How to lay the tiles?
The tiling should start with planning, determining the axes of laying, taking the spacing into consideration, and "dry laying" the tiles on the floor. After the planning, collect the tiles and step by step arrange them on the evenly distributed adhesive mortar. The mortar layer should be no thicker than recommended by the manufacturer of the adhesive. For this purpose, a serrated trowel is required to provide a complete covering of the back of the tiles with adhesive (e.g., a 10 mm or 12 mm toothing should be used for adhesive mortar max. 5 mm thick). In the case of underfloor heating, the incomplete covering of tiles' back surface with adhesive mortar will result in a significant loss of floor heating performance.
Adhesives for ceramic tiles must be applied according to the technology recommended by their manufacturer. In practice, two technological solutions are used:
a) Basic, in which the adhesive is spread on the floor with a smooth trowel and then profiled with a serrated trowel. You apply the tile to the mortar by slightly pressing and sliding it. This method ensures a strong bonding of the adhesive with the base, achieving a uniform thickness of the adhesive layer and adequate interlayer adhesion. It is called a "floating method".
b) The second possible solution is to apply the adhesive to both surfaces being bonded – the base and the back of a tile. When using this method, it is important to apply enough adhesive to ensure that its total thickness does not exceed the thickness recommended by the manufacturer. It is called a "floating and buttering method" method, but in practice, the names of "combined method" or "double smearing method" are used. This solution is recommended for laying floor tiles indoors, as well as laying wall and floor tiles outdoors, as it makes the complete filling of the space between the base and the back of the tile, and its even support throughout the whole surface easier.
The method of applying adhesive only to the back of the tiles is incorrect and not recommended. It is only permitted in exceptional situations, such as when placing narrow strips of tiles from the bottom of the walls, fixing tiles on plinths or when replacing one tile in the entire cladding.
In the case of laying tiles on underfloor heating, it is important to remember to keep the surface expansion joints that separate independent heating zones. It is important due to thermal expansion of materials. Taking temperature fluctuations into account, the floor should be divided, if possible, every 9-16 m2. When spacing the surface, try to create square shaped areas, with edge spacing between flooring and walls, separating the floor surface from the wall. Expansion joints in the layer of tiles should be compatible with the existing expansion joints in the base.
For large tiles, we recommend the use of tile levelling systems, which greatly improve the visual appearance of the floor and allow for the removal of obstructions caused by unevenness of the base, glazing imperfections and curvature of the tiles. It is also worth remembering that the method of bonding the tile has a great effect on its strength, so it is important to perform this task very carefully.