The most popular are universal cement mortars, mixed with water. They may be used for most wall and floor tiling. On average, their setting time is 6 hours. For even substrates, thin-layer mortars are sufficient while for uneven substrates and for adhering tiles of a highly profiled bottom, thick-layer mortars are needed. On old tiling or on floors with under-floor heating, mortars of increased elasticity and adherence should be used. To check if the mortar may be used on old substrate, stick single tiles in various places and break them off after a few days. The renovation time may be significantly reduced if you use quick-drying mortars which set as fast as after 4 hours. Some mortars are produced for a particular type of tiling. This is because various types of tiles are different. Stoneware adhesives make it possible to stick large and heavy tiles without the risk they may slide down on the walls. They also have a prolonged window of opportunity for correcting the tile position which facilitates precise placing of elements.

 

This is the real size of a tile, marked in millimetres. Each factory has its own marking system, displayed on the tile packages. The calibre may be given in numbers (1, 2, 3...) or letters (A, B, C...). Their sizes may vary significantly (in the case of 300×300 mm tiles, even up to 5 mm). Thanks to the process of calibration, tiles of various batches or series, halves or quarters of the main format may be joined on one surface.

There must be no free space that is not filled with the adhesive – it is applied onto the wall or floor with the even side of the trowel and then it is combed with the notched side. Additionally, the bottom side of tiles is covered with the adhesive. When you adhere the tiles – especially those of a large format – to the wall, press against them well to remove possible air bubbles. This is not necessary on the floor – even if the tile is moved slightly, the adhesive fills the space below it. The order of applying tiles is also important: they are laid on the walls first (usually from bottom to top, but there are also mortars that allow for laying them from the top to the bottom) and only afterwards onto the floor (starting from the most exposed point). This way, if a wall tile falls down, it will not damage a floor tile.

It is defined for glazed tiles according to the PEI method (wet abrasion test). The higher it is, the slower tile abrasion will be. This parameter should be selected according to the intensity of floor use. If you walk barefoot or wear slippers in the room, the class 1 resistance to abrasion is enough. In the bathroom, class 2 will be needed, in an entrance, hall and kitchen - classes 3 or 4 of abrasion resistance.

This is usually necessary as it is hardly ever possible to select such tile size that the wall or floor surface – both width and length – would exactly be a multiple of the tile size. While the comparatively soft glazed tiles may be cut with a glass knife and breaklike glass, this is not possible in the case of hard stoneware or terra cotta tiles. For this purpose, a cutter or a special machine is used; it cuts the tile surface first and then cracks it along the cut. For cutting large tiles or cutting out rectangular openings for sockets or switches, it is recommended to use a wet cutting saw. It is fitted with a diamond cutting edge and an adjustable guide which ensures the high precision of cutting. To make circular or semi-circular cuttings in the tile, openings within the marked perimeter are cut with an appropriate drill (carbon or tungsten one). Then, the unnecessary part of the tile is carefully removed with special pliers and the uneven edges are filed. However, cutting circular openings is much easier using a drill with an appropriate mill.

Also known as the size of tiles. It is decisive mainly for the appearance of tiling, but also for the type of adhesives or grouts to be used and for the duration of work. It seems that large elements are quicker and easier to lay than the smaller ones; however, the larger ones require more care and precision. As a result, the work is slower. Information on the tile size is located on the packages. Take care: the nominal size, written in centimetres, defines the general format of the tiles and it is different from the real size, written in millimetres and according to the calibration table of a particular manufacturer.

These are tiles produced with the technology of firing the tile body (biscuit) and then glazing it (covering with glaze) in a separate process. In other words, a glazed tile is a brick covered with varnish. The glaze is not resistant to abrasion, therefore, it is used on walls only. What is more, such tiles are soft (and, thus, easy to process) and of high absorbability – 10-20%.

Filling the gaps between tiles. It may be performed only after the adhesive mortar sets because the grouting mass hinders drying of the adhesive. Thus, grouting may start – depending on the materials used – after 6 to 48 hours. Then, the joints must be carefully prepared: remove the tile spacers and remaining adhesive from the gaps and wet tile edges with water. If the tiling is made of non-glazed tiles of a rough or porous surface, this is the right moment to check that the grouting mass will not affect the colour of the tiles. If the grouting mass has left irremovable stains, the tiling must be grounded with an appropriate agent before grouting. The grouting mortar should be semi-fluid for floor tiles and viscous for wall tiles so that it will not flow out from the joints. For mixing the grouting mass, add the amount of water recommended by the manufacturer. Excess water brings colour differences, grouted joint brittleness, cracking and reduced hardness. Apply the grout mass with a spatula or trowel, first with an oblique hand movement, then perpendicularly to the tile edge. The mass must be used within 30-60 minutes after preparation. After the excess of grouting mass has been removed, the tile surface is cleaned and after the joint dries (10-15 minutes), they are shaped. To avoid differing shades of the joints, the colour grout must be cleaned with an equally wet sponge, as well as with the same intensity and time of striking. This applies mainly to the grouting masses of very intense colours. As the works are finished, wipe the tiles with a slightly wet sponge but make sure the fresh grout is not washed out. The grout will bond better if it is slightly wetted during the first few days.

It is decisive for the tiles ability to resist scratching. Hardness is determined by using the Mohs Scale, with numbers from 1 to 10. In home conditions, a hardness of 5-6 is sufficient. Remember that the harder the tiles, the more difficult cutting them will be.

Grouted joint – the filling between tiles which enables them to respond to thermal or construction stresses of the substrate. If free deformation was ensured by an empty gap between the tiles, water and dirt would end up there. The joint width must be adjusted not only to the user’s taste but mainly to the size of tiles and temperature differences in the room. The higher the differences, the wider the joints should be. Although there is no one universal principle that would define the joint width, generally, it is assumed to be as follows: for a mosaic – 1 mm, for medium tiles – 3-5 mm and for large format tiles – 7-10 mm. To maintain the same joint width, use tile spacers.

 

They are selected according to the anticipated conditions of use, to the adhesive used for laying the ceramic tiles and to the joint width. Due to functional reasons, it is not recommended to use light-coloured grouting masses on floors. Exposed to much dirt, they sooner or later become a grey-brown colour. Selecting the grout, you must take into account the type of adhesive mortar used for tiling. If the adhesives are permanently elastic, the grout should also have similar properties. The use of a cheaper rigid grout in these places may cause their eventual cracking.

 

This characteristic is important in each room where a floor may be spattered with water, i.e. in the kitchen, bathroom or entrance, as well as outside – on the stairs. Manufacturers take care of our safety and mark the tiles with appropriate symbols: from R9 to R13 (tiles marked below R9 are not non-slip). The symbols apply to the angle of slope of a tile surface covered with oil, on which a person wearing particular type of shoes will slide down. The non-slip factor is increased by relief, i.e. convex pattern on the whole surface, as well as convex or concave straight elements along one edge of the tile. The tiles may also be covered with a non-slip glaze or an impregnating agent.
 

Means applying the priming agent which limits absorbability and improves adherence of the substrate. If you are not sure whether the substrate has been grounded, do it once again. Without grounding, the adhesive will not be effective and new tiling may drop off.

It is a result of the tile structure and surface smoothness. The higher the resistance is (expressed in a scale of between 1 and 5), the easier the tiling is to keep clean. This characteristic is particularly important in the kitchen and bathroom because in these rooms strong detergents and products that can stain are used most often. If the tiles are not resistant to stains, impregnation is recommended.

These are floor tiles, 15-25 mm thick. They are formed by hand, of pure clay from Mediterranean and Latin America regions. The colour of such tiles (reds and browns), their uneven edges, cracks and scratches on the non-glazed, matt surface make them ideal for rustic interiors. Unlike the glazed tile, rustic terra cotta gains a specific patina with time, which gives the floor much charm.

This is the colour characteristic for a particular batch of tiles. During production, it is difficult to obtain all tiles of the same shade. Shades in one collection are acceptable colour departures which do not change the character of the tile. Thus, to facilitate buying tiles of the same or a similar shade, manufacturers mark their shade on the package, usually with subsequent letters of the alphabet.

This type of wall or floor tiles is 6-30 mm thick. They are produced of natural raw material mixtures: white-fired clays, kaolin, feldspars and mineral dyes. As the components are mixed, tiles are formed on presses of a very high pressure and then they are fired in a temperature above 1200°C. The surface of the stoneware tiles may be glazed or not, some ornamentation or texture may also be added. From among all types of ceramic tiles, the widest range of stoneware ones are available. They imitate natural stone, wood or metal excellently.

 

It requires careful preparation. It must be even, tough and clean. During renovation, it is better to remove the previous wall and floor finishing – although the costs and time of works increase. After the old ceramic tiles, terrazzo or parquet are removed, it is necessary to level the substrate with mortars. It is also possible to lay water-resistant panels, gypsum fireboards or OSB. However, laying new ceramic tiles does not necessarily mean that the old finishing must be removed. New tiles may be laid on old ones, terrazzo, even on wood. This eliminates hewing and there is no problem of how to utilise crushed bricks – this means the time of renovation is significantly reduced. In order to use such a solution, old finishing layers must be still tightly bonded with the substrate. Otherwise, the new tiling could loosen as the adhesive may bond it well to the old layer but not to the substrate. You should also remember that if the new floor tiling is laid on top of  the old one, the floor level will rise by approx. 2 cm. Similarly, the distance between walls will also decrease by the tile and adhesive thickness.

This is a slightly historical name for stoneware tiles, usually covered with glaze. The highly fired material of which the terra cotta is made, is characteristic of low absorbability and resistance to strong acid or base solutions. Terra cotta is more brittle than stoneware tiles and thus of less impact strength. Nowadays, it is most often used as a floor tile.