Pour the concrete screed onto the wooden floor. Self-leveling floors and wooden base

Appreciated for their quality and high wear resistance. This is a long-lasting coating that is really capable of not only making the floor even, but also beautiful. But in order for such floors to serve for many years and look really presentable, it is important to fill them correctly. In this case, one of the important aspects of the pouring process is correct preparation grounds. I wonder what you can make a self-leveling floor on wooden base, not just solid concrete. What features of installation are important to consider in this case?

Self-leveling floors are made of special polymer mixtures, which, when solidified, can become a solid, neat and even base if the installation was done correctly. The composition of the mixtures used to create them can include cement, gypsum, all kinds of fillers, as well as a number of modifying additives that give the floors certain properties - for example, strength, ability to resist impacts, speed of mixture setting, etc.

They are appreciated for the following benefits:

high level wear resistance;
a large selection of colors;
environmental friendliness;
excellent moisture insulating properties;
antistatic;
durability;
seamlessness - you can pour floors of this type throughout the apartment without a single joint;
resistance to a number of mechanical influences, as well as to the effects of almost all existing chemicals.

It is necessary to fill the self-leveling floors on a properly prepared base. And many doubt whether it is possible to equip them on top. It turns out you can. It is only important to properly prepare such a foundation. It is also important to choose the right type of mixture for pouring.

Table. Types of mixtures for pouring.

Mix type	Characteristic
Epoxy	From such a mixture, good floors are obtained, completely not afraid of the effects of water. They usually settle in rooms where the humidity level is high. Such a floor can be poured onto a wooden base.
Polyurethane	One of the most durable floors with relatively severe long-term impacts. Perfect for setting up in areas with high traffic.
Methyl methacrylate	This mixture is intended for creating foundations in rooms without heating. Perfect for those where winter time no heating.
Epoxy-urethane	Robust floors that are highly resistant to a wide range of influences. An alternative to the polyurethane floor.

On a note! Floor casting compounds can be either two-component or one-component. In the first case, you can create floors with beautiful pattern, and mixtures of the second type are used to create a base for other materials such as tiles, stone, etc.

Prices for self-leveling floors "Prospectors"

self-leveling floors prospectors

Choosing a pouring mix

Usually, each package with a mixture for the manufacture of a self-leveling base indicates its purpose. That is, for example, some are suitable for creating floors on concrete base, others can be used on a wooden one. Most often, mixtures containing gypsum and cement are excellent for these purposes.

Important! Do not confuse flooring mixes with compositions intended for leveling the surface. Such compositions are poured in a thin layer of only a few millimeters. For pouring a floor on a wooden base, the thickness of the poured layer must be greater.

In order to choose the right mixture for pouring wood flooring, it is important to carefully study the instructions.

What do you need?

To make a self-leveling floor yourself, you may need certain tools. The list of things to buy or rent includes:

directly the mixture itself;
wide spatula equipped with a long handle;
construction mixer either conventional drill with a special attachment;
a needle roller, which is used to remove air bubbles from the filled mixture;

building level of any type - necessary to assess the final result;
grinding agents ( Sander, sandpaper etc.);
waterproofing materials (at least a dense polyethylene film);
construction vacuum cleaner;

hammer, nails, nail puller;
a sealing compound with which it will be possible to eliminate gaps between floorboards or plywood sheets. Can be replaced with putty.

The screed on the wooden floor is not the best solution for the device of a new floor. However, despite this opinion, subject to all technologies, it is really feasible. In addition, there are wooden floor structures, which, being in good condition, are easier to fill with a self-leveling floor than to redo the entire floor structure.

This article will be useful for those who are building their own Vacation home... Having made a self-leveling floor over a wooden one, it is easy to lay tiles in a bathroom or kitchen at home.

Also for owners country houses information about septic tanks from concrete rings... You can get information about septic tanks and make an order.

Wooden floor constructions

Before starting a conversation about a screed on a wooden floor, you need to understand about the structures of wooden, plank floors.

It hardly makes sense to do a screed along wooden floor, which is laid on joists and a floor slab with a thickness of 220 mm. The thickness of such a wooden floor is 70-77 mm and the best solution for such a floor would be to remove the wooden floor together with the logs and make a screed along concrete slab overlap.

It makes sense to do a screed on a wooden floor if the floor logs are on high brick pillars... The height of such pillars can reach 30-40 cm (and more) and it is not possible to replace them with a screed. You can see two photos of schemes of such floors below.

It is precisely about floors of this design that we can talk about as a possible basis for a screed.

Features of screed on a wooden floor

Before deciding to make a screed on a wooden floor, pay attention to the following:

A screed on a wooden floor refers to unbound screeds, that is, the layer of such a screed will not be connected to the bottom layer of the base and will be isolated, not connected to anything by the floor layer. Hence, some of the features of the screed on a wooden floor follow.

Firstly, the wooden base for the screed must be very strong and completely motionless. Damping, which is so characteristic of a wooden floor, must be completely eliminated. With a possible vibration of the wooden floor, the screed above it will crack, which is unacceptable.

Secondly, depending on the selected screed material, the screed thickness can be quite thick. For example, using for screed cement-sand mixture, the thickness of the screed should be from 10-12 cm. The weight of such a screed will significantly increase the load on the wooden floor. If we take into account that the wooden floor is laid on the logs, and there is a step between the logs (the distance between the logs), then with an increase in the load on the wooden floor, the distance between the logs must be reduced. V large rooms the distance between the lags can reach 85 cm. Therefore, deciding to make a cement-sand screed in big room, you have to disassemble the floor, reduce the step between the logs by placing new logs and restore the wooden floor again.

It's still a job, and, perhaps, it is worth thinking a hundred times before making a cement-sand screed on a wooden floor in a large room.

In order not to disassemble the floor and not to reduce the distance between the joists, use not a cement-sand mixture, but for example, anhydrite floor leveling agents. The thickness of such a screed is from 30 mm, the leveler does not require reinforcement and can be used for loose screeds.

Thirdly, a cement-sand screed on a wooden floor is made, always with a reinforcing mesh. This is done, again, to increase the strength of the screed. Moreover, the fiber in the screed will not relieve you of the use of a reinforcing mesh. That is, for a semi-dry screed, you will also have to make a reinforcing mesh with cells of 100 × 100 mm.

Conclusion. The use of a cement-sand screed for large rooms with a wooden floor is not justified by time-consuming work. But. If the circumstances and conditions are such that it is impossible to avoid screed on a wooden floor, then for the screed device it is better to take a leveler suitable for an independent screed, and not use a cement-sand mixture. And in general, I would not consider a cement-sand screed as a priority for screed on a wooden floor, although the use of a high-quality leveling agent will significantly increase the cost of the screed material.

Screed material for wooden floors

To perform a screed on a wooden floor, you will need the following material:

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Polyethylene film with a thickness of 200 microns, for waterproofing the screed layer from wood and walls;
Screed mixture. Read about the choice of a mixture just above. If you choose a cement-sand mixture, then prepare a reinforcing mesh, preferably with a stainless coating. The net should not be in rolls. Why not in rolls?

You have to fix the reinforcing mesh on a wooden base, while you must not break the waterproofing, that is, do not tear the film. Think about how you will attach the mesh. At the same time, think over how you will fix the beacons for the DSP screed, because there is nothing to fix the beacons, the base for attaching the beacons is polyethylene.

Why am I making these notes. In my opinion, the device cement-sand screed it is better not to do it on a wooden base in large rooms. The amount of work and problems will completely overshadow the result. Replace the DSP with the "Equalizer" for insulated bases (loose screed). For example, an anhydrite floor screed.

Wood screed technology

The wood floor must be strong, motionless, dry and not rotten. The same applies not only to the floorboards, but also to the logs and posts on which it is laid. Rotten boards need to be replaced.

Important! Do not screed on a freshly laid wooden floor, it may deform. The age of the screed wood floor must be more than one year when the floor is used in the domestic temperature range. Although I have no idea who needs to screed the new wooden floor.

The heads of nails with which the boards are nailed must be drowned a few millimeters so that they do not tear the layer of waterproofing film, which must be laid on top of the boards.

If your apartment is on the ground floor and there is a basement or ground below you, then the seams between the boards need to be putty with epoxy putty. Epoxy putty is chosen because it is moisture resistant. Seams are closed so that vapor does not form between the film laid under the screed and the boards.

If the joints between the wall and the floor are wide, then seal them up. construction foam, and on top with epoxy putty and liquid waterproofing.

After the putty dries, polyethylene 200 microns thick is spread on the wooden base. Polyethylene is spread over the walls with an overlap of 10-15 cm. Two adjacent pieces of polyethylene are laid with an overlap of 20-25 cm. Seal the joint between the pieces of polyethylene with non-soaking assembly tape. Use duct tape to glue the gaps to the wall.

The polyethylene should lie flat, without wrinkles. There should be a clean wood base with no debris underneath the polyethylene.

Preparation of the solution

Let me remind you, we are making a screed from a mixture of roving. We make the screed solution according to the instructions on the package. The roving mixture is added to the water, not vice versa. The mixture is stirred to a state of thick sour cream mechanically, with a mixer at low speeds.

How to check the thickness of the mixture

To check if the mixture is thick enough, find a container with a diameter of 70 mm to hold 1 liter of solution. From this cylinder, pour 1 liter of the solution onto a plexiglass plate 50 × 50 cm. The diameter of the spread solution should be 34-38 cm. This means that the thickness of the solution is correct. The density of the solution must be checked constantly.

Set the screed level

The unbound screed with a leveler must be more than 30 mm. For a wooden floor, choose 50 - 60 mm. It is better to measure the level of the screed with a laser level. If the room is very small, enough building level... At the level of the laser, draw a screed line along the wall and set bench mark beacons (levels on the legs) along the floor surface.

Filling the screed

The ready-made leveling compound is poured continuously over the entire floor surface from the far corner to the outlet. For a successful fill, you will need helpers. One dilutes the mixture, the second continuously pours the solution, the third evens the solution according to the level of the beacons and marks, with a special metal bar with oscillatory movements (raising and lowering the bar) along and across the cast surface.

Care of the filled screed

There should be no drafts in the room with a filled-in screed and low temperatures... If you nevertheless used a solution from DSP, then cover the screed with polyethylene. Anhydrite self-leveling floor must be protected from excessive insolation (direct rays of the sun) for 2 days, too high temperature, drafts and water. After two days, the room needs to be ventilated.

Some conclusions of the article

Before screed, evaluate the structure of your wooden floor;
The cement-sand screed is very heavy and will put a heavy load on the wooden floor, therefore, you may need to reinforce the wooden floor;
If possible, replace the DSP with a high-quality leveling device for an independent screed;
DSP screed on a wooden floor is cost-effective only for small rooms, kitchens, baths;
Think a hundred times before applying a screed to a wooden floor in houses with wooden floors, be aware of the load.

And the last thing. If you plan to use tiles as finishing, replace the screed on the wooden floor, if possible at a level, by laying cement-bonded boards (DSP).

Self-leveling floors in Lately began to gain great popularity. This is due to the fact that thanks to them, you can get an almost ideal surface that is resistant to mechanical stress and can easily transfer a humid environment.

At the same time, the components of such mixtures are able to allow the installation of a self-leveling floor on a wooden floor, without first creating a screed.

Installation

First of all, it should be noted that the wooden surface should not be rotten or loose. There should be no significant damage or large irregularities on it. Otherwise, self-leveling floors should not be applied to a wooden floor.

Preparatory work

First you need to dismantle the old ones. In this case, the elements of their fastening are also removed.
At the next stage, it is necessary to scrape the floor, removing a small layer of material. This is done not only in order to detect all the cracks, but also taking into account that the self-leveling floor on the wooden base will raise its level, which means that it is necessary to remove a little surface.
Next, the floor is carefully inspected to detect cracks, which are marked with a marker. The gaps between the boards can also be attributed to this defect.

Then, with the help of a putty, all damage is repaired. It is worth noting that the installation instructions recommend using a material designed for working with wood.
After that, the surface is covered with a layer of primer with an antibacterial coating. It should not only increase adhesion, but also become a protection for wood.

So that the self-leveling floor for wooden bases received good connection with the surface it is necessary to apply a second layer after 4 hours. In this case, a small amount of sieved corundum can be added to the mixture.

Advice!
Some craftsmen recommend first applying a coat of primer intended for working with wood, and then, a material for concrete work.
However, this is not necessary and, if the components are not selected correctly, it can lead to an unnecessary reaction.

Fill

Before applying the self-leveling floor on the wooden floor, you need to install a special tape around the perimeter of the walls. It will act as a damper pad, protecting the surface from the effects of expansion when heated.

It is also necessary to install special bench mark beacons.... This is necessary so that self-leveling wood floors have a certain level, which is controlled by them.

It is worth noting that the beacons are set according to the water level, and the distance from the floor is set in accordance with the required layer of the future screed. It should be remembered that for this type of work it is better to use thin-layer mixtures, which make it possible to obtain a coating with a thickness of 1 to 5 mm. This is due to the fact that the coating is applied to the finished floor, which means that there is no need to create drops on the threshold.

After all preparatory work produced, it is necessary to check the room humidity and air temperature. Compliance with certain values \ u200b \ u200bof these parameters often requires production technology, and given the fact that self-leveling floors are arranged in a wooden house, this requirement should be approached especially carefully.

The floor is poured in one step, starting from the deepest places.... In this case, you can use a special soft spatula with which the material is spread over the surface. You can make it yourself by attaching a soft but wide tool to a long wooden handle.

During installation, quite often it becomes necessary to move along a surface that has already been filled... For this, developed special overlays on the soles of shoes with spikes.

So that the self-leveling floor in a wooden house does not contain small air bubbles, you should walk over it with a plastic roller with long spikes. It is specially designed for the installation of such floors and especially for fast setting mixes.

When self-leveling floors are applied to a wooden base, all beacons should be removed from the surface... After that, you need to wait until it solidifies completely.

It is worth noting that the period through which you can walk on the surface is indicated on the package of the mixture.... At the same time, professionals recommend not to start other work on the floor earlier than a week later.

Advice!
A household air heater with a fan can be used to remove moisture from the room and maintain the required temperature in it.
So this process will be much faster.

Conclusion

It should be noted that there are special brands of mixtures for self-leveling surfaces, which were developed for application to wood. They have a high level of adhesion to this material and have great plasticity, while retaining all the necessary properties. However, not all manufacturers release them, arguing that they have universal components for such works. "Width =" 640 "height =" 360 "frameborder =" 0 "allowfullscreen =" allowfullscreen ">

Conclusion

In the video below, you will find additional information on this topic. Also, based on the above text, it can be concluded that the price of work on the creation of self-leveling floors on wooden surface will be slightly less than when organizing a preliminary screed or leveling large differences. Therefore, if the coating is in a satisfactory condition, then pouring is performed directly on it.

It should be noted that there are special brands of mixtures for self-leveling surfaces, which were developed for application to wood. They have a high level of adhesion to this material and have great plasticity, while retaining all the necessary properties. However, not all manufacturers produce them, citing the fact that they have universal components for such works.

Tiled and self-leveling floors on wooden floors cannot be made without a leveling screed.

Wood base leveling can be done from wet cement-sand mortar, a semi-dry mixture with fiberglass, gypsum fiber board, or Knauf floor slabs over a layer of insulation.

Figure 1. Screed by wooden floor.

Feature of the screed device for wooden floors

The cement-sand screed, after drying and gaining strength, turns into a monolithic slab that is not subject to linear changes. And the tree has the properties to expand or dry out under the influence of humidity and temperature changes. The screed connected to the base, under the influence of unstable wooden structures, will crack and collapse.

Consequently, the main condition when installing a concrete screed on a wooden base is its isolation from wooden structures so that the screed solution does not touch the wood of the walls and floor.

In addition, the screed should not overload the floor.

Preparation of the base for the screed

Before deciding to pour a concrete screed on a wooden floor, carefully examine the base. Check the condition of the logs and floor boards.

The wooden covering must be tough and durable, free from mold and decay.

If the coating does not inspire confidence, you can strengthen it by installing additional logs, or replacing worn out floorboards.

Figure 2. Repair of a wooden floor.

Before installing the leveling screed on the repaired wooden base, we carry out the preparatory measures:

We seal large cracks and abutments to the walls with epoxy putty or polyurethane foam. After hardening, cut off the excess sealant, grind irregularities.
We clean the floor surface of debris and dust and treat it with an antiseptic, and then with a primer two times.
To the walls, along the perimeter of the room, we attach the damper tape to double-sided tape. It will separate the concrete of the floor from wooden wall... The tape should be 5-10 centimeters wider than the height of the tie.

You can use expanded polystyrene or a wooden board for these purposes.

We put a dense plastic wrap, at least 100 microns thick, separating the screed and floor boards. We lay the strips of film overlapping, fastening together with adhesive tape, with an approach to the walls by 15-20 centimeters.

Figure 3. Insulation of wood flooring.

We strictly monitor the integrity of the coating to ensure the tightness of the insulation. Do not allow moisture to enter the wooden floors, both during the installation of the screed, and during the operation of the coating.

Wet screed, arranged on a wooden floor, must be reinforced. To do this, lay on the insulated surface steel mesh, with a cell of 10x10. When pouring, the mesh should fall into the screed array, therefore it is better to lay it on supports from the solution.

Important!
Semi-dry screed does not require additional reinforcement, since the reinforcing fiber is included in the composition of the solution.

Using a laser or hydraulic level, we mark the height of the screed. To do this, transfer the horizon line to the wall; it can be at a height of one meter from the floor. Then, using measurements, we find the highest point of the floor and from it, adding three centimeters of the thickness of the screed, we find the mark of the screed surface. We transfer this line to the wall along the perimeter of the premises.
Along the insulating layer, we expose the guide beacons along which the screeds will be aligned. We make them from mortar, in the form of continuous strips, or a steel profile installed on slides from a solution. You cannot screw the profile to the base with self-tapping screws, so as not to violate the integrity of the insulation.

The height of the beacons is regulated strictly according to the level, pressing the slats into the mixture or adding a solution under them.

We arrange the first row of lighthouses at a distance of 15-20 centimeters from the wall, and the next - after 1-1.5 meters from each other, but not more length regulations.

Pouring the screed can only be started after the solution of the beacons has dried.

Semi-dry screed device

Semi-dry screed is made of cement, sand, modifying additives and reinforcing fiber. The minimum amount of water is added to the mixture, which is necessary only to hydrate the cement.

It is necessary to carry out such a screed in strict accordance with the manufacturing technology and building regulations... Observing a certain sequence.

Preparation of the solution

Solution, in large quantities preparing for construction site, in a pneumosupercharger. This device acts as a mortar mixer and concrete pump, eliminating the need for lifting mechanisms.

Figure 4. Production and supply of the solution using a pneumatic blower.

All components of the solution are loaded into the container of the device in a certain sequence and thoroughly mixed. Under the pressure of compressed air, the mixture is supplied through a hose to the place of work.

For uniform distribution the mixture flowing through the hose, special dampers are used.

The mortar, directly at the place of installation, can be prepared in a mortar mixer or in a container using a construction mixer.

It is better to use ready-made dry mix in bags for such purposes.

If it is not there, we take cement and sand, in a ratio of one to three, and stirring, gradually add fiber, at the rate of about 700 grams of fiber, per one cubic meter of mortar.

At the end of the process, add a little water and mix until smooth.

You can facilitate styling by adding plasticizers to the finished mixture.

Important!
We check the consistency by squeezing a small amount of the mixture in a fist. Ready solution should turn into a dense lump that does not release water when squeezed.

Screed device

It is necessary to lay the semi-dry mixture strictly according to the installed beacons, starting from the far wall of the room.

We level and compact the solution using a rule and a vibrating screed, carefully filling all the joints.

Two hours after installation, the beacons can be removed, and the resulting cavities can be repaired with a solution.

Figure 5. Grouting a semi-dry screed.

Wipe the entire screed with a disc grinder... Rub the corners and abutments to the walls with a trowel. At the same time, it is better to move along the freshly laid screed in special concrete steps in order to avoid its pushing and damage.

If the room is more than 20 square meters, on the surface of the screed we cut expansion joints.

After grouting, the surface becomes perfectly smooth and even.

After a day, you can walk on the screed, and after three to four days you can start finishing.

Semi-dry screed is an ideal base for tiles or other covering on a wooden base.

It has many advantages over wet or dry screed:

the finished coating is highly durable and abrasion resistant;
due to the semi-dry porous structure, it is much lighter than a wet screed, its device does not significantly load wooden structures;
has high soundproofing and thermal performance;
the use of a minimum amount of water mixed with reinforcing fiberglass, excludes the formation of cracks and shrinkage of the finished screed;
dirty wet processes and the ingress of water from the solution to the ceiling and lower floors are excluded;
Modern technology and efficient equipment allows the production of large volumes of semi-dry screeds in a short time.

The permissible thickness of a semi-dry screed is from three to five centimeters.

It is possible to perform a semi-dry screed on the underfloor heating system.

In this case, it is necessary to lay polystyrene foam on a wooden base, and then roll insulation with a foil layer.

Figure 6. Diagram of the device of the underfloor heating system in a screed on a wooden floor.

Place on insulation cable system warm floor.

Recommend!
When installing underfloor heating systems in wooden houses, it is better to give preference to heating mats or infrared heater in the form of a film with heating elements that can be laid on the finished screed in a layer of tile adhesive.

Wet screed

Screed by wet technology made of cement and sand, in a ratio of 1: 3 with the addition of water, to a plastic, creamy state.

Such a screed requires careful waterproofing of the base, preventing the penetration of water from the solution onto wooden structures.

The solution is prepared directly at the pouring site and laid in an even layer over the beacons.

On a wooden floor, a wet screed is undesirable for the following reasons:

due to the severity, wet screed requires a rigid and solid foundation;
the wet process increases the humidity in the house, which is not desirable for wooden structures;
in case of minor damage to the film waterproofing, water from the screed can get on the wooden base and lower floors;
a wet screed requires mandatory reinforcement, which additionally makes the structure heavier;
the drying time and curing of a wet screed is 28 days;
the entire drying period, a wet screed requires care: protection from drafts and moisture.

Figure 7. The device of a wet cement-sand screed.

Dry screed device on a wooden base

A dry screed consists of a layer of insulation and a hard coating of gypsum fiber board, gypsum board or special two-layer floor slabs of the Knauf system.

As a heater, you can use expanded clay of different fractions, hard mineral slabs or Penoplex.

Under the expanded clay, we lay a layer of waterproofing made of dense polyethylene, 200 microns thick, so that it does not get damaged when backfilling and tamping expanded clay.

Important!
We put polyethylene on the walls 10-15 centimeters above the screed mark and fix it with construction tape. We lay the strips of polyethylene in an overlap and glue them together with adhesive tape.

We mark the height of the expanded clay layer using laser level... We transfer the marks to the walls along the perimeter of the premises.

We install beacons from a metal profile for drywall. We verify the lighthouses strictly according to the marks of the building level.

We pour a layer of expanded clay, carefully compacting and leveling with a long strip. We fill and ram the abutments to the walls.

Figure 8. GVL screed device for expanded clay.

A day later, on the caked expanded clay layer, we lay drywall sheets or floor slabs of the KNAUF system.

In the case of using sheets, we lay out the first layer on the surface of expanded clay, leaving deformation gaps between the sheets of 1 millimeter, with an offset in the seams.

We cover the first layer with glue and lay the second layer of sheets on it, also displacing the seams by at least 30-40 centimeters. We fasten the layers together with self-tapping screws.

When using ready-made Knauf panels, we lay them on a tamped surface and fasten them using special locking joints.

Seams, joints and grooves from self-tapping screws are sealed with putty, grinded and covered with two layers of primer.

Advantages of dry screed:

perfectly flat base;
excellent sound and heat insulation due to expanded clay;
low weight does not require reinforcement of structures;
the surface is ready for finishing immediately after installation;

Figure 9. Diagram of a GVL screed device on a wooden base.

The only drawback of a dry screed with insulation is its large thickness, which does not allow its use in rooms with low ceilings.

Which screed to choose

If you have a solid and rigid wooden base, it is better to choose a semi-dry floor screed.

It will not load the floor too much, the water from the screed will not get onto the wooden structures, even if the integrity of the waterproofing is violated. Will create a reliable foundation for styling any finishing coating floor.

When leveling floors in old and dilapidated wooden houses, dry flooring should be preferred. A dry screed is suitable if you need to insulate the floor of the first floor or the ceiling over an unheated basement.

If you decide to make a screed for a wooden floor, contact the specialists who will help you choose the best option leveling your floor and perform the work efficiently, quickly and professionally.

Wood floors are rarely leveled with concrete. According to the firmly established opinion of builders, it makes no sense to erect a too heavy monolithic slab on a wooden floor. The wooden base and the concrete layer are not very "friendly", both during the hardening period and during operation, which is why the overwhelming number of experts recommend preferring dry alignment schemes. However, those wishing to lay tiles in the washing compartment or arrange underfloor heating are still looking for ways according to which a concrete floor screed can be poured over a wood base. There are methods, and they have specific features.

The nuances of working with a wooden floor

Wood is a special material, which, in addition to a lot of technological advantages, has one significant drawback. It is not static, even after construction the lumber continues to "live" according to their own laws. Fluctuations in the level of humidity, changes in the temperature background force construction timber increase and decrease in volume, shrink in height, stretch and contract in linear dimension... For this reason, after the construction of the log house, no finishing is carried out for two years.

Attention. Pouring concrete over a new wooden floor is strictly prohibited. Leveling with concrete is possible only after 3–4 years of operation.

The timber structures continue to move after the completion of the two-year post-construction shrinkage, albeit without the previous agility. Wood floors equipped with underfloor heating systems set in motion every switch on and then switch off.

Unlike sawn timber, an artificially created stone slab slightly changes geometric parameters in a linear direction during the hydration period. After complete hardening, the concrete layer does not show any tendency to move at all. If they were in a tight bundle, the instability of the "fast" wood would cause crumbling cracks in the concrete. So, in order to allow each of the structural elements to act according to their characteristic principles, without harming each other, the technology of alignment, unrelated to the base and to the walls, was invented.

Technological principle of leveling with concrete

The essence of the technology, according to which a concrete screed is poured onto a wooden floor, is to create a boundary between movable components made of wood and monolithic slab... To do this, the leveling layer is cut off from the walls of the room being equipped with a damper tape, and from the base plastic wrap... The result is a floating deck that is not connected to the walls of a bar or log, or to the base. Thanks to this, the wooden elements of the structure can continue to move in any direction, and the screed lying like a tray will not crack and crumble from the continuous change in the position of the rough base.

Why is plastic wrap used?

After all, contact with it negatively affects the wood, providing conditions for the flourishing of rot and fungus. Usually, in wooden structures, instead of this budget waterproofing, glassine is used, bituminous mastic, roofing material or new roll materials with bituminous impregnation. The fact is that concrete does not adhere to polyethylene at all, due to which:

both the base and the screed will be able to "ride" along the insulating border;
layer concrete leveling will not pull polyethylene behind it, tear it and stretch it;
the indestructible limit will remain intact, will not allow wood to suck moisture from the hardening concrete, which causes shells to form;
the concrete will not absorb moisture from the wood base, causing it to crack.

Note! Those who decide that the concrete floor screed will be laid with their own hands, you must definitely take care of the very foundation and minimize the negative from contact with polyethylene. Wooden elements structures before laying the waterproofing layer will need to be treated with an antiseptic and a primer "Aquastop" with water-repellent properties.

Floating screed technology

We figured out the principle, it remains to implement. Traditionally, you need to start with the preparation:

we remove the boardwalk and conduct a thorough audit;
we identify lags that do not inspire confidence, irrevocably change everything that is unreliable;
in case of insufficient bearing capacity lag systems, we increase their number, that is, we set additional bar so that the step between the lags becomes approximately 30-40 cm;
we fasten the floorboards back, if they are in good condition, it is better to turn slightly damaged boards;
blow out the gaps between the boards with sealant.

Finished with the preparation, we maintain the time indicated on the packaging of the sealed "putty", and generously cover the wooden floor with waterproof primer, after which we let it hydrolyze.

Mark on the walls at an arbitrary height zero level found with a conventional level gauge or laser device. This landmark can be located at an arbitrary height, approximately 30-70 cm from the plane of the dismantled pavement. From the obtained points of the zero horizontal, we set aside equal distances down, taking into account the thickness of the future concrete screed. It will be more convenient to immediately put off the power flooring so that if the height is exceeded, the thickness of the leveling layer can be slightly reduced.

Note. The standard thickness of a concrete floating slab is considered to be 5 cm. Note that a layer of 1 cm will "pile up" on 1 m2 of a wooden floor with a weight of 100-120 kg. Withstand such pressure without strengthening the lag system wooden structure unable. If possible, builders recommend wooden beams generally change to a metal channel.

Insulation device for leveling with concrete

Further actions for the construction of a leveling concrete screed are associated with the construction of isolation barriers between wooden parts floor and the future leveling layer. As a result, you should get a kind of pallet made of material that does not allow water to pass through:

First, along the walls, we will create a fence made of foam polystyrene tape, attaching it around the perimeter of the room with a stapler, but better with scotch tape. The width of the strip should be greater than the thickness of the screed being constructed, the thickness is 1-2 cm. In addition to creating a barrier, this element will damp sound vibrations, and will also provide the floating slab with the opportunity to slightly expand and lengthen. After laying the final coating, the excess protruding above the surface is cut off, and this technological gap is closed with a plinth or its venerable substitute - a 10 cm board with a galvanized ventilation grill.
Then we lay polyethylene with a 15-20 cm overlap on the walls and with a 10 cm overlap on the previous strips.

Note. Folds, gaps, punctures, especially holes in the waterproofing should not be. All further actions for the construction of the concrete screed should also be carried out, trying not to pierce, tear, pierce the insulating layer. Holes that appear accidentally need to be patched with plastic.

It is desirable that the waterproofing layer does not have any joints at all, but if this has not been avoided, all joints with mandatory overlaps are firmly glued with tape. Perfect tightness of the insulation is the key to excellent performance of the leveling layer.

Construction of alignment beacons

It is necessary to carry out these actions with special care, in no case using self-tapping screws and nails. The best way- the formation of beds from a solution with the same composition and consistency as that of the future screed over the entire area to be equipped. A continuous strip of solution will firmly press the polyethylene to the base and prevent it from warping and bullying when the master walks on the floor.

Note. Between the wall and the extreme bed, the distance should be 20-30 cm. Between the parallel ridges there should be a meter or 1.2 m, so that, relying on the rule on the beacons, it would be convenient to level the screed.

We lay a metal profile on the top of the constructed ridges and drown it in the mixture, reaching the previously marked height, that is, the level of the leveling layer. It is advisable to perform all actions for installing beacons an hour after mixing the solution, until it begins to set.

Using microfiber instead of reinforcement

A fairly thick concrete layer needs reinforcement. Usually it was a metal mesh, trivially laid on the floor. I hope those wishing to know how to correctly and reliably do concrete screed wooden base, do not forget that it is important to preserve the integrity of the insulation separating layer. You must admit that it would be difficult to move along a metal mesh, and even work without hooking or perforating polyethylene.

Let's remember that the reinforcement should not only strengthen the “bottom” of the leveling layer. Its place is in the body of concrete, and to achieve correct location, it would be necessary to fill the screed in at least two steps:

first layer first;
then laying the mesh with the installation of beacons and the final pouring.

Those who are in the know and know perfectly well how long each layer of concrete screed will dry, this option probably puzzled. Between the first stages and the second, you need to withstand almost a month (28 days), and the same amount after the completion of all work.

In order not to turn the leveling of the floor into a long-term epic, it is better to use fiber fibers for strengthening. They are introduced to concrete mix during the cooking period. The chaotic arrangement of polymer fibers will provide strong bonds in all possible directions. In addition, the weight of the heavy screed will be significantly reduced due to the rejection of traditional heavy reinforcement.

Directly pouring concrete

It is carried out according to the traditional technological scheme. Depending on the area of the upcoming leveling, the mixture is filled with:

or in turn each room, separated from the adjacent room by a kind of formwork - a partition from a board;
or the entire area with the start of work from the wall opposite the front door.

These rails must be removed one day after leveling along the beacons. Treat the remaining furrows from the profiles with soil, fill with mortar and level with a trowel.

The rules for caring for a concrete screed and for cement-sand leveling are similar. A day after pouring, the screed is abundantly moistened, then sprinkled with water every day for another week. For four days, the fresh concrete floor must be covered with polyethylene so that the screed is evenly parted with moisture throughout its entire capacity. It is necessary to ensure the stability and uniformity of the temperature background and the percentage of moisture in the air.

PCI Periplan ready mix alignment video

It is also worth getting acquainted with the technological intricacies of those who independently take on the difficult task of installing a screed concrete mortar, and those who decided to contact the builders. Failure to follow the rules results in an inevitable costly rework.