How to make a concrete screed on a wooden floor. Screed on a wooden floor under tiles You can make a screed on a wooden floor

Our project expert, Natalya Kaplunova, answers

Photo: www.topdom.ru

Screed on wooden floor differs from pouring onto another base. A wooden base has completely different characteristics than a stone base, which must be taken into account. Wooden floors are prone to deformation, so concrete screed It should not cling so firmly to the tree as to impede its natural movement, otherwise cracks cannot be avoided. And the wood itself “breathes” and can affect concrete, so insulation between these materials is necessary. This technology is called unbonded screed.

Preparatory work includes replacing damaged floor boards. Some boards can be flipped over to give a smoother, cleaner surface. Next, the surface is thoroughly cleaned, including removing loose paint. The heads of nails or screws are recessed deeper so as not to damage the insulation. The cracks are sealed with epoxy putty; in problem areas you can use polyurethane foam. It is advisable to treat the joints of the boards with a sealant that has a silicone or acrylic base. The prepared surface should be coated with a layer of moisture-resistant primer (as an option - water-resistant paint).

Before pouring concrete, the wooden floor should be tensioned without wrinkles. plastic film so that the concrete and the base do not touch. Joints and possible suspicious places should be reinforced with tape to ensure truly airtight insulation. Attach the edges of the film with a stapler to the walls. The allowance above the edge of the planned screed is taken up to 5 cm.

Next, “beacons” (slats made of metal or wood) are placed along which the solution will be poured. The height of the screed should be at least 5 cm. It would be good if additional reinforcing mesh was laid. It is worth adding plasticizers to the solution, which will both accelerate the development of maximum strength and increase water resistance. If a self-leveling mixture is used, then stretched threads can serve as beacons, although this method will be more expensive.

The room must be filled completely at one time; filling in parts is not allowed. When laying, pierce the surface with a metal rod or a special needle roller so that the coating does not have any air bubbles, deteriorating strength. After pouring the prepared solution, the surface is perfectly leveled using a rule or at least a spatula.

Strength gains only over time, so proper drying must be ensured. While the solution is drying, you should periodically moisten the surface with water (the first few days). Only after the solution has dried can the slats be removed and primed, sealed and rubbed over the voids cement mixture. Next, the surface is wetted again and covered with polyethylene for two weeks. After this, the polyethylene allowances can be cut off.

Before deciding to pour a concrete screed, you need to make sure that the foundation can withstand a significant increase in load. You cannot apply a screed to a fresh wooden floor: the new wooden floor may deform too much, which will damage the top covering.

And finally, we suggest you look videos about leveling a wooden floor.

Flooring made from wood is rarely covered with a concrete mixture for leveling. Many experts argue that using heavy monolithic slab there is no point in going on a wooden platform. This is explained by the incompatibility of the wooden base and concrete. Masters recommend using dry leveling methods. But if floor screed is necessary for further installation of tiles, it should be done on a wooden base, but some nuances should be taken into account.

Features of working with wood flooring

Wood is a material that has some negative properties. It is not static; even after the lumber is laid, it will exist according to its own laws. Changes in humidity and temperature levels cause wood to change its volume, decrease or increase in height, and shrink in linear dimension. For these reasons, after building a wooden house, finishing work is not carried out on it for several years.

Wood for flooring that needs filling

How to make a screed on a wood floor tiles? It is important to remember that floor repairs wooden house may be problematic. After a certain period of time, the surface begins to creak and lose its evenness. Various other damages are also possible. To reduce the time of repair work, you can not remove the old coating. But if you correctly understand how to make a screed on a wooden floor, there will be no problems later.

Before performing such a coating, you need to know that there are several options:

standard pouring of concrete mixture;
use of the dry method.

The second option has advantages:

light weight;
convenience during installation;
the ability to immediately correct shortcomings;
no “wet” effect;
dry cement screed does not need to dry.

You can also highlight the pros and cons:

reducing the height of the room, as greater thickness is required;
Due to the significant thickness, more material is consumed compared to the conventional method.

Depending on the conditions, you can choose one of the options. The concrete screed is made using a technology that includes the so-called non-cohesive screed, which ensures the elimination of possible deformations of the wood.

Uncoupled screed on wooden surface

Fill cement mortar is advised only when there is a need for flat surface with fixed solids flooring materials. A similar screed can be used to install heated floors, although craftsmen have differing opinions on this matter. This is due to the fact that wood can become deformed when exposed to moisture or different temperatures when turning the underfloor heating system on or off.

Therefore, the question often arises whether it is possible to screed a wooden floor. First you need to weigh the pros and cons. If you nevertheless decide to carry out screeding, then you must follow the recommendations for such work:

carefully examine the condition of the base, coat it with a special primer containing moisture-proof components;
do waterproofing layer using plastic film, overlapping it;
install beacons;
prepare concrete mixture for screed;
spread the prepared solution to a height of at least 5 cm.

Laying features

Pouring screed onto a wooden floor has the following features:

the weight of the solution must be sufficient to ensure a tight fit to the floor;
The screed itself should not be tied to the wood surface (the film layer will prevent this);
It is not recommended to pour the solution onto the wooden covering, but only onto the waterproofing layer;
It would be good to first lay the DSP board, prime it and only then install the floor covering;
When preparing the mixture, plasticizers should be used to ensure mobility, high strength and ductility.

Screed by wooden joists can be practical when using tiles or heated floors. It may become deformed during hardening. Subsequently, no changes occur to such a surface.

Subtleties of the screed device

The essence concrete method for a wooden floor is that it is necessary to insulate each layer separately. Therefore, the concrete screed is separated from the walls in the room with a special damper tape, and from the base - with insulating material.

How insulating material You can use polyethylene film, roofing felt or special bitumen mastic. Recently, a lot of rolled materials or glassine have also been used.

Although polyethylene film creates a greenhouse effect, it still has some advantages for concrete screed:

she has smooth surface, does not cause adhesion to the concrete base;
when shrinkage or deformation occurs, the screed that is not bonded to the film does not pull it along with it;
an intact insulation layer does not allow moisture to be absorbed from concrete that has not yet hardened;
To avoid the negative impact of polyethylene on a wooden surface, all elements should be coated with an antiseptic and it would not be a bad idea to use a water-repellent primer.

Device technology

If you will use a floor screed along joists, you need to know that the process technology consists of several stages. The first to be executed preparatory work which should include:

removal and inspection of the board;
replacement of damaged or cracked ones;
inspect the logs, if there are unreliable ones, replace them with new ones;
it is important to check the distance between the logs, it should be no more than 40 cm;
if the interval is greater than necessary, additional beams must be used to increase the load-bearing capacity of the flooring;
fix the floorboards in place;
if the board is damaged only on one side, it can be turned over to the other side;
Fill the gaps between the boards with sealant;
after this product has hardened, you can treat the surface with a primer and give time for impregnation;
Make marks on the wall of the room using a laser level.

When determining the height of the screed, it is important to take into account that every centimeter of the concrete layer puts pressure on wood weighing 100 kg. If it is necessary to make a thick screed, the beams need additional reinforcement. It can be made from a metal channel.

Installation of insulation

On at this stage You should make a waterproof container from a special material for pouring concrete. Therefore you need to do the following:

attach a damper tape around the perimeter of the entire room along the walls or replace it with a strip of foamed polystyrene;
Double-sided tape can serve as a fixation for this material, or you can secure it with a construction stapler;
it should be fixed a few centimeters above the screed; it will serve as a soundproofing barrier, except for deformation movements;
the ends of the tape sticking out to the sides should be cut off;
lay polyethylene film with an overlap of 10 cm;
Secure the connections of the film parts with tape;
lay the films so that the edges extend onto the wall 15 cm high;
The prepared screed solution can be poured into the resulting container.

Execution of a waterproofing layer

In this case, the film should not be damaged or contain holes. If such are observed, they must be sealed or soldered.

Execution of beacons

Guide beacons should be placed on the floor. It is strictly forbidden to fix them to the surface with nails or self-tapping screws. They should be attached to the mortar, laid on the floor in rows or small cakes. The first beacon should be located at a distance of 20 cm from the wall, the guides relative to each other should be located at intervals of no more than 1 m, the main thing is that the size of the rule is not exceeded.

Installation of beacons

Metal plasterboard profiles can be used as beacons. If they are placed on the mortar cakes, this will greatly facilitate the installation of a clean floor. The lighthouse must be pressed to the floor so that it sinks into the concrete mixture, and then checked with a level to ensure evenness.

It is important to achieve the required mark. To make the solution harden faster, you can add alabaster to it.

Reinforcement of concrete screed

So that the floating screed, located on wooden floor, was of high quality, additional reinforcement should be performed. This is especially necessary when the screed exceeds a height of 5 cm. Most often you can see that reinforcement is made using thick wire, reinforcement or metal mesh.

Reinforcement of screed on a wooden surface

But if the floors are installed on joists, then you need to use a slightly lighter material that does not additionally load the screed. Metal materials may break through the insulation layer when pouring occurs. For this reason, it is best to use fiber as a reinforcement material. It must be added to the solution during mixing. Fiber fibers, randomly located along the screed, make it strong in all directions.

Pouring the mixture

Pouring concrete mortar can be done using two methods.

If the filling should be done in a large room, then it is better to divide the entire area into small squares. Separate them from each other with formwork and fill each card separately. In this case, breaks in work can be allowed. Fill in several approaches.

Pouring a wooden floor in parts

Fill in small room can be done in one go. The process should begin from the far corner. During work, it is not allowed to take a break so that the result is smooth and beautiful surface. This type of work is best done together. While one is leveling the poured solution, the second is preparing the next portion.

Each portion of the solution must be placed slightly above the lighthouse, and then level it using the rule. Place the rule on the guide strips and pull it while moving it to the sides to even out the mixture.

Pouring the mixture

The beacons can be removed from the solution the next day, and traces of them can be treated with a primer and filled with freshly prepared solution. For the first week, the surface of such a screed must be sprayed with water and covered with film so that the moisture evaporates evenly. After this, you can apply a floor covering or some kind of coloring composition.

How to make your own screed on a wooden floor can be seen in this video:

Wood floors are unstable surfaces, so they are leveled only when absolutely necessary. There is no point in placing a heavy monolithic slab on a wooden base, because now the market offers a wide selection of dry leveling mixtures that are light in weight. However, if you plan to lay as a topcoat ceramic tiles, then a rigid screed on a wooden floor will be the best choice.

The technology for laying such flooring has a number of features, which we will consider in more detail.

Features of wooden floors

Despite the strength and durability of any wooden structure, over time, under the influence of humidity and temperature environment, it changes its linear dimensions, which causes shrinkage. In addition, wood is “breathable” building material, according to wooden beams The cracks begin to “spread”. That is why you should never pour screed onto a fresh wooden floor immediately after building a house. Leveling can begin no earlier than 3 years after the wood base has completely dried and settled.

It is recommended to lay a monolithic concrete slab on wooden joists (on which the floorboards are supported) if the beams are installed on brick columns with a height of at least 300 mm. If the logs are laid directly on the floor slabs (which is most often the case), then you can only install a “floating” screed. In this case, some advise removing the floor boards and pouring the concrete slab in the traditional way, but in this case the screed will be fastened to a wooden base, and at the slightest deformation the flooring will crack. Therefore, we will consider the most reliable technology for laying a “non-cohesive” screed that will not connect to the walls and ceiling.

Preparing the base

Before you make a screed on a wooden floor yourself, you must carefully prepare the surface. To do this:

Dismantle the boardwalk and carefully check all elements for damage and the presence of mold and mildew. Degrease the surface and get rid of any remaining glue. Be sure to remove any debris that has accumulated under the floor. The best way to do this is to use construction vacuum cleaner(if you watch the video below you will understand why).

The distance between the logs should be no more than 40 cm. If they are located further from each other, then install auxiliary beams between them.
If wooden joists are not securely fastened, secure them with self-tapping screws.
Reinstall the boardwalk and secure it with nails, recessing their heads by 2-3 mm.
Turn over damaged floorboards (if the damage is too severe, it is better to replace them).
Remove the baseboards and install thin slats instead that will cover the gaps between the wall and the base. There is no point in attaching these boards “tightly”, since they are then dismantled anyway.
Seal all cracks in the base. For small potholes, you can use sealant or parquet putty based on wood dust (4 parts sawdust to 1 part oil paint), and for deep ones - mounting tape.

After this, marking is done. To do this, using a level, mark a zero level around the perimeter of the room (approximately at a height of 35 cm from the wooden base) and set equal distances from it, taking into account the thickness of the screed.

Important! The thickness of a floating floor screed in a wooden house should not exceed 5 cm. Each extra centimeter of the slab will exert a load on the plank base equal to 110 kg per 1 m 2.

At this point, the preparation is complete and you can begin waterproofing.

Waterproofing screed on wooden floors

To prevent the floor screed from “clinging” to the walls and from allowing moisture to pass through, it is necessary to glue (using tape) a damper tape around the perimeter of the room with a thickness of at least 10 mm and a width exceeding the height of the concrete flooring.

After this, a plastic film with a thickness of at least 100 microns must be laid on the floor. It is laid with an overlap and should extend onto the walls by at least 15-20 cm.

It is believed that it is not worth using polyethylene as a waterproofing layer for screeds on wooden joists, as it will provoke the growth of putrefactive formations and fungus. However, unlike bitumen mastics and roofing felt, it is polyethylene film that is most suitable for a floating base. There are several reasons for this:

Polyethylene does not stick to concrete or wood. Thanks to this, the base and screed will move freely without stretching the waterproofing layer.
Swelling or narrowing of the wooden surface will not affect the integrity of the screed in any way.
Between concrete flooring and the wooden base forms the necessary border. Wood and concrete will not “pull” moisture from each other.

To minimize negative impact polyethylene on a wood surface, before laying this material, it is enough to treat the wood with an antiseptic and Aquastop primer, which has water-repellent properties (applied in 2 layers).

Important! The waterproofing layer must be smooth, without folds or damage. If you accidentally tear the film, the resulting holes must be covered with plastic patches.

Reinforcement

It is not recommended to lay reinforcing mesh on the waterproofing layer, as it will simply tear it (in addition, the film should be in direct contact with the concrete). To strengthen the base in this way, you will have to perform the following work:

Pour the first layer of cement-sand mixture.
Wait 28 days for it to dry.
Lay with cells 10 x 10 cm.
Install beacons.
Pour the second layer of screed.
Wait almost another month.

The use of reinforcing mesh will be justified only if flooring you chose carpet or linoleum. Due to the elasticity of these materials, they require a stronger base.

It is much easier to use fiber, which simply needs to be added to the leveling composition during the mixing process. In addition, fiber is considered the optimal component if ceramic tiles are laid on the screed.

Installation of beacons

Beacons must be installed on the insulating layer of the future screed. The use of nails and screws for this is strictly prohibited.

It is most convenient to make strips of cement-sand mortar as beacons, at a distance of 1-1.2 m from each other. In this case, there should be 20-30 cm between the outer “bed” and the wall. Next, metal or wooden profiles so that they sink slightly into the solution until the required level markings.

Preparation of the solution

You can prepare the screed solution yourself or purchase a ready-made dry mixture, for example:

UMIX M 150 costs 110 rubles per bag.
“Stone Flower” M 150 for 160 rubles.
Kreisel-440 for 170 rubles per package.

Typically, such formulations are sold in bags of 25 and 50 kg. To prepare the mixture, you need to add water to the mixture (in the amount indicated in the instructions) and mix everything thoroughly using an electric drill and a mixer attachment.

If you want to save money, you can obtain the desired composition by mixing cement M 400 with sifted sand in a ratio of 1:3 and diluting the resulting mass with water. This solution can be used over the next 1.5-2 hours.

When preparing the solution, you should not overdo it with water, as it will increase the setting time of the concrete and increase the humidity in the room.

Healthy! To increase the strength characteristics of the mixture, you can add a ready-made plasticizer or washing powder to it..

Filling the screed

The concrete slab is poured using standard technology:

Pour the solution onto the surface, starting from the far wall. The easiest way is to pour a portion of the solution between two “beds” in stages.
Level the mixture using the rule, moving along the beacons.
Fill all other stripes in the same way.
Wait 24 hours.
Dismantle the beacons, fill the resulting voids with cement mortar and level the surface with a trowel.
Remove the slats that were installed in place of the baseboards.
Trim and remove any protruding parts of the damper tape.
Remove excess mixture with a rule and a wide spatula.

The technology for preparing the surface and pouring the solution is clearly shown in the following video:

In conclusion

At this point, the concrete screed on the wooden floor is almost complete. All that remains is to cover the monolithic slab with polyethylene and moisten it with water daily over the next week. This is necessary so that moisture evaporates evenly from the concrete and it does not crack.

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Quite rarely, plank floors are leveled using. Experts believe that it is not very rational to burden a wooden covering with heavy concrete slab. In addition, the wood base and the cement layer do not coexist very well, both during the process of pouring and hardening, and during operation. Many professionals prefer other leveling schemes over pouring - dry ones. However, there are many who want to make an underground floor in a wooden house, or lay it in the kitchen and hallway - in such and similar cases, arranging a concrete floor on a wood base helps out. Methods for this exist, and they have some characteristic features.

What does this give us? The wooden component of the structure can move as it pleases, but the screed lying motionless will not crack or begin to crumble due to changes in the configuration of the rough base.

Features of installing a concrete floor in a house: using film

Scheme of a concrete screed on a wooden floor

A reasonable question arises: why polyethylene film? It is not so favorable for proximity to a rather capricious tree, it contributes. Moreover, in wooden buildings it is successfully replaced with glassine, bitumen mastic or roll materials with impregnations. It turns out that concrete does not stick to polyethylene film at all.

Thanks to this feature:

on both sides of the border (film), both the screed and the base can move freely;
wood and cement do not interact with each other, wood will not suck moisture from the hardening concrete, causing the formation of cavities and sinkholes;
poured layer cement leveling will not stretch polyethylene, will not stretch or tear it;
after hardening, the concrete will not gradually begin to absorb moisture from the wood, contributing to the formation of cracks in the wood.

Important necessary measures precautions for those who decide to tackle concrete floors in the house with their own hands. You will have to treat all wooden parts of the structure, even before starting work, with the water-repellent primer “Aquastop”. This way you can minimize the negative impact of polyethylene on wood and reliably protect the base.

Floating screed: installing a concrete floor in a house

We have examined the principle of the technology; now let us dwell on the progress of work and their order:

it is necessary to remove the flooring boards and carry out a thorough inspection;
all unusable logs, unreliable and not inspiring confidence, must be removed and replaced;
if the bearing capacity of all joists is insufficient for the planned load, then they must be strengthened with additional beams. The step between the individual components should be no more than 0.3-0.4 meters;
floorboards are returned to their place, damaged ones can be turned over;
We seal the gaps between the individual boards with sealant.

We mark the zero level on the walls, at a height convenient for you. It is determined using a meter.

Concrete screed - reinforced

The height is chosen arbitrarily; it can range from 0.3 to 0.7 m from the base of the dismantled coating. Equal segments are laid down from the line of the vertical level drawn on the wall, their size depends on the planned thickness of the future screed. It will be quite convenient to immediately mark the width on the wall. In this case, if the height is exceeded, it will be easier to immediately slightly reduce the thickness of the leveling layer.

What should you pay attention to? Standard floating power cement slab is five centimeters. It should be remembered that a layer already one centimeter thick will put pressure on one square wooden covering weighing about 120 kg. Without proper strengthening of the lags, they wooden structure unable to withstand such a mass. The logs must either be securely reinforced, or (if possible) replaced with a metal channel.

Pouring a concrete floor: insulation installation

The next steps in the manufacture of a leveling screed involve the construction of insulating cut-off barriers that will be located between the planned leveling layer and the wooden base of the floor. The result of our actions should be a kind of pallet, the walls of which do not allow water to pass through.

Floor insulation diagram

A fence made of foam polystyrene is constructed along the perimeter of the room, along all four walls. A tape of this material is attached with tape or a stapler (the first is better). Its thickness is 1-2 centimeters, and its width should be greater than the capacity of the future screed. In addition to acting as a barrier, this part can neutralize sound vibrations. Also, with its help, the floating slab will be able to lengthen and expand a little. When will it be laid finishing coat, the excess coming to the surface is cut off, and these places are covered with a plinth or its substitute.
A layer of polyethylene film is laid with an overlap of 10 cm and overlapping the walls by 15-20 cm.

What is extremely important? The presence of holes, folds, slits and tears is strictly prohibited in waterproofing. Work should be carried out carefully, trying not to pierce or tear the layer of waterproofing material. If any gaps do appear, they should be covered with patches made of the same material.

It is best when the layer of polyethylene film does not have any joints at all. If this does not work, then all existing joints, with inevitable overlaps, must be securely taped.

Carefully sealed insulation will ensure the quality and reliability of the leveling layer.

Beacons for leveling concrete floors in a private house

Beacons for concrete screed - for a flat floor

Performing this task requires special care and accuracy. Do not use metal nails or screws. It is most convenient to form special beds over the entire surface to be developed. They are made from the same solution, the same consistency and composition as the planned screed. A heavy strip of mortar will prevent the film from lifting and creasing when the master walks, since it will be pressed tightly to the base.

The distance from the outer bed to the wall should be approximately 20-30 cm. The distance between individual ridges should be one meter or a little more. This is necessary so that it is convenient to level the screed, relying as a rule on the beacons.

It is placed on the tops of the ridges made, and slightly sunk in the solution to a pre-marked height (leveling level).

It is advisable to carry out all the necessary measures for installing beacons within an hour after the start of preparing the cement mass, since later it will begin to set.

Screed in a wooden house: reinforcement or microfiber?

Reinforcing mesh for floor

A thick cement pad, which is a screed, needs reinforcement. Most often, its role is played by a metal mesh, simply laid on the floor. But above we have already noted the extreme importance of the integrity of the insulating film separating the cement mass and wooden base. It is quite difficult to move on a rigid film lying on a polyethylene film without tearing the latter.

Let us also draw attention to the fact that the reinforcement is intended to strengthen not only the very bottom of the concrete layer.

It must be deep in the concrete mass, and to ensure such its location, it is advisable to pour cement not in one step, but at least in two or more:

initial layer;
laying the mesh, placing beacons, finishing filling.

Knowledgeable about performance characteristics concrete they probably have a good idea of how long each one takes to dry separate layer such a screed. Between these two steps you will have to wait at least 28 days, that's almost a month, and you will have to wait the same amount after pouring the last layer.

Is there a way to avoid such a long wait? Yes, there is such a method, but then it is better to use fiberglass instead of a metal mesh. During the preparation of the concrete mixture, they are introduced into its composition, and their randomly placed parts provide good adhesion of the material in all directions. An additional plus is that the already heavy screed will be noticeably lighter, because the fiber weighs several times less than the reinforcement.

Comments:

Renovating a house or apartment always brings a lot of trouble. For example, not everyone knows how to install a concrete screed on a wooden floor. A concrete-based screed is work surface, on which the finishing floor covering will subsequently be laid. Concrete flooring is very common nowadays. The liquid mixture can be poured onto any surface, including wood. What are the main stages of making a screed and is it necessary? complete replacement wooden floor to concrete?

Sequence of work

Concrete screed on a wooden floor requires preparation of the base. If the wooden base of the floor is in good condition, you only need to remove debris and dust with a vacuum cleaner. If there are damaged and rotten boards, it is recommended to replace them. It must be remembered that the base for the concrete screed must be level and clean.

It is necessary to remove paint from the surface of the boards or varnish coating. The gaps between the boards must be sealed with putty; you can also use polyurethane foam. To protect the floor from moisture, a special water-repellent paint is applied over the new boards.

To prevent the concrete floor (screed) from coming into contact with the wooden base, it is necessary to lay a plastic film on top. It is advisable to lay it one large sheet, and it must be fixed to the walls along the entire perimeter of the room to a height equal to the height of the concrete screed. It is attached using a construction stapler.

The film provides protection for enclosing structures from moisture. The film must be taken whole, without torn areas or holes. The next stage of repair is marking the room. To do this you will need a water or laser level. Laser level is installed in the middle of the room, after which a mark is applied according to the location of the beam. To make a concrete floor, you will need to determine the zero point.

Better navigate next room. Using a ruler or tape measure, measure the distance from the base to the threshold. From the resulting value you will need to subtract the thickness of the future floor covering. If the latter is a tile, then its thickness is about 2 cm. The optimal thickness of the concrete screed is at least 5 cm.

Concrete screed on a wooden floor requires the installation of guides (beacons). Suitable for this wooden slats. They are laid parallel to each other, the distance between the slats is 150 cm. The beacons are fixed to the surface using self-tapping screws with dowels. The slats are positioned so that their surface coincides with the previously marked zero level.

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Priming and insulation process

Screed on a wooden floor after installing the guides involves priming, applying a waterproofing and thermal insulation layer. The primer must be diluted in water according to the attached instructions, then applied to the surface.

It is preferable to use a primer deep penetration. After it dries, waterproofing is carried out. This is done using coating mastic. All joints and corners must be carefully processed. Often, residents additionally reinforce the screed using metal mesh. It gives the structure rigidity and strength.

You can take a ready-made metal mesh or make it from steel rods. The size of the cells is 40-50 mm. The rods need to be connected to each other using wire or welded. It is recommended to lay the mesh not on the base itself, but on supports. They are made low. The mesh is placed over the entire surface of the floor. It must be remembered that the mesh must be made of stainless metal. Otherwise, when corrosion occurs, the screed may delaminate.

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Technology of pouring concrete mixture

The most important stage of repair is pouring concrete. Cement mortar or concrete can be used as a mixture for the screed. In the first case, you will need cement powder and sand. The cement used is a grade no lower than M400, and the ratio of cement to sand is 1:3. Concrete mortar characterized by the presence of a coarse-grained component (crushed stone or gravel).

The ratio of cement powder, sand and crushed stone in the presence of M400 cement is 1:1.9:3.7. This proportion is used only when it is necessary to obtain concrete measuring M300. Sand should not contain much clay. It must first be cleaned and dried. It is not advisable to use river sand.

Or cement mortar is best mixed using a concrete mixer or mixer. Manual method is not suitable because it does not allow you to obtain a homogeneous mass. First, the bulk components (cement powder and sand) are mixed, then some water is added, after which the crushed stone is poured out.

If the future finishing coating requires a perfectly flat surface, then cement screed would be more suitable. It turns out more even and smooth. After preparing the mixture, it needs to sit for a few minutes. After this you need to mix it again.

Filling must be done by two people. One person prepares the mixture, and the second distributes it on the floor. You need to start pouring from the far corner of the room and gradually move towards the center. Leveling and tightening of concrete is carried out according to the rule. Using a trowel, the worker removes all unevenness. To ensure that the floor is level, pouring is carried out at the level of the beacons. It is better to fill the screed within 1 day, this will ensure uniformity and evenness of the coating.