Leveling the floor under the laminate, depending on the base and the nature of the irregularities. Choosing the optimal thickness of the floor screed Dry floor screed under the laminate

Buying an apartment in a new building, every owner will certainly want to make repairs in it. This is due to the fact that new houses are often put into operation without finishing work. In addition, even if your apartment was sold with finishing, its quality can rarely be called worthy, so you have to redo a lot in such a room.

In apartments located in houses old building, floor leveling, a burning issue for their owners. This is due to the fact that in panel houses built several decades ago, they laid under a concrete screed as a heater mineral wool or other similar insulation material. And over time, under the influence of loads, the cement-sand screed sagged, and cracks formed on it.

IN ordinary apartments furniture, most often, is located along the walls, so the most trampled down place is the center of the room. Sagging of the screed in this place can reach ten centimeters, which makes life in such an apartment uncomfortable, and the floor itself looks ugly. Therefore, in such apartments, as in many new buildings, you also have to level the floor before you start laying the flooring, be it linoleum, parquet, tile or the now popular laminate.

If the owner of the apartment has sufficient knowledge and experience, then you can level the floor for laying the laminate on your own in just one day. If you doubt your abilities, then it is better to contact a specialized company that will professionally perform a screed under the laminate. But, it often happens that after buying an apartment, there is no longer enough money to attract specialists to carry out repairs, so you have to develop largely on your own. This article will help you better understand the technology of leveling the floor with a screed for laying laminate.

Leveling the floor is the most important part of the laying work. floor covering, especially laminate, and this process begins with a screed device.

The screed is capable of performing several fairly important functions for your home:

Level the floor, and you can’t do without it if you want to mount the floor covering and significantly extend its service life.
Give the base of the floor sufficient rigidity.
Evenly distribute the load from walking and furniture on the layers below.
Disguise communications, pipes, electric wires etc.
Create sound and heat insulation for your floor.

The screed can be made and several various materials e.g. expanded clay concrete, lightweight concrete, special self-levelling mix, gypsum mix, cement-sand mortar.

If there is a need to save on materials, then the screed device can be made from several different layers. For example, the main layer can be made from a cement-sand mortar, and upper layer made from a self-leveling compound, which is excellent for laying laminate.

But, before proceeding with the screed device, it is necessary to perform a number of preparatory work.

Preparatory work for the screed

Begin preparatory work for a screed device to free the room from furniture and other items that will interfere with the process. You must make the room completely empty. The next stage of preparation is getting rid of the skirting boards, they must be torn off. The same must be done with old flooring, tiles, linoleum, etc. For the screed device, you need to clean the base of the floor to the concrete slab.

Then it is necessary to clean the base of the floor from small debris, greasy spots, old putty, paint and dust, for this it is best to use a vacuum cleaner. After the base has been vacuumed, it must be wiped with a damp cloth, so you will get rid of dust much more effectively.

After cleaning the surface, it is necessary to mark the horizon line of the future screed on the walls of the room. This can be done with water or laser level. The screed level marks should be every two meters, they must be connected with a line using the rule. The thickness of the screed should not be less than three or four centimeters, otherwise it will be too thin and start to crack.

It is also necessary to check whether the protrusions of the base will be below the horizon of the future screed. To check, you can use a paint cord or fishing line, which are pulled from one corner of the room to another. If the protrusions are small, they must be leveled with a perforator.

The next stage of base preparation is the application of a special deep penetration primer to the surface, for example, brands such as CERESIT CT-17, TM Triora, Acryl Grundierung, CERESIT MOMENT, etc. It is these primers that will allow the cement-sand screed to be fixed with the base in the most qualitative way. For a room of 16-18 square meters you will need about 10 liters of primer.

Along the entire perimeter of the walls, it is necessary to lay a bituminous or waterproofing tape, this is necessary to create a waterproofing of the floor. When performing these works, it is important to take into account that the tape should protrude 15 centimeters from the level of the finished floor.

Then you need to install beacons. To do this, you need to pull the cords, based on the level of the floor, which will mimic the height of the final floor. Beacons must be set at the height of these cords, which are fixed cement-sand mortar. The distance between the beacons directly depends on the length of the rule used, but, as a rule, average length distance is two meters.

An important stage in the installation of a screed for a laminate is the preparation of a cement-sand mortar. To do this, you will need: 1 part cement, 3 parts sand and water.

How to prepare a mortar for screed:

Take three parts of sand.
Add one part cement to the sand.
Add water to the mixture, stirring constantly, until the desired consistency is reached.

You can make a cement-sand mortar more durable with the help of building lime dough.

Tie tools:

Construction mixer, puncher or drill with a special nozzle for mixing the solution.
A container for preparing a solution, you can use a bucket with a volume of 15 liters (but you can do without a container, the solution in such cases is started directly on the base of the floor).
Rule for leveling the solution, with a length of 1.5 meters.
Two spatulas for leveling the mortar and sealing holes from lighthouses, 10 and 40 centimeters wide.
metal beacons.
Brush or roller for applying the primer to the substrate.
Level.

Ready mixes

To install a screed for a laminate, you can use not only a self-prepared cement-sand mortar, but also special ready-made mixtures sold in hardware stores, for example, CM-10, CM-11, CM-12, Tink-10 " etc.

Part ready mixes for the screed device, not only cement and fine cleaned sand are included, but also polymer and mineral additives. When using building mixtures, the question of installing a screed in one day becomes simpler.

If the height difference of the base in the center of the room is 8-10 centimeters, then about 35 bags of building mixture can be used to create a screed for a laminate.

Screed device for laminate

The screed device begins with the preparation of a cement-sand mortar and its distribution over the entire surface of the floor. In this case, the excess solution is leveled as a rule according to the level of the beacons. It is worth noting that the solution must be laid, starting from the far wall of the room.

30 minutes after the mortar has been laid on the base, the screed must be rubbed with graters. This must be done until the surface of the screed becomes smooth and rough.

When installing a screed, it is important to consider one thing strict rule All work must be completed in one day. Extending the period of work can significantly reduce the quality of the future screed.

In the next three days after laying the screed, its surface must be moistened with water, this reduces the appearance of cracks. After three days beacons can be removed. The holes formed after the removal of the beacons must be treated with a primer and rubbed with a solution. After that, the screed must be covered with a plastic film, on top of which pour sand moistened with water. You need to leave this design for 10 days, while, as the sand dries, it will need to be moistened.

After ten days, the film with sand must be removed and the screed should be left for another 15 days to dry completely. Only after 28 days have elapsed from the moment the screed was installed, it will be possible to start laying the laminate.

Semi-dry screed technology is ideal for preparing the substrate for laying laminate flooring, it dries faster than a cement-sand screed made with a "wet" method. And the Expressscreed company will perform work on the installation of a semi-dry screed in just one day, regardless of the area of \u200b\u200bthe room.

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A semi-dry screed is an ideal coating for laminate flooring. In this article, we will try to maximize the advantages of our floor screed under the laminate.

The work of leveling the floor base is a very important part of the construction activities for the further laying of the laminate flooring. Begins this process with pouring floor screed, which is designed to perform the following functions:

Extends the service life of the finish coat by leveling the floor base.
Makes the concrete floor hard.
Distributes the load on the lower layers under various physical impacts.
Closes various communications: pipelines, electrical wiring.
Increases sound insulation and thermal protection of your future floor.

Why under the laminate is a semi-dry floor screed?

The most preferred way to prepare the base for laying laminate is a semi-dry floor screed. It not only significantly saves material and cash, but also the timing, which is important. Using this method of leveling the floor, you can get a very strong and even coating, on which in just a few days it is possible to lay top coat. Semi-dry screed allows you to significantly speed up Finishing work for laying laminate flooring.

Preparatory work

To carry out flooring work, it is necessary to carry out some preparations. Need to clear the area of rubbish and building materials, which will interfere with the screed device. After cleaning the room, the level of the future screed is marked on the walls. You need to know that the thickness of the screed must be at least 40 millimeters, otherwise the future floor will begin to crack and collapse. To prevent moisture from evaporating prematurely, concrete base polyethylene film is laid. To increase the waterproofing properties, a waterproofing tape is laid around the perimeter.

Screed installation

The main step for carrying out quality work on the installation of a floor screed for a laminate - this is preparation cement-sand mixture. The ratio of sand and cement is taken at the rate of three to one, respectively. Further, these materials are well mixed, after which water is added to the mixture to obtain the required consistency.

After preparing the cement-sand mortar, it should be distributed among the beacons, starting from the far wall of the room. With a gradual distribution mortar mixture, it is necessary to periodically level it with the rule according to existing beacons. After laying the screed, after half an hour, you need to wipe the base with a special trowel and grater. It is necessary to carry out grouting work so that the screed is additionally compacted and becomes even. Over the next three days, in order to prevent the appearance of cracks and chips, the screed must be moistened with water and covered plastic wrap to create the necessary microclimate, for better hydration concrete mortar. After 3 days, you can remove the film and let the screed dry. naturally. And after 10 days from the beginning construction works according to the screed device, you can start laying the laminate.

If you are doing repairs in a private house or apartment, and you urgently need a high-quality floor screed for laminate flooring, contact the professionals. Experienced specialists from Moscow offer inexpensive services for cement and dry floor screed on the website youdo.com. They can also perform any repair and finishing work.

Types of floor screeds and technology for applying compositions

Before laying the laminate, you need to carefully level the surface of the floor. To do this, use the following mixtures:

cement-sand (semi-dry)
dry

Cement screed is carried out in cases where the floors in the room are old, with serious defects. For its implementation it is necessary:

make cement mix
carry out surface preparation work
fill cracks and potholes with cement mortar
coat the surface with gypsum primer
mark floor height with beacons
lay the cement-sand mixture on the concrete base in an even layer.

If you need to repair an apartment in a new building, you can make a dry floor screed. For this work, special dry mixes are used.

The scope of work includes:

covering with polyethylene
edgeband decking
leveling work (distribution of dry composition on the floor)
installation of plasterboard sheets

A dry screed under a laminate is done much faster than a cement-concrete one.

All these works are very complex and require some preparation. Entrust the leveling of the floors in the new building to the performers Yud. Experts will determine which technology is better to choose for leveling the floor in a private house or apartment.

Work completion time

To pour cement and gypsum mixtures for installing laminate, you need to spend a lot of time. It is better to entrust the leveling of the flooring to professionals - they will do the work efficiently and in a short time.

The repair masters that you will find using our website will be able to quickly level the floors for any type of floor covering, including laminate flooring. When the performers inspect the room and measure its area, they will tell you how long the screed will take. The turnaround time depends on:

surface area
building type ( old house or new building)
features of the room (uneven floors, wet air and etc.)

Benefits of ordering repair services at Yuda

If you want to install new flooring in a room, do cement screed or dry, order the services of performers Yuda. They do a great job of leveling the floor. The performers know how to properly carry out the work (distribution of layers, installation of laminate, etc.).

Masters registered on youdo.com will offer you:

free budgeting
purchase of mixtures and other materials
post-repair cleaning
services at a bargain price

Cost of work

If you need a floor screed, contacting repair companies is not profitable. Order services on Yuda. The performers have the most inexpensive screed for laminate - the price directly depends on the amount of work performed.

The following factors affect the cost of services:

surface condition
floor area
material price

You can specify the cost of work in the application or discuss with the selected contractor.

If you urgently need an inexpensive laminate floor screed, fill out the form on this page and create a task.

Laminate flooring for finishing floors, consisting of separate plates, assembled into a single structure with the help of interlocks.

The peculiarity of laminate plates is their rigidity and inability to take the shape of the base. And their most vulnerable spot is special locking joints.

An uneven base can lead to the appearance of deformations, creaks, breakage of locks.

bulging of ends and joints;
breakage of lock connections;
the appearance of squeaks and pops;
rapid wear and deformation of coatings.

Figure 1. Laminate flooring.

The coating during installation is not attached to the base, it is mounted in a floating way. A gap is arranged along the perimeter of the walls to prevent possible deformations from changes in humidity in the premises and temperature changes.

Foundation Requirements

The main requirements for the base under the laminate - evenness, strength and rigidity. Permissible curvature of the coating by one running meter premises - no more than two millimeters, and linear deviations are allowed within four millimeters

The surface to be laminated must be dry and clean.

To fulfill such conditions, there are several ways to prepare the base for the laminate, depending on the type and condition of the floor, time constraints and financial capabilities.

Types of screeds for laminate

For alignment concrete floors There are several proven methods:

dry leveling with GKL, GVL sheets or two-layer Knauf floor slabs over a layer of dry insulation;
installation of a semi-dry screed from a mixture of cement, sand and plasticizers, with the addition of reinforcing fiber and a minimum amount of water;
pouring cement-sand screed;
self leveling floor.

Preparation of the base for the screed

When installing any screed, you must first prepare the base.

The preparation of concrete floors is prepared in the following sequence:

We clean the surface of old coatings, remove exfoliated and destroyed places.
If there is exposed reinforcement, we clean it and treat it with phosphoric acid to remove rust
We carefully embroider the cracks, clean the seams between the plates.
We cover the places prepared for repair with primers and seal them with cement-sand mortar or special repair mixtures.

As a result, we get a rigid, solid, clean base, ready for any screed.

Foundation waterproofing

Waterproofing of a reinforced concrete base can be performed

dense polyethylene film;
ruberoid;
roofing membrane;
liquid bituminous mastic.

We apply insulation or wind it up on the walls 10-15 centimeters above the backfill mark.

Figure 2. Waterproofing the base under the screed.

We lay the film sheets and the membrane in whole sheets, if necessary, fasten them together with adhesive tape.

We glue the roofing material on the bases with an overlap and sizing with bitumen.

For waterproofing the passages of the risers through the ceilings, we use sleeves and silicone sealants.

Important!
In places of passage of riser pipes engineering systems, install the sleeves and seal the joints with silicone sealants.

Dry screed

Dry screed can be used if the height of the room allows, as well as, if necessary, insulation and soundproofing of floors.

First of all, on the prepared base, we install beacons from a bar or metal profiles, according to the marks of the top of the backfill.

We have lighthouses in such a step that it is convenient to level the dry backfill with a rule or a wooden lath.

We check their horizontal level with a hydraulic or laser level.

Important!
Along the perimeter of the room, fix a damper tape made of polyethylene foam on the wall to prevent deformation of the coating.

Between the lighthouses we fall asleep expanded clay.

Figure 3. Expanded clay backfill device.

To create a dense base, it is better to use a mixture of expanded clay of various fractions.

The backfill is carefully tamped and leveled. We give a day for the mixture to thicken.

On the backfill, we lay two-layer gypsum panels of the Knauf system, specially designed for flooring. Can be used GVL sheets, laying out in a run in two layers, fastening together with self-tapping screws.

Joints between sheets and panels, as well as recesses from self-tapping screws, are sealed with putty. We remove excess putty, and grind the surface to give a perfectly even state.

Figure 4. Dry screed device.

Dry screed is ready for laying laminate immediately after production.

I do not advise!
Arrange a dry screed in kitchens and bathrooms where flooding is possible. If water gets into the thickness of expanded clay, it can be removed only by dismantling the coating and removing all wet backfill.

Such a screed does not weigh down the floors and underlying structures, due to the lightness of the expanded clay used in its composition.

The insulation is not affected by microorganisms and rodents, is fire resistant and durable.

Excellent heat and sound insulation performance allows you to use it over unheated and noisy rooms: garages, boiler rooms, pump rooms. It's easy to hide engineering Communication and wiring.

Semi-dry screed

A semi-dry screed is very popular when installing screeds in new buildings, operated premises, it is excellent as a base for laying linoleum.

Due to the presence of reinforcing fiber in the solution, it is not subject to shrinkage and does not crack. Almost dry consistency allows it to be laid in exploited high-rise buildings without fear of moisture from the solution on the lower floors. High mechanization during its laying allows you to perform large volumes in a short time.

The peculiarity of such a screed is the minimum amount of water in the solution. In its preparation, water is only needed to hydrate the cement.

The sequence of manufacturing a semi-dry screed

The screed is carried out by a floating method, without connection with the base, therefore it is better to insulate from the reinforced concrete coating with a plastic film or membrane.
Along the perimeter of the room on the wall, we glue a damper tape that protects the screed from deformation.
Using a hydraulic or laser level, we mark the marks of the top of the screed and transfer them to all walls, along the perimeter of the room, using a chopping cord.
Strictly according to the level, we install beacons from a metal profile, fixed with a screed solution.
We prepare a solution. For the manufacture of screeds in large volumes, we use a pneumatic blower mounted on construction site. In small volumes, the mortar is prepared at the installation site from ready-made building mixtures for semi-dry screeds, in strict accordance with the instructions on the package. For mixing use construction mixer or a puncher with nozzles designed for this.

Figure 5. Grouting a semi-dry screed.

We start laying the mortar from the far wall of the room, compacting and leveling it, using a rule and a vibrating rail. After 2-3 hours, the beacons can be removed, and the resulting seams can be sealed with a solution.
We perform the final leveling with a trowel.

A perfectly even base is ready for laying the laminate after complete drying, but not earlier than two weeks later.

Wet screed

Traditional, cement-sand screed for leveling concrete bases.

For greater strength and to prevent cracking, it is better to reinforce it with a steel or special plastic mesh.

We install beacons from a metal profile. For these purposes, you can use steel pipes. We fix them with quick-drying mixtures of gypsum or alabaster.

We prepare the solution in a mortar mixer or any suitable container using a perforator with nozzles or a construction mixer.

Pour cement and sand into a container with water, in a ratio of 1: 3 and mix thoroughly.

I recommend!
To prepare a screed solution, use ready-made building mixtures. They contain a balanced composition necessary components, increasing the plasticity of the solution and the quality of the base.

We put the finished solution between the beacons and level it with the rule.

After a day, we remove the beacons, and seal the cavities from them with a solution and overwrite them.

The finished screed must be covered with a film, or moistened regularly.

Such a screed dries for at least a month.

After drying, the surface is covered with two layers of primer.

Laying the laminate is allowed after the screed has completely dried.

Figure 6. Installation of a reinforced cement-sand screed.

self-leveling floor

Self-levelling screeds are made from ready-made dry compositions, including binder fillers from sand and cement, modifying additives and plasticizers.

For even application bulk composition it is better to use special beacons made in the form of metal tripods with an adjustable core.

Beacons are easily removed a day after pouring the floor.

Figure 7. The device of the bulk screed.

The mixture is poured onto the finished base and leveled with a spatula or a special comb.

You can walk on such a screed the very next day, and lay the laminate in 5-15 days, depending on the thickness.

After pouring, the coating must be protected from even the slightest drafts.

Figure 8. Rolling the self-leveling floor with a spiked roller to remove bubbles.

conclusions

The choice of a base for a laminate depends on many factors: the type and condition of the floor, financial capabilities and personal preferences of the owners of the buildings.

If you need a base for a laminate floor heating system, perfect option- semi-dry screed. It can be laid in high-rise buildings, without the risk of flooding the underlying floors. Semi-dry screed is the leader in terms of the number of positive technical and operational characteristics among the main types of coatings.

If there is an unreliable base that cannot be additionally loaded, give preference to a dry screed. Such a screed is ideal for laying floors on the ground or over unheated basements or garages. It can be used to level and insulate wooden floors.

If there are no special requirements for the quality and conditions of pouring, do the traditional cement-sand screed wet way.

The main thing is to entrust the screed device to a reliable company that will provide you with a durable, strong and reliable base for laminate flooring.

The screed is the upper part of the floor structure, which serves as the basis for laying the decorative floor covering. Modern renovation, carried out both in a new building and in apartments of old high-rise buildings, necessarily includes work on filling the floor with a screed. In order to independently engage in the arrangement of floors, you need to know what materials will be required and what thickness of the floor screed for your apartment will be optimal. The nature of the work will largely depend on the characteristics of the room and the desired characteristics of the future floor.

Primary requirements

The screed layer in the entire floor structure performs a certain list of functions. With the help of this layer, the dynamic and static strength of the flooring is ensured, as well as a flat surface is created, which is necessary for high-quality laying of tiles, laminate or linoleum. The screed allows you to evenly distribute the load on those layers of the floor that are under it, thereby extending their life. With the help of a screed, they not only level the floor, but also create the slopes provided for by the repair project.

The screed in the living area must be strong enough to withstand physical exercise resulting from the arrangement of furniture and the movement of people living in it around the room. The screed layer must be equally dense throughout the floor, any voids inside it, as well as chips and cracks, are not allowed. If the room does not specifically provide for the organization of the floor with a slope of a certain degree, then in standard cases the surface after pouring should be horizontally flat with a maximum slope of 0.2%.

The thickness of the screed has a direct relationship with the duration of the service life and the strength of the floor structure. A specific number representing optimal thickness subfloor, no. The thickness of the fill depends on the room in which the repair is being carried out, for what loads the floor is intended, and also what type of soil is used as a base. Both the choice of the thickness of the screed and the choice of the brand of cement for pouring it, the use or absence of reinforcing elements in the process of work depend on these indicators.

What can be a screed?

As a standard, there are three types of screed with respect to its thickness. The first type includes a draft floor of small thickness. What screed thickness is used in this case? To fill the floor, self-leveling mixtures are used, which are poured to a height of up to 2 cm. Pre-laying of reinforcing elements in this case is not performed.

The second type of coating includes a floor with a height of up to 7 cm. Such a coating provides for the presence of reinforcement or reinforcing mesh and is made of reinforced concrete. The third type of subfloor is a screed with a maximum thickness of up to 15 cm, which is a monolith with reinforcement inside. A thick screed is used in cases where it must simultaneously play the role of both the floor and the foundation of the house, connected into one system.

The final thickness of the screed depends on the materials used in the process of arranging the floor. So, concrete pouring with the addition of crushed stone can no longer have a minimum thickness. In this case, due to the crushed stone fraction, a thin layer of the subfloor cannot be made. For pouring a thin layer the best option there will be the use of self-leveling and other mixtures intended for finishing the floor before laying the floor covering. With the help of the mixture, a thin and even layer of screed is created, which, after drying, can be immediately used as a base for decorative material.

Particular attention is paid to the thickness of the screed when arranging underfloor heating. It is important here that the filling completely covers the heating elements. At standard sizes pipes of 2.5 cm, the total thickness of the screed for a warm water floor can be from 5 to 7 cm. It is not recommended to pour concrete to a height of more than 7 cm. According to experts, for the normal functioning of the floor and heating the room, a layer of concrete above the pipes of 4 cm is enough. A thicker layer will complicate the adjustment of the heat supply, since it will spend most of the energy on heating the concrete itself.

The maximum thickness of the screed can lead to another unpleasant consequence in the form of wall deformation. The concrete part of the floor expands when heated and has a mechanical effect on the walls of the room. The thicker the screed layer, the stronger this effect will be. For exclusion possible consequences before pouring concrete mix it is recommended to paste over the walls around the perimeter with a special tape.

Minimum screed

According to SNiP minimum height screeds in the floor structure can be equal to 2 cm. But there is one feature here, which is that, depending on the material, the minimum height of the screed can be different. If the screed is made on the basis of metal cement, then a layer of 2 cm will be enough. If no reinforcing element is provided in the fill, then the minimum layer height cannot be less than 4 cm.

Such a requirement for a minimum screed is due to the fact that the flooring must be characterized by a certain strength and wear resistance. A thin screed simply cannot provide the required performance.

Filling a thin coating can only be carried out under several conditions, which include an existing subfloor, a surface leveled with a rough screed and the absence of reinforcement. thin screed it is not recommended to use it in technical rooms, as well as where the mechanical load on the floors is very high. In an apartment, such rooms include a kitchen, a bathroom and an entrance hall - here experts advise pouring a rather thick screed.

A thin screed is used to create a leveling layer necessary for further work. The sequence of work on a flat ground surface is as follows:

A layer of crushed stone and sand is poured, leveled and compacted with high quality;
Waterproofing is laid, which is suitable for a simple plastic film;
A reinforcing mesh is installed and beacons are set up;
The concrete solution is poured.

Minimum Thickness floor screeds using a reinforcing mesh cannot be less than 4 cm. Due to the presence of a mesh and a small height of the screed, the concrete used for pouring must be made from fine crushed stone. Compliance with this requirement will allow you to fill the solution with a thin layer, and the final screed will be quite strong. To increase the strength of the coating, it is recommended to add special plasticizers to the solution.

Maximum screed

There is no specific maximum possible thickness of the screed. The height of the fill will depend on many factors: the value is determined separately for each case. In terms of technology, a height of more than 15-17 cm does not make sense; structures with such a height are created only if necessary, since they require a lot of time and materials.

It makes sense to thicken the layer if you are arranging the floor in a room where there are heavy loads on the floor. The simplest example of such a room is a garage: the weight of the car and its impact on the floor when moving are large, so the height of the screed of 15 cm is fully justified.

A high screed is also used in situations where it will be part of load-bearing structure. In this case, a monolithic pour of great thickness becomes not only a floor, but a foundation. Experts recommend increasing the thickness of the screed if problematic soil acts as the base of the floor structure.

Sometimes height concrete pouring increase in order to hide significant surface differences. In practice, significant irregularities in the original surface are quite common, but a large screed thickness is not the only way to eliminate them.

Before deciding to pour a 15 cm high screed, many builders advise evaluating the possibility of using crushed stone or expanded clay to level the differences. Fix sharp drops with a powerful jackhammer. If surface defects can be corrected in these ways, then the need for pouring concrete to a great height disappears by itself.

The minimum fill layer in this situation is also not suitable, however, you will need a much smaller amount of material to screed the floor. If you level huge surface differences of 15 cm in size only with the help of concrete mortar, then your costs for the concrete itself and for the payment of the builders' work will add up to a round sum. Most often, large expenses will not be justified, so you should at least do partial alignment using a bulk layer of crushed stone.

Pouring a screed of maximum thickness during the installation of warm water floors is also not financially justified. Large thickness of the cement layer over heating elements will cause the floor to warm up slowly. The efficiency of such a design will ultimately be low, and heating costs will be simply huge.

How to fill?

Filling the floor screed can be done in two ways: either with cement mortar or with a special dry mix. With the first method, you will get a concrete screed as a result, in the second - a semi-dry screed. Which option to choose?

Concrete pouring is the most popular, but to use it you need to know a few important points. The solution itself is prepared from cement, sand and water. Experts recommend buying cement not lower than the M-300 grade - with a particle fraction of 3-5 mm, such material will provide high quality final coverage. The use of not sand, but its screening for the preparation of a solution, will also have a positive effect on the final result: the adhesion of screening particles is much better.

To increase the strength of the future flooring and prevent cracking and destruction of the screed into crumbs in cement mortar plasticizers must be added. At this point, you should pay attention Special attention those who are going to make a screed for warm water floors. Plasticizers are special additives that increase the strength and plasticity of the concrete layer.

The use of plasticizers for the preparation of a solution is also necessary for thin flooring. The minimum thickness of the screed without them can be only 4-5 cm, for a concrete floor of a smaller thickness, the addition of plasticizers to the solution is a necessary condition.

Concrete screed takes a long time to dry. The solution must dry itself; it is strictly forbidden to turn on a warm floor for this. Drying of the floor is carried out within a month, and the surface is periodically wetted with water to avoid cracking.

Arrangement of the floor with the help of special semi-dry mixtures in Lately gain popularity. Such a screed does not require the addition of a large amount of water, dries faster and has greater strength. The range of special mixtures for the repair of floors today is quite large.

Unlike a concrete solution, a semi-dry screed will take a much shorter amount of time, the main thing is to wait for the period specified by the manufacturer. After its expiration, you can start laying decorative coating and turn on the heating system if you installed a warm floor. The use of dry mixes for pouring floors looks preferable when the time allotted for repair work, are limited.

Semi-dry screed requires less financial costs, but performance characteristics final coverage significantly exceed the indicators concrete screed. The coating of such mixtures has better noise and heat insulation, is more resistant to cracks and delamination. After the material hardens, a perfectly flat surface is obtained, ready for laying laminate or parquet boards.