Floor leveling is one of the most important stages repair work. Before laying the final floor covering, the floor in the apartment is screeded. During the construction of multi-storey residential buildings As flooring, a reinforced concrete slab is used, which has a smooth surface on only one side. The smooth part is always laid towards the ceiling, therefore, the side with defects serves as the floor. In this article we will look at how to make a floor screed in an apartment, types and rules for preparing mixtures.

Screed functions

The screed eliminates differences in floor height and defects and allows for high-quality installation of the finishing floor covering. If you lay linoleum on an uneven floor, it will crack over time where there are changes in height.

Functions of the screed in the apartment:

• strengthens the concrete base;
• perceives and distributes loads arising during operation;
• increases heat and sound insulation;
• Due to the perfectly flat surface, it protects the floor covering from damage;
• allows you to arrange a technological slope for the floors of the kitchen and bathroom to drain water in case of flooding due to failure of communications.

Using a screed you can raise the floor level. During the execution of work, it is necessary to take into account permissible loads on the stove. It is impossible to pour concrete more than 70 mm in thickness, since the ceiling may not withstand the load.

Types of mixtures

Questions often arise about how floor screed is made in a new building, which is better. We choose the technology for laying the subfloor depending on the design features slabs

Stages of dry screeding

1. Dry and semi-dry screeds are used for height differences of 30-50 mm. Compared to other types, lighter materials are used, thereby reducing the load on the slab.
2. Installation concrete screed Suitable for damaged floors big difference heights, increasing heat saving and sound insulation.
3. Self-leveling mixtures are used for height differences of up to 30 mm. They include two stages of work: leveling with the starting mixture and finishing coating.

We select the type of screed depending on the condition concrete slab, functional features and flooring.

Preparatory work

The floor in a new building often has to be leveled at the stage of moving into an apartment.

Preparation stages:

1. We remove the old floor covering, inspect the slab for cracks, depressions, and protruding reinforcement.
2. We widen the cracks with a grinder, clean their edges, and fill concrete mortar; For better adhesion of materials, the surface must be moistened.
3. After the cement has hardened, remove dust from the slab with a vacuum cleaner.
4. We lay damper tape at the junctions between the floor and the walls. It will serve as an expansion joint when the concrete expands during drying and will protect the lower apartment from water leakage.

Floor marking

Marking is done from the lowest part of the floor

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The thickness of the screed and the choice of material for its installation depend on differences in floor height.

We find the lowest and highest point of the floor. We make markings using a laser or water level.

If the highest point is a threshold, you can pour a concrete base. If the corners of the room are above the threshold, there are two algorithms of action:

• we dismantle the old screed to the slab, pour concrete, adjusting it to the floor level in the adjacent room;
• pour concrete onto the old base, but keep in mind that the floor height in this room will be higher than in the adjacent one. This is justified if you plan to install new floors throughout the entire apartment.

To correctly mark the floor boundary, you need to place the guides parallel to each other at a distance of 150-200 mm from the wall. The distance between the guides should be less than the width of the tool to distribute the mixture.

We use T-shaped profiles as guides, designed for alignment vertical surfaces. To level them, we use plastic and metal strips or install beacons on gypsum (cement) mortar.

Cardboard, chipboard and wood cannot be used as supports for lighthouses, as they lose their shape when exposed to moisture.

Calculation of the number of components for concrete

Screed volume is measured in liters

To determine the amount of sand, cement and water, we calculate the volume of the screed in liters. To do this, we multiply the average height by the length and width of the room, we get the volume.

Let's say, taking a room with a width of 4 m and a height of 3.5 m, we fill the screed with a thickness of 25 mm at the lowest point and 40 mm at the highest point.

Calculate the average thickness concrete covering(25+40) / 2 = 32.5 mm.

We calculate the area of ​​the room: S = length 4 m * width 3.5 m = 14 m.

Volume = 32.5 * 14 = 497 l.

You will need as much sand as the volume of the screed. But sand weighs 1.5 times more than water, so 497 * 1.5 = 745.5 kg.

And you will need 1 part cement to 3 parts sand. 745.5 / 3 = 248.5 kg.

The volume of water used depends on the moisture content of the sand. Add water until the consistency of thick sour cream is obtained.

High quality concrete solution

Mix ingredients in a specific order

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After marking the floor, we begin preparing the concrete. The preparation scheme is standard, for one part quality cement(M 200) accounts for three parts of sand.

Mix the ingredients correctly:

1. First you need to mix the dry ingredients well: cement and sand. Since a large volume of solution is mixed, you need to prepare a drill with a special attachment or a construction mixer in advance, since it will not be possible to mix the components properly by hand.
2. To protect the surface from cracking during drying and further use, it is recommended to add plasticizers to the solution. The technology and proportions are indicated on the packaging for the composition.
3. We check the quality of the solution by squeezing a handful of solution into a fist. It should not crumble or crack when compressed.

Concrete grade	Application	Cement consumption in kg per 1 cubic meter of concrete
M100	Minimum strength. Used for concreting road curbs and fences	165
M200	It is used when installing floor screeds in new buildings, when repair work. Suitable for foundations	240
M300	Used for installation of foundations, floors, etc.	320
M400	For the construction of structures subject to significant loads: bridges, load-bearing supports on overpasses	417

To make it work homogeneous mixture, pour dry ingredients into water. If you do it in the reverse order, the sand and cement will remain at the bottom and it will be difficult to mix them.

Concrete screed device

Let's look at how to properly screed a floor in an apartment. We start installation from the far corner of the room. We fill the floor in one go, with large thickness We reinforce the screeds with a thin metal mesh. For more information about the process, watch this video:

Stages of work:

1. Pour the solution onto the floor between the guides and level it with a trowel.
2. Using the rule, we level the mixture, moving it towards ourselves. We compact the solution so that the air comes out and there are no voids left.
3. After a day, we take out the guides and fill the places where they were with solution.

You can walk on the floor after 4 days. The concrete dries completely and gains strength within 30 days.

The deviation in the horizontal plane should not exceed 0.2%.

After installing the screed in the apartment, we eliminate drafts by sealing all the cracks, and regularly moisten the concrete so that the coating does not crack. Final alignment We do it after the screed has completely dried. You can use mixtures for self-leveling floors.

Dry screed

This type of coating lightens the load on the slab and increases the thermal insulation of the floor. We lay the dry screed using expanded clay or other bulk material small fraction. For more information about dry screed, watch this video:

The marking of the room and installation of beacons is carried out according to the principle described above.

In order to properly make a floor screed based on cement mortars and concrete, the screed must correspond to the purpose of the room and have the necessary parameters for this.

The screed can become a solid foundation for the floor in any room of the house. Cement screed is not afraid of moisture and is convenient to use as a base for flooring in damp rooms, as well as outside the house - on terraces, in the garage. The installation of heated floors in rooms is also not complete without a screed.

Screed solutions

Cement-sand mortar for screed

For the construction of screeds, traditional cement-based sand mortar grades not lower than M75. To prepare the solution, prepare a mixture of one part cement and three parts sand. The strength of the finished screed increases if the solution for laying the screed has a thick consistency.

Cement-sand mortar is easier to prepare and easier to lay in a screed than concrete. But the consumption of cement for constructing a screed of the required strength is greater than for concrete. That's why, A mortar screed is more expensive than a concrete screed.

Lime should not be added to the solution. Although lime increases the plasticity of the mortar, it reduces the strength of the screed.

Concrete of normal, densely plastic consistency

Concrete of classes B10, B15, B20 is used for constructing screeds. Crushed stone and gravel are used as concrete filler. The size of the filler granules must be at least three times smaller than the thickness of the screed.

Concrete for semi-dry screed (prance)

To prepare concrete for semi-dry screed, significantly less water is used than usual. A semi-dry screed has a higher compressive strength (up to 35 mPa) than screeds made from mortar and plastic concrete. In addition, it is less susceptible to shrinkage, which reduces the risk of cracks in the screed.

Semi-dry screed is suitable for installing heated floors. It is convenient to prepare concrete for semi-dry screed on a construction site in a special concrete mixer - mixocrete, which prepares the concrete and immediately supplies it with a pneumatic pump. flexible pipe to the installation site.

Composition of cement mortars for concrete floor screed

Cement mortars and concrete can be prepared at the construction site. It is recommended to include additives in their composition to increase plasticity, accelerate setting and reduce water permeability of the screed.

To obtain concrete of the required compressive strength class, It is recommended to use the following grades and quantities of cement:

During storage, cement loses its activity. The cement consumption indicated in the table is indicated for cement with a shelf life of no more than two months. The consumption of cement with a shelf life under normal conditions of more than 3 months is increased by 20%; more than 6 months - by 30-40%.

It is not recommended to use cement with a shelf life of more than 12 months.

When using old cement, the mixing time of the mixture is increased by 2-4 times. It is recommended to introduce additives that accelerate concrete hardening.

To prepare medium-strength concrete, use a mixture of 1 part (by volume) cement, 2.5 parts medium-sized sand and 4 parts aggregate - gravel or crushed stone.

The indicated ratio of mixture ingredients is approximate and depends on many factors. For example, the amount of sand in the mixture should be sufficient to fill all the spaces between the aggregate granules. For large granule sizes, the amount of sand is slightly increased, and for fine aggregate, on the contrary, it is reduced. Cement consumption is also adjusted depending on its brand, shelf life and required concrete strength (see table above).

The prepared cement mortar must have good plasticity and mobility. This solution is easier to level and compacts better. To increase plasticity, special additives are used - sulfite-yeast mash (SYB) in an amount of 0.15-0.25% by weight of cement; soap naft (M1) - 0.1-0.2% by weight of cement, and others. At home, craftsmen often add a small amount of grated laundry soap to a concrete mixer.

The mobility of the concrete mixture also depends on the ratio between sand and crushed stone. The best mobility is achieved at a certain optimal ratio, at which the thickness of the cement paste layer is maximum. If the sand content in the aggregate mixture exceeds this value concrete mixture becomes less mobile, which is explained by an increase in the surface area of ​​the aggregate mixture.

To make the concrete mixture plastic, much more water is often added to concrete than necessary (40...70% by weight of cement). Concrete should not be made too liquid, adding a lot of water. A screed made from such concrete will take several months to dry and will have reduced strength and frost resistance. The risk of significant shrinkage and cracking of the screed increases.

Excess water that has not entered chemical reaction with cement, remains in the concrete in the form of water pores and capillaries or evaporates, leaving air pores. In both cases, the concrete will be weakened by the presence of pores and the more water, the more pores and thus the less strength and frost resistance of the concrete.

Dry mixtures for floor screed

The best option, although more expensive, is to use ready-made dry mixtures for screeding. Such mixtures are commercially available at construction market. The mixture already includes the necessary additives.

Manufacturers can include microfiber in the mixture - fibers that serve as reinforcement. Microfiber screed is more resistant to shrinkage and cracking.

There are mixtures specifically designed for underfloor heating. This should be indicated on the packaging of the mixture.

There are quick-setting compounds. On a screed made from such a mixture you can lay floor tiles within 24 hours.

The packaging of the dry mixture should contain information about what screeds and installation conditions it is intended for, what compressive strength of the screed the use of the mixture will provide.

For residential premises, the compressive strength of the screed must be at least 12 mPa, for a garage - at least 20 mPa.

Types of floor screeds

According to their design, screeds can be connected to the base on which they are laid, or laid on separation layer, or floating.

Screeds connected to the base, are carried out if the base is also made of concrete. For example, a screed reinforced concrete slab ceilings or concrete floor preparation. To ensure adhesion of the screed to the base, the surface of the latter is specially prepared - dust-free and primed. The minimum thickness of the screed is 2.5 cm.

In screeds on the separating layer between a concrete base (reinforced concrete slab or concrete preparation) and a layer is laid with a screed waterproofing film thickness of at least 0.2 mm. The edges of the film panels are laid with an overlap of at least 10 cm and sealed with adhesive tape. The edges of the film are wrapped on the walls.

The film separating layer prevents water leakage from freshly laid concrete. Dewatering of concrete reduces the strength of the screed. The screed concrete must be laid on a separating layer of film in all cases where water leakage from the concrete into the base of the screed is possible.

The minimum thickness of the screed on the separating layer is 3.5 cm.

Floating screed laid on a layer of insulation or sound insulation, for example, when installing or Minimum screed thickness 4.5 cm. subject to reinforcement. Floating screed with a thickness of more than 7-8 cm. it is allowed not to reinforce.

Technology of floor screeding in a private house

The screed is laid at a base and air temperature above +5 degrees C. The technology for laying the screed does not change depending on what is used for laying cement-sand mortar or concrete, including semi-dry consistency.

The work is performed in the following sequence.

Prepare the base on which the screed will be laid. For a screed connected to the base, the surface of the base is cleaned of debris, dusted with a vacuum cleaner and primed.

To install a screed on a separating layer and a floating one, a layer of sound and heat insulation is laid, and a separating layer of waterproofing film is laid on top.

On walls and others vertical structures glue strips of polystyrene foam or edge tape made of polyurethane foam with a thickness of 1-2 cm. for creating expansion joint.

On quick-setting flatbreads cement mortar lay guide rails - beacons. Beacons are laid over the entire surface of the base in parallel rows with a pitch of approximately 1.5 m. and at a distance of 20 cm from the walls. They are used as beacons wooden slats or various metal profiles, pipes.

Special galvanized steel profiles for installing beacons are available for sale. Profiles are convenient because they do not need to be removed from the screed layer. But such profiles have little mechanical strength, increased flexibility and require careful alignment when installing on flats and accuracy when pouring concrete.

The upper surface of the beacons is leveled in one plane. If necessary, provide the required plane slope.

The solution prepared in a concrete mixer is supplied to the work site, and moving towards the door, it is evenly distributed between the beacons so that the thickness of the solution is slightly higher than the level of the beacons.

Using a grater, the solution is pre-distributed between the beacons and compacted. Finally, the solution is leveled with a wooden or metal lath - usually by moving it along the beacons in a zigzag motion towards itself. If shells remain behind the lath in the screed, they are filled with mortar and leveled again using the rule.

After the solution begins to harden and can support the weight of the worker, the beacons are removed from the screed. This is done in a timely manner, until the solution has completely set, and carefully so as not to damage the screed. If a semi-dry screed is laid, then the beacons can be removed within 3-4 hours.

The gaps in the screed left after removing the beacons are filled with mortar and smoothed with a grater, making circular movements.

Until the mortar has completely hardened, furrows are made in certain places on the screed, cutting through the mortar with a spatula to the required depth. After the solution has set, such grooves will have to be cut with a power tool with a diamond blade.

Expansion joints in the screed

A wall expansion joint separates the screed from walls and other vertical structural elements buildings - columns, staircase supports, etc. The seam is necessary in order to eliminate the mutual transfer of stresses between the screed and the structures of the house. Stresses can arise as a result of thermal expansion of materials or their shrinkage, as well as as a result of deformations under the influence of loads.

In addition, the seam improves the sound insulation of rooms, making it difficult to transmit sounds from the walls to the floor structures and back.

To create a seam along the walls and other elements of the building, an elastic tape with a thickness of 1 cm. to the full height of the screed.

When placing heated floor pipes in a screed An expansion joint across the entire thickness of the screed is used to separate adjacent fields of underfloor heating pipes.

In addition to the expansion joint near the walls, cuts are made in the screed, which divide the screed into smaller rectangular sections. One side of the plot should be no more than 3-6 m. IN narrow corridors compensation cuts are made across the corridor, every 2-2.5 times the width of the corridor.

In addition, compensation cuts are made at the junctions of different floor coverings, as well as at the boundary of changes in screed thickness, in door openings and in other openings at the boundary of different rooms of the house.

Compensation cuts are necessary to compensate for the shrinkage of the screed material during drying. Without them, cracking of the screed may occur. The cuts are made to a depth of 1/3 - 1/2 of the thickness of the screed. The width of the cuts depends on the thickness of the screed and the presence of heated floor pipes in the screed.

If the screed is reinforced with mesh, then the expansion cuts should be located above the joints of individual mesh sheets.

If the floor covering along the screed is tiles, then the compensation cut should coincide with the joint of the tiles.

Compensation cuts may remain empty if the flooring is parquet or laminate. The cuts are filled with waterproof silicone sealant if the floor covering is tiles.

How to properly reinforce a screed

Be sure to reinforce thin ties with a thickness of 4.5-5 cm on a separating film layer. Floating screeds, the base of which is a layer of insulation (sound insulation) or compacted soil, are reinforced with a screed thickness of 7-8 cm. and less.

If the screed has a thickness greater than that specified above, then the need for reinforcement is determined depending on the operational load. For example, a floor screed in a garage for passenger car or on an open terrace on compacted soil, it is recommended to reinforce with a screed thickness of up to 10 cm.

Screeds made from a ready-made dry mixture containing reinforcing microfiber fibers in many cases do not require additional reinforcement.

Typically, the screed is reinforced with a mesh of steel wire with a diameter of 3-4 mm. The mesh should have cells measuring 100x100 or 150x150 mm.

The steel mesh is laid on spacer pads so that it is approximately in the middle of the screed layer. Protective layer there must be at least 2 concrete to the grid cm. indoors, and at least 4 cm. when the concrete screed comes into contact with the ground.

On top of the mesh, as usual, beacons are placed on cakes of mortar and leveled.

Thickness and level of screed in the premises of the house

When choosing the thickness of the screed, the strength of the base on which the screed is laid, the presence or absence of screed reinforcement and the operational load are taken into account. In addition, there are restrictions on minimum thickness different types screeds (see sections of the article above).

IN different rooms floor, the thickness of the screed, chosen for design reasons, may be different. For example, the thickness of the screed in rooms with warm floors should be such as to cover the heating tubes with a layer of at least 3 cm.

It is convenient in the house to have floors located in all rooms of the floor on the same level. Only in rooms where water may be spilled on the floor - in a bathroom, toilet, it is recommended to make the floor level lower by 1 cm. than in neighboring rooms.

To make the floors in the rooms at the same level, it is necessary to take into account that the floor covering that is laid on the screed in the rooms may have different thickness. For example, the thickness of the porcelain tile flooring in the kitchen differs from the thickness of the parquet flooring in the living room.

In order to determine the level of the screed surface in the room, first mark the level of finishing floor covering on the floor. To do this, choose a room where the total thickness of the screed and floor covering is greatest. The level of the finished floor in this room is taken as the level of the finished floor of the floor.

Then, the selected level of the finished floor of the floor is transferred to other rooms. The screed level in the room should be lower by the thickness of the floor covering.

In floor rooms, the thickness of the screed, selected for structural reasons, is adjusted to the specified level. If possible, adjust the level of the screed base, for example, change the thickness heat and sound insulation under the screed. Choose the most economical option.

To determine the levels of surfaces when installing screeds in a house, it is convenient to use a laser device - a level gauge, or a hydraulic level - a transparent tube filled with water. Application of slats with bubble level will not provide the required accuracy.

Laying the screed

Laying the screed indoors is done in one step, without interruptions. When planning work, take into account that the traditional solution must be laid within two hours after preparation. The shelf life for mortars prepared from ready-mixes is indicated on their packaging.

The solution is placed a few centimeters outside the doorway, and then the excess is cut off along the border of the expansion joint.

The surface of the screed is smoothed over with a trowel 8-10 hours after laying, until the concrete has completely set. The semi-dry concrete screed laid using a concrete pump is rubbed down after 3-4 hours. Smoothing eliminates minor roughness on the surface. There is no need to grout the screed if tiles will be laid on the screed.

Screed care

The screed should remain damp for a week after installation. At this time, the screed should not lose moisture, otherwise the strength of the screed will decrease. To prevent the screed from drying out, cover it plastic film or sprayed with water daily.

After seven days, the film is removed, the room is ventilated and the screed is left to dry. After another three to four weeks, tiles can be laid on the screed. Moisture-sensitive floor coverings are laid on the screed after four to six weeks, when the moisture content of the screed is less than 3%.

Floating screed in the floor on the ceiling

A floating floor with a concrete screed is installed on the reinforced concrete floor between floors. The floor is called floating because the screed does not have a rigid connection with the structure of the house.

The floating screed is separated from the walls and ceiling by a layer of elastic mineral wool. This floor design provides sound insulation between rooms of the house, and also allows the screed to move with changes in temperature and humidity.

If the floor is dry, with a humidity of no more than 3%, and the lower room is heated, then soundproofing slabs can be laid directly on the floor concrete. Otherwise, a vapor-waterproofing film is laid between the ceiling and the sound insulation slabs.

How to choose a material for sound insulation -

Sound insulation layer made of slabs mineral wool Cover the top with construction polyethylene film. The sheets of film are placed on the walls to a height of about 20 cm. The film strips are overlapped. Overlap amount 20 cm.

The film prevents the penetration of cement laitance from the freshly laid mortar into the sound insulation layer and into the edge strip.

A reinforcing mesh of steel wire with a diameter of 3 - 4 is laid on the film. mm. with cells measuring 100 x 100 mm. or 150 x 150 mm.

The floor screed can accommodate heating pipes to radiators, as well as pipes with electrical wiring. The pipes are laid on top of the reinforcing mesh and secured to it with plastic clamps.

It is recommended to wear corrugated covers on heating pipes and wires. plastic pipe. In the covers, heating pipes will be able to move freely when the temperature changes. In addition, corrugated pipes protect communications laid in the screed from mechanical damage during pouring cement mixture.

To level the cement mortar in the screed, beacons made of pipes or other profiles are placed on the reinforcing mesh. Beacon pipes are laid in increments of about 1.5 m. and align in horizontal plane using a level. The position of the beacons determines the thickness of the screed. Recommended screed thickness for residential premises is no more than 6 cm.

A cement mixture is placed in the space between adjacent beacons. Moving along the beacons rule or edged board distribute the mixture and level the surface.

Eight to ten hours after installation, the surface of the screed is smoothed (rubbed). Grouting can be omitted if ceramic or stone tiles will be laid on the screed.

After the cement mixture has hardened, the parts protruding from the screed are cut off edge tape and construction film.

Watch the video, which shows in detail how to mark the level and thickness of the screed in the premises.

Features of screed for heated floors

If pipes will be laid in the screed, then it is better to use a ready-made dry mixture specially designed for this purpose to prepare the solution. IN ready mixture for heated floors contains additives that increase the elasticity of the solution.

If the mixture is prepared independently, then an emulsion is added to the solution to increase elasticity. For example, home craftsmen add PVA glue at the rate of 2 l. by 1 m 3 solution.

The screed should cover the underfloor heating pipes with a layer thickness of at least 4–5 cm. Thus, the total thickness (taking into account the diameter of the tubes is 1.6 cm) will be – 6–8 cm.

Caring for the heated floor screed for the first three weeks is carried out in the same way as usual. Before laying on the screed finishing coating, the screed must be thoroughly dried. To do this, 21 days after laying the screed, turn on the heating and increase the temperature by 5 every day. °C until it reaches the limit - 24 °C.

This temperature should be maintained for 14 days, and then reduced daily by 5 °C. Consequently, heating of the screed lasts another 23–24 days, which should be taken into account when scheduling finishing work.

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Repairing an old coating is impossible to imagine without quality basis. Screeding a floor with your own hands is a completely doable undertaking that allows you to save on paying for hired craftsmen. To deal with it quickly and without extra costs, it is necessary to prepare both theoretically and practically. The greatest difficulty is usually caused by two stages: preparing the solution and installing the beacons. However, with a certain dexterity, many, even novice masters, manage to complete them without much difficulty.

The screed is rough coating, the thickness and quality of which are determined by the conditions of further operation and the unevenness of the base. Its device is required for leveling the surface, when raising the floor level, replacing wooden flooring. It can be wet and dry. Concrete screed is popular. Although it is labor-intensive and requires a lot of time for the solution to dry, it is highly durable.

A standard set of materials that you will need to prepare a floor screed with your own hands:

• cement grade M400 or M500;
• clean, sifted sand at a small thickness, with the addition of stones to create a thicker base;
• water;
• plasticizer - improves the characteristics of the finished mixture, promotes its rapid drying, makes it more plastic;
• container for preparing the solution, ideal option is a concrete mixer.

In addition, you need to take care in advance of a water hose with a spray nozzle, screws for fixing the beacons, a screwdriver, a level, a trowel and a rule. It doesn’t matter where you plan to screed the floor in a private house or in an apartment. The set of tools may vary slightly depending on the capabilities and characteristics of the work in a particular location. Let's consider step by step order, dividing it into five stages for convenience.

Stage one is preparatory. Completely remove the old coating. The surface is thoroughly cleaned of debris, dirt and dust. Then it is primed. Instead of soil, you can moisten it well with ordinary water, supplying the liquid with a hose with a sprayer. Here you need to find " golden mean": we don’t spare water, but we shouldn’t create a swamp either. If the heated floor screed has a large area, you can wet it gradually as the work progresses.

Stage two – installing beacons. They can be wooden or aluminum, which one to choose is up to everyone to decide for themselves. Let's briefly look at their features:

• wooden - secured with self-tapping screws, they will need to be removed from the finished screed;
• aluminum ones - they are placed “on the solution”, there is no need to take them out.

Beacons are installed at a distance of about 1 m from each other. This will make it easier to “tug” the solution with the rule in the future. The quality of the finished coating depends on the correct placement of the beacons. Therefore, be sure to use a level and securely fasten the slats.

Stage three - prepare the solution. First, mix the components of the mixture in proportions of 1 to 2 or 3 - cement and sand (for a bucket of cement, 2 or 3 buckets of sand, respectively). The most difficult thing is to add the right amount of water: the mixture should turn out thick and plastic, like good sour cream. The “correct” mixture does not stick to the instrument and does not spread. The prepared solution is evenly filled into the space between the beacons.

Stage four – leveling (tightening) the solution. The rule is laid on the slats so that it closely touches the beacons. Then they pull it together, creating flat surface. The resulting shells are filled with solution and tightened.

Stage five – removal of beacons. This point does not apply to those who used aluminum slats. The procedure should be performed approximately 3-4 hours after the start of setting. In order not to compromise the integrity of the coating, a pair of wide boards are laid on it for movement. For convenience, we screw several screws into the rail, hook it with a nail puller and take out the beacon. Fill the resulting void with solution. The finished coating is left to set and dry. This will take 2-3 weeks, after which you can begin further work.

Requirements for floor screed

When the screed is ready, it is necessary to evaluate the quality of its implementation step by step. For a professional this will not be difficult. To help the novice master, we will formulate the main points:

1. Visual control. The coating should be smooth, look uniform, and have a uniform gray color.
2. Accuracy check. It is carried out with a rule of approximately 2 m in length to identify gaps. If their size does not exceed 4 mm, the job is done well.
3. Coverage quality. Using a regular hammer we check the mechanical strength of the surface. Make several tangential blows with a hammer. There should be no traces of them.

To avoid cracking of the coating during the drying process, especially if the house is hot enough, the screed is moistened with water throughout the entire period.

When screeding on the ground, for example, in a garage or outbuildings, it is necessary to take into account some features. Firstly, you will need cement of at least M300, and secondly, in case of unstable soils, it is necessary to additionally make a reinforcing mesh. It will give the coating strength. A brief procedure for performing such a screed:

• thorough soil compaction;
• drainage bedding made of sand and gravel;
• laying reinforcing mesh;
• placing formwork and beacons;
• pouring concrete.

In some cases, another so-called finishing layer is made. First, thermal insulation, vapor barrier, and reinforcing mesh are laid. Then it is filled with a cement-sand mixture or a special flooring compound.

Building codes offer several options for rough screed, the choice of which depends on the proximity of groundwater and location relative to ground level.

Experts advise be sure to remove upper layer soil:

• it is loose, which means more effort will be required to compact it;
• plant and animal remains will begin to rot, negatively affecting general state coverings.

The thickness of the layers depends on the region: the warmer, the thinner. It is important not to forget about waterproofing. If groundwater located high, it is necessary to provide measures for their removal.

DIY floor screed

Owners of private houses without a basement often face the question: should they screed on the ground or with a ventilated underground? Do-it-yourself floor screed, laid directly on the soil, is deservedly popular. It is simple to implement, inexpensive, and often serves as the basis for a heating structure. You should refuse this option only in a few cases:

1. It requires adding soil to a height of about 1 m.
2. The building is placed on a columnar or pile foundation.

The labor costs for backfilling and compaction under such conditions are unreasonably high.

Preparation of the solution

The basis of the screed is a concrete mixture of cement, sand and water. Popular question: how to make a floor screed solution? The easiest way is to use special mixtures. They are purchased in hardware store, prepare according to instructions. If this is not possible, then you can do it on your own.

Standard ratio: 1 to 3. This means that 3 parts of sand are taken for one part of M500 cement. If cement brand M400 is purchased, then the ratio is changed to 1 to 2. The components are thoroughly mixed and water is gradually added. Ready solution It should be neither dry nor runny. If mixing takes place in a concrete mixer, the mixture should not stick to the walls, rolling around like a wave during mixing. A few words need to be said about the plasticizer. Many consider its addition just an unnecessary waste of money. However, it is inexpensive, its consumption will be no more than 2% of the weight of cement. At the same time, it has a positive effect on the quality of the finished mixture.

Pouring the floor

The ideal option is when pouring the floor screed of one room is done at a time. When performing this, you should remember: the setting time of the solution is no more than an hour, it will not be possible to level or correct flaws after this. Adding water to a solution that is laid on the surface is strictly prohibited.

Start pouring the screed under the heated floor from the side opposite the door. The strip between the beacons is filled with the solution, then it is leveled using the rule. Movements should be uniform, with slight movements to the sides. Having finished one section, you should pierce it in several places with wire. This will allow the air to escape. You can reach the surface in about 2-3 hours. It is best to use a sheet of plywood for support.

For coatings that require a perfectly flat base, a finishing floor screed is performed. In some cases, it is enough to sand the concrete thoroughly by installing a grinding wheel on the grinder. You will have to apply another layer of mortar under the self-leveling floor. It is made more liquid so that it spreads and creates a smooth surface under the influence of gravity.

Leveling a wooden floor

There is often debate among builders about how best to make a screed on a wooden floor. Some are categorically against the “wet” option, insisting that concrete and wood “will not make friends.” Therefore, it is recommended to give preference to the dry version. However, when installing a heated floor or upcoming installation tiles You can’t do without a concrete base. Knowing some nuances and secrets, it can be completed without loss of quality.

The peculiarity of wood is that lumber, even after use, constantly changes its characteristics (moisture level, size). Concrete, on the contrary, after gaining strength, practically stops any “movement”. Therefore, the combination of these materials can lead to a violation of the integrity of the concrete layer.

Do finishing fill It is strictly forbidden to use a new wooden floor. Must be at least 3-4 years of operation.

A reasonable question arises: how to make heated floors on wooden floor using concrete pouring? For this purpose, a simple but efficient technology. Its essence: to create a boundary between wood and concrete. The process of creating such a “pie”:

• carefully examine wooden base to remove rotten or cracked boards;
• secure the joists and floorboards, seal the cracks with sealant;
• Fill the tree with waterproof soil and wait for the time specified in the instructions;
• draw a clean floor line on the walls;
• attach a damper tape or strip of foam polystyrene around the perimeter of the room;
• cover the floor with polyethylene, extending it 15 cm along the walls;
• install beacons on the solution;
• pour the solution.

When the screed wooden floors completed with your own hands, it is generously moistened for a day, covered with polyethylene after sprinkling water on top. The key to a solid foundation is maintaining stable temperature and humidity conditions.

A screed is a layer between the concrete base of the floor and its top covering. It is necessary for high-quality leveling of the floor. The durability of the work result depends on the screed. Installation of the screed is necessary regardless of the type of coating used: parquet, tiles, linoleum, laminate, carpet, etc.

By manufacturing method

1. Wet. It is a cement-sand mixture. A special dry composition is also sold - it is made using cement based, or using gypsum. It is poured over and the surface is completely leveled. If cement or sand was used for the screed, the surface is reinforced. Dry mixtures do not require this procedure. The option is universal and common in construction. 10 cm or less is the optimal layer thickness.
2. Dry. Also called prefabricated screed. It is a structure made of large sheets with a thickness of 15 to 30 mm. In case of strong differences in surface levels, the dryness of the screed will not allow achieving the desired degree of leveling. Then, under the floor covering, a layer of dry screed is placed on top of the wet one.
3. Semi-dry. It differs from the classic, wet production method by a significantly smaller amount of water in the mixture. Benefits of this type screeds are a short period of time between laying the screed and the floor, no leaks. The presence of fiber fiber in the mixture helps to minimize the number of shrinkage cracks.

   
   

Mechanized semi-dry floor screed provides a minimum amount of construction waste after installation. The mixture is usually mixed outside and supplied through a hose.

By number of layers

1. Single layer. It is laid at a time to the required thickness.
2. Multilayer. Consists of rough and finishing surfaces. For example, to ensure rigidity at the junction of the slabs with the floor, first lay rough concrete option, and when finishing, an absolutely smooth layer is laid on top finishing screed. The rough screed thickness is 20 mm or more, the finishing screed is from 3 to 20 mm.

By connection type

1. Solid. It is firmly adhered to the base coating layer.
2. Floating. Not connected to anything. It is used when it is necessary to use a film with waterproofing properties, as well as sound or heat insulation. The optimal thickness is 35 mm or more.

Screed materials

Cement is the most common binder for screeds, as is gypsum. The following fillers improve the properties of the mixture: sand, polymers, mineral-based additives. To obtain the required consistency, the composition is diluted with water.

1. . Its screed is moisture-resistant and can be used for any type of floor structure. Cement is mixed with sand, the optimal ratio is 1 part cement to 3 parts sand.

   There is also sand concrete - a mixture sold in stores. Sand concrete has a drawback - rapid shrinkage. Therefore, it is necessary to ensure the uniformity of the composition and the thickness of the poured layer, which must be at least 30 mm, otherwise the screed will crack.

   To ensure uniform stress distribution and protection from cracking, the screed is reinforced from the inside or a portion of propylene-based fiber is added to the solution. After installation, the screed is periodically wetted for approximately 10-14 days. The screed takes a long time to dry and for moisture-sensitive coatings - laminate and parquet - it will remain too wet for at least 20 days.

2. Gypsum. Plastic, easy to install screed. Does not shrink, it can be laid thin layer. Complete drying– in 1-2 days. Recommended for wooden floors. But not suitable for rooms with high humidity, as the plaster will become like dough. If polymers are added to the plaster, the screed can be used in rooms with moderate humidity.
3. Concrete. In terms of composition and manufacturing technology, concrete screed is similar to cement screed. The main difference is that it is added to the mixture cellular concrete. There are different types of concrete screed: foam concrete, expanded clay concrete, perlite concrete.
4. Self-leveling or self-leveling mixture. Sold in finished form, designed for various floor coverings. It can be thin-layer, from 2 to 7 mm, and thick-layer, from 5 to 30 mm. If the floor unevenness is large, first make a rough rough screed, and a self-leveling mixture is placed on top.
5. . The composition is similar to drywall. It is a durable building board coated with a waterproofing compound. Laying is done on a pre-filled layer of polystyrene. The slabs are laid slightly overlapping each other to close the joints. The main advantage of the screed is that you don’t have to wait for it to dry. The final floor covering can be installed the next day. Often used for installing screeds in apartments.

Materials

1. 1. 1. Concrete mixer.
      2. Hydraulic level.
      3. Rule.
      4. Construction bubble level.
      5. Master OK.
      6. Drill with mixing attachment.
      7. Stationery knife.
      8. Bucket.
      9. Pencil, marker.
      10. Roulette.
      11. Ruler.

Stages of work

Stage 1. Defining the horizon

The zero level is measured using a spirit level - otherwise called the water level. Marks are placed in all rooms. Optimal height- from 1.2 to 1.5 m from the floor level. The starting mark can be placed anywhere. The second and all subsequent ones are marked by the water level along the horizon, but not the floor.

All points are connected and a zero level is obtained. Throughout all installation work, it will determine the horizontal plane. Check the accuracy several times zero level.

Sometimes expanded clay or gravel is poured under the screed. Then they retreat a few cm from the marked point and make an additional line for pouring the selected pillow material along this level under the screed.

Stage 2. Determine elevation differences

This is necessary to calculate the correct screed level and the required volume of solution.

IN different rooms measure the distance from the old floor to the zero level point. We write the resulting value at each measurement location. It is better to make more points so that the measurements are more accurate. The minimum value is the maximum level of the old floor, and highest value shows it minimum height. The difference in values ​​is the difference in height of the old floor.

For example, max = 1.30 m, min = 1.25 m.

1,30 – 1,25 = 0,05.

That is, the height difference is 5 cm.

30 mm – minimum thickness cement screed, where a plasticizer is added. We mentioned earlier that otherwise cracks will appear along the screed. Builders sometimes add liquid soap as a plasticizer. And on the packaging of the self-leveling mixture, the manufacturer indicates optimal thickness layer.

For multi-level screeds, calculate the difference in heights. Height differences in floor level at the joints of coverings are not allowed. The screed is planned differently according to levels: the thickness of the coatings is not identical. The difference in it must be compensated for by differences in screed levels.

Let's say in the kitchen - ceramic tile, the room has parquet. The layer under parquet will be thicker than for tiles, and it is multi-layered. We sum up the thickness of all layers, including the parquet itself, and subtract the sum of the tile layers, including the tile itself. We get a screed difference. It is recommended to take a spare 2 mm from the tile side if the layer for the parquet turns out to be higher.

Stage 3. Surface preparation

Clean the base coat. Commonly used construction vacuum cleaner. If it is missing, you can simply sweep it well, then wash everything with a regular cleaning agent. Using a primer you can do additional dust removal. It is optimal to use the Betonokontakt product - it provides good adhesion for the screed and the base, making the surface rough.

Temporary waterproofing is required for partitions and walls. For this purpose, you can use roofing material. The height of the roofing felt tape is 10-15 cm from the level of the screed.

Next, we inspect the base. Peelings are not allowed, they must be cleaned. If there are large cracks, cover them with a thick mortar based on non-shrink cement. If the floors were “ironized” during construction or coated with “cement milk”, then the film is removed so that there is proper adhesion to the base coating.

Stage 4. Placing beacons

The screed is aligned along them. Typically, rigid elements are used as these - metal profiles that can be fixed in a stationary position and not be afraid that they will bend at an unnecessary moment.

The mounting method is different: you can build a slide from cement or simply screw the beacons into the floor. An important requirement is the parallelism of the guides. The distance between adjacent ones should allow you to put on the ends of the rail, along which the composition will be leveled.

Using a rack level, the beacons are aligned in length and in relation to each other. Where differences in height occur, plywood formwork is placed so that the solution cannot flow into another room or area.

Stage 5. Mixing the composition and pouring the screed

Few people do it manually; more often they use a concrete mixer - this way the composition turns out to be more uniform. You should not increase the proportion of water to make the mixture homogeneous, otherwise the screed will be fragile. For this purpose, special additives are sold that make the solution plastic and homogeneous.

The filling should resemble a thick dough without lumps, spreading, but not spreading over the surface. It is used for 1-1.5 hours and in one go. It is not allowed to leave it for several days. Also, you should not flood the room in parts over several days. The exception is different levels of screed or different rooms.

The solution is poured between the beacons and leveled with a rule, which is moved strictly along the beacons, shifting the excess mixture. To level the surface of the screed, the rule is to additionally make left-right movements.

The process of leveling a concrete mass using a rule

Video - Floor screed

Stage 6. Post-installation care

A simple operation, often ignored by workers. It consists of watering the coating 2 times a day. If this is not done, the screed will crack. The watering period is 10 days.

The cement screed needs up to 28 days until it becomes strong enough. What happens at the same time chemical processes require sufficient quantity moisture.

The beacons are pulled out approximately 3 days after the installation of the screed is completed. The recesses are primed and filled with a new portion of the solution. After this, we wet the coating again and cover it with polyethylene film for 2 weeks. In some cases, this is not recommended, then moisturizing is also done often - 2 times a day.

Stage 7. Checking the work

It is done in several stages.

Leveling the floor according to beacons

The screed is used to level the floor, strengthening weak concrete foundations, repair minor defects, pouring heated floors. It is also necessary as a base for most floor coverings. The main types of screed are cement-sand mixture (can be poured and semi-dry), self-leveling mixture, combined and examples - GVL technology.

Before making a floor screed, you should decide what operational strength of the screed is required. For residential premises it is sufficient if the strength is equivalent to M-150 concrete and, therefore, simple cement-sand mixtures can be used, for commercial or industrial premises polymer-cement ones are required, equal in strength to M-400 concrete.

Cement to sand ratio table

First you need to find the highest point on the floor. If the height difference is 1-1.5 cm, then it is recommended to use a self-leveling leveling compound; if more, use a cement-sand mixture.

It is necessary to apply a special primer mixture to the floor to increase the adhesion of the screed to the concrete. The degree of dilution of the primer also depends on the degree of unevenness of the floor. It is believed that if the height difference is up to 2.5 cm, it must be diluted to the state of “jelly”, more than 2.5 cm - to the state of “sour cream”.

Screeding the floor with your own hands using a self-leveling mixture is the easiest way. Simply dilute the mixture according to the instructions and apply it to the floor. Next, you need to carry out preliminary leveling with a large roller. The mixture will level itself to a horizontal level due to its high fluidity. The mixture will gain full strength in two weeks. The most common method is screed with a cement-sand mixture.

Currently, fast and inexpensive way This .

After detecting the highest point of the floor, you need to install beacons. It should be noted that the height of the screed should be 3 cm above this point. The beacons are attached with alabaster, or they can be installed in specially drilled holes in the floor. Now we dilute the mixture and apply it to the floor. Using bulk mixture, it is enough to apply the required amount to the floor and level it with a rule of 2 meters in length, periodically checking with a level. If you take a semi-dry mixture, then first apply base layer, put it on it metal mesh and apply a second layer of the mixture, which is narrower and leveled with a wide spatula. If necessary, the mixture can be added.

When the screed can support the weight of the body, remove the beacons and cover everything with film or a damp rag for 10 days. This will create optimal conditions for drying and acquiring strength properties. The screed will dry completely in four weeks.