- What is the peculiarity of working with porcelain stoneware
- Which stone format is better to use
- Suitable types of bearing bases
- Surface preparation
- Gluing: process and optimal glue selection
Despite the fact that porcelain stoneware is a rather heavy and peculiar finishing material, its laying on walls is not uncommon. We will tell you how to implement such an idea correctly and ensure high quality and durability of the finish.
What is the peculiarity of working with porcelain stoneware
Slip tiles or porcelain stoneware have the greatest similarity with eco-class finishing materials due to their high density and natural appearance. The popularity of the use of porcelain stoneware in interior decoration is due to its high similarity with natural materials, in particular, there is a visual similarity with marble and polished sandstone. The high aesthetic value of porcelain stoneware is attributed both to the excellent color fastness and the consistency of geometry, which is ensured by the rectification of the edges..
Many tilers considered porcelain stoneware to be a very worthy, noble material, at the same time, its installation requires high skill. Unlike tile, porcelain stoneware has a significant thickness, which is reflected in a significant increase in the weight of the finishing layer. If, when laying on the floor, this factor does not really matter, then wall cladding requires a more careful approach. From a technical point of view, it is required:
- use of special types of glue;
- correct preparation of the base;
- temporary fixing of tiles until the glue sets;
- special equipment for cutting and grinding.
There is another side of the question – the aesthetic one. Porcelain stoneware is laid on the floor in a mostly seamless way, which is not always appropriate for wall decoration. The exact shape of the tiles requires careful adjustment and alignment: if the bevel on the tile helps to smooth out installation flaws and deviations from the dimensions, then ideally even and precise edges of porcelain stoneware need not only to be precisely aligned, but also to properly grind the seams. For these reasons, not all types of textures are suitable for cladding interior walls. Priority should be given to sanded, polished and water-jet surfaces..
Which stone format is better to use
Ceramic tiles are limited in size due to warpage and shrinkage during annealing. For porcelain stoneware, the concept of caliber is absent as such; accordingly, it is made in all possible variations of sizes and aspect ratios. Choosing among all this variety is not so easy to make, you need to look for the right approach.
One of the options is the same type of wall and floor cladding. In such cases, it is very convenient to focus on the format of porcelain stoneware laid in a horizontal plane. So, if the floor is covered with 60×60 cm slabs, then for the walls it is recommended to use the same overall size, but already with an aspect ratio of 2: 1 or 3: 1, that is, 20 or 30 cm wide.
If you plan to lay your own porcelain stoneware, it is better to give preference to tiles with the most “convenient” format. The hands of an amateur will confidently cope with stones of medium size – from 20 to 45 cm wide and up to 80 cm long. Too small tiles will cause difficulties in leveling, and large porcelain stoneware will require special devices for gripping and temporary fixing.
For floors, the recommended thickness of porcelain stoneware is at least 8 mm, for walls there are no such restrictions. Even at 3mm thick, this finish exhibits excellent resistance to shock and static loads, however, using tiles that are too thin can damage the tiles when cutting and handling with inexperienced hands. The optimal range of thickness of porcelain stoneware for walls is 5-10 mm, thicker stones need temporary fixation and sequential laying of rows with long intervals of time necessary for the setting of the underlying elements to the base.
Suitable types of bearing bases
Not every wall and partition can be faced with porcelain stoneware. The main factor of suitability for this kind of finishing is the presence of additional bearing capacity, comparable to the weight of the tile and adhesive layer. Additionally, the stability of the foundation should be taken into account – both seismic stability and the tendency of the material itself to linearly expand under the influence of external factors play a role. The third criterion for the suitability of the substrate is adhesion, but this can almost always be improved by additional preparation.
Almost all enclosing structures have sufficient bearing capacity. The exceptions are walls made of sandwich panels, as well as frame walls with sheet sheathing without internal stone lining. An additional limitation for laying porcelain stoneware is the temperature regime of the building: inside the temperature range determined by the manufacturer of the glue must be maintained, on average it is from +10 ° C to +35 ° C.
Separately, it should be said about the false walls, sheathed with gypsum fiber board or aquapanel. Their flatness, stability and adhesion do not cause any problems, but there are problems with ensuring sufficient bearing capacity. For porcelain stoneware, the construction of a frame subsystem is required from a profile with a metal thickness of at least 0.6 mm and an increased density of rack elements – no more than 40 cm. The use of ceiling profiles (CD) as frame racks is unacceptable. For cladding, only moisture-resistant grades of gypsum board and gypsum plasterboard should be used with a thickness of at least 16 mm with a fastening density of at least 30 self-tapping screws per m2.
The general technique for preparing walls for facing with porcelain stoneware is the same as before laying ceramic tiles. There are only a few key points, in general, work is underway to correct geometry and improve adhesion.
Depending on the material of the base layer, different leveling methods are used. For brick and block masonry, alignment with cement or gypsum plaster along the beacons is optimal. It is very important that the furrows left after the removal of the beacons are filled with material that is as homogeneous as possible with the main wall covering. Alignment tolerance is no more than 2 mm / m and no more than 4 mm in the general plane of the wall.
For wooden walls, it is possible to recommend leveling with sheet sheathing from gypsum board, gypsum plasterboard or LSU, depending on the climatic regime of the building and the design features. The assembly of the false wall is necessary to compensate for the shrinkage of the wood, the technology of work was described above. It is also possible to align with composite panels based on EPS or PU foam, but only if it is technically necessary to provide additional heat and noise insulation.
Absolutely all surfaces must be dedusted and primed before laying. In general, it is recommended to use a water-dispersible acrylic primer, preferably from the same manufacturer as the adhesive mixture. For application on gypsum plasterboard, deeply penetrating compounds should be used that increase absorbency and adhesion; for plastered walls, strengthening primers that do not reduce porosity are well suited.
Gluing: process and optimal glue selection
When laying on walls, it is better to join porcelain stoneware with visible joints with a thickness of about 2–3.5 mm. In the corners, the docking is done with a burr, which requires an electric tile cutter with a circle of the appropriate type. Straight cuts for the manufacture of ordinary accessories are conveniently performed on a manual tile cutter designed for working with porcelain stoneware. From other tools, you will need a mixer, distance crosses, wedges and a scraper to clean the seams. The glue is applied with a comb trowel, and since the concept of caliber does not apply to porcelain stoneware, the height of the tooth does not depend on the size and thickness of the tiles and is on average 8-10 mm. The alignment of creamogranite on the walls is carried out only with the help of a laser axial plotter, the comparison of adjacent tiles – using a curved ruler.
The range of adhesives for porcelain stoneware is quite wide. There are both unnecessarily expensive options for mixtures with optional qualities (water resistance, frost resistance), and frankly cheap compositions with a clearly underestimated concentration of the polymer binder. The correct solution would be to use glue from a trusted supplier, such as Ceresit CM 11, or the cheaper domestic “Moment” Elast. Special brands of glue for porcelain stoneware, such as “Litokol” or UNIS, do not always justify the costs of them, mixtures with a high content of elasticizers are recommended if there is insufficient confidence in the quality of adhesion to the base, as well as when laying stones with a format over 45×45 cm.
In general, the technique of laying porcelain stoneware has much in common with cladding with ordinary tiles, although it differs in more stringent requirements for the quality of leveling. In addition, a number of points can be noted that are mandatory:
- The glue is applied to the wall with a comb trowel, while the reverse side of the tile is carefully wiped with a flat trowel, leaving a minimum layer of mixture.
- The starting row is laid out along a rigid guide rail fixed close to the wall.
- When laying tiles weighing over 8-10 kg, they must be temporarily fixed. It is usually performed with parallel clamps fixed to the wall above the cladding line..
- The joints between the tiles are cleaned immediately and to the full depth;
- The use of tile leveling systems is encouraged.