How to make an even screed indoors. Perfectly flat floor: we make a screed

Floor screeds are made in order to leveling the base or giving it a certain rigidity. Such work allows you to get a prepared surface and provide a standardized heat assimilation of the floor. In addition, the creation of a screed contributes to the formation of the necessary slope and shelter of most communications.

Screed types

a multi-layer type of screed consists of several sequentially laid layers with the implementation of an obligatory interlayer adhesion.

Screeds can serve as a finishing surface for floors or be used as an intermediate layer, followed by the laying of a selected topcoat (for example, for).

By design features, all floor screeds are divided into a solid type, including multi-layer and single-layer types, as well as a prefabricated type.

a single-layer type of screed is laid over the entire thickness at once and in one layer;
a multi-layer type of screed consists of several sequentially laid layers with the implementation of mandatory interlayer adhesion;
the prefabricated type of screed includes several elements that are absolutely ready for direct laying on the floors.

The type of slab adhesion allows the screeds to be divided into the following categories:

coupled to the base of the screed

They are characterized by the absence of separation layers between the base and the screed and are highly dependent on the moisture content of the floors themselves. Such screeds perfectly withstand heavy loads, but are characterized by uneven shrinkage, which can provoke the formation of numerous cracks.

screeds on separating layers

They help to reduce the dependence of the screed on the moisture content of the base itself and are based on the use of a separating layer that prevents adhesion between the screed and the overlap. The separating layer can be made of bituminous or oiled paper, as well as polyethylene films. The specified strength is based on the thickness, which for this type of screed must be more than three centimeters.

Screed "floating" on the insulating layer

They are independent building structures in which the underlying layer is represented by heat and sound insulating materials. Stone or mineral wool, expanded polystyrene, cork or any fibreboard can be used as an interlayer from concrete floors to a "floating" screed. The thickness of such screeds should not be less than five centimeters.

"Floating" screeds are characterized by a high degree of heat and sound insulation of floors and do not depend on the moisture content of the concrete base. The main disadvantage is the insufficient degree of compressive strength and the significant thickness of the entire structure. Additional reinforcement may be required for the top layer of the screed.

In addition, there are several types of floor leveling screeds (read about self-leveling floors), which are most often performed in the process of renovating apartments, baths (for laying tiles on the bathroom walls) and other residential premises, as well as small offices. The varieties of such screeds include cement screeds, dry and semi-dry screeds.

Traditional cement screeds based on ready-made dry mixes

The best option is a mixture of M - 300, but the use of M - 200 or M - 150 is allowed.

They replaced the standard cement-sand mixture - concrete, which was produced directly at the place of repair work or delivered in a form ready for pouring. The basis of such mixtures is represented by cement, sand and fine gravel. The best option is a mixture of M - 300, but the use of M - 200 or M - 150 is allowed.

The main advantages of such mixtures are as follows:

the presence of an optimally selected composition;
the weight is lower than that of standard concrete solutions (read also a useful article about technical ones), which allows you to reduce transport costs, labor costs and loads on floor slabs;
no need for kneading use a special technique, and the whole process is easily carried out by means of a conventional construction mixer or a mixing attachment on an electric drill;
the ability to reduce the thickness of the poured layer to five millimeters without losing strength and quality characteristics;
the presence of special additives in the dry mixture makes it possible to increase the strength and solidity of the base for any finishing;
the ability to choose the best option for the mixture for the planned operating conditions of the floor or the type of finish;
the use of dry mixes allows you to reduce the hardening time of the screed;
there is no need for any construction skills, and the process of self-pouring is based on strict adherence to the instructions attached to the mixture.

Modern dry mixes, depending on the category of the main binders, are divided into cement and gypsum.

Cement-based mixtures:

with the presence of large fractions of sand, expanded clay or granite chips to perform "rough" leveling with a layer thickness of three to eight centimeters;
with the presence of a filler of fine fractions for finishing leveling with a layer thickness of about five millimeters;
self-leveling mixtures with good spreading and self-leveling of a layer of five millimeters;
ready-made dry mixes for special purposes for screed in the "warm floors" system.

Gypsum-based mixtures:

short curing times;
environmental friendliness;
excellent thermal insulation properties.

Self-leveling screed

Such mixtures are characterized by a high level of self-leveling and have a variety of purposes. Self-leveling screeds based on dry building mixtures are used to obtain an even horizontal base. The composition of these screeds includes a cement base and a coarse-grained mineral filler with a fraction size of less than 0.5 millimeters.

It is advisable to level the floor surfaces with self-leveling screeds in apartments, private houses, garages, public or industrial premises with large differences in height. The indicator of the differences can vary from three to fifteen centimeters.

Modern dry screed

The main advantage is the ability to carry out finishing work immediately after dry leveling.

A fairly common screed for floors, including wood flooring. It is characterized by the absence of the need to use water, and the leveling process is carried out by installing special beacons.

The mixture leveled according to such elements is covered with sheet material, which can be used as gypsum fiber sheets or OSB boards. Such materials can act as a base for a floor finish.

The composition of the mixtures is based on certain proportions of expanded clay sand or polystyrene granulate, which makes dry screed an excellent heat-insulating and sound-absorbing material. The main advantage is the ability to carry out finishing work immediately after dry leveling.

Do-it-yourself alignment with mixtures

The required amount of mixture for dry screed is calculated as follows:

calculate the planned volume by multiplying the area of the room in square meters by the required layer thickness in meters;
the required value is divided by 0.1, and multiplied by the rate of consumption of the mixture per square meter with the parameters of the screed thickness of one centimeter. The calculated value in kilograms is correlated with the weight of the mixture in bags.

The technological process for the device of a screed based on ready-made dry mixes is similar to work with concrete mortar. At the initial stage, a zero level is determined and a beacon system is placed, along which filling and alignment is performed.

The main difference lies in the preparation of a working solution from a ready-made optimized composition. After adding the required amount of water, according to the instructions, to the mixture, stirring is performed with a construction mixer or a drill attachment, followed by infusion of the solution for five minutes. The finished solution must be thoroughly mixed again.

Major mistakes

Most often, the technology for preparing a working solution and performing leveling is violated.

Most often, the technology for preparing a working solution and performing leveling is violated in the following situations:

the solution thoroughly mixed to the desired consistency did not have time to infuse and was immediately used for pouring;
ready mixes based on gypsum divorced in large quantities and are not consumed for a short time, which contributes to excessive thickening of the finished solution;
an increase in the time interval for pouring two adjacent surface areas, which violates the solidity of the resulting coating;
In addition to periodic stirring, an additional amount of water is added to a highly thickened working solution, which makes the working mixture unsuitable for further use.

Material consumption and estimated cost

cement mixture with polystyrene fillers "Knauf-UBO" - 7.5 kg at a thickness of 1 cm / sq. m. at a price of 357 rubles. for 25 kg.;
plaster mix for finishing screed "Knauf-BODEN 15" - 16 kg at a thickness of 1 cm / sq. m. at a price of 557 rubles. for 25 kg.;
universal mixture with a self-leveling effect "Ceresit-CN 175" - 16 kg at a thickness of 1 cm / sq. m. at a price of 437 rubles. for 25 kg.;
extra-strong universal mix for the "BergaufBase" screed - 20 kg at a thickness of 1 cm / sq. m. at a price of 237 rubles. for 25 kg.;
high-strength cement screed "Osnovit-Startoline T41" - 20 kg at a thickness of 1 cm / sq. m. at a price of 207 rubles. for 25 kg.;
screed for reinforcement with fiberglass "Armmix-Pol" - 22 kg with a thickness of 1 cm / sq. m. at a price of 327 rubles. for 50 kg.

In order for your floor to serve you for a large number of years, and look perfectly flat, before you start laying floor tiles, you should first make preparatory work and level the floor surface. Now let's try to consider how it is worthwhile to competently approach the solution of this problem. Let's, together with the portal, learn how to make a floor screed indoors.

What is the screed

If you do not know how to make a floor screed with your own hands, then you should watch the video below. Before you start talking about this process, you need to talk about what a floor screed is.

So, floor screed can be done using all kinds of materials and using different techniques. There are the following types of screeds:

Concrete screed. This type of screed is one of the most common. Such a screed is mainly used for the initial leveling of the surface of the floor. If the surface has a large number of drops, then this method can be called the most suitable. The fillers for this leveling method are usually sand and cement. But to complete this work, you will need to spend a lot of time and effort.

Self-leveling screed is performed mainly from prepared mixtures. The layer for leveling in thickness comes out about 3 cm.It is used at the end of work to level various differences in the floor surface. This method is suitable for almost all types of existing flooring.

Dry screed It is mainly produced if you need to level a floor that has very large irregularities with a height of 4 to 11 cm. There are two options for manufacturing this type of screed.

A) Alignment to lags. Materials such as plywood, chipboard or various other types of sheet materials are used.

B) Leveling using gypsum fiber sheets. For this type of screed, German materials from Knauf are quite often used. For the correct choice of the material required for leveling the floor, you need to know what is the general condition of the floor surface and what type of floor covering you will use at the end of all work.

The purpose of the screed

In order to make complex repairs to your floor, in any case, you should make a screed of its surface. Now let's try to find out what all the same functions this screed has.

The main purpose of the screed is to form a flat floor surface. For example, a material such as laminate, parquet or linoleum requires a perfectly flat base on the floor surface.
Another main function of this base is to increase the rigidity of structures.
The base has excellent heat and sound insulation properties.
Thanks to the use of the screed, it is possible to raise the floor to any level without any problems.

Floor screed requirements

To maximize the performance of its functions, the screed must meet all the necessary requirements and standards. Namely:

The screed must be strong in order to withstand the specified compressive loads.
The density of the constituent substance of the screed over the entire surface of the room should have the same thickness.
If the screed is poured over the soundproofing layer, then its thickness should be at least 4 cm and not more than 2.5 cm, along the floor slabs.
The screed should be 2 cm thicker than the diameter of the pipes that need to be hidden in it.
When pouring onto a soundproofing layer, you need to retreat 3-6 cm from the edge of the wall. This indentation will also be filled with soundproofing in the future.
A monolithic layer is poured onto the waterproofing. For this, as a rule, a film of very thick polyethylene is used or roofing material is used. In this case, the waterproofing layer is placed 6-11 cm on the walls of the room.
The surface layers of the screed should not have chips or cracks.

Necessary preparatory work

The amount of work that, as a rule, must be done before starting laying the screed depends mainly on its type and on what state the floor surface has. But still it will be necessary to resort to performing the following actions:

To begin with, you should conduct a survey of the floor, and if necessary, dismantle the old coating.
After dismantling, it is necessary to carry out a complete cleaning of debris.
Now it is worth doing wet or dry cleaning of the floor surface with a brush or vacuum cleaner.
Determine the required floor level for its subsequent lifting, using a laser tape measure.
Now it's worth installing the beacons.

Work technology and features

In this article, we are talking about how a do-it-yourself floor screed in an apartment should look like. In addition to our tips, there is a video in this article that will also help you see this.

The correct implementation of the floor screed depends on the fulfillment of all the standards provided for this work. You should know what composition of the mixture should be used in this case, as well as how to properly knead and install it. The order of your further actions will depend on what type of screed you have chosen.

Carrying out work on laying a concrete screed.

Leveling the floor in this way is very popular and quite common, despite the fact that this work is quite difficult and time-consuming. First of all, it is necessary to completely free the entire surface of the floor from objects: remove furniture, various interior items, etc. from the room. Then they begin to remove its old coating from the floor, while painstakingly examining its bases. The composition of a concrete screed, as a rule, includes the following components: sand, cement and other fillers. To complete these works, you will need:

Building level.
Roulette.
Beacons.
Spatula and trowel.
Mixing utensils.
Construction knife.
A drill with a nozzle for mixing the mixture.

Most construction stores sell pre-prepared mixtures of sand and cement for the manufacture of concrete mortar. As a rule, all these elements are already present in them. But if you do not want to spend money, then it is quite possible to make this solution with your own hands, provided that you have all the necessary ingredients in the right proportional ratio.

Basically, in order to make a screed, three parts of sand should be taken for one part of cement. And plasticizers will help the mixture become more elastic, and it will not harden quickly enough, which will prevent the appearance of chips and cracks on it. If you need to level the floor with large differences (more than 6 cm), then add fiber that has reinforcing properties to this mixture, or use a metal mesh for laying.

Pay attention to the article of the site: How to glaze a balcony with your own hands

The screed of the floor surface in the room with concrete mortar should be carried out in the following sequence:

The floor surface is measured using a building level, then all existing differences and irregularities are determined.
All chips and cracks on the floor surface are carefully cleaned and embroidered.
The surface of the floor covering is cleaned of debris and dirt.
The waterproofing layer is being laid (if necessary).
With the help of the building level, the beacons are installed and fixed on the floor surface.
Now they are priming the floor.
After that, a concrete solution is made from a dry ready-mixed mixture and additional components. As a rule, immediately after the mixture is made, it is laid on the floor surface.
When leveling the solution, you should pay attention to the installed beacons. In one room, you should try to lay the solution in one day. In order for the adhesion of individual areas filled with mortar to occur better, it is necessary to use a metal mesh or reinforcement.
After all the work on pouring the floor is completed, you need to start laying it on its entire surface with a polyethylene film and leave it until it completely hardens. This procedure will help you avoid cracking.

You should also ensure that the room is completely protected from drafts and the sun. Depending on what mixture was used to fill the floor, the first steps on it can be done only after 4 days. With the help of a building level, you need to carefully check the floor surface again for whether it is even, or somewhere there are small irregularities that, immediately after detection, will need to be wiped with a special device. It must always be remembered that the time for complete hardening of the concrete screed is 25-30 days. Only after the expiry of the specified period, you can start laying the flooring or laying the thermal insulation. An exceptional option in this case is the laying of ceramic tiles. This work can be done as early as 6 days after screed.

Self-leveling screed installation

This screed is used mainly in order to obtain a perfectly flat floor surface. In this case, we mean the finishing laying of linoleum, laminate, or any polymer coatings. The main part of building stores is selling a variety of self-leveling mixtures, the preparation of which is carried out at home according to the instructions attached to them. These works should be performed in the following order. All debris and dirt should be removed from the entire surface of the floor. This work must be done with special care, since the small debris that may remain after cleaning can float to the surface of the flooded layer.

According to the instructions, it is necessary to start preparing the solution. When making it, in order to avoid the appearance of lumps, the mixture should be added to the liquid, but not vice versa. A construction mixer will help you stir the mixture thoroughly. The resulting solution should look like a creamy mass. It is saturated with oxygen, leaving for 10 minutes.

Pouring is performed, as a rule, starting from the farthest corner of the room to the corner of the door along its entire wall.

Thanks to the use of a metal brush and a needle-shaped roller, the mortar is leveled and its thickness. Based on this, the surface of the floor dries quickly enough, unlike concrete. It will be possible to make the first steps on the floor after 9-10 hours. These terms can depend on the indoor climate in the room and the thickness of the resulting layer. After pouring the floor, it must be protected from sunlight and drafts, as well as water ingress on its surface.

If you try to follow all of the above recommendations, then you will end up with a very hard surface that will not absorb any moisture in the future.

Nowadays, the answer to the question of why it is necessary to level the floor will be obvious: an even floor is the main component of a successful renovation of the entire room, the best base for covering the floor with laminate, parquet or ceramic tiles.

The main component of a successful home renovation is a flat floor.

To level the floor, you must first make a flat screed. To do this, you need a concrete solution, this type of work can be done independently.

In recent years, self-leveling concrete floors, despite the laboriousness and duration of the process, have become very popular. Their main task is to withstand a certain load.

Views

The material is classified according to the type of binder. The most common types are concrete and cement-sand. They are used for floor repair in any premises and buildings. For concrete materials, a concrete solution is used, which is laid on a layer of gravel or crushed stone, and for cement-sand materials, a mixture of cement, sand and water is used.

Anhydrite bonds are made from gypsum (binder), sand, water and gravel. They are characterized by great strength, lack of deformation, but at the same time, the reaction of water-soluble gypsum with moisture, which can cause minor problems.

Depending on the type of construction, floor screeds are rigid, dividing, floating.

The basis of magnesite materials includes caustic magnesite, bischofite solution, as well as organic or mineral fillers.
Self-leveling floors are a novelty in the construction industry. They are made on the basis of mixtures of cement, sand, aggregates and plasticizers. In addition, screeds are available in mosaic, asphalt and epoxy.

By type of construction, it can be divided into:

rigid, laid directly on the floor;
separating, which are laid on a special layer that prevents the screed from adhesion to the overlap;
"Floating", which cover heat and sound insulating materials.

Preparatory work

Before you start making a screed, you need to prepare all the tools: a building level, as a rule, a trowel, a container for mortar, an electric drill with a mixer attachment, boards or metal profiles.

How to get it right? First, the surface must be thoroughly swept, cleaned of debris and dust, primed. Ideally, dust is best removed with a special vacuum cleaner. Any peeling of the surface must be cleaned, and cracks must be covered with a thick solution. We need a list of the following tools and materials:

Building level.
Rule.
Master OK.
Mortar (concrete).
Solution container.
Electric drill with mixer attachment.
Boards or metal profiles.

It is necessary to waterproof all walls and partitions to which the screed will touch, that is, to protect them from moisture absorption. To do this, a strip of roofing material is glued to the walls so that the upper edge of the tape protrudes 15 cm above the level. Next, using the level, we make the markup that determines the level. If you only have a water level, then mark the desired equal height on the wall in several places and use straight lines to connect the marks.

When installing "beacons", the distance between them should be no more than 1.5 cm.

To make it even, it is necessary to install beacons, which can be used as ordinary boards or metal profiles, attached to the surface with screws or thick mortar. The distance between the "beacons" should be no more than 1.5 cm.

After installing the beacons, they proceed directly to the preparation of the solution in order to make a self-leveling mixture.

Using a bucket or basin, we prepare a solution for the material, mixing, for example, sand and cement with an electric drill with a special mixer attachment. In terms of density, the solution should resemble a tough dough. It is necessary to prepare the solution immediately before use, because after 1.5 hours it becomes unusable.
It is recommended to start laying from the highest point, that is, from the greatest distance between the base and the mark. The solution is laid in such a way that the surface of the "beacons" is closed, but not more than 1 cm. Then it is leveled, rolled with a needle roller in order to avoid the appearance of irregularities and air gaps. Excess solution is cut off by the rule, applying it to the "beacons".
In order for the screed to have sufficient strength, its thickness must be at least 4-5 cm. An important condition for successful work on the screed is the temperature, which should not exceed 20 ° C, and the absence of drafts. It is recommended to start and finish the screed of one level or one room in one day.

After finishing the main screed in a large room, do not forget to fill the expansion joints (small gaps between the screed parts), and also moisten the finished screed with water so that it does not crack. After a couple of days, you can take out the "beacons", and fill the resulting voids with a solution.

Smooth floors in the house are not just an indicator of a beautifully and well-made repair. A perfectly flat floor is a 100% functional use of both furniture, doors and the flooring itself. Indeed, in the presence of even, on one level throughout the apartment, floors, you can not think about how to join all kinds of floor coverings on one level, without steps and drops. With properly organized even floors, you can easily and easily open and close interior doors, not correct or repair floor surfaces that are hanging due to incorrect slopes and irregularities, constantly opening cabinet doors and drawers.

What is a flat floor for?

Floor renovation is the first and one of the most basic steps in any renovation.

Smooth floor, subsequently - this is:

quickly, efficiently and beautifully laid and correctly functioning floor covering:

if the floor is uneven, then the laminate also diverges at the seams and rises like a "house" and completely loses its aesthetic appearance;
linoleum lays down in waves and only emphasizes the unevenness of the floor, and subsequently, bubbles and quickly wipes and tears;
wooden floor boards creak, sag;
laying ceramic tiles on the floor is faster and, albeit not with lower financial costs, because a screed device is required, the cost of tile glue, although it will be required several times less than when laying on layers, the quality will increase significantly. Ceramic tiles laid on a flat floor will not "float", as when laid on layers, with an uneven rough floor covering, during subsequent use, will not come off due to the presence of voids and a decrease in adhesion, due to the more viscous tile adhesive.
no steps and drops when joining different kinds of floor coverings within the same apartment: everything lies in one beautiful, functional and safe carpet, which is much easier to clean and wash and are not afraid to stumble, forgetting about the presence of an inappropriate and unplanned step.

Nicely, quickly and correctly installed and functioning interior doors:

in the case of uneven floors, the interior doors installed according to the level do not visually appear as such, because the gaps between the door and the floor can be of different levels or even waves;
interior doors installed by a not quite competent and experienced master, in an apartment with uneven floors, may not close or, conversely, not open fully - they will need to be filed, violating the integrity and beauty of the entire door.

Furniture on flat floors not only costs better, but also lasts longer:

installed on uneven cabinet floors, dressers, kitchens and other furniture, even despite the presence of adjustable legs, stand unevenly, and sometimes even very dangerous due to the instability of the entire structure;
doors, drawers (closers), if the furniture is on an uneven surface, can open spontaneously. And this, again, is the possibility of injury, violation of the general aesthetic appearance of the furniture, as well as the rapid wear of the closers.

Therefore, people who have made an even floor in their apartment or house reviews about its operation, as well as about the quality of all repairs, leave only positive

How to make a flat floor: types of screed

An even floor, the price for which makes up a significant percentage of their estimate of the entire renovation of the premises, is a prerequisite for any high-quality repair.

You can level the floor in the following ways and types of screed:

- dry screed: type of screed for lighthouses, the main material of which is dry bulk materials - expanded clay, expanded clay sand, slag. On top of the screed material, a rough base of gypsum fiber boards, plywood is laid, which do not allow the screed to deform during operation, i.e. the floor remains level.

Advantages of dry screed: it is carried out quickly, with a fairly minimal financial cost, does not make the floor structure heavier, therefore it can reach a layer thickness of up to 20 cm. In addition, a dry screed is a good insulation and sound insulator of the floor.

- semi-dry screed: type of screed by lighthouses, the main material of the screed itself is a cement-sand mixture with a minimum addition of water. The tamping makes such a screed even, requiring skill, patience and time and, preferably, a special tool. The layer of the screed itself must be at least 5 cm or more. That is why, it is more often used on an industrial scale when organizing a subfloor.

Pros of a semi-dry screed: due to the small amount of liquid in the mixture, it is practically impossible to flood the neighbors from below, if it is practically impossible to level the floors in the apartment with it.

- cement floor screed: type of screed for lighthouses, the main material of which is ready-made cement mixtures or home-made cement-sand mixtures. The minimum layer of cement screed is from 1.5 cm.Although, with such a screed thickness, self-leveling mixtures are more often used to level the floor, and it is advisable to use a cement screed when the required layer thickness is 3-10 cm.Cement screed is a monolith that heavily makes the floor structure heavier , therefore, it is highly undesirable to use it on loggias, balconies, in houses with wooden floors. The cement screed dries, reaching full readiness - 28 days, which is long enough, because all this time, you must not start laying the final floor covering.

Pros of cement screed: evens out unevenness from the floor with significant differences in height, durable, suitable for organizing warm floors.

- self-leveling floor screed: type of floor screed for lighthouses, purchased self-leveling mixtures on a gypsum basis are used as material. Evens out irregularities from a few millimeters to 5 cm. But, due to the decent cost, it is used for leveling, the minimum height differences remaining after leveling the floor with a semi-dry or cement screed, making the floor rather smooth, not even. When the floor is poured, it dries quickly enough, therefore it requires skills and experience. Due to its fragility, it is not advisable to walk on the finished floor covering due to its possible chipping, it requires a quick organization of the finished floor. For this reason, a self-leveling screed is set up immediately before laying the finished floor.

Advantages of a self-leveling screed: dries quickly, makes the floors not only perfectly flat, but also perfectly smooth.

- floor on adjustable joists: a special type of floor used to organize a flat wooden floor. The logs are set according to the level, to some extent, they themselves are beacons and the supporting structure of the floor, at the same time.

Advantages of the floor on adjustable logs: ideal for leveling wooden floors, it is done quickly and cleanly, does not weigh down the floor structure, allowing you to level differences and raise the floor level by 5 - 25 cm.

In the process of organizing any kind of screed or method of leveling the floor, you need to know how to check if the floor is even. For this, it is best to use a quality instrument - a laser level, because bubble levels require constant calibration because the error of such levels increases during active operation.

How to make a flat floor: types of flooring

According to the results of the repair, we see only a final, finishing floor covering. And it, like the rough screed, should be even. To do this, consider the following:

- laminate best placed on a firm, level surface: dry, cementitious, self-leveling screed.

- for laying ceramic tiles you also need a solid base, therefore, a cement screed is best suited for laying it. Tiles can also be laid on a dry screed, but only with the help of special tile adhesives

- linoleum will lie evenly, for a long time and with high quality on a flat floor made with a cement screed and additionally leveled and smoothed with self-leveling mixtures. But laying it on floors on adjustable logs, as well as on a dry screed, is not desirable: the floor on a wooden or gypsum-fibrous base under the linoleum begins to condense, and then mold and rot.

- plank (wooden) floor it is impossible to lay it evenly and correctly without organizing adjustable logs, with the help of which wooden floors become even, ventilated, and therefore will last a long time. In the case of laying floorboards on a cement, albeit even, screed, it will be almost impossible to fix the boards, with a 99% guarantee, it will lead them from moisture from the screed itself, there is no ventilation gap between the screed and the wooden flooring.

Smooth floor with your own hands

There are general principles for the device for leveling the floor:

We clean the floor surface, prime it.

We organize waterproofing with special liquid mastics or film (in the case of a dry screed).

We expose and install beacons.

Pour the screed mixture, tighten it according to the lighthouse rule (cement screed, semi-dry and dry screed), level the mixture with a special spatula and a roller (self-leveling screed).

We are waiting for drying.

Before laying the finished floor, clean the screed and prime it again. After the soil has dried, the screed and rough flat floor are ready.

How you can make a flat floor of the video will tell you more clearly:

This is how the floor is leveled using self-leveling mixtures:

Level the floor with a dry screed

And the filling of the cement screed looks like this

How to make a wooden floor even can be found here:

Arrangement of a floor screed is a process that, with a good repair and even more construction, no one will be able to avoid. And in this process, a lot of dusty, dirty and wet work is usually done. After them, the screed must be left to "ripen", "helpfully" moistened for several days, without walking on the floor for quite a long time. Not to mention the money spent.

To make the result pleasing to the eye, and the process to proceed in an organized and quick manner, we suggest that you familiarize yourself with this article, which will tell readers how to make the floor screed themselves. Moreover, there is nothing supernatural and prohibitively difficult in this, of which we intend to convince our readers.

A floor screed is an intermediate layer that is organized between any base and the floor finish. What is a screed for?

To give the floor the required rigidity and strength in accordance with the expected loads.
For leveling the floor horizontally or, conversely, giving the desired slope in some areas, for example, in shower cabins.

No matter how funny it sounds, the screed is sometimes made for thermal insulation, since some of its types are capable of this.
The screed in warm floors plays the role of a large radiator, therefore, we can say that it is needed for the desired heat assimilation and distribution.
For sheltering the elements of engineering systems: electrical wiring, heating pipes and underfloor heating coils, sewer pipes.

For covering and protecting the thermal insulation layer from mechanical stress.

In some cases, the screed itself is already a finishing floor covering. For example, in garages, any technical or industrial premises, where no other coating will be laid in the future. Then, we can say that such a screed - single layer .

In many other cases, screeds make two-layer .

The first layer aligns the surface horizontally, or gives the desired slopes. Usually it is made of a cement-sand mixture or concrete. It is customary to say that the first layer is rough screed ... It is already possible to lay tiles or porcelain stoneware on it in the future.
The second layer is called clean screed ... It already makes the surface perfectly flat, under the finishing coat of the floor, for example, under the laminate, parquet, carpet. Very often, the final screed is performed giving a perfect surface when used correctly.

The screed can be laid on different substrates: compacted soil, concrete or even wood. Depending on the connection with the screed bases, you can divided into the following views:

Tied screed , which is characterized by the fact that it is firmly attached to the previous layer. More often it is a concrete screed on a concrete floor slab. The desired adhesion and uniformity of this design also provides excellent mechanical strength. Such screeds can be done only in those rooms where the humidity of the base will not be high. They are used on the second and subsequent floors of various buildings.

Screed on a separating layer ... This design must be in contact between two different materials. For example, when a concrete screed is made on the ground. Or in the case when gypsum or dry screed is laid on concrete. And also the use of a separating layer is mandatory if the moisture content of the underlying layer is higher than normal. Various roll materials based on bitumen (roofing felt), polymer films or coating compounds can be used as a separator. Obviously, the screed will already be a separate structure, so it is advisable to reinforce it and make it at least 3-5 cm thick.
Floating floor screed is a further continuation of the previous one. She will definitely arrange it if you need to apply any insulation. The floating screed is separated from the base by a layer of insulation together with waterproofing. It is also necessarily separated from the walls. It can be insulation, but of a lesser thickness, or a special damper tape. Warm water floors are necessarily accompanied by a floating screed, since in addition to mechanical loads, such a screed will still change in size from temperature exposure. Working in such conditions forces you to use reinforcement and have a thickness of at least 5 cm.
Prefabricated or dry floor screed. In our country, this is a relatively new phenomenon, but in Europe it has been used for a long time. On a prepared and insulated base of such a screed, an aggregate is poured in the form of a dry bulk material. Most often, granular is used, which is a good heat and sound insulator. Sheets are laid on top of it gypsum fiber plates fastened together. Such a screed is equipped very quickly and this is its main advantage. However, a dry screed can only be done in rooms with guaranteed low humidity and with a low or medium load on the floor.

Screeds can also vary in the way they are installed. Let's list them:

Continuous wet screed ... This is the most common, one might even say the classic way. The solution, mixed with water, is applied to the prepared base and leveled according to the lighthouses with the rule. Since the main binder for the wet process is 95% cement, such screeds gain full strength only after 28 days, which is a big disadvantage.
Continuous floor screed, performed "semi-dry" method ... This direction began to develop relatively recently. The meaning of this approach is that exactly the amount of water that is needed to hydrate the cement is added to the working solution. Such screeds dry out faster - the next day you can walk, and lay the tiles in a week. A plasticizer is introduced into the solution, which improves mobility and plasticity during installation. In addition, in semi-dry screeds, micro-fiber reinforcement (polypropylene or basalt) is often used. A fiber tie is better in terms of strength, wear resistance, tensile and bending characteristics than classic wire mesh reinforcement... The technology for laying semi-dry screeds is more complicated, the preparation of the solution assumes exact adherence to the recipes.

Laying, leveling and sanding a semi-dry screed - all in one day

Continuous floor screed using self-leveling compounds ... This method is also referred to as "wet". As we noted in this way, it is very convenient to make a clean screed. Such screeds are made with a thin layer of 0.5-20 mm, first of all for economic reasons, since dry mixes for the preparation of solutions are very expensive. But the styling technology and the result observed later are above all praise. The working solution is simply poured in strips over the surface, rolled with a needle roller to remove bubbles, and, in fact, that's it.
Dry or prefabricated floor screeds. We have already mentioned them earlier. You can read more about them in our portal.

All floor screeds, with the exception of prefabricated (dry) ones, are made on based on two main binders component - cement or gypsum. There are also others - magnesia, bitumen, anhydride - but they are not used for housing construction, therefore they will not be considered. Let's point out the strengths and weaknesses of these two main materials.

Cement screed prices

cement strainer

Cement based screeds have high strength, durability and, most importantly, resistance to water. The weak points of such screeds are the tendency to shrink when dry and the long maturation time.
Plaster based screeds strong enough and durable. The solutions are very plastic and do not shrink when dry. They have good thermal insulation properties. Can be applied to any substrate including wood. The ripening period is several times less than that of cement screeds. But there is one main disadvantage - this is the "fear" of water.

Naturally, in addition to the binder component, which is the main one, the composition of any modern solution or dry mixture also includes other components: fillers and modifiers, both of natural origin and obtained in chemical industries. Therefore, modern mixtures cannot be called only cement or gypsum. It is more correct to speak cement-polymer or gypsum-polymer .

In cement screeds, foam polystyrene chips are often used as one of the fillers, which gives the coating thermal insulation properties. The bearing capacity and rigidity of such screeds is less, this must be taken into account. At the same time, a second leveling and reinforcing layer with more durable fillers is also required.

If you need to create a screed with thermal insulation properties of great thickness, then another material comes to the rescue - expanded clay, obtained by firing clay. It is an excellent filler that has good thermal insulation properties, is inert, does not decompose with water, and is strong enough. Another plus of using expanded clay as a filler is a significant saving in cement and a decrease in the labor intensity of laying the screed.

With the help of fillers and modifiers, modern cement screeds dry faster and shrink less, and gypsum screeds partially overcome the "fear of water". But I must say that "hereditary diseases" in one form or another still remain. Therefore, cement-based screeds are still the most versatile. Gypsum-polymer also has a place, but only in dry rooms, where the effect of water in any form is excluded.

Let's move on to the practical part of the floor screed implementation. To do this, we will divide this process into stages, each of which will be considered separately. What are these stages?

Foundation preparation;
Exposing lighthouses;
Solution preparation;
Floor screed device.

At each stage, we will try to explain in detail the whole process, accompanied by photos and videos. So let's get started.

Preparation of the base for the floor screed

We will consider only three types of foundations: soil, old floor screed and concrete surface. We will not deliberately consider the wooden base, since we believe that it is easier to equip floors on it without a screed, using other equalizers: plywood or OSB sheets.

The base of the screed is soil

The best time to equip rough floor screeds on the ground is the foundation stage. Then all excavation and other work is much easier to carry out. And in modern construction they do just that. If you do this in an existing house, then, of course, the task is greatly complicated, but it is not fundamentally different. Let's note the main stages of preparation.

The first thing to do is to select the soil at a depth of at least 50 cm. In each case, the depth may be different. The bottom of the pit is cleaned and compacted.
If the soil is clay or loamy soils, then it is necessary to take care of drainage so that moisture does not "prop up" the floors from below.
Next, the creation of the so-called filtration or drainage layer begins. For this, sand is poured with a layer of at least 100 mm. It is possible and more, but note that 100 mm is the lower limit. Thereafter, the sand is tamped by hand tamping or using an electric or gasoline tamping machine.

It should be noted that the maximum allowable a layer of sand that need to be tamped - this is 200 mm. If a larger layer is planned, then the compaction work is divided into stages, but not more than 200 mm at a time. In the process of tamping, it is necessary to periodically water the sand with a hose.
A layer of crushed stone or coarse gravel is poured onto the sand. The minimum thickness is also 100 mm. This layer is rammed manually or mechanically. Crushed stone or gravel helps to better compact the sand layer and give the filter layer a rigid base.

The next step depends on how much space is left to the level from which the future floor screed will already be formed on the ground.

Vibratory plate prices

vibrating plates

If you still have 150-200 mm at your disposal, then you can lay a layer of concrete with the addition of expanded clay on a gravel-sand cushion. This will be the first stage of thermal insulation, but which will still be insufficient for most regions of Russia. Per layer expanded clay concrete then a layer of 40-100 cm of "lean" concrete is laid and compacted. It is called "skinny" because it has a low content of an astringent - cement. Skinny concrete is usually M 100 (B7.5) or M 150 (B10). The task of such a layer is not to carry the main load, but to fill in the unevenness of the underlying layer, level the surface and prepare it for waterproofing.
Another case in the preparation of ground floors for screed is the absence of 150-200 mm for the expanded clay concrete layer. Then skinny concrete comes to the rescue again. It is laid directly on the crushed stone, and the concrete layer should also not exceed 100 mm, 40-60 mm is more than enough. When laying it, be sure to tamp it so that the solution penetrates into the space between the rubble stones. Using a trowel, a rule and a float, it is necessary to form a flat outer surface, which will be the basis for the future floor screed.

The subsequent steps are the same for both cases. After the dry "gasket" of lean concrete, it is imperative to carry out waterproofing measures. For this, bituminous mastics are used, with which the entire surface is coated in at least two layers. Do not forget that the walls should be coated with mastic to a height not less than the height of the floor screed. In regions with a high level of groundwater, after the mastic, it is not at all out of place to roll on the basis of bitumen or a dense polyethylene film laid with an overlap.

Screed base - old screed

Those who got this option should not be jealous, since in most cases the old screed will have to be dismantled. Even if it gives the impression of reliability and impeccability. Even if it does not "bunch" when tapped and has a smooth surface without cracks. Here are the arguments.

a new screed, the "perfection" of the old one can easily be broken. In new conditions, delamination from the base, cracks may occur, which will affect the upper layer.

A new screed on top of the old one is an additional load on the base. This is especially true for floors on the upper floors. A slab with an area of 1 m² of cement-sand screed with a thickness of 5 cm already weighs 110 kg.

Each screed "eats up" at least 5 cm of space, which is already very significant in a standard housing. In addition, there may be problems with radiators, pipes suitable for them, thresholds and door leaf.

Screeds are never made so that they cannot be dismantled. It seems to be logical sometimes to connect two layers with reinforcing bars or wire, but no. Even tied concrete screeds stick to each other only due to adhesion and will delaminate quite easily under mechanical stress.

To dismantle the screed, it is best to call a team of workers specializing in this. From experience - it will come out much cheaper. You shouldn't even try to do it alone, as both the owners and neighbors will be exhausted if the screed is removed in an apartment building. A professional team immediately arrives with all the necessary slotting and stone cutting equipment, shovels, garbage bags, and a vacuum cleaner. They immediately take away all the garbage collected during slotting work and the owner does not need to worry about calling a separate machine. The work of professionals goes on in a continuous mode: one or two people hammer, another one or two immediately collect garbage in bags, and the rest take it out and load it into a car.

The main task of the owners is to negotiate with everyone who may be uncomfortable with the noise. In panel houses, this is the whole house. And, of course, make sure that after the brigade's departure there are no traces of the “noisy guys” and dust from the old screed on the site and in the entrance.

In private houses, everything is simpler, there is no need to negotiate with neighbors. You can try it yourself, but you still can't do without helpers. To dismantle the old screed, you will definitely need a powerful hammer drill with a chuck not SDS +, not SDS-Max. Chisels are also needed for the hammer drill. Sometimes jackhammers are used, but such a step can only be taken if this tool is in the hands of a professional. Improper use of the heavy-duty demolition hammer can easily cause the concrete slab to break.

In addition to a hammer drill, a 230 mm grinder with a stone-cutting disc, a construction vacuum cleaner, shovels, brooms, a large number of durable bags can be very useful. Work must be carried out in work clothes made of thick fabric and in a headdress, in gloves, in a mask or glasses. Since there will be a lot of dust, a respirator is required. It is better to protect the hearing organs with headphones, as there will be a lot of noise. Not every master has such a set of tools in his arsenal, but all this is rented in any region. In order not to overpay for rent, it is better to fit all the work into one day, so assistants are definitely needed. Let's describe the main stages of dismantling the old screed.

If in the room under the screed there are electrical wiring routes, heating or water supply pipes, then a scheme that should remain after installation is desirable. If it is not there, then you will have to use a special device - a detector of hidden wiring and metal, which must examine the entire area of the room and mark these places on the surface with a bright marker.
It is better to start dismantling the screed from the entrance to the room and then move deeper into it. This will make it easier to immediately remove the exfoliated pieces of the old screed. But before starting dismantling, it is necessary to carry out "exploratory drilling". To do this, cuts are made in a small area with a grinder with a stone-cutting disc, and then small pieces of the screed are broken off with a perforator with a spatula or a jackhammer to get to the next "cultural layer". If that layer is the required supporting plate, then you need to measure the thickness of the screed to be removed with a tape measure in order to know the reference point.
To beat off the old tie, you need to start with low rotations of the perforator engine and break off at first in small pieces. Further, when the degree of adhesion of the screed to the base is already clear, then it is possible to increase the speed and chip off in large pieces. Everything will be intuitively clear. When working, you should always take a stable body position and hold the tool with only two hands. It is not necessary to press hard on a perforator or a jackhammer, this does not affect the force from the blow, but the hands will get tired faster.
It is better to remove the pieces of the breakaway screed immediately with shovels, load them into strong bags and take them out to a certain place for subsequent export. This is another argument for the need for helpers.

Breaks are required during work. This is necessary both for resting the hands and for cooling the instrument. After 15 minutes of work - rest for 5 minutes. And it is also desirable that their operators also change behind the perforator or jackhammer. But this can only be done if others have good skill with the instrument.
If the old screed is reinforced with a wire mesh, then before dismantling the grinder with a stone-cutting disc, it is necessary to make cuts to such a depth that would ensure the cutting of the reinforcing mesh. The work of the grinder must be combined with the work of a vacuum cleaner, since there was a lot from cutting concrete. The surface is "shredded" into rectangles, such that it is convenient to carry them away in bags, and only then chiselling is performed.
Where pipes or hidden wiring pass, a large hammer drill or jackhammer should be bypassed. In these areas, then after the "heavy artillery" it is better to work with a small hammer drill or even a hand chisel and hammer. And you also need to be careful in the corners and near the partitions, especially if they are made of drywall or cellular concrete.
After dismantling and taking out all the debris, the surface of the base is cleaned with a perforator with a wide blade from the remnants of the old screed. Then the room is swept, the floor and air are sprayed with water from a sprayer and 15-20 minutes are given for all the dust to settle. A vacuum cleaner removes the remaining dirt.

Prices for polystyrene concrete

polystyrene concrete

It happens that after dismantling the screed, a "cultural layer" with ceramic tiles laid on the floor is exposed. Moreover it happens that this tile was laid back in the 50-60s of the last century. On the construction and repair forums, the question often arises of what to do with this tile? To beat her back or not? Opinions vary on this issue. Our opinion is unequivocal - to beat off!

Tiles laid during the days of developed socialism in the USSR have two extremes when dismantled. Either she literally "jumps" from the base, or "stands to the last." Moreover it happens that in one area the tiles behave differently. And all because before the masters did not have tile adhesives with predictable properties in their arsenal. Therefore, they glued who to what. They used just cement, cement with PVA, and Bustilat glue, and even epoxy resin and some other “brutal” compounds with ammonia. Moreover, they were glued without any mineral base in the form of sand, chalk or lime. Therefore, dismantling old tiles can be a problem.

Some DIYers mistakenly believe that the harder the hammer blow, the more willingly the tile will lag behind the base. However, practice shows that a small hammer drill with a sharp blade can handle old tiles better than a "monster", but with a blunt blade. That is, when dismantling an old tiled coating, it is not the strength that is more important, but the place of its application.

After dismantling the old screed and thorough cleaning, the preparation of the surface for the new screed will hardly differ from what will be described in the next chapter.

The base of the screed is a concrete slab

It is most pleasant to do the screed on such a surface, when you do not have to do earthwork or dismantle old coatings. Nevertheless, the surface must be prepared. What steps should surface preparation include?

First of all, it is necessary to provide the workplace with good lighting, in which the slightest flaws in the surface will be visible.
All joints of reinforced concrete slabs (if any) are cleaned, processed, and then sealed with a cement-sand mortar of the same recipe that will be used for the future screed. And also this solution can be used to seal up the junction of the walls and floor, in which there may be gaps.
All the dried splashes of solution, lime and others on the surface, as well as everything that lends itself to a spatula and a hammer, is beaten off and cleaned.
If there are large depressions on the upper surface of the slabs, then they can also be covered with the same mortar as the joints between the slabs.
If there are cracks, then they are cut to a width of at least 5 mm, and then filled with special repair compounds for concrete.

After all the solutions have dried, the room is thoroughly cleaned, and then a deep penetration primer is applied with a roller. After the first layer has dried, the second is applied. Priming is required in any case, even if a screed is to be made on the separating layer.
If the screed is bound, it is recommended to use a special composition - "Betonkontakt", which contains a complex of polymers, cement and quartz sand. After treatment with this primer, the surface becomes rough, to which all building materials "stick with pleasure". However, we advise you to apply "Betonkontakt" already after placing the beacons in order to exclude damage to the surface created by this soil.

If the screed is with a separating layer, then a dense plastic film is laid on the floor. The joint of the strips should have an overlap of at least 100 mm, and the approach to the walls should be the thickness of the future screed plus 20 mm.
A damper tape is glued to the walls around the perimeter of the room, which serves to compensate for temperature expansion.

At this stage, the preliminary surface preparation stage can be considered complete.

Prices for "Betonkontakt"

concrete contact

Exposing beacons for floor screed

The floor surface intended for the screed is rarely completely flat. In addition to the unevenness of the relief and the profile of the floor slabs themselves, in most cases the rough surface has a slope in one direction. If in a separate room a slope of 3 mm per 1 meter is imperceptible, then on the scale of the house it may already turn into several centimeters, which is unacceptable. It is always necessary to ensure that the floor in the entire apartment or floor of a private house is on the same level. The exception is the bathrooms, which should be 15-20 mm lower. Therefore, with proper repair, it cannot be so that in each separate room the screed is made only in his interests. In no case! You can do a screed in a room, but taking into account the whole apartment or the whole house.

In order for the floor level in an apartment or house not to "dance" as it pleases, it is necessary to beat off the zero level in all rooms. It is very easy to do this if you have a laser plane builder at your disposal, which has long ceased to be a luxury. Let's describe the technique.

In a certain place, a laser level is installed on a tripod so that it can capture the maximum number of rooms with its beam. It is better to install it at a comfortable height for work - about 140-150 cm. Beam position marks are made on the walls of the premises with a marker.

The level is transferred to some room where there is already a mark and is exposed on her . Further, the position of this mark is transferred to all walls. With the help of a paint cord, the horizontal baseline is bounced off.
Similar actions are performed in all rooms. As a result, it should turn out that a horizontal baseline is drawn on all the walls, relative to which the floor level and the thickness of the screed will be calculated.
Measurement points are marked on the baseline with a certain frequency (1.5-2 meters). Then the vertical distance from the measurement points to the floor level is measured and recorded with a marker or pencil directly on the wall.

Finds the minimum and maximum distance from the baseline to the floor surface. In the example shown, the minimum distance is 1420 mm and the maximum is 1445 mm. The height difference is 25 mm.
Let's say the recommended minimum screed thickness for any grade of sand concrete is 30 mm. This means that from the highest point it is necessary to set aside 30 mm and get that the zero level will be 1420-30 = 1390 mm from the baseline. In this case, the thickness of the screed will vary from 30 mm to 55 mm. This is perfectly acceptable.

It is very appropriate to put these calculations on the plan of the house. Such a document will be very useful in the future, since the screed is usually not done immediately in the entire apartment or floor of the house, but gradually, moving from one room to another.

Now is the time to learn how to place the beacons correctly. These actions cannot be called hard physical labor, but a lot depends on the correct placement of the beacons. It is they who set the surface of the floor and from the slightest mistake, all further work can lead, in the worst case, to further elimination of shortcomings, and in the best - to banal overspending of dry mix, from which the screed solution will be prepared.

Let's give an example. Let's say you have an apartment of 100 m² in which you need it. For this, sand concrete M 300 will be used, with a minimum layer size of 30 mm. When beating the zero level, it turned out that the thickness of the screed can be from 30 mm to 55 mm (we gave this example earlier). This means that the average thickness of the screed will be approximately (30 + 55) / 2 = 42.5 mm or 4.25 cm. The average consumption of sand concrete M 300 is 20 kg per 1 cm of thickness and an area of 1 m². It turns out that there will be consumption for the whole apartment: 4.25 * 100 * 20 = 8500 kg of dry mixture, which will be 212.5 bags of 40 kg each.

Now imagine that when installing the lighthouses, the master, instead of the minimum 3 cm at the highest point, set 4 cm with the "iron" argument "the pocket does not pull the stock". We recalculate: an extra 1 cm added to the screed over the entire area of 100 m² will result in 20 * 100 = 2000 kg, which in 40 kg bags will have an additional 50 bags. It turns out that the stock "pulled the pocket". And it's not so much about money, but about the extra load on the floor. The extra 2 tons will lie on the base of the floor. The extra 2 tons will need to be dragged, prepared, and laid.

All readers probably know that the most inconvenient during transportation and especially lifting to the floors is the piano. Movers shy away from it "like fire" and calculate at a special rate. The average weight of one piano is 250 kg. It turns out that plus 1 cm of the screed in the considered example is equal in weight to about 8 conventional pianos or one conventional Lexus RX 400 SUV.

There are too many ways to display beacons to describe them all in one article. Each master has his own favorite method, which does not have to be similar to the others. In principle, what's the difference if two masters get equally good results with different methods of setting beacons. We propose to consider a method that will be understandable to everyone and even a beginner can reproduce it.

Completely different objects and devices are used as beacons for floor screed. Someone prefers to make lighthouses from a solution, someone uses pipe sections. The ceiling guide profile is very widely used, " borrowed"In plasterboard systems, which we know as PN 28 * 27 or UD 28 * 27. Its shape and sufficient rigidity allow it to be used for lighthouses. For example, how it is done in the picture.

In the method of placing beacons described by us, we will use the PM-10 beacon profile, originally conceived for plastering, but successfully used in screeds. It is made of galvanized sheet steel and has a shape that also provides it with good rigidity. Side shelves PM-10 are perforated to facilitate its attachment to the leveling surface in different ways.

Very often, beacon profiles are fixed with mortars. To do this, on the previously marked line, on which the beacon should be located, at the beginning and at the end of it, screws are screwed into the previously installed dowels. Then, using a laser level or other measuring tool, the caps of the self-tapping screws are set so that their upper plane is in the plane of the future screed. Along the line of placing the beacon, slides are made of cement-sand or other mortar at a certain frequency, and then the beacon profile is placed on them and pressed with a rule that is pressed against the caps of the screws.

When the beacon profile is pressed into the mortar pad, make sure that it is pressed against the rule along its entire length. The excess protruding above the lighthouse is cleaned up. When the mortar is dry, you can start the main work on the screed. For a cement-sand mortar, at least 1-2 days must pass for the lighthouse to be fixed, therefore, to speed up the process, some craftsmen use glue gypsum solutions or even alabaster. In this case, the lighthouse is fixed almost instantly and work on laying the screed can be started immediately. Everything seems to be fine, but it turns out that in the body of the screed there will be foreign inclusions from other materials. During the operation of the screed, in those places where there are "outsiders", cracks are likely to form, since the coefficients of linear thermal expansion differ for different materials. Therefore, beacons should be installed only on the solution with which the screed will be made.

The method of installing beacons on a solution has a main drawback - it is the impossibility of correcting the position in case of an error. Only the dismantling of the lighthouse and re-installation will be able to rectify the situation. Therefore, it is better to use a method that will make it easy to mount, dismantle the lighthouse and correct its position. This is easily realized using self-tapping screws with dowels and a special attachment - a plastic clip for attaching beacons.

This clip consists of two parts - the clip itself and the lock that fixes the beacon. This type of beacon attachment is good because the clip itself can be attached to the head of the self-tapping screw after it has been screwed in and adjusted in height. There is a special groove for this. Later, already after the lighthouse is wound into the clip, and the final fixation with the lock is in progress. The result is a very reliable mount that can still be adjusted in height. The price of such clips is cheap - 100 pieces cost 250-300 rubles.

Consider the process placing beacons with plastic clips... For convenience, we will present it in the form of a table.

Image	Process description
	On the prepared surface of the floor, the marking of the position of the beacons is made, which should be installed in the direction of pouring the screed from the far wall of the room to the entrance door parallel to the side walls (if the room is rectangular). An interval of 200-300 mm must be maintained from the side walls to the guides nearest to them. The distance between adjacent lighthouses is 1-1.5 meters. The rule laid on adjacent beacons must still have a margin of at least 200 mm on both sides.
	On the lines of the position of the lighthouses with an interval of 500 mm, holes are drilled with a puncher, into which the dowels are immediately hammered.
	The room where the beacons are placed is the highest point, according to earlier calculations. A self-tapping screw is screwed in at this point corresponding to this point, but not completely. The laser level is set and set according to the base line previously drawn on the walls.
	On a straight wooden block, a mark is made for the position of the screw head relative to the baseline, but taking into account the height of the beacon (10 mm) and the clip (2 mm). That is, 12 mm is added to the previously calculated level of the screed relative to the baseline. The bar is installed vertically on the head of the self-tapping screw and the position of the mark is controlled.
	By screwing or unscrewing the self-tapping screw with a screwdriver, they achieve the coincidence of the mark on the bar and the laser level beam. The self-tapping screw at this point can be considered exposed, and all the rest must be set on the same level with it.
	The laser level is installed on the floor and its beam should be higher than the head of the exposed self-tapping screw. A long bit is clamped into a screwdriver. Then the bit is inserted into the slots of the exposed self-tapping screw vertically and it is controlled that the laser beam is on it.
	A strip of white masking tape is glued onto the bat in a circle, then it is again placed in the self-tapping slots vertically and a marker is made to mark the position of the laser beam.
	Self-tapping screws are added to all previously mounted dowels.
	With a screwdriver, all the screws are sequentially tightened to the level determined by the mark on the bit and the laser beam.
	Clips are put on the heads of the self-tapping screws, and the adjacent ones should be oriented opposite to each other.
	The position of the clips is checked by the rule, the level and the laser beam. The rule should lie strictly horizontally on all clips.
	Beacon profiles are inserted into the grooves of the clips. All joints of the profiles should only fall on the clips.
	The profiles in clips are fixed with latches.
	The room is cleaned with a vacuum cleaner.
	The floor surface is primed with a deep penetration compound.
	After the primer has dried, a semi-dry solution of sand concrete is mixed and all lighthouses are strengthened with it. The same solution can be used to fix the position of the damper tape.

The proposed method is also good in that the level can be set without the beacons themselves, and they can be put on immediately before laying the solution. This is very useful when the screed is being reinforced.

Floor screed reinforcement

The question often arises about the expediency of reinforcing the screed, because by its purpose it is often not a power element that carries the main load. And this is partly true. But the lack of reinforcement can only be justified in connected screeds, laid on a reliable concrete base, and in all other cases it will not be superfluous. Consider the cases where reinforcement is required.

Screeds in the underfloor heating system are necessarily reinforced, as they are subject to thermal expansion and contraction.
Floating screeds, laid on insulation plates, are also necessarily reinforced, since it has a much lower bearing capacity.
Screeds on the ground should be reinforced with reinforcement, since they are usually laid on a loose foundation. External factors such as seasonal swelling can be another reason for reinforcement.
If heavy objects are installed in the room or the screed is subject to any dynamic loads, then reinforcement is required.
Screeds with a height of more than 5 cm are reinforced to avoid cracking during the drying process.

Various materials can be used for reinforcement. Let's consider which ones.

Reinforcement of the screed with metal meshes

The oldest proven method of screed reinforcement is steel mesh made of reinforcement or wire. the former are used for power heavily loaded floors on the ground, for example, in garages, and the latter in all other cases. Meshes for reinforcing screeds are made of wire BP-1 with a diameter of 2.5 mm to 6 mm. If earlier the frame was formed with the help of thin wire, which was used to twist the laid rods, nowadays we offer grids connected by spot welding. The cells can be square or rectangular in size from 50 to 200 mm. Obviously, the smaller the cell size and the thicker the wire, the more reliable the tie will be. Thin wire nets (up to 3 mm in diameter) can be sold in rolls, and thicker ones as cards of 0.5 * 2, 1 * 2 and 2 * 3 meters.

A very important element in any wire mesh is the presence of notches on the bars, located with a step of 2-3 mm along the entire length. They significantly increase the area of adhesion of the frame to the concrete solution, which strengthens the finished screed. When buying a wire mesh, it is necessary to strictly monitor that all wire intersections are welded, since not all manufacturers do this. And it is also worth checking the meshes for the absence of strong foci of corrosion, which will expand in a highly alkaline concrete solution when it solidifies.

There are many sources on the Internet that tell you how to "correctly" reinforce a floating screed with floor heating pipes. A wire mesh is placed on the layer of heat and waterproofing, and only then the pipes of the warm floor are attached to it with plastic clamps. The deeds of such "craftsmen" can be seen in the photograph.

This “reinforcement” is possible in essence - it is hiding expensive wire mesh under a layer of concrete. They do not perform any reinforcing function, since they will simply "roll around" under the screed. In order for the reinforcement not to be useless, the meshes must be inside the concrete, while they must be spaced from the base on a protective layer with a thickness of at least 15-20 mm. In thin screeds, the mesh will be located approximately in the middle, and in thick ones it is better to place it in the lower third, so it will work better under various arising loads.

When forming screed frame made of steel mesh be sure to overlap 1 cell, but not less than 10 cm.For example, if a grid with a cell of 10 * 10 cm is used, then the neighboring canvases should overlap exactly 1 cell, and if 20 * 20 cm, then half of it is enough ... In order for the mesh to be spaced from the base at the same distance, several methods are used:

The mesh is installed on slides made of cement mortar - exactly the same as the screed will be poured into. Sometimes this is combined with the installation of beacons. This is a completely acceptable method, but its main drawback is the non-simultaneous drying of the slides and the screed itself. This can lead to heterogeneity of its structure and delamination. It is unacceptable to use gypsum solutions!
The reinforcing mesh is installed on supports made of pieces of broken brick, fragments of concrete or other materials at hand. This method is also allowed, but it is quite difficult to set the mesh at the same distance from the base. And then, when the screed is laid and moved along the mesh, some homemade supports may fly out. The use of wooden blocks is unacceptable, as they will increase in volume from the water and "tear" the screed.
The most modern and best way to install reinforcing meshes is to use special reinforcement clamps. They are made of plastic, have calibrated dimensions and are selected for any type of reinforcing mesh, for any thickness of the protective layer and for any base. Such "implanted" racks do not in the least affect the concrete or cement-sandy screed structure for the worse. These products can be easily found in any normal building materials store or market. The price for them is penny: about 0.8-1.6 rubles per 1 piece, if you take packages of 1000 pieces. It is recommended to use at least 8-12 clamps per 1 m². It depends on the diameter of the reinforcement or wire, the mesh spacing and the base material.

Rebar clamps - a modern and best solution for installing reinforcing meshes

The most common reason why screed reinforcement is necessary in residential premises is a warm water floor. But placing a metal mesh on the base, and then attaching pipes to it is a rather dubious exercise. The effectiveness of such "reinforcement" is close to zero. The most correct thing is to fix the pipes to the thermal insulation, and on top of them, place steel nets on the reinforcement clamps.

Let's note the advantages of using steel reinforcing meshes for screeds:

Such screeds have the highest tensile strength, bending, for stretching and compression.
Excellent resistance to temperature extremes over a very wide range.
Steel meshes laid on top of floor heating pipes make it possible to evenly distribute temperature gradients, since metal has a thermal conductivity many times higher than concrete.
Correctly installed screeds with steel reinforcements have a long service life.

There are few drawbacks to steel reinforcement - it is a high price and the ability to corrode if stored and installed improperly.

Reinforcement of the screed with polymer and composite elements

Progress does not stand still, so to replace traditional reinforcing steel elements others come from various polymers or composite materials. For a long time there was no alternative to traditional steel reinforcement, but now a worthy rival has emerged - reinforcement and mesh made of polymer and composite materials. Let's briefly review them and immediately note the advantages and disadvantages.

Composite reinforcement is rods of various diameters, which can have ribs similar to those on steel reinforcement, or for better adhesion, they are coated with sand. The rods are formed from fibers and polymer binder, which is why such reinforcement is called composite. The fibers are used glass, basalt or carbon and therefore the reinforcement is called fiberglass, basalt-plastic or carbon fiber.

Composite reinforcement has a number of advantages, we will list them:

Let's note the disadvantages of composite reinforcement:

Lower stiffness of composite reinforcement than steel.
Lack of ductility - high fragility.
The heat resistance of composite reinforcement is worse. GRP loses its properties at 150 ° C, carbon fiber at 300 ° C, and steel only at 500 ° C.
When cutting composite rebar, a large amount of harmful dust is generated. This is especially true for fiberglass reinforcement.

They work with composite reinforcement in the same way as with metal ones. When knitting frames, wire or plastic clamps are also used, and for installation - clamps or mortar cushions. The correspondence between the diameters of steel and fiberglass reinforcement can be seen in the following table. The price of composite reinforcement is not lower than traditional steel reinforcement, however, if there are high logistics costs for delivery to the site, then in the end its use can be cheaper. True, when installing the frame and pouring the screed, care must be taken, because composite reinforcement is much easier to break than steel, since it works much worse in bending.

Prices for fiberglass fittings

fiberglass reinforcement

For the reinforcement of screeds located on reliable bases, plastic nets are now widely used. They are made of polypropylene or fiberglass with a special impregnation that prevents the action of an alkaline environment inside the concrete. The nets are produced in a very wide range, with different mesh sizes. For screeds, polypropylene meshes with a mesh size of 35 to 50 mm are most often used. The width of the web is from 50 cm to 4 meters, and the length of the net roll is from 10 to 50 meters. Of course, this is very convenient. Let's note the advantages of plastic nets for reinforcing the floor screed.

The only drawback of plastic nets is the impossibility of using them in rough screeds on the ground.

Reinforcement of the screed with fiber

The reinforcement of the screed with microfibers (fiber) differs from all the others in that the actual frame itself is not visible. But the reinforcement in the concrete mixture is still in the form of thin fibers, evenly distributed in the solution, and after drying, in the thickness of the screed. It is they who reinforce concrete in all planes, since they are located chaotically. Their addition, even in small quantities, significantly increases the grade of concrete, impact resistance and strength. In fiber-reinforced concrete (this is what concrete is called with the addition of fiber) there is also an almost complete absence of shrinkage cracks. Fiber can be made from different materials:

Steel fiber - is a piece of high quality steel wire with a diameter of 0.2-1.2 mm and a length of 25-60 mm. For better adhesion to concrete, the ends of the wires are curved. Steel fiber is the strongest, but not used in screeds. Its purpose is concrete for massive monolithic structures, mainly prefabricated.

Fiberglass fiber - significantly improves the quality of concrete, which reduces the amount of cement up to 15%, and water up to 20%. It is not used in monolithic structures and screeds, since fibers from special alkali resistant zirconia glass is very expensive. Therefore, fiberglass fiber found his application in decorative and structural plasters.
Basalt fiber is a piece of basalt fiber with a diameter of 20 to 500 microns and a length of 1 to 150 mm. Reinforcement of concrete with basalt fiber increases its strength 4-5 times, abrasion resistance - 2-3 times, tensile strength - 2-3 times, compressive strength - 1.5-2 times, water resistance - 2 times. This type of fiber can partially dissolve in cement mortar, but from this it only gains strength. It turns out that the reinforcement is both chemical and mechanical. Consumption - approximately 0.8-1.2 kg per 1 m³ of ready-mixed concrete.

Polypropylene fiber is the most common a type of micro-reinforcement of floor screeds, since along with the excellent characteristics of concrete (almost like with basalt fiber), its prices are lower. Polypropylene fiber does not react chemically with the concrete solution and does not change its properties during the entire life of the concrete. The consumption of polypropylene fiber is approximately 0.6-1 kg per 1 m³ of the finished solution.

It is very simple to add fiber to concrete, there are two ways for this - dry and wet. All types of fiber, except for basalt, can be dry kneaded. This means that the basalt fiber is first soaked in water, and then the dry ingredients of the mixture are added. Steel fiber is added only dry. That is, it is added to the sand, mixed, then cement is added, and then water.

It should be noted that mixing solutions with fiberglass will be of high quality only when it is done mechanically - using concrete mixer or a mixer. The mixing time with the fiber should be increased by at least 30% so that it is distributed as evenly as possible throughout the volume.

Conclusions regarding the reinforcement of the floor screed

The opinion of the authors of the article about reinforcement is unambiguous - it is necessary in any case in one form or another. This is based primarily on personal experience, but also on the analysis of the opinions of professionals in numerous thematic construction forums. Here are the arguments:

Any reinforcement done correctly makes the screed better.
Highly loaded screeds, as well as those made on the ground, must be reinforced with a reinforcing cage.
Composite reinforcement does not offer any advantages over steel at current prices.
Any reinforcing frame must be inside the screed, and the thickness of the protective layer must be 15 mm or more.
on a reliable basis, it is enough to use a polypropylene reinforcing mesh.
Reinforcement with polypropylene or basalt fiber is always best done, since the costs for this are incomparably less than for all other components of the solution, and the result, when used correctly, is obvious.

Preparation of floor screed mortar

The question of the correct preparation of the solution in the arrangement of the floor screed is extremely important, since both the quality of the installation and the period of further operation depend on it. If you "rewind" 20-30 years ago, then at the construction sites of private houses in the territory of the former USSR, there were no questions with this. Either simply on the floor surface, or in homemade troughs, a solution consisting of cement, sand and water was kneaded with shovels, and then it was laid on the floor surface using wooden floats, slats, pieces of edged boards and other improvised means. And many ties made then serve to this day. But this does not mean that we should continue to use these "old-fashioned" methods.

Modern screeds are often made on a layer of insulation, and warm floors are no longer a luxury item either. Accordingly, the requirements for what kind of solution should be prepared also increase. Let's tell the readers right away that mixing with shovels on the floor or in the trough, as some current sources can even talk about, is an outdated approach. A good screed must have a homogeneous structure, therefore, the preparation of a solution for it is better compared with the craft of a pharmacist, which is from various containersusing beakers accurately measures the right amount of ingredients, and then mixes them until smooth. It is clear that the volumes of the pharmacist and the builder are different, but the attitude should be similar. And, of course, the preparation of the solution should be carried out only using mechanisms - mixers or concrete mixers (concrete mixers).

A drill mixer is a very useful device that will come in handy in the household more than once.

Floor screed solutions can be prepared in two ways, each with its own advantages and disadvantages.

The first way is to prepare the solution yourself. At the same time, the necessary ingredients are purchased in the required volume, which are mixed in certain proportions. It should be borne in mind that with this method, experience or clear instructions are desirable, not to mention the quality of the individual components of the solution.
The second method is the use of ready-made dry building mixtures, which are specially designed for floor screed. This makes the job easier, but more expensive.

Let's consider these methods separately and in more detail.

Self-preparation of floor screed mortar

Modern SNiPs do not at all interfere with the independent preparation of the solution, but its grade should in no way be less than M -150, which means that each square centimeter of the screed must withstand a load of 150 kg. This is sufficient for simple screeds, but may not be enough for underfloor heating. In addition to the traditional components of the screed - cement and sand, it is also recommended to use a special additive - plasticizer ... What does it do?

In order for cement to turn into stone, it needs a certain amount of water, approximately equal to a quarter of its mass. For 100 kg of cement, approximately 25 liters of water are needed. But such a ratio will not allow obtaining a plastic and flowable cement solution with fillers, therefore, an additional amount of water is introduced into the mixture, which makes it convenient to lay the solution. Plasticizers make it possible to minimize the water-cement ratio, which has a beneficial effect both on the rate of solidification and on the final strength of the structure or coating.

Plasticizers are not a luxury, but a necessity

The use of a plasticizer avoids the appearance of air bubbles in the screed body. This is especially true when pouring underfloor heating screeds. The air when laying the screed, due to the plasticity of the mortar, freely escapes itself, and the cement-sand mortar better "grabs" the underfloor heating pipeline.
The branded strength of the ready-to-use solution increases by 20-40% when a plasticizer is used.
Solutions with a plasticizer have 50% higher frost resistance than without it.
The "life" of the solution, at which it can be worked with when laying the screed, is significantly increased. This allows you to mix in large quantities and increase productivity.
The water resistance of screeds with a plasticizer is significantly higher than without it.

We hope that we have convinced our readers of the need to use a plasticizer for the screed. It can be found easily on sale in liquid or in powder form. It can be called in different ways, but in terms of chemical composition and in fact in 99% of cases it is a C-3 plasticizer. The liquid form is more convenient, since the plasticizer can be added directly to the water to prepare the solution, and the powder requires preliminary dissolution of a certain amount in measured volume of water. All instructions for the use of the plasticizer are always indicated on the packaging.

Now let's look at how to prepare a time-tested screed solution.

As a binder, it is necessary to use Portland cement itself widespread brand M 400. You can also use M 500, then the screed will be even stronger. Usually it is sold packaged in 50 kg bags, but for ease of transportation there are also 25 kg bags. Of course, it is necessary to check that the expiration date of the cement is not exceeded.

It is recommended to use quarry sand as a filler, in which grains of sand have an irregular shape with sharp edges. In a screed, such sand will adhere well by itself with you, with cement and the base. River sand with prolonged exposure to water takes on a smoother shape, which means it will more readily flake off the screed.
Water for the preparation of the solution should be used only clean, free from impurities of oil products, fats and other contaminants. Naturally, the containers for water must also be clean and intended only for it. It should be noted that the required amount of water does not need to be added immediately, since a solution with a very high water content can be obtained. This will have a negative effect on the ease of installation and the strength of the screed. The sand may already contain a certain amount of water and the use of a plasticizer also greatly affects the water-cement ratio.

Now about the proportions of the ingredients of the screed solution. The proven "classic" for years is one part of cement for three parts of sand. We suggest calculating the exact amount using a calculator.

Calculator for calculating the amount of ingredients for floor screed mortar

The offered calculator is very easy to use, requires a minimum amount of initial data, and gives the result with good accuracy. The only explanation for its use is the point about the height difference of the screed. This is nothing more than the difference between the highest point of the base and the lowest, expressed in millimeters. We talked about this in our article when we considered the installation of beacons.

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