Self-leveling concrete floor step by step. Leveling concrete floors with cement mortar. How to level uneven floors

Before finishing the floor, it is necessary to level it, for which a screed is installed. At the same time, the performance characteristics depend on the quality of the screed. flooring, laid on top of it. If mistakes are made during the work, they will certainly complicate the installation of linoleum, laminate or carpet, and will shorten the service life of floor coverings. However, there is nothing overly complicated about screeding, so if you want and have free time, home craftsmen who do not have any experience in finishing can level the floor with their own hands.

• cement-sand;
• plaster;
• self-leveling mixtures (self-leveling floor).

2. Dry (prefabricated) screed made from building slabs.

Installation of cement-sand screed

1. This method is chosen if the difference in floor level in the room exceeds 5 cm. To determine this value, find zero level rooms using a water level. Using this tool, points on the wall are measured at a height of about one and a half meters from the floor and connected into a single line. Then measure the distance from this line to the floor in several places. Shortest distance will serve as the maximum possible floor height. Several points are marked along the bottom of the wall, which are also connected into one line, which will play the role of a virtual edge of the screed being performed. At the same time, remember that minimum thickness cement-sand screed equals three centimeters, and the maximum is 7 cm.

2. Next, begin preparing the surface. concrete base floor. The surface is thoroughly swept and dust is removed using a vacuum cleaner. Next, the base is primed and filled with waterproofing solution. After this, the priming procedure is repeated again. This will ensure better adhesion of the screed to the subfloor.

3. On next stage they set up beacons that will make the floor perfectly flat. Beacons (T-shaped metal guides) are attached to a concrete base using adjustable screws or simply placed on thick cement-sand mortar laid out in slides. Instead of a solution, you can use Rotband - high quality gypsum plaster, produced by the German company KNAUF. The beacons must be aligned using building level and a stretched cord in height. The first guide is placed from the corner at a distance of 20 cm. The next guides are placed parallel to the first, while maintaining a distance between them that is 40 cm less than the length of the rule.

4. The material can be a mixture of sand and cement M-300 or ready-made dry mixtures intended for floor screed. When adding water, you should adhere to the proportion indicated by the manufacturer on the packaging of the mixture. When mixing the screed, use a construction mixer, in the absence of which they make do with a special attachment attached to a drill. The solution is stirred until the consistency of a thick dough, and there should be no lumps in it. The prepared mixture should spread slightly on a flat surface, but not spread. The solution is prepared for the entire area of ​​the room at once and used for a maximum of one and a half hours.

5. A portion of the mixed solution is poured between two beacons, after which, using the rule, it is leveled across the beacons, moving it towards you. Start from the far corner of the room, gradually moving towards the doors. Do-it-yourself floor screeding is best done with an assistant. One person will level the mixture, and the second will stir the next portion of the solution. During the screed pouring process professional builders it is recommended to “pierce” the freshly laid sand-cement mortar more often using a thin metal rod. This will avoid the formation of air voids in the thickness concrete screed.

6. It takes several days for the screed to dry, after which it can be walked on. However, complete drying occurs only after 2-3 weeks. To prevent the screed from becoming cracked, it should be covered, if possible, with plastic film during this time. Instead of laying film, you can evenly wet the screed twice a day.

7. You can check the quality of the floor screed using several criteria:

• the color should be gray and uniform throughout the entire area of ​​the room;
• an even screed, when checked as a rule, forms a gap not exceeding two millimeters;
• The horizontal deviation should not exceed 0.2%; to visually represent this value, an example can be given: in a four-meter room, the deviation can be no more than 8 mm.
• the same sound produced when the screed is tapped with a wooden block.

8. The selected floor covering can be laid on the finished screed.

How to level a concrete floor: video

Leveling mixtures - self-leveling floors

In the case of a small difference in floor levels of no more than 3 cm, floor leveling mixtures are used, which are divided into two types. Some are able to spread over the surface of the base on their own, which is why they are called self-leveling mixtures. Another type of mixture requires human intervention, who manually spreads it on the floor using a spatula.

Self-leveling mixtures intended for finishing floors are otherwise called self-leveling floors, floor levelers, self-leveling mixtures, etc. The main purpose of these mixtures is to prepare floors made of various building materials (concrete, wood, gypsum) for finishing floor coverings such as:

• linoleum;
• carpet;
• PVC materials;
• cork;
• ceramic tile.

Produces dry self-leveling mixtures using cement based, containing special modifying additives that increase the plasticity and fluidity of the mixed solution. Some compositions contain fibrous reinforcing additives that inhibit the development of microcracks. After drying, self-leveling floors form a fairly dense and durable layer. However, they are not intended for use without a floor covering, since an unprotected surface can become dusty and absorb moisture, oil, etc.

Thin-layer self-leveling mixtures are available for sale, which are intended for finishing. You can also buy special mixtures, suitable for rough leveling of bases that have significant unevenness. These mixtures are applied in a layer, the thickness of which can reach 30-40 mm. At the same time, polypropylene foam tape is laid around the perimeter of the room, which relieves the stress created by the self-leveling floor. Since these mixtures have reduced fluidity, it is not possible to obtain a perfectly flat surface. Therefore, a thin layer finish is usually applied on top.

Pouring a self-leveling floor

1. Work begins with preparing the base, which must be dry and durable. In the room where the floor will be poured, it is necessary to exclude the occurrence of drafts and air drafts. There are also requirements for the floor temperature, which should not be lower than 5-10 degrees Celsius. The base is cleaned of various types of contaminants that can reduce adhesion. Weak and flaking areas of the old coating are removed. All cracks and holes through which the mixture could leak are sealed. Dust is removed with a vacuum cleaner; sweeping the surface alone is not enough.

2. Next, the cleaned base is treated with a primer, otherwise called a primer, which is applied in a thin layer with a brush, roller or spray. The use of a primer is mandatory, as it increases the adhesion of the leveling compound to the subfloor. The primer also prevents the formation of bubbles by limiting the adsorption of water from the mixed mixture during its hardening. It is advisable to choose those primer compositions that are recommended by the manufacturer of the leveling mixture.

3. At the next stage, begin preparing the mixture. This operation is carried out in strict accordance with the instructions, without allowing any amateur activity. For intensive stirring, use an electric drill with an attachment, which allows you to achieve a homogeneous mass, free of lumps and clots. The mixture is prepared in portions, as its qualities are preserved for 10-20 minutes. Exact time indicated on the original packaging.

4. Immediately after preparation, the leveling mixture is applied to the floor in the form of strips, the width of which reaches 30-50 cm. Using a wide steel spatula mounted on a rod, distribute the solution over the surface of the base. You should not hesitate when pouring, because you should not allow the edge of the previously applied strip to dry out. It is advisable to pour the floor into the room in one step. If its area is large, then the filling is carried out in strips, and professionals who have experience working with self-leveling floors can achieve a perfectly flat floor surface. Many companies involved in installing self-leveling floors have special pumping equipment that allows them to apply self-leveling mixtures with greater productivity.

Leveling the self-leveling floor: needle roller

Important! You cannot change the thickness of the self-leveling floor layer recommended by the manufacturer of the leveling mixture. Since this may lead to a decrease performance qualities completed screed.

5. The drying time and complete hardening of the self-leveling field depends on:

• on the thickness of the applied layer;
• on room temperature;
• on the humidity level.

Usually they begin to walk on the surface of the self-leveling floor after 6-12 hours, and full load is possible only after three days. Before gluing the finishing floor covering, control the moisture content of the leveling layer. The obtained result is compared with the humidity level selected for finishing material permitted by the manufacturer.

GVL - dry “clean” leveling

Dry floor screed involves the use of gypsum fiber sheets (GVL) to level the floor, which are laid on a layer of expanded clay, which has thermal insulation properties. Instead of expanded clay, you can use other bulk building materials that have similar qualities.

When choosing this technology, leveling the floor occurs faster and cleaner, but in quality it is inferior to a monolithic concrete screed.

Dry screed installation: progress of work

1. A waterproofing material is laid on the cleaned surface of the base, which can be an ordinary polyethylene film, the thickness of which is 50 microns. Lay strips of film with an overlap of 10-20 cm, and at the same time make a ten-centimeter overlap on the walls. Also, an edge strip made of porous material is laid around the perimeter of the room. Position the tape so that it is between the film and the layer of expanded clay poured a little later.

2. Beacons are not provided for in this technology, however, some people who do dry screed with their own hands use them. This makes it easier for them to pour the expanded clay evenly and makes it easier for them to move along its layer. For lighthouses, U-shaped metal profiles are chosen, which are laid base down, leveled and secured. The void in the profile is filled with expanded clay.

3. Expanded clay is scattered and leveled in accordance with the beacons.

4. Then they begin laying gypsum fiber sheets, which have edges along which they are aligned and fastened with special cone-shaped screws. Additionally, PVA glue is also applied to the edges. This ensures reliable adhesion of the sheets to each other, turning into a single, flat floor. So, for sheets laid away from the wall, this edge is cut off to provide a double layer of material. When laying sheets, you cannot move them along the expanded clay layer, so you must try, despite their decent weight, to place them immediately on Right place.

5. At the final stage, the joints of the gypsum plasterboard sheets and the places where the screws are attached are primed. Then the entire surface of the dry screed is treated with a primer. Excess plastic film and edge tape carefully cut to the level of the screed.

Important! Unlike concrete screed, work can be carried out in several stages, which is very convenient when doing the work yourself.

How to dry screed: video

Now you have learned several ways to properly level the floor in a room, so you can choose the most suitable option. The main thing is to take your time and follow the technology for performing each operation, then the result will be brilliant. If you think that you cannot cope with the volume of work on your own, then invite professionals.

Flooring materials, for example, linoleum or ceramic tiles, require a completely flat base. Surface defects and unevenness usually have a negative impact on the performance characteristics of the coating and its durability. Therefore, many are interested in how to level a concrete floor.

How to level concrete floors

There are quite a lot of floor leveling technologies. However, all of them can be divided into two main groups:

• wet method, which includes the use cement-sand mortar or self-leveling mixture;
• dry - on logs, which involves the use of plywood, chipboard, etc.

When choosing how to level a concrete floor, consider:

• what condition is the floor in?
• maximum height difference of the base;
• type of decorative coating.

• Self-leveling floors will become ideal solution when the floor surface has slight unevenness. The height difference should not exceed 3.5 cm.
• When leveling with a large layer of screed, the option of leveling using beacons is more suitable. This is the approximate height level for the new concrete base. It is also used if it is intended to lay some communications through the floor and hide them under the leveling solution.
• Alignment with joists is ideal for cold floors, particularly in own home or the first floor in apartment building, since the space remaining between the floor and the slab is effectively used for thermal insulation. Ventilation, drainage, and other dimensional communications can be carried out through it.

Preparing the base for leveling

At the first stage it is necessary to carry out preparatory work. Big indicator heat losses through cement screed is the main disadvantage of this type of floor. Therefore, they first do the insulation, and only then choose how to properly level the concrete floor.

The type of insulation is pre-selected and installed according to technological scheme. For this you can use basalt wool, polystyrene foam or expanded clay. However, the work does not end there. After pouring the subfloor and its final cooling, a number of defects form.

• Regardless of the technology chosen, the base must be thoroughly cleaned of old coating, baseboards, etc., and, of course, any debris that has formed.
• Any defects on the old screed: bumps, chips, depressions or other irregularities need to be leveled out. For pouring, use a concrete mixture, various mastics or grouts.
• As already noted, one of the important aspects of leveling a concrete base is the magnitude of the height difference, which is quite simple to calculate. Existing surface irregularities are determined using two levels: long and small.
• The floor surface is primed to increase the adhesion of the screed to the floor. This is especially true for self-leveling floor technology. In this way, you can reduce the likelihood of cracks forming in the layer of the future screed, as well as waterproof the floor. If the surface strongly absorbs moisture, it is advisable to repeat the priming procedure.

Preparation procedure:

• Removing cracks. Visually determine their location. Then you need to widen them using a hammer and chisel. To fill the resulting cavity, you can use cement mortar or special construction compounds;
• High mounds. It is recommended to remove them using cutting tool– hammer drill or angular grinding machine. In the latter case, a disc for concrete is required;
• Pits. To remove them, you do not need to make a completely new screed. After treating the floor with a grinder, the resulting containers are filled with fine, dry crushed stone. Then a solution of two-component epoxy concrete is prepared. The height of the repair screed is usually from 2 to 6 mm. Final drying time is about 50 minutes.

In these ways, defects can be locally corrected. But how to level concrete floors if the level of height difference is significant? There are several effective ways that will help solve this problem.

All work must be carried out only after the concrete screed has completely dried. This process can take from 20 to 60 days depending on its thickness and volume of water.

How to level a concrete floor in an apartment

For significant unevenness that exceeds 10 mm per 1 m.p. It is recommended to make a new screed. But you need to be prepared that this process will take a lot of time. This method used for leveling floors in utility rooms: garages, private boiler rooms, it is also possible to fill on the first floors of buildings.

Let's look at step by step how to level a concrete floor for linoleum, laminate and other popular floor coverings.

Cement-sand screed

Beacons are laid along the room, which are metal slats, perforated corners or other similar material. They actually divide the floor into strips. The distance between them depends on the area and configuration of the room. As a rule, the step is about 1 m. The DSP mixture is poured between the strips and “pulled apart”. Next, the solution is leveled using the rule. They move it in four directions: to the sides, towards themselves and away from themselves, leaning on the beacons. Each leveled area must have a length less than a meter. It will take at least three days for such a floor to dry.

The main disadvantage is the increase in the mass of the interfloor ceiling. The weight of the screed is first calculated and the possibility of pouring it is checked. The technology is no different from the standard one. Since the concrete floor in the garage needs to be leveled as correctly as possible, preparatory work is being carried out. The premises are completely vacated and the above-described preparatory work is carried out.

Execution stages.

1. Setting the fill level. This is done using a building level. The best option– use of a laser tool.
2. Installation of reinforcing mesh.
3. Using a galvanized profile for drywall, poles are installed. They are fixed at the required height with a cement mixture.
4. Preparing and pouring the solution. It should evenly fill the entire volume without going beyond the profile.

After completing the work, you need to moisten the surface with water for 2-3 days. This will prevent cracks from appearing. Final drying time is usually around 25 days.

Self-leveling solution

The above method will not always be relevant. This is especially true for apartments, where additional loads on the interfloor ceilings. Alternative way consists of pouring self-leveling mixtures. This is one of modern methods leveling the base for flooring Decoration Materials. Leveling mixtures are supplied in the form of dry powder. They may differ in composition: base, additives or fillers. It is important to choose the right type and composition. If the difference is more than 3 mm, you will need to use two types of mixtures. The first to be formed is a rough surface, which will eliminate obvious defects. The second, finishing, is intended for final processing. For this reason, the preparation of the mixture for use may differ and is carried out in full accordance with the instructions on the package. However, they share common points:

• The mixture is prepared immediately before use, as the solution dries out after about 30 minutes. To dilute it you need a container. Experienced craftsmen recommend a plastic bucket, since it is much more convenient to pour the mixture.
• The solution is poured at certain conditions. In particular, the door and windows in the room must be tightly closed to prevent possible drafts. The temperature regime also has some limitations, above 10°, which must be maintained not only while working with the mixture, but also when the self-leveling floor dries.

• If necessary, additional heating in the room can be arranged.
• Although manufacturers claim that self-leveling floor you can walk in a couple of hours, however, practical experience shows that it would be safer to wait two or three days.

Manufacturers offer two main types of self-leveling mixtures. Under a laminate or other coating, use the option for rough leveling. If we are talking about how to level a concrete floor in a garage or other similar premises, then they are additionally coated with a mixture for finishing leveling, on which paint, varnish, etc. can be applied.

How to level a concrete floor with expanded clay concrete, plywood without joists and other leveling methods

Another technology for leveling the subfloor is dry screed, which simultaneously serves as thermal and sound insulation. This perfect option for surfaces with significant differences in height. After preparing the base, polyethylene is spread over it and log profiles are installed. Granular material is poured between the guides, the excess of which is shifted in the direction of exit.

Special sheets of Superfloor are laid on the backfill material, secured to the guides using self-tapping screws. The joints are taped.

Expanded clay concrete floors

Using the same technology, the floor is leveled with expanded clay concrete. The difference lies in the composition of the solution. During its preparation, fine expanded clay (up to 5 mm) is additionally added. As a result, the specific gravity decreases, since the solution will contain hollow components - expanded clay granules. At the same time, the pressure on the rough surface is reduced.

The disadvantage of this method is its low mechanical strength. It can only be used for private houses or apartments. If the critical pressure value is exceeded, local destruction of the floor will occur.

Screed with expanded clay can be done in other ways:

• The entire surface of the base is covered with a layer of expanded clay 80–100 mm high, leveled and filled with a layer of PCB.
• Expanded clay is scattered over the floor surface, leveled and watered with laitance. They give it time to “set” and fill it with sand-cement screed, which is then leveled.
• Initially, an expanded clay-sand-cement layer of the required thickness is laid on the concrete base. After about a day, the hardened layer is filled with leveling PCB.

Attention

You cannot fill when negative temperatures. The water will crystallize, which will lead to the destruction of the leveling layer.

Using plywood

A special feature of this method is the increased requirements for the foundation. The level of height difference should not exceed 1.5 cm. However, unlike the methods described above, plywood has several positive qualities.

The main one is good level thermal insulation. Together with the previously installed insulation, they will reduce heat loss in the room; plywood also has soundproofing properties. After its installation, the noise level in the room should decrease.

Before leveling a concrete floor with plywood without joists, you need to select the appropriate material. It must have moisture resistance and sufficient mechanical strength.

To protect from moisture, the cement base is covered with polyethylene film. The floor is first dried. Then you need to do the following.

1. Prepare a diagram for the arrangement of plywood sheets. According to the received plan, the material is purchased.
2. Installation of sheets is carried out butt-butt. You can use construction tape to seal the seams.
3. Fastening to the base is done using dowels. Installation with adhesive is not recommended, since cement flooring and plywood have different thermal expansion values.

After final installation, it is necessary to check the level of the plane again. If the height difference remains the same, a different leveling technology should be used. It consists of installing joists onto which sheets of plywood will later be attached.

After installing the leveling coating, it is necessary to reduce the likelihood of moisture getting on concrete surface. To do this, plywood panels must be sealed as much as possible.

In practice, there are many ways to level a concrete floor. But the above are the most effective and less labor-intensive.

Watch how to properly level a concrete floor video.

If you have become the owner of an apartment in a new building or purchased housing that requires overhaul, then be sure to ask yourself about leveling the concrete floor and high-quality installation of the finishing floor covering, which will last for a long time.

Among all the options for uneven concrete floors that require elimination, the following are distinguished:

• cracks, minor chips, roughness;
• bumps, significant bulges and holes visible to the naked eye;
• differences in height, floor bevel towards one of the walls.

Depending on the defects and their number, the method of leveling the concrete floor will be chosen. Before starting work, do not forget to clean, remove dust, and, if necessary, cover the radiator and external heating pipes with film. If there is paint, oil or grease on the concrete, the top layer of concrete is removed using a mosaic grinder or shot blasting machine. Dust can then be removed more efficiently construction vacuum cleaner.

Cracks may appear in an old screed or in a recently poured one, but with technological errors. There are also frequent cases of cracking between concrete slabs, resulting in a difference in floor height. Such defects cannot be ignored.

Step one. We visually inspect the room and use a level to check the horizontal position. It is important not only to repair the cracks, but also to create the most even floor possible.

Step two. Prepare the chisel and hammer. Each crack will have to be tapped, driving the chisel as deep as possible. This is necessary to expand the gap under the leveling mixture and detect possible hidden chips. We remove all dirt and pieces of loose concrete.

If the cracks are dynamic, it is worth doing their transverse reinforcement. We hollow out narrow grooves across the crack in several places and place dowels or short pieces of metal rods in them.

Fill the floor with water, removing the last dust, wait until it dries, treat the inner surface with a primer (for example, from Grund) and begin preparing the mixture.

Step three. Mix water and cement M 400 (dry powder). To stir the mixture, use a drill with a mixing attachment. Add an equal volume of PVA glue or PVA glue to the cement solution (medium liquid). liquid glass. Mix the ingredients until smooth.

Step four. Uniform and sufficient liquid solution pour into the crack. Adhesive composition should protrude slightly above the floor surface, as shrinkage will occur during the drying process. We work through each crack and wait for it to dry.

Step five. All that remains is to rub over the poured cement to hide all traces of the repairs. Most convenient to use grinder, but in the absence of such grouting is done with an abrasive wheel. Press the abrasive onto the floor with your hand and make circular movements to remove excess cement.

Similarly, it is worth wiping out any existing roughness on the concrete floor. Even minor microcracks can simply be treated with a primer. deep penetration and tile adhesive.

Removing bumps from concrete floors

An uneven, lumpy floor will lead to instability of subsequently installed furniture and fracture of the laminate joint, as well as other defects finishing coating.

To get rid of the bumps, you will need a diamond end mill and, accordingly, a milling machine. We process the concrete floor, simultaneously checking the horizontal level.

Note! Inclusions of crushed stone or reinforcement present in the mounds cannot be removed with a milling cutter. The reinforcement is cut with a grinder, and pieces of crushed stone are beaten with a hammer and chisel.

Leveling a concrete floor with holes

If there are visible local holes in the screed, they must be repaired. At the same time, it is not at all necessary to build up the screed over the entire area (provided the surface is sufficiently horizontal).

We eliminate differences in floor heights with a self-leveling mixture

It happens that visually a concrete floor has no defects or unevenness, but nevertheless, when checking with a laser level, differences in height towards one of the walls of the room are revealed. In this case, the difference between the highest and lowest points can be up to 5 centimeters. In this case, it is most convenient and quick to level the concrete floor with a special self-leveling mixture.

If the height difference is significant (over 3 cm), you will need a mixture for rough leveling. It is better to fill screed of small thickness with finishing self-leveling mixtures, which are characterized by a smoother finished surface and attractive appearance.

Stage one. We dust the rough concrete floor with a construction vacuum cleaner, removing all particles of dirt and debris. Using a laser level, we make markings on the walls in order to fill the layer of new screed as efficiently as possible.

Stage two. We treat the entire surface of the concrete floor with a deep penetration primer to improve the quality of adhesion between the old concrete floor and the screed being poured. In addition, the primer has a positive effect on the quality and drying speed of the leveling solution. It is recommended to glue edge tape up to 8 cm wide to the walls around the perimeter of the room.

Stage three. Mix the solution by combining the powder with water according to the instructions that each manufacturer includes with the product.

Note! Start work early to fill the entire area in one day. Self-leveling screeds prevent technological interruptions in work.

Stage four. Pour the solution from the bucket onto the floor. We move from the far corner of the room, gradually pouring the mixture onto the floor (in a strip up to 30 cm wide) and leveling it with a squeegee or rule. Don't expect the mixture to spread on its own. Perform the alignment using the marks on the walls. We must treat each filled area with a needle roller. Choose a roller according to the thickness of your screed. Thin layer The self-leveling mixture is processed with a roller with the shortest plastic spikes.

If you plan to walk on wet floors, wear special shoes with spikes.

Drying times for the mixture are always indicated on the packaging. After the stated period of time, the level surface is ready for the installation of a final floor covering, e.g. ceramic tiles.

If the existing concrete coating is too uneven, it is better to pour a new screed on top of it. However, this option is not suitable for those who are in a hurry to complete the renovation and do not have enough time. Pouring a new screed is optimal for the first floors of buildings, garages, private houses; the coating is the most durable and durable.

The technological process is simple, however, the work of mixing and leveling the cement is not easy.

Step one. We examine the old concrete floor. We remove all dirt and widen large cracks with a chisel.

Step two. We use a laser level to mark and accurately level the concrete floor horizontally. We stretch beacon threads across the walls for easy installation of profiles.

Step three. Cutting perforated corner profiles, based on the length of the room. We place the profiles along the room. We maintain a distance of 30 centimeters from the walls and 100 cm between the corners or equal to length rules. We attach the corners to the floor with plaster or thick cement mortar. We use a level so that the profiles are positioned strictly horizontally. We wait until the fastening mixture under the corners hardens.

Step four. Prepare and pour mixed cement mortar between the perforated profiles. We move from the far corner towards the door, usually shifting the excess mixture (we make movements along the slats and in a circle, filling all the existing voids).

Step five. We wait for the screed to dry, moistening the coating with water in the first three days after the work. When the monolithic screed hardens, all that remains is to pull out the beacons and fill the voids using a primer and liquid cement mass in combination with a plasticizer.

Video - How to level a concrete floor with a cement-sand screed

Other ways to level a concrete floor

You can level a rough concrete floor by laying a dry screed, which is additionally noise- and thermal insulation material. This option is applicable if there is a significant horizontal difference. The thickness of the dry screed can be up to 7-10 cm.

Preparation of the concrete surface comes down to cleaning it (sweeping) and sealing it excessively large cracks. Next, polyethylene is laid, guide profiles-logs are installed at the level, between which granular material (for example, expanded clay) is poured. The rule is surplus bulk material move away from walls and corners towards the exit.

Superfloor sheets are laid on the filled expanded clay

A perfectly flat surface is ready for laying any finishing surface, be it carpet, linoleum, parquet or tile, etc.

Video - Leveling a concrete floor with a dry screed

If you are leveling a concrete floor on a glazed covered loggia, pay attention to the option of leveling the concrete base with sheets of plywood on joists that are attached to galvanized beacons. You can lay a layer of insulation between the joists, and any finishing coating on top of the plywood.

When making major repairs or partially finishing a room, leveling the concrete floor is indispensable. This is one of the mandatory conditions when installing linoleum, laminate and other similar materials. If the surface preparation is not completed, the final result of the finishing is unlikely to please its owner.

Even in new buildings, the concrete floor is often not perfectly level. The most problematic areas are the joints. In old houses, the floor surface is often in poor condition. If the concrete has not been subjected special treatment, then over time it begins to gather dust, crumble, and chips and cracks appear on it. Many owners are faced with the question of how to level a concrete floor correctly?

Reasons for leveling a concrete floor:

• the installation technique of many types of floor finishing requires mandatory surface preparation (linoleum, parquet, laminate, tile);
• elimination of construction defects on concrete slabs: cracks, chips, differences between slabs, unsuccessful joints;
• installation of sound, heat, waterproofing material;
• strengthening the strength and rigidity of load-bearing floors;
• An uneven surface makes it difficult to arrange furniture and interior items.

How to prepare for leveling

Before leveling the concrete floor and deciding on the choice of technology and materials for eliminating unevenness and defects with your own hands, it is necessary to determine the nature and scope of the work, as well as how severe the deviation from the norm and the angle of inclination are. Then appropriate measurements are taken. To do this, the old coating is first disassembled. After which the unevenness is assessed.

The entire floor surface is checked with a building level. First of all, the highest point is determined, which should be immediately noted. Then you need to inspect the defects of the concrete slabs: worn areas, chips, cracks. It is also recommended to mark the deepest point.

Properly taken measurements will help prevent errors in the process of further alignment.

If you carry out work without determining these points or make incorrect measurements, then there may be consequences that are difficult to correct: doors will stop closing, the height of the floor may interfere with the heating, linoleum and other coverings will not lie flat. Eliminating such errors is very difficult and will take a lot of time.

Alignment methods

Installation of a concrete coating is the very first thing that begins during a major renovation of a room. The quality of the remaining finishing work depends on the evenness of the floor.

There are two main technologies:

• alignment by beacons;
• filling surface device.

If the room is small and the angle of inclination of the plane does not exceed 3.5 cm, then the most appropriate method would be to install a self-leveling floor. If this indicator is exceeded, the technology for leveling concrete slabs will be carried out according to the exposed beacons.

When choosing one of the methods, it is important to understand that each option for eliminating unevenness has both its advantages and disadvantages, so you should carefully study the technique and weigh the pros and cons.

The use of this technology allows you to do the work yourself even for those who are not professionals in the field of finishing. The method is well suited for implementation in large rooms.

First on concrete plates special beacons, which are metal slats, are laid and fixed. These are a kind of guidelines that serve to correct execution surface screed work.

The entire alignment process requires minimal effort and is completed quickly. At minimum investment it allows you to get a quality product. The installation itself is completed in a short period of time, but it takes an average of 10 to 30 days to harden the surface. The drying time of the screed depends on the thickness of the applied layer and the temperature conditions inside the room. If you are short on time, we recommend choosing another method.

What do you need for work?

Tools for screeding a concrete floor:

• vacuum cleaner or broom for surface preparation;
• Master OK;
• perforated corners;
• rule;
• building level;
• large container for mixing the solution.

Surface preparation, installation of beacons

Before carrying out any construction work important point is preparatory stage. The entire surface is thoroughly swept or vacuumed. Accumulated debris, dust and dirt must be removed.

After this, beacons are installed, which are perforated metal corners. They are placed across the width of the entire room. The first and final beacons are installed at a distance of 30 cm from the side walls. The remaining elements are placed at the same distance from each other. It should not be more than 1 meter.

Installation is carried out in the following sequence. First the marking is done. Beacons are installed along the lines; they are attached to cement or plaster. All this is controlled using a building level. The structure is left to dry.

After the metal slats have set, the entire remaining space under them is filled with cement mortar. At this time, it is possible to correct the position of the beacons and correct them.

The main task is to make the most flat surface. Everything must be left to fix the elements.

After everything has dried, you should begin work on leveling the resulting plane.

Fill

To make the screed, a cement mortar is prepared. The consistency of the material should resemble thick sour cream in appearance. If you mix a steeper solution, it will be difficult to level it well with your own hands. A mixture that is too liquid takes a long time to set; such a surface will not have increased strength characteristics.

Leveling work should be carried out from the furthest point towards the exit. Typically, filling occurs in rows. The first and second are filled simultaneously. After them there is a line for the last two rows. Then further work is done one strip from each edge. The end should be on the center path. This row is aligned especially carefully. The material fills the structure in small portions at a distance no further than arm's length.

The resulting solution is poured into the distance between two linear beacons. Using a trowel, all hard-to-reach areas are filled. After each strip is poured onto the beacons, a rule is established that is carried out several times to level the floor surface.

During the work process, do not forget to periodically stir the product; this will ensure uniform distribution of the material for better drying. Only after complete hardening can you begin the subsequent finishing of the floor. Linoleum will fit perfectly on a flat floor.

Installing a self-leveling floor is the most modern and simplest way to prepare a floor for laying linoleum or laminate. To obtain a smooth surface, use special building mixtures. They are developed using a special technology that allows the material to level itself. It is enough to pour it onto a concrete base, let it dry, and the base for linoleum is ready.

The mixture has specific characteristics. It spreads over the floor surface in a thin, even layer.

Tools for using leveling solutions:

• vacuum cleaner or other items for cleaning concrete slabs;
• foam roller;
• needle roller.

Work order

The entire surface is first cleaned. After this, it is treated with a soil substance. Then, according to the instructions, the finished powder of the self-leveling mixture is diluted, which is simply poured onto the floor.

To help the product spread evenly over the surface and eliminate air bubbles in the substance, it is necessary to use a needle roller. They should go in all directions. The work is carried out in special shoes with spikes, which will not allow you to step on the flooded floor.

The material dries in a few hours, after which you can immediately begin further finishing of the room. The disadvantage of such a mixture is that the maximum permissible thickness should not be greater than that specified by the manufacturer (usually no more than 10 cm, often significantly less). If the surface has a greater slope, then leveling the concrete floor in this way is impossible.

A concrete base that has not been treated with special compounds begins to deteriorate over time, despite the apparent strength of the stone. The coating begins to gather dust, and chips and gouges appear on its surface. This can happen for several reasons. Quite often, another problem arises, which is that the base of the floor is initially lumpy, far from perfectly flat, and the floor slabs are laid crookedly. In any case, a reasonable question arises: how to level a concrete floor? Let's try to consider several options that will suit both new residents and old-timers who have decided to renovate.

The choice of concrete floor leveling method depends on:

• from the flooring material;
• on the magnitude of the existing height difference;
• depending on the number of cracks and chips.

In addition to leveling the concrete base, dry screed performs the functions of insulation and sound insulation. The process of its installation is quite simple, even a beginner who is just starting his journey in the construction business can handle it.

The concrete base is cleaned, after which a primer is applied to it in order to increase the strength and waterproofing properties of concrete. After the composition has dried, a plastic film is placed on the leveled surface, overlapping by 17-20 cm, gluing the edges with tape. Along the perimeter of the room and in other places where walls and partitions meet, allowances for bends of 13-15 cm are left, which are subsequently glued with damper tape.

The film acts as a waterproofing layer.

A leveling mixture five to seven centimeters thick is poured onto the prepared surface, which may consist of:

• from expanded clay;
• from quartz sand;
• from expanded polystyrene;
• from granulate.

Place on top:

• plywood;
• moisture-resistant gypsum fiber sheets;
• Chipboard or fibreboard.

Leveling concrete floors with dry screed has a number of advantages. In particular:

• there is no need to mix the solution;
• there is a possibility self-execution works, without assistants;
• it is allowed to level the surface in separate small sections;
• no additional heat and sound insulation devices are required;
• there is a possibility of laying the necessary communications inside the layer;
• the work is carried out quickly, after its completion you can immediately begin laying the flooring.

The classic option for leveling a concrete base is a cement-concrete screed. Professionals are inclined towards this point of view, since the result is a strong, perfectly level base for laying the finishing coating.

The thickness of the cement-sand screed must be at least three centimeters, otherwise its strength will not meet the necessary requirements.

Wet screed has proven itself positively when leveling floor slabs and with large differences in floor levels - up to six centimeters. The technology of its device is quite labor-intensive and has certain difficulties. But with high-quality work, the result remains unchanged - reliability and strength will be guaranteed.

Before starting work, the concrete base is cleared of unstable areas, construction waste, dust and dirt. Oil stains are also recommended to be removed. Next, a layer of waterproofing is laid, for which any available material. The main thing is that the joints and overlaps are securely taped to prevent leaks onto the neighbors’ ceilings. Do not forget about the allowances for waterproofing material that must be left near the walls.

At the next stage, beacons are installed when using conventional or laser levels. To install beacons, choose metal profiles that are installed on a thick solution or quickly hardening gypsum mixture. For the convenience of pouring and leveling the screed, the distance between the guides is no more than 0.9-1 meter.

The mixed solution is poured in parts between the profiles, immediately distributing and leveling the mixture as a rule. It is not only guided along the guides, but also the tool is moved from side to side. This helps fill voids and also compacts the screed layer.

When laying the mortar, long breaks in work should be avoided, otherwise there is a high probability of the formation of so-called cold joints. This process negatively affects the strength of the cement-sand layer.

At large thickness screeds, it is additionally strengthened with reinforcement. The material can be any; its choice depends on the height of the leveling layer and the type of floor covering.

To prevent the appearance of cracks in the finished screed, experts recommend cutting shrinkage joints in it every three meters.

A day after laying the mortar, the cement-sand surface is wetted. To do this, you can use a paint roller with a long handle or a spray bottle. On the third day, check the degree of setting of the solution. If, when walking on the screed, no traces remain on it, proceed to removing the metal profiles and filling the resulting voids with a mixture.

The surface of the screed is moistened again and covered with polyethylene so that the solution cannot dry out too quickly and crack. The wetting process is carried out for several days in a row (usually a week), after which the film is removed and the screed is kept at natural humidity.

Full hardening wet screed occurs over a period of at least two weeks, but it would be better not to start further work for a month.

To get perfect smooth surface The screed is sanded, but only if necessary. In order to eliminate unevenness, the coating is simply rubbed with a special machine in two opposite directions.

Leveling a concrete floor with a self-leveling mixture is convenient and quite affordable. The solution is mixed in a container using construction mixer, poured onto the base and spread over it with notched spatulas or special needle rollers that remove unnecessary air bubbles. The work can be done quickly, as the mixture can begin to set within ten minutes. This is its main drawback.

The fluidity period of the material is indicated on the packaging. Based on this indicator, the amount of material required for mixing is calculated. Deviation from the manufacturer's instructions is not allowed!

The advantage of self-leveling mixtures is their spontaneous spreading over concrete floor. This results in a smooth, horizontal base surface for the floor covering. The advantages include the small thickness of the leveling layer, which is an undoubted benefit for low rooms.

Before starting pouring, prepare the concrete base. For this purpose in mandatory seal deep and wide cracks and cracks with mortar, and then allow it to dry.

It is recommended to use self-leveling mixtures for height differences of less than three centimeters. Otherwise, the layer may crack in the future.

An interesting fact is that the solution can harden within half an hour. But that's no reason to start further work. It is necessary to allow the base to stand for three days. It should be noted that a self-leveling mixture requires a finishing coating, since the hardened surface does not have sufficient strength. It is also not intended for painting.

Leveling a concrete floor for some types of flooring

To finishing coat If the floor has served for as long as possible, it is necessary to take a responsible approach to leveling the concrete base for the flooring. For each material, one or another option and quality of surface leveling are suitable.

For example, laminate does not tolerate changes of even 4mm. In this case, laying a soft substrate cannot prevent damage to the locks or divergence of the joints. Under the laminated coating, one of three types of leveling of the concrete base is performed. The main thing is to get a flat, horizontal surface.

Linoleum is not as capricious in its evenness as it is in the smoothness of concrete. Any pebble can push through elastic material. Linoleum will lie softly over uneven surfaces, but will not be able to hide them. When viewed from the side, all curves will be noticeable. Concrete floors under linoleum can be leveled using all available methods.

Large differences in the base are eliminated using plywood laid along the joists. This option is also used if it is necessary to raise the floor level, regardless of the type of floor covering subsequently laid. The main thing is that the material is not heavy.

For ceramic tiles, it is recommended to install a full-fledged cement-sand screed laid over a carefully constructed waterproofing layer. Moreover, the base additionally levels the layer of tile adhesive. The main condition in in this case, is the absence of differences in height.

Leveling the floor in the garage and basement

IN utility rooms The finishing coat is rarely applied. The floor here is usually left concrete. It is leveled using a screed and strengthened with special impregnations and reinforcing compounds called toppings. They prevent dust and destruction of the concrete surface.

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