on the tile surface.
Some decorations are "accomplished" within a single tile, so that each tile of the same batch is identical, while other decorations involve several tiles, to be installed in order to create a complex and lager design. Unglazed tiles are usually not decorated, yet, porcelain stoneware represents an exception to the rule; in fact, thanks to the development of special techniques, like silk-screening, decorated inserts, satin motifs on a polished surface and vice versa, it offers interesting solutions.
Relief-decorations, obtained through pressing, are available both for glazed and unglazed tiles, and can be very helpful in reducing slip resistance.