The base is always found

Floor screed device: Material for the base of floor covering, specifications of leveling mixtures, styling technology.

Designer Y.Trubilin

Photo by D.Minkina

The water level is based on the principle of reporting vessels

The screed level is noted using self-press, which is screwed at the desired depth

To build a horizontal line on different sides of the self-pressing, supports the same height with it. The accuracy of the work is controlled by the level

To ensure the required strength of the cement and sand mixture, the reinforcing mesh is required. So that the grid is inside the layer, the pieces of ceramic tiles are under it

On top of the grid on the self-tapping screw and two supports fasten the beacon profile with a height of 10mm

The binder mixture for the device supports should be the same as the mixture for a screed

The mixture is evenly distributed over the surface, the joints with the walls are leaving to cells

The viability of the solution is about 2h. Therefore, some workers produce damn, others distribute the mixture, third align

Rechal-tool for alignment. It has two adjustable stops for setting the thickness of the screed layer

Even self-leveling

Summer mass should be slightly helped to host the floor area. This is done with the help of Rakly (a) or comb. To displacing air bubbles from the layer, it is recommended to go through the surface with a needle roller (b)

With large areas, it is required to ensure the continuity of the process, as the mass retains self-leveling

Properties are not more than 20.

For movement along an unrestal surface of a thin bulk sex, in order to correct small defects to shoes, the soles with nails are attached

Opening the instructions for laying any floor covering, you will definitely read the phrase: "The basis should be even, durable, dry and clean." How to get a covered horizontal surface if the initially floor is far from the ideal?

Paul-parquet, ceramic or anyone else is a multi-layered design. One of the layers, as a rule, is a screed. It serves to align the underlying slabs of overlapping (carrier structures) and is the basis for laying the finishing floor covering.

Preference is given to concrete

Figure schematically shows the location of the design elements of the cement-sand screed. Self-tapping screw and two supports build on one line and at one height. The lighthouse profile is put on top. The reinforcing mesh is located inside the thickness of the concrete base can sometimes be several millimeters. For a thin layer device, the so-called bulk sex (2-30 mm thick), use special self-leveling mixtures. But, as a rule, the curvature plates of overlapping or engineering tasks, such as laying of communications, require greater layer thickness, that is, the screed devices. Usually, the "pie" under the piston floor covering, stacked on the bearing base, includes the underlying layer (concrete preparation with a thickness of up to 80mm), a layer of heat and waterproofing and protecting their screed layer. But in practice, the insulation is most often not necessary to arrange, which means that the underlying layer is not required, and the screed is placed directly on the bearing slabs of the overlap. Its thickness begins from 20mm (according to SNiP 2.03.13- 88).

Due to the adhesion (bonding contacting surfaces), the screed forms a single integer with the supporting structures. Durable monolith not only closes irregularities, but also tightens the cracks, eliminating the likelihood of mud propagation, the propagation of insects, rodents, seeding water, which is its advantage in comparison with the floor on lags that do not form a solid base.

Two technologies of the "wet" screed are used to enter. The traditional technology implies the use of cement with sand and reinforcing mesh, evenly distributing the voltage arising in the screed, and a greater durability of the concrete layer. The new technology has emerged with the advent of special building mixtures, developed directly for the device of the smooth base of the floor. The selection of components in such a mixture and the homogeneity of their distribution makes it possible to obtain a monolithic layer with the desired improved properties, with the required strength throughout the volume without the use of the reinforcing grid.

Universal problems

For the kneading a homogeneous solution from a special building mixture, it is recommended to use an industrial mixer. According to technology, stirring is produced twice with 5min synencal. According to the traditional technology, the working solution is prepared from a universal dry mixture, for example M-150, consisting of 1 part of cement and 3 parts of sand. The cement-sand tie obtained from it is characterized by a number of shortcomings. First, cement solutions have a property with solidification to decrease in volume, that is, to give shrinkage. Secondly, due to the unevenness of the distribution of cement particles and sand in volume, as well as the differences in the size and forms of grain (imbalances of the structure of the filler and the structure of the binder) in the process of the formation of strength in the layer there are foci of voltage, leading to its cracking. In order for the screed does not crack, its surface is recommended for several days to be wrapped with water, thus adjusting the uniformity of hardening and removing the internal stresses. Thirdly, the total strength of the monolithic layer increases with its thickness, and get a reliable base of a small thickness (less than 30mm) using a mixture of cement with sand, it is impossible. Such a layer is necessarily cracking and under the influence of loads can be detached from concrete floors.

With a manual method, a special care is required, because the uniform distribution of strength in terms of the screed depends on this, the heterogeneity of the particle size distribution in volume leads to the fact that the strength in different parts of the layer is not the same. For this reason, the base of the final sex is exposed to erosion with different intensity. Where cement turned out to be less, the screed was stronger. Loading places "stone" under the influence of loads crumble and over the years in the form of the smallest particles are transferred to other sections. Under the flooring formed sinks (recesses). Therefore, small-piece materials laid on the base can be moved by places, and the linoleum will acquire a slightly tangible relief.

It must be said that the construction teams forced to work with cement and sand exist their tricks to improve the properties of the working mixture. Thus, cement is added to the solution for greater strength to the solution, for the best plasticity of PVA or synthetic additives-plasticizers. However, these measures do not guarantee the result. After all, it is difficult to achieve a good homogeneity in the manufacture of a working solution by manual dosing and kneading, and the likelihood that improving properties will occur only in some places.

Narrow specialization

Modern technology is based on the use of special modified mixtures, designed specifically for the screed device. The main advantage and difference of new high-tech mixtures is the selection of components and homogeneity of their distribution throughout the volume, which guarantees stable specified properties on any section of the layer. In addition to the binder (portland cement and polymeric components), fillers (sands of various fractions) in their composition include modifying additives, improving the properties of both directly screed and working solutions. Some components are normalized by shrinkage, the speed of hardening, others simplify the knee, the third displaces the air, the fourth increase strength, the fifth reduce the drying time, the sixth improves the "fluidity" of the solution. Recall that the reinforcing grid is not required in this case. In addition, the amount of water required for the preparation of the solution from the mixture bag, as well as its consumption is shown on the package.

According to the new technology, the filling unit is a step of the finishing screed alignment. To do this, use special self-leveling

mixtures forming the flowing solution with water, well distributed

The tie high drops are made in two stages along the entire surface at large differences. Pre-floor is roughly aligned with the help of so-called leveling mixtures. The mixture is embeded with water, distributed over the surface and aligned with a rules. About a day, the layer solidifies and dries. Such a screed is no longer required for several days to make water, it herself regulates its drying. At this stage, great irregularities and differences are cleaned. Such a mixture is cheaper than the finishing self-leveling, therefore allows you to save money. However, without certain labor and skills, it will not be possible to get an ideal horizontal surface.

At the second stage, the finishing alignment is made using a different type of mixing, self-leveling. It is also bred by water, and the resulting solution, which is reminded by ripples, poured into the floor, helping the fluid to host the vaccine surface and a special needle roller. The raised and frozen mixture will make the surface perfectly horizontal. Depending on the initial leveling of the base and the results of coarse alignment, two types of mixture for the "Finish" can be used: thin layer (thickness from 2 to 5-7 mm) or a thick-layer (5-30 mm).

Accuracy according to the laws of physics

For convenience, all measurements are produced from the line (called the horizon), which is at about the level of the eye. It is placed using a water level. Works on the base device, regardless of technology, precede measurement and calculations. First, it is necessary to determine the difference of the height between the lowest and highest points of the floor formed by the overlap plates. The height of the screed is considered from the highest point. If, for example, the height difference is 15 mm, then the height of the screed from cement and sand should be 45mm in the thick part. For convenience, all measurements produce from the line at about the eye level. This line is called the horizon. The exhibition of the horizon is performed using a water level-long hollow transparent plastic tube filled with water. This device works on the principle of communicating vessels, and the error when applying two tags around the perimeter of the room, along which the horizontal line is further built, does not exceed 1mm. Agree that it is extremely important for the floor. After all, when under the legs of the swinging table or the cabinet will have to put the pieces of cardboard, it will be too late to accuse workers who made a mistake when measured.

By the way, the standard of quality of construction work is allowed to the height of the finished floor not more than 5mm on 2 p. m floor length. The roughness of the black floor in the apartment located in the new building is not normalized in general, and according to the side of the stove of inter overlap must be aligned additionally.

Traditional technology

The screed is made by stripes with a width of about 1m. This is due to the convenience of aligning the surface by the Rake rule along the guide lines of the beacon profiles. Profiles can leave the horizontal plane inside the screed, which closes all the irregularities and the heights of the height of the ceiling slabs, is displayed using the simplest beams, which serve ordinary self-tapping screws. For the convenience of alignment by the Rhoke-Rule, the screed is made by fragments of the meter width bands. Lighthouse profiles are served by the bands. To install one profile at a given altitude (at the height of the so-called level of the first floor, one for all rooms, unless, of course, the design project does not intend to otherwise) you need to screw only one self-tapping screw. Focusing on the level of the horizon line, builders find the position of the head of the self-press. The top of his caps should be below the screed level smoothly to the height of the beacon profile (usually 10mm).

To obtain an ideal horizontal line on which the beacon profiles can be laid, on the same level with a screw of the self-hardening construction mixture in one row with a self-tapping screw building two supports. The reinforcing grid is placed on the floor. So that the grid does not come into contact with the floor and was inside the layer of the screed, the pieces of ceramic tiles are put under it. On tags arranged from screws screwed into the floor and additional supports, the light air profiles are installed on top, which form the boundaries of the space poured by a solution. Light profiles are firmly attached using a fast-rigging mixture. The space between them is filled with the working solution, and then aligned with the rules.

How to calculate the consumption of materials

Mixes for devices of the floor are characterized by technical specifications. Based on the standing tasks, it is possible to choose the most appropriate composition before calculating the consumption of cement and sand mixed in proportions 1: 3, it is necessary to determine the volume to be filled with a solution. The operation is not very complex: it is necessary to multiply the area to the thickness of the screed. But here it is important to know that when the dry ingredients are shown, the mass obtained by the "wet" decreases in the volume and from 1m3 of the dry mixture can be released 0.7-0.8 m3 of the building solution. This happens because in the air medium the mixture is in the so-called squash ("free") state. When the air is shifted with water, and the volume decreases. Trying to increase the volume by cooking a solution more liquid consistency. Excess water "kill" solution: There will be a bundle on fractions (smaller particles will fall down, and the largest will pop up upstairs). And the "stone" as such may not work. The Avoda, which gave part of the volume of the solution, evaporating, will lead to the shrinkage and the appearance of cracks. There should be 400-500kg cement in 1 m3 solution.

When using packaged mixtures, calculations are simplified. Thus, a bag of universal building mixture weighing 50kg will be required for a layer device with a thickness of 10mm on an area of ​​5m2. Remaining manufacturers of special mixtures Consumption is specified on the package, and, as a rule, for a layer of 1mm thick on Square 1M2, 1.5-1.8 kg of dry mixture is required. After conducting preliminary calculations, you can purchase and bring all the necessary materials (and once, not twice).

Doubtful savings

Due to the homogeneity of the composition, the presence of modifying additives, special mixtures are more expensive than universal. Plopobeton bag price 50kg is about 100 rubles. Today, for the device, the tie on traditional technology is often used by sand-concrete-domestic building mixtures, containing as a filler in addition to the sand fraction of small rubble (pebbles), partially playing the role of fittings and prevent cracking.

The cost of special mixtures for the screed device is 4 times more. But in this case, it will not be necessary to buy a reinforcing grid (about 100 rubles. For 1 mm), lighthouse profiles (30 rubles. For a product with a length of 3m), the work of work will be simplified, the time of preparation and processing will significantly decrease, it will not be necessary to water the surface with water days. Asaable main - high quality screed will be guaranteed.

Alignment mixtures for the base floor base device

Manufacturer	Name	Purpose	Packaging, kg.	Approximate value, rub.
"Saint-goben Weber Rus"	Weber.niv.trm.	Mix for alignment of interior floors from 10 to 70mm	25.	180.
Weber.niv FS30.	Self-leveling mixture from 5 to 30mm	25.	520.
"Maxit Group"	"Old 5000"	Mix for alignment of concrete bases from 3 to 80mm	25.	360.
"Old 3000"	Self-leveling mixture from 0 to 5mm	25.	500.
"Mirage"	IVSIL-TIE-ROD-IV	Self-evaporation, fast-hardening mixture for flooring from 2 to 100mm	twenty	240.
IVSIL-TIE-ROD-II	Blend for final surface alignment from 2 to 10mm	25.	290.
"STROYMONTAZH MS"	"Bests T-41"	For the production of high strength and even base from 30 to 150mm	fifty	123.
"Best T-42"	Self-leveling floor to create a smooth surface from 3 to 30mm	25.	226.

The editorial board thanks the company "Saint-Goben Weber Rus" and "Dilemma-Stroy" for help in the preparation of the material.