Floor screed with expanded clay: pros and cons. Technology of wet floor screed with expanded clay Do-it-yourself expanded clay floor screed

In case of significant differences in floor height, if necessary, to hide the communications passing in the floor, or if you want to use tiles, laminate or parquet as a finishing coating, a screed with expanded clay is an ideal way to organize the floor. And that's why.

Expanded clay - what is it?

Expanded clay is a material made of foamed fired clay. It is a porous, lightweight, ultra-strong and environmentally friendly building material. In appearance, expanded clay is granules of different fractions, often of a round or oval shape.

A floor screed with expanded clay is a reliable solution for a long-term floor service.

Expanded clay concrete screed: stages of work

Consider a way to organize a screed from expanded clay concrete.

Cooking the surface

we clean the base of the floor from dust, construction debris;
masking holes and recesses in the floor with plaster with a cement base;
we lay waterproofing (you can lay both film and insulation from liquid mastic).

Photo 1 - Waterproofing layer

Level markings, installation of beacons

On the walls, using a laser or ordinary building level, we make marks corresponding to the required height of the future screed. Expanded clay screed can take from 3 to 15 cm.

IMPORTANT! In the corners of the room, the lines on the designation of the screed level, drawn by you, should coincide with the minimum error.

It is necessary to install beacons along the lines, placing the guides (you can use ceiling profiles) about 60 cm from each other. Correctly fix the lighthouses on alabaster - the cement mortar dries longer.

Expanded clay backfill

Expanded clay under the screed is poured between the guide rails and leveled with a trowel / rule. Please note that there should be at least 2 cm between the upper level of the expanded clay backfill and the upper level of the guides, i.e. the thickness of the expanded clay layer should be lower than the beacons - we will subsequently fill this height with a cement screed.

Photo 2 - Installation of beacons

Cement screed device

Evenly cover the surface of expanded clay with the so-called "cement milk" (in equal proportions dilute pure cement and a cement-sand mixture with a large amount of water), lightly tamping expanded clay. Simultaneous pouring and tamping of expanded clay is necessary so that the granules of the material do not subsequently "float" to the surface of the screed. However, this is not yet a screed.

IMPORTANT! Do-it-yourself expanded clay floor screed can be arranged only after a day after the "cement milk" has dried.

Having prepared a cement-sand mortar, pour it between the beacons, leveling it with the rule (take into account the calculation of the height of the finishing floor). Consumption of the mixture, if the layer thickness is 2 cm, - 50 kg / m².
How long does such a solution dry? Until it solidifies completely - at least 14 days, however, after a day, when the solution just grabs, remove the beacons, filling the voids with a solution (the beacons can not be dismantled if expanded clay was laid in the voids under the guides). Minor irregularities of the screed, if necessary, are rubbed with cement mortar.

Photo 3 - Backfilling of expanded clay on lighthouses

IMPORTANT! The floor surface will be ready to withstand light pedestrian loads after 2 days. The finishing coat should be laid only after two weeks. The cement composition will fully harden after 28 days.

Such a technology for organizing the floor screed will provide the best sound and heat insulation. The advantage of this method is that it is quite possible to make such a screed with your own hands.

Before making a screed with expanded clay, make sure that you have sufficient floor height to backfill the granules and grout.

Photo 4 - Gradual grouting

Floor screed with expanded clay: VIDEO

$ Screed with expanded clay: the price of materials

The average cost of materials for arranging such a screed:

expanded clay backfill - from 6.5 $ / 40 l;
waterproofing film - from $ 0.8 / running meter;
edging tape - from $ 5.7 / roll;
guides - from 0.9 $ / 3 m;
cement - from 4.7 $ / 25 kg.

$ Screed floor with expanded clay: the price of the services of the craftsmen

in Moscow - from 235 rubles / m²;
in Kiev - from 52 UAH / m².

According to reviews, the easiest and most affordable way to level the floor for self-fulfillment is the device of a lightweight aggregate concrete layer. Do-it-yourself floor screed with expanded clay can be done in two ways. The choice of this or that method depends on the purpose of the room and the characteristics of the base. A detailed video instruction from our article will help you to adhere exactly to the technology for performing claydite-concrete leveling. To understand what price your screed will get, you should calculate it. You can also find out how to do it right here.

Advantages of screed with expanded clay

Expanded clay is an environmentally friendly, durable and practical material that improves the heat and sound insulation characteristics of the floor. Expanded clay concrete screed is used if it is necessary to thoroughly raise the floor level. Strength of expanded clay mixture is not lower than that of cement mortar. In addition, the solution has the following advantages, provided that the proportion of its preparation is observed:

good vapor and air permeability;
frost resistance;
resistance to high temperatures;
the material is not subject to combustion, decay and corrosion;
the small weight of the solution facilitates its transportation and laying;
expanded clay concrete allows to reduce floor loads;
the material copes even with significant irregularities in the base.

An equally important advantage of such a solution is that the floor screed with expanded clay can be laid with your own hands.

When is expanded clay concrete used?

The device of expanded clay concrete screed in some cases is simply irreplaceable:

If the height of the leveling layer is 10-15 cm, then the use of pure cement mortar or concrete is not possible due to too much load on the floor slabs. In this case, it remains only to make a composition with expanded clay.
Sometimes even a low screed is too heavy for laying over an existing floor, for example, in an old building. In this case, the device of a low expanded clay layer will help not to load the floor.
When leveling a wooden floor with wet screeds, it is also better to use a lightweight mortar. In this case, the expanded clay leveling layer can be combined with an interlayer of foam or other lightweight materials.
The price of cement is not small, therefore, in order to reduce the cost of the screed, expanded clay is used as a filler for the solution. According to reviews, making expanded clay leveling is cheaper than using cement mortar. But do not forget to respect the proportions.

The choice of expanded clay for mortar

Expanded clay is of different fractions. Accordingly, its price differs. The choice of the fraction of this material is made according to the type of work. So, according to the diameter of the elements, expanded clay is divided into the following types:

expanded clay sand - fraction size from 0.1 to 5.5 mm (this material is often used when installing dry floor screed);
round and oval expanded clay has dimensions of 5-40 mm (obtained in the process of clay swelling);
the particle size of angular expanded clay can be up to 4 cm.

The last two types of granular material are used to make concrete and cement-sand screeds. If you want the leveling layer not to shrink too much, it is better to use expanded clay of different fractions. To understand how much material you need to buy, you can make a simple calculation or use an online calculator from the Internet.

Advice: for the device of a leveling layer with expanded clay, it is better to choose granular material with a size of 5 to 20 mm.

Preparation of the base

Before laying the expanded clay concrete screed, you need to prepare the base:

The evenness of the floor must be measured with a building level.
Then, using a laser device, mark the level of the screed on the walls of the room.
Beacons are installed starting from the highest point of the base. At this point, the screed should not be less than 6 mm.
All beacons are leveled (see video).

As beacons, you can use profiles for drywall, slats, boards or pipes. Usually they are laid on mortar heaps or beds. According to reviews, it is better to lay on a cement or plaster mortar.

Dry method for arranging expanded clay leveling

To make a dry expanded clay screed, you need to purchase fine-grained material. Further work is carried out in this order:

Preparation of the base and installation of beacons is done as described above.
Expanded clay is poured onto the floor and leveled so that the height of the expanded clay layer is 2-2.5 cm below the expected level of the screed. Most likely, you will not achieve a perfectly flat surface, but it is necessary to observe horizontality. You can calculate the amount of expanded clay using the online calculator on the building materials website.
Now, using a level, we check the evenness of the backfill.
To ensure better adhesion of the expanded clay layer to the screed, pour it with cement milk. As a result, a film forms on the surface of the granular backfill, which will protect the material from shrinkage due to the absorption of moisture from the screed.

Advice: cement milk is made from water and cement in a ratio of 4: 1, that is, water needs exactly twice as much as for the preparation of ordinary cement mortar.

Fill the screed. With our own hands, we prepare an ordinary cement-sand or concrete mortar, fill it and level it over the poppies using the rule. The height of the layer should be such that the mixture, when leveling, turns out to be along the upper border of the beacons. To do this, we lay the rule on the guides and pull towards ourselves, leveling the mixture.
After a day, you can take out the beacons, and the resulting voids can be primed and repaired with fresh mortar. The surface of the floor in these places is rubbed with a scraper (see video).

Wet expanded clay concrete leveling

After reading reviews on the network, you can understand that this method of installation can reduce the time for screed installation. The work is carried out in the following order:

First, the first layer is made. For this, expanded clay is mixed with a solution. It is difficult to specify the exact proportions for mixing. And the calculation will not help here. There should be just enough water to evenly wet the expanded clay surface. Sand with cement is added gradually until a not dry, thick, homogeneous mass without lumps is obtained.
We put the mortar on the floor so thick that it does not reach 2-2.5 cm to the expected level of the screed. We level the mixture (see video).
Now, without waiting for the mixture to dry, we fill in the finishing layer from an ordinary cement-sand mortar.
Carefully align the top layer with the lighthouse rule.
After a day, we take out the lighthouses, and fill the voids with a solution after preliminary priming.

Video instruction for performing expanded clay leveling:

Calculation of expanded clay concrete

To find out how much expanded clay is needed for the screed, you need to make a simple calculation. The proportions of materials may be different, but keep in mind that the more expanded clay you add, the warmer, but less durable the screed will turn out.

The calculation of the proportion of expanded clay per leveling layer can be made taking into account the bearing capacity of the base, the required thermal insulation properties of the floor and the thickness of the structure. The optimal ratio of strength and thermal conductivity of the leveling layer is achieved when expanded clay makes up half of the total volume of the mortar. When calculating the price and volume of expanded clay, keep in mind that it is supplied in bags, but it is counted in liters.

Any transformation of a living space into a new and more comfortable nest cannot do without a perfect floor. The smooth surface not only pleases the eye with its perfection, but also embodies an excellent basis for any floor covering. One of the simplest and most affordable leveling methods for everyone is a floor screed with expanded clay. But is it? Let's take a look at all the intricacies and twists and turns of this traditional and very popular technology.

Basic properties and functions of a floor screed with expanded clay backfill

In addition to the main problem that the expanded clay screed solves - high-quality leveling of any, even problematic base, adding a filler performs the following tasks:

leveling the level;
sound insulation increases;
such screeds provide excellent thermal insulation, which, in turn, reduces the cost of heating the room. Therefore, floor insulation with expanded clay under the screed is not only the easiest, but also the most profitable choice;
due to the porous structure, expanded clay does not allow the room to overheat in the hot season.

The amorphous filler has a relatively low weight and density. But at the same time, the concrete layer gives good strength. The tandem of such building materials as a result gives rise to an excellent floor base, which not only loads the floor to a minimum, but also does not lose its characteristics during operation.

If we take a closer look at expanded clay and its properties, we can conclude that the porous structure endows the granules not only with heat-saving characteristics, but also with water-repellent properties. In addition, it is inert and possesses rare qualities - compatibility with any building material and ensuring a high level of adhesion.

Do-it-yourself floor screed with expanded clay is relevant in the following cases:

when the base is represented by reinforced concrete slabs;
leveling floors under one level, provided that their difference is more than 10 mm;
if communications are hidden below;
minimizing the concrete mix;
if heating is carried out electrically or infrared;
low noise permeability.

Expanded claythe screed is indispensable for obvious flaws in the base, which can not only appear on the finish coating, but also spoil it.

Types of expanded clay backfill and which one to prefer

Expanded clay is a material obtained in the factory by high-temperature firing of finely dispersed foamed clay. Three types of fractions of expanded clay aggregate for floor screed are produced:

crushed stone, with coal particles, no more than 40 mm in size;
gravel - round or oval granules with a fraction of up to 40 mm;
sand, with a particle size of up to 5 mm.

Depending on the type, expanded clay is used in screeds with different requirements. For a traditional screed, a fractional aggregate is used, since it is subsequently covered with either an even concrete layer or other materials that level the surface. Therefore, the size and shape of the granules are not critical.

It is a misconception that expanded clay sand is most suitable for arranging a base with a minimum weight. But it has a higher density than a related aggregate, as a result of which the weight of the screed itself also increases.

But fine-grained sand is indispensable in cases where backfill with less shrinkage is required, for example, for leveling the base with a large difference in levels - more than 10 mm. It is also best to use sand for difficult areas with severely damaged surfaces and when installing block parquet flooring.

Types of technologies for installing screed with expanded clay aggregate

The flexible characteristics of the aggregate itself make it possible to use it in different ways, depending on the circumstances and the room itself. There are three main types of screed installation.

Dry method

It is applied when:

the device of communications at the floor level;
if you need to make a screed in a short time. After 24 hours, you can not only carry out finishing work, but also lay the topcoat;
if there is a need to install a screed with a minimum weight;
if desired, carry out clean work;
when installing the maximum heat-absorbing floor.

Bulk method

Installation using bulk mixes for various purposes. A screed device with a self-leveling coating is used in cases of total leveling of the base under one level, but subject to a small layer. It is perfectly suited for renovation in apartment buildings.

Typesetting technology

Traditional concrete screeds on expanded clay are used to insulate and level the base. This method can be distinguished among the main ones by a relatively low cost and a large leveling layer, which is ideal for heavily damaged bases.

In any case, by whatever method the floor is pulled out, the technology of other plastering work must be carried out in advance.

Dry screed

Consider in detail the dry method of installing a floor screed with expanded clay. In addition to the filler itself, sheets of GVLV will be required, which will cover the expanded clay layer. To prevent the screed from sagging in the future, it is best to use expanded clay fraction for screed floor no more than 5 mm.

The essence of preparing the base is to carefully dismantle the old floor covering to the base and to clean the entire area before work is carried out. To do this, you must carefully get rid of debris and dust. If there are cracks, hollow seams and joints with the wall, then they are not well covered with cement mortar. Only after complete drying can you continue to work.

The first layer of the new floor is a vapor barrier, necessary to protect the screed from any condensation, from the lower floor, basement or soil, which can harm its evenness and integrity.

Depending on the type of base, the following types are used:

for a concrete base - polyethylene with a thickness of 200 microns;
for a wooden base - paper or parchment with bitumen impregnation;
special vapor and moisture proof materials are equally suitable for any base.

Laying any of the three types of material is quite simple - lay it on the floor with an overlap of 15 - 20 cm and secure the seams with ordinary tape. The film must necessarily cover the wall to the height of the future screed - about 7 cm. For reassurance, you can leave more. After carrying out the work, cut off the film or bend it during installation.

To avoid the unpleasant knocking and grinding of expanded clay filler against the walls, you just need to glue the damper tape that absorbs any sounds. It is connected to the base using PVA glue or double-sided tape.

Exposing lighthouses

To level the future backfill, it is most reliable to install beacons, and not rely on an eye. This will require:

self-tapping screws;
laser level;
rule;
screwdriver;
some concrete solution.

Stage 1. Screw a self-tapping screw into one of the corners to the level of the backfill layer. Place the rule on it in an upright position. Place the level in the middle of the room, and where its beam touches the rule on the wall, you need to make a mark.

Step 2. Do a similar step in another corner of the room. If the marks do not match, simply adjust the screws.

Stage 3. When all the markings are made, fix the self-tapping screws to the concrete mortar corresponding to them. It will ensure that the beacons do not move during the backfill process. After the solution has solidified, you can safely continue working.

Screed installation

Step 1. Fill the base with aggregate to the required thickness.

Stage 2. Using the rule and focusing on the level of the exposed lighthouses, properly level the expanded clay layer. It is best to start at the far end of the room, gradually moving towards the exit from the room.

Stage 3. The time has come to lay the GVLV. In order not to damage the leveled base, the sheets need to be mounted from the exit side. This is done quite simply using an adhesive or ordinary self-tapping screws. To make the assembly seam invisible, putty and sand it.

As you can see, installing a dry screed is a simple matter and everyone can cope with it. If you have any questions about its device, you can watch the attached video.

Expanded clay screed based on typesetting technology

Such a screed hardens from two to four weeks, depending on the solution used. Only after this time can you continue finishing work.

There are two variations of surface leveling.

Method 1. Pouring the solution onto a prepared claydite pillow

The preparation of the base is absolutely identical to the process outlined above. After its completion, you can proceed to the subsequent installation.

Installing the frame

Instead of installing small beacons, the frame is being installed. To arrange it, you will need boards with a cut size of 50 * 100 mm. They will be used as spacers to be inserted between parallel walls. They can be replaced with lightweight specialized metal profiles. They are installed at a distance of 30-40 cm, but they are not thoroughly attached, since after pouring the finishing layer they are removed. If you have any questions about installing landmarks, check out the video.

Backfill

The gaps between the frame struts are covered with expanded clay. Its layer should not reach the top level of the lighthouses by about two centimeters. This gap will go to the concrete pavement device. The rule is to carefully align the aggregate from the far wall to the exit.

Filling with rough mortar

The first layer is a traditional cement-sand mortar. For its manufacture, standard proportions of cement and sand are taken, however, it is necessary to calculate the water so that it is three times more than in an ordinary screed solution. Drying of the first layer should not exceed 24 hours.

Finishing screed device

To complete the screed, special dry mixes are used with the addition of plasticizers, which accelerate the hardening process and give additional strength characteristics. The method of their preparation is taken from the attached instructions.

Specialized mixtures can be replaced with traditional cement and pure river sand mortar. The proportions for him are standard 1: 3. The amount of water should be sufficient for good quality hand placement, but the concrete should not be too runny. To impart special characteristics, plasticizers are added.

The poured layer is carefully leveled and left to harden for the time specified by the manufacturer of the mixture used. After it has passed, the guides can be removed, and the resulting voids are filled with a solution, their surface is leveled. If required by the installation conditions of the screed, it is reinforced with an ordinary metal mesh. But this is more the exception than the rule.

Method 2. Pouring a solution with expanded clay concrete

Preparation and breakdown of the base into working segments using a frame - a lighthouse is carried out according to the above algorithm of work. Only in this case dry backfill is not required. Expanded clay is introduced into the concrete solution in the process of mixing it. It is laid gradually, but quickly enough so that hardening does not occur. The laid mortar is leveled using a rule.

Self-leveling coating on expanded clay screed

A distinctive feature of bulk solutions is their unique composition, prone to self-leveling. In addition, special additives have been added to it, not only accelerating the hardening processes, but also significantly increasing wear resistance and strength.

Otherwise, the method of pouring such a screed is very similar to the process of arranging the first method of leveling the surface on a pre-filled layer of expanded clay. There is only one significant difference - a waterproofing film is laid on the expanded clay backfill, and a self-leveling solution is already applied to it. All air bubbles must be expelled from this layer using a needle roller. Such a screed freezes for at least a week, after which you can safely carry out subsequent finishing work.

There are a lot of methods and technologies for installing screeds using expanded clay. Each has individual characteristics. But they are all pretty simple for an independent device, and the end result is striking in performance. The attached videos will tell you more about how to make a floor screed with expanded clay.

It is impossible to imagine a quality repair without an impeccably even floor - a guarantee of the subsequent technically correct laying of the coating. In turn, with gross mistakes of builders and significant differences in the levels of the lower surfaces, it is difficult to install door structures and plasterboard partitions, and various tricks are required when decorating the walls. How to create a flat surface and get rid of possible errors? The answer to this question will be a floor screed with expanded clay, which allows to achieve not only perfect alignment, but also an increase in insulating characteristics. Expanded clay reduces sound vibrations and perfectly protects against heat loss, which allows you to reduce costs in the winter season and do without an air conditioner in the summer.

When a floor screed with expanded clay is used

It is rational to use a floor screed with expanded clay in such cases:

The difference in floor level in the room exceeding 10 cm.
reinforced concrete or concrete slabs lying in the base for laying the floor.
The presence of a floor covering that does not allow the flaws of the subfloor, from which its appearance and quality suffer (floating floors made of natural materials, ceramic tiles, parquet or even practical linoleum).
Installation of an infrared or electrical heating system.
The need to reduce the consumption of cement slurry.
Improving sound insulation.
Placement of communications in the lower floor slab.

Screed with expanded clay perfectly combines lightness and strength. Expanded clay granules, crushed stone, sand and their combination minimizes the load on the floors. Due to the low specific gravity of the material, the floor withstands static and dynamic loads with dignity, so that during many years of intensive use, its quality does not suffer at all.

The priority of expanded clay is due to the specifics of its production. Its material is low-melting, finely dispersed clay, foamed in a special way, and subjected to high-temperature firing. The result is the production of light edges with a strong outer shell that does not allow moisture to pass through. Low thermal conductivity and excellent thermal insulation properties are due to the presence of cavities and air bubbles. By the way, they also explain the low specific weight.

According to the criteria of the fractional size and the presence of acute-angled elements, expanded clay is presented:

sand, the particles of which are up to 5 mm, obtained after the fired amorphous mass is sieved;
gravel with its round and oval particles up to 40 mm in diameter;
crushed stone with angular particles up to 40 mm in diameter.

Often a fractional mixture is used for such a screed, due to which the insulating-leveling layer increases its density. And since usually the expanded clay layer covers the self-leveling floor, gypsum fiber sheets or other material for leveling, the size and configuration of the particles are completely unimportant. True, to minimize the weight of the structure, you should not use expanded clay sand, since if the density of the material is increased, the weight also increases. But in some cases, for example, when block parquet is laid, only fine-grained material is required.

The figure shows the process of leveling the floor using expanded clay sand

If you have to deal with the most difficult area, it is better to use expanded clay sand as giving the least shrinkage.

In modern construction, repair and restoration work, three methods of screed are used:

leveling and insulation of the floor using expanded clay and cement-sand mortar;
installation of a self-leveling floor using expanded clay aggregate;
dry screed with expanded clay.

Let's consider each of them in more detail.

Leveling and insulation of the floor using expanded clay and cement-sand mortar

To level the subfloor, you can contact a construction and repair organization, or you can, without waiting for specialists, perform this simple but time-consuming process yourself, having purchased the required amount of materials. For this, it is important to correctly calculate the costs, based on the data given in the manufacturer's instructions. Knowing the technical information about the material and the area of the floor to be leveled, it is easy to calculate the need for the material and make an approximate estimate.

Floor leveling traditionally begins with dismantling the floor covering and preparing the area to be treated. The floor is dismantled to the ground, and then the debris is removed. The holes in the floor are thoroughly cleaned, and the cables and wires in it are wrapped in polyethylene. The joints of the polyethylene insulation are tightly wrapped with tape, protecting them from crumbs, dust or mortar.

The next stage is waterproofing the base, which is also applicable when laying self-leveling floors. Here you can use a special mastic, but, as a rule, they use polyethylene film, izolan or waterproofing. Using waterproofing materials

a damper layer is created between the wall and the screed;
the adhesion of the mortar to building materials is prevented, often leading to cracking of the cement screed when it dries;
the transmission of sound waves from the screed to the partitions and supporting structures is reduced.

Waterproofing cannot be dispensed with if you have to cover thermal insulation with a screed, arrange parquet flooring, process ceilings in contact with the basement. The installation of rolled thermal insulation materials is 15 cm higher than the marked level of the screed. After the flooring work is completed, the materials are cut at the level of the upper plane.

At the last stage, beacons are set up - landmarks for leveling the surface at the same level. For this ueli, you can use ordinary self-tapping screws or special metal T-shaped devices specially designed for arranging the screed. Correct marking is easily done using an inexpensive laser level or, at worst, an elementary homemade hydro level made from a transparent hose. Lighthouses are set in accordance with the marks left on the walls in the process of making markings.

A screed with expanded clay is poured in two ways:

first, there is backfilling, tamping and leveling of expanded clay aggregate, the surface of which should not reach the level of the floor marked by beacons. The distance from the expanded clay layer to the marks should not be more than 2 cm. Then the entire treated area is poured with cement "milk", which fixes the expanded clay granules. After they have hardened, you can fill them with a cement mortar that includes sifted sand and M-4 marking cement. To eliminate errors with proportions, you can also use a ready-made screed mixture;
first, expanded clay is introduced into the solution, kneading it with a construction mixer. To make it easier to apply the mixture, the floor is divided into segments with the help of beacons, which are sequentially processed. The laid out expanded clay mixture is leveled with a rule device, and cement is added to the places where pits and puddles form.

But in any case, the floor screed is carried out starting from any of the walls and moving towards the door opening. And both methods are suitable for arranging a sub-floor under any floor covering.

Installation of a self-leveling floor using expanded clay aggregate

With the help of self-leveling floors, you can form a perfectly flat surface due to the ability of the composition to spontaneous leveling. Completely such a floor hardens in a maximum of a week, which is two to three times faster than the previous method. Currently, a ready-made mixture with expanded clay for the installation of a self-leveling floor is being sold, which includes additives that improve the characteristics of the floor structure. In the absence of a ready-made composition, the screed begins with a uniform distribution of expanded clay scattered over the entire area. When laying expanded clay on a dry base, waterproofing is optional. Tamped and leveled as in the previous method, the material is covered with plastic wrap or new insulation. Everything is poured with a solution, from which excess air is expelled with a needle roller.

Dry screed with expanded clay

Such a screed is the fastest, cheapest and most practical. Work on it includes the following stages:

marking the future floor height;
laying a layer of waterproofing on the base;
fixing defimer film around the perimeter of the treated floor;
backfilling, compaction and leveling of expanded clay layer;
installation of gypsum fiber sheets on top of expanded clay, processing of butt joints with PVC glue and fixing the elements with self-tapping screws.

The work carried out on the basis of technological requirements and building standards allows the floor to serve for a long time, the communication systems under it and the floor covering. Such a floor will not need cosmetic and major repairs for a long time.

Video - expanded clay floor screed

Expanded clay for dry floor screed is an excellent material that allows you to significantly simplify the process of leveling it with a minimum budget, time and amount of labor. You will learn how to make a do-it-yourself floor screed from our article.

Floor screed is, in any case, a laborious process that requires time and effort. However, the characteristics of expanded clay make it possible to get the best result in a relatively short period of time.

Expanded clay itself is durable, reliable, lightweight, easy to use and completely environmentally friendly material. It has excellent performance in sound and heat insulation. The material is fired clay, which is compacted and hardened due to the high temperature.

For you, it will be needed primarily in order to raise the floor level to the desired height, insulate it and significantly strengthen it. Screed floor with expanded clay is much more effective than mortar of sand and cement. Mainly due to the fact that it is able to pass the required amount of steam and air.

Among the main advantages are the following:

resistance to high and low temperatures;
the ability to use in any residential or commercial premises;
expanded clay does not ignite, does not rot, weighs little;
the ability to level out even strong irregularities that other mixtures cannot cope with;
ease of screed performance even without additional skills.

When do you need to fill the floor with expanded clay?

There are often cases when no alternative other than expanded clay is simply not suitable:

It is necessary to process an area exceeding 15 centimeters in height. In this case, the cement mortar will cost much more, and its strength will be an order of magnitude lower.
When it is impossible for the screed to greatly add the weight of the building due to a weak foundation.
The presence of wooden floors (together with expanded clay, it is also recommended to use foam as a heat insulator with a low weight).
Unless you have a large renovation budget and want to spend less on the materials you use.

How does the floor screed with expanded clay do it yourself. Preparatory stage and calculation of materials

Instruments:

level;
construction mixer;
ruler;
rope;
slats and profiles;
rule.

Materials:

expanded clay;
sand;
cement;
water.

Initially, you need to get rid of the old coating and bring the base to the desired state - remove construction debris, clean it of foreign objects.

disassemble the old floor;
vacuum or sweep small debris;
clean and cement any minor holes in the floor.

As with most modern construction work, it all starts with the markup. Initially, decide on what height you will raise the floor, install beacons around the perimeter. The step between the beacons should be up to a meter. All slats must be exactly level.

Important! If the screed will be carried out in all rooms, make sure that the level is the same.

First, you need to determine the highest point of the floor. To do this, you can use a laser level (it is more convenient and faster to work with it). If it is not there, you can replace it with a regular water one. But in this case, you will need to use a rope to mark the level accurately.

Place beacons starting from the top point. At the highest point, the width of your screed in most cases will not exceed 5-6 millimeters, gradually increasing in the lower parts of the room. Plaster or cement mortar can be used to fix the beacons. But the second implies the need to work quickly until the solution has frozen and began to harden.

It is not difficult to calculate the required ratio of expanded clay to standard cement mortar. The more this material is used, the better thermal insulation the screed will provide. But if you overdo it, then its strength will deteriorate greatly. In the calculation, it is necessary to take into account the thickness of the base, the strength of the foundation, the thermal insulation characteristics. The optimal ratio of expanded clay and mortar is 1: 1.

Keep in mind that the density of the material of different fractions can vary within 250-600 kilograms per cubic meter.

The standard number of components per cubic meter of expanded clay concrete is as follows:

cement - up to 300 kg;
sand - 300 kg;
expanded clay - one cube (weight may differ due to different density, so when buying, focus on volume).

A more accurate calculation can be done using the following example:

As a reference, let's take a room with dimensions of 9 square meters and an average layer thickness of 60-65 mm. We make a calculation: 9 x 0.06 = 0.54 cubic meters. m., which is exactly 540 liters. screed solution.

There are several ways to make a floor screed. We offer two simplest and most effective options:

Screed option No. 1

After you take measurements and mark the level of the screed, you need to fill in small expanded clay throughout the entire area. A small fraction at this stage is needed so that expanded clay is better compacted. The layer should be no higher than 2.3 centimeters to the top of the future screed. Using a level, make the expanded clay layer completely even and distribute it over the surface.
The resulting layer can be filled with cement milk for better density.

To prepare it, you need to make a standard screed solution, but there should be twice as much water in it. By itself, the "milk" material will not hold together, but it forms a film on it, which will prevent the absorption of liquid by expanded clay. As a result, the consumption of the solution will decrease when pouring. It will take a day for such a film to form and harden. At this stage, finished. Now you just have to wait.

At the end of the day, you can proceed directly to the finishing screed. Fill in the required amount of expanded clay over the entire area and level again using a level. Now pour the finished solution onto the surface, level it with a rule and leave to dry for 2-3 days.
When the screed is dry, remove the beacons, and seal the holes formed with cement.

Screed option No. 2

In this case, expanded clay will also have to be put in two layers, but the whole process is noticeably faster than in the first option.

Prepare a screed solution. To make it suitable for use, you must first fill the expanded clay into a large container, fill it with water and mix with a construction mixer. Next, add cement and sand in the required amount to the container and also mix everything. There is no exact proportion in this case.
Gradually add sand and cement to the mortar until it becomes a homogeneous, viscous mass without lumps.
Pour the finished composition to a height of 2.5 cm from the floor. Please note that in this case, unlike the previous one, you do not have to wait a day, but you can immediately continue working.
When you start finishing pouring, do not reach the edge of the bottom a few centimeters.
Align the top layer of the screed carefully. There may still be bumps in some areas. They need to be found and eliminated in time. Avoid puddles, gouges, surface bubbles, etc.

If there are wires and any communications under the screed, it is necessary to wrap them with plastic wrap and fix them in the desired position with tape or electrical tape.
It is best to put a layer of waterproofing under the expanded clay. For this purpose, you can use mastic, plastic wrap or hydrosol.
Profiles and slats are the best options for beacons.
The screed will take at least a month to dry completely at standard room temperature and humidity.
During the drying process, the surface should be regularly watered with a small amount of water to avoid cracking.
If a plasticizer is added to the solution, the likelihood of cracking is significantly reduced.
If you use expanded clay mainly to improve thermal insulation, its layer should be at least 10 cm.
Use expanded clay of different fractions to get a tighter screed.
Expanded clay can be effectively used together with self-leveling floors. By themselves, they perfectly level the surface due to a fairly liquid consistency. If expanded clay is mixed with such a solution, you can achieve higher strength and thermal insulation.
During the screed, work the building rule for yourself over the entire surface area.
Reinforcing the screed surface is an optional but useful step that can significantly strengthen it.

As you can see, filling the floor with expanded clay with your own hands is a fairly simple method that allows you to get a good result for little money. No expensive tools and materials.