Preparation of the base for the subsequent laying of decorative flooring in the house is a responsible task, the quality of which depends on the durability of the coating. The most reliable way to build a stable roughing platform is a screed. Traditionally, it is performed on a sand-cement basis, but today the segment of self-leveling floors with polymer inclusions is developing more and more actively. Such mixtures favorably differ in technical and operational qualities and greatly simplify the installation process.
Technology overview
The peculiarity of the self-leveling screed method is the formation of a smooth, durable and (in some cases) aesthetically attractive surface. With a small cost, you can get a base suitable for finishing floor work with a minimum number of defects. Cement-polymer compositionfloor mortar is also resistant to dusting, mechanical abrasion and small chips. These operational properties determine the prevalence of the method in relation to public and commercial premises, where it is necessary to provide a large area with a flat floor base in a short time. At the same time, it is important to separate the finishing self-leveling floor mixtures and quick-hardening screed mortars. Both compositions belong to self-leveling floors, but differ in purpose. Thin leveling mixtures form a ready-to-use coating, representing a decorative value. Materials for fast-hardening screeds form durable surfaces for subsequent application of finishing coatings - parquet, laminate, carpet, etc.
Characteristics of mixtures
In the market, the initial fillers for self-leveling floors are represented by dry mixes in bags and packages with an average weight of 20-25 kg. Depending on the type of components, the grain size can be 0.6-0.8 mm. Accordingly, a fine fraction is suitable for finishing coatings, and a large fraction is suitable for a rough base. Adhesive or strength indicators are expressed in the allowable load under pressure - an average of 1.5-2 MPa. The higher this value, the more durable the coating base will be. High-strength mixtures are suitable for commercial use, while a high wear resistance class is not necessary for the home. Freezing time should also be taken into account. Standard self-levelling floors gain optimum strength in 3-4 hours. Record figures showthin topcoats that cure in as little as 30 minutes. In the case of mixtures for industrial use, this time can reach up to a day. As for the thickness, it is from 2 to 10 cm.
Pouring mixture tool
In the work you will need tools and fixtures that are usually used in plastering activities. At a minimum, you should arm yourself with a spatula, a container for mixing the solution and a mixer (it is advisable to use an electric model). Experienced craftsmen recommend using a needle roller at the stage of leveling the mixture poured onto the site. Even the most accurate filling of the floor with a self-leveling mixture will not exclude the presence of air bubbles in the structure of the future layer, but the pin design of the tool will reduce their number. Additional consumables can be represented by corners, formwork elements, beacons and other mounting accessories, which will allow you to technically organize the formation of the liquid floor at the pouring stage.
Preparing the surface for pouring
Although one of the goals of a self-leveling coating is to hide the defects in the rough surface, this does not mean that deep holes, cracks and chips can be left. In the future, these defects will make themselves felt, deforming the newly laid screed. Therefore, at the preparation stage, all deep flaws should be repaired and, if necessary, primer problem areas. The target area is also marked. In order for self-levelling floors to lie strictly ondesignated area, a formwork is created from wooden boards and panels. It can be formed with small slats or a metal profile - the main thing is that it matches the height of the planned coating thickness.
Material consumption
The manufacturers themselves indicate that, on average, 1.5 kg of the mixture should be prepared for 1 m2, provided that the thickness is 1 mm. As the height of the coating increases, the consumption will also increase in the same proportions. In the case of coarse levelers, which form a fast-hardening, durable base for decorative surfaces, the volume may increase. For the same 1 m2 you need to stock up already 2-2.5 kg. Much will also depend on the quality of the calculation of the optimal layer thickness. The height is determined not only by the type of coating, but also by the requirements for finishing the specific area on which the self-leveling floor is laid. Consumption can be kept within the normative values of 20 kg per 10 m2 in conditions of height differences up to 80 mm, if deep recesses are sealed in advance. In this case, the need for excess volume will disappear by itself. In addition, you can save on the mixture by adding sand. This method is appropriate if you plan to lay the material over a large area.
Filling the floor
Contrary to the popular belief that at the first stage the prepared solution is simply poured into the center of the target area, initially a small fraction of the mass should be scattered by hand and smeared. This is necessary so that the primary layerprovided sufficient adhesion for a fight with a rough surface. The latter, by the way, will not be superfluous to pre-degrease and clean. Then the main volume of the mixture is applied once to an area of 1.5 m22. From this point in the future, you need to smooth the self-leveling floor with your own hands, using a spatula and a spiked roller. But before that, you should wait 10-15 minutes until the poured solution disperses over the entire limited surface.
Floor leveling
This is the most critical stage of work activities, since both the strength characteristics of the coating structure and the preservation of its optimal shape will depend on it. Sometimes, after arbitrary smoothing, differences in height remain - they need to be de alt with with a spatula, maintaining the accuracy of the redistribution of mass. As for the needle roller, they should go through the entire flooded area, releasing air bubbles at different depths. As a result of this study, self-leveling floors become denser and more uniform. In some cases, auxiliary modifiers with plasticizers are also added at this stage. They can improve certain coating performance, including fire resistance, adhesion, solidity, etc.
General workflow guidelines
The quality of the new coating will depend on how well the subfloor has been treated. Particular attention is also paid to the conditions of maintenance of the coating. If the room is differenthigh humidity, then an appropriate insulator spreads on the laying surface. Membrane hydrovapor insulators, for example, do not increase the height level of the coating, but reliably protect the polymer composition from the negative effects of moisture. In the question of how to pour a self-leveling floor without errors at the stage of primary distribution, it is important to take into account the time factor. As already noted, the hardening time for some compositions can be up to 30 minutes. Therefore, you need to act quickly so that there is a margin for high-quality comprehensive alignment with the passes with a spiked roller. It is also necessary to calculate the possibility of preliminary distribution of the mixture over the rough surface before pouring. The lower and main layers should not have different solidification periods, otherwise this difference will adversely affect the strength properties of the coating structure.
Conclusion
An important place in the design of flooring with building mix for screed is also the origin of the material. This segment of the market is represented by many well-known manufacturers. For example, preference should be given to Knauf and Ceresit. Although a self-leveling self-leveling floor on such bases will cost more (300-350 rubles per 20 kg), the service life will also be much longer. Budget series are presented by Axton, Volma and Bolars. In this case, the cost of a small bag of 20 kg will be 200-250 rubles. And again, do not forget about additional modifiers that will improve the technical and physical qualities of the coating. Miscellaneous additivesprescriptions are produced under the same brands.
