How to make a floor screed in the apartment. How to make a floor screed in a bathroom or living room How to make a rule for working with a screed

Floor leveling is one of the most important stages of repair work. Before laying the final floor covering, the floor screed in the apartment is performed. In the construction of multi-storey residential buildings, reinforced concrete slabs are used as floors, which have a smooth surface on only one side. The flat part is always laid in the direction of the ceiling, therefore, the side with defects serves as the floor. In this article, we will consider how to make a floor screed in an apartment, the types and rules for preparing mixtures.

Screed functions

The screed eliminates the difference in the height of the floor and its defects, allows you to lay the finish flooring with high quality. If you lay linoleum on an uneven floor, it will crack over time in places of height differences.

Functions of the screed in the apartment:

• strengthens the concrete base;
• perceives and distributes the loads arising during operation;
• increases heat and noise insulation;
• due to a perfectly flat surface, it protects the floor covering from damage;
• allows you to arrange a technological slope of the floors of the kitchen and bathroom to drain water in case of flooding when communications fail.

With the help of a screed, you can raise the level of the floor. In the course of work, it is necessary to take into account the permissible loads on the plate. It is impossible to pour concrete more than 70 mm in thickness, since the ceiling may not withstand the load.

Types of mixtures

Often there are questions about how a floor screed is made in a new building, which one is better. We choose the technology of laying the subfloor depending on design features plates.

Stages of dry screed

1. Dry and semi-dry screed is used for height differences of 30-50 mm. Compared to other types, lighter materials are used, due to this, the load on the plate is reduced.
2. Installation of a concrete screed is used for damaged floors with a large height difference, increasing heat saving and sound insulation.
3. Self-leveling compounds are used for height differences up to 30 mm. They include two stages of work: leveling with the starting mixture and the finishing bulk coating.

The type of screed is selected depending on the condition of the concrete slab, functional features and floor covering.

Preparatory work

The floor in a new building often has to be leveled at the stage of settling in an apartment.

Stages of preparation:

1. We remove the old floor covering, inspect the slab for cracks, depressions, protruding reinforcement.
2. We expand the cracks with a grinder, clean their edges, fill them with concrete mortar; for better adhesion of materials, the surface must be moistened.
3. After the cement has hardened, remove the dust from the plate with a vacuum cleaner.
4. At the joints of the floor with the walls, we lay a damper tape. It will serve as an expansion joint when the concrete expands during drying and will protect the lower apartment from water leakage.

Floor marking

Marking is carried out from the lowest part of the floor

The thickness of the screed and the choice of material for its installation depend on the differences in floor height.

Find the lowest and highest point of the floor. We make markings using a laser or water level.

If the threshold turned out to be the highest point, a concrete base can be poured. If the corners of the room are above the threshold, there are two algorithms for action:

• we dismantle the old screed to the slab, pour concrete, adjusting it to the floor level in the adjacent room;
• we pour concrete on the old base, but we take into account that the floor height in this room will be higher than in the adjacent one. This is justified if you plan to make new floors throughout the apartment.

To correctly mark the floor boundary, you need to place the guides parallel to each other at a distance of 150-200 mm from the wall. The distance between the guides must be less than the width of the mix spreading tool.

As guides, we use T-shaped profiles designed to align vertical surfaces. To set them to the level, we use plastic and metal strips or install beacons on a gypsum (cement) mortar.

Cardboard, chipboard and wood cannot be used as supports for beacons, as they lose their shape from moisture.

Calculation of the number of components for concrete

The volume of the screed is measured in liters

To determine the amount of sand, cement and water, we calculate the volume of the screed in liters. To do this, we multiply the average height by the length and width of the room, we get the volume.

Suppose, taking a room with a width of 4 m and a height of 3.5 m, we fill the screed with a thickness of 25 mm at the lower point, and 40 mm at the highest.

We calculate the average thickness of the concrete pavement (25 + 40) / 2 = 32.5 mm.

We calculate the area of ​​​​the room: S \u003d length 4 m * width 3.5 m \u003d 14 m.

Volume \u003d 32.5 * 14 \u003d 497 liters.

Sand will need as much as the volume of the screed. But sand weighs 1.5 times more than water, so 497 * 1.5 = 745.5 kg.

And cement will need 1 part to 3 parts of sand. 745.5 / 3 = 248.5 kg.

The amount of water used depends on the moisture content of the sand. Add water until the consistency of thick sour cream is obtained.

High quality concrete mortar

Mix the ingredients in a specific order

After marking the floor, we proceed to the preparation of concrete. The preparation scheme is standard, for one part of high-quality cement (M 200) there are three parts of sand.

We mix the ingredients correctly:

1. First you need to mix the dry ingredients well together: cement and sand. Since a large volume of the solution is mixed, it is necessary to prepare a drill with a special nozzle or a construction mixer in advance, since manually mixing the components will not work.
2. To protect the surface from cracking during drying and further operation, it is recommended to add plasticizers to the solution. Technology and proportions are indicated on the packaging to the composition.
3. We check the quality of the solution by squeezing a handful of the solution into a fist. It should not crumble and crack when compressed.

Concrete brand	Application	Consumption of cement in kg per 1 cube of concrete
M100	Minimum strength. It is used when concreting road curbs, fences	165
M200	It is used when installing floor screed in new buildings, when repair work. Suitable for foundations	240
M300	It is used for the installation of foundations, ceilings, etc.	320
M400	For the construction of structures subjected to significant loads: bridges bearing supports on overpasses	417

To get a homogeneous mixture, we pour the dry ingredients into water. If done in reverse order, then the sand and cement will remain at the bottom, and it will be difficult to mix them.

Concrete screed device

Consider how to properly make a floor screed in an apartment. We start installation from the far corner of the room. We fill the floor in one go, with a large thickness of the screed we reinforce it with a thin metal mesh. For more information about the process, see this video:

Stages of work:

1. Pour the solution onto the floor between the guides, level with a trowel.
2. Using the rule, we level the mixture by moving it towards ourselves. We seal the solution so that air comes out and there are no voids left.
3. After a day, we take out the guides, fill the place where they were with a solution.

You can walk on the floor after 4 days. Concrete dries completely and gains strength within 30 days.

The deviation in the horizontal plane should not exceed 0.2%.

At the end of the installation of the screed in the apartment, we exclude drafts, smearing all the cracks, and regularly moisten the concrete so that the coating does not crack. Finishing alignment is done after the screed has completely dried. You can use mixtures for self-leveling floors.

Dry screed

This type of coating facilitates the load on the plate and increases the thermal insulation of the floor. Dry screed is laid using expanded clay or other bulk material small fraction. For more information about dry screed, see this video:

The layout of the premises and the installation of beacons is carried out according to the above principle.

We select leveling elements for a dry screed device in a new building depending on the level of humidity in the room:

• expanded polystyrene plates provide heat preservation and sound insulation;
• chipboard OSB;
• moisture resistant gypsum, gypsum-fiber sheets, plywood.

We use expanded clay, quartz sand, fine-grained slag as backfill for floors.

Do-it-yourself dry floor screed provides for the following sequence of work:

1. We make the markup, find the lower and upper points of the screed.
2. We install the guides: the first profile is near the wall, the rest are parallel to each other with a step of 1.5 m. We use pieces of timber, plastic, polystyrene foam as supports for setting the height.
3. Pour expanded clay between the guides to the marked level, tamp well.
4. On the extreme sheets, we cut off the folds so that they do not go deep into the backfill. We join the remaining sheets along the seam edge, which we coat with glue and fix with screws. We start laying leveling sheets from the entrance. Walking on the sheets until the end of work is not recommended.

Lighthouses are taken out as the plates are laid. If you leave them, then the floor will shrink during operation, and the guides will remain in place.

Self-levelling screed

It is important to install a coating on the first floors that provides increased thermal insulation of the floor.

With a small difference in height, it is easy to make a floor screed in the apartment with your own hands using a self-leveling mixture.

Sequence of work:

1. We prepare the surface of the plate, fill cracks, chips, depressions with a solution.
2. We prime the floor in several layers for better adhesion of materials.
3. We dilute the mixture according to the instructions on the package. Installation starts from the far corner.
4. We stretch the solution with a spiked roller.

The floor dries within 4-5 days depending on the temperature and humidity in the room.

floating screed

It differs in that the upper concrete coating is not bonded to the slab, as it is laid through the film on a layer thermal insulation material.

• plaster mortar;
• finishing flooring;
• concrete or calcium sulfate screed;
• polyethylene film is laid as a barrier to the penetration of concrete solution to the heat-insulating material;
• mineral wool or expanded polystyrene;
• damper tape with a thickness of more than 10 mm;
• plate.

damper tape

We fix the damper tape before laying the heat-insulating material, its height must be at least the total thickness of the floor structure: from the slab to the finishing floor covering. Trimming is carried out after laying the floor covering.

The heat-insulating material is laid strictly in a horizontal plane, uneven laying leads to the formation of cracks in the cement mortar.

One of the ways to prepare the surface for laying floor materials is its alignment with a coupler. Now there are several technologies that can be used to make a full-fledged platform that meets the requirements.

How to make a floor screed in the apartment different ways? The answer to this question is in our article.

Types of screeds

Depending on the material from which the screeds are made, they can be divided into several types: Cement-sand- the simplest, most affordable and widespread material when working with a screed is cement-sand mortar. It has two big pluses - its wide availability and relative cheapness. However, there are many downsides as well. Cement-sand mortar is a rather capricious material, it requires at least basic skills to work with it. It takes a long time to dry and may crack.

Floor installation on a cement-sand reinforced screed

Gypsum- gypsum comes out completely natural material. Its density is relatively low. However, gypsum is endowed with excellent heat and sound insulation qualities. Dust does not linger on it, and it is not able to burn. These parameters are extremely important when it comes to residential premises. The use of gypsum-based screed allows you to slightly adjust the "climate" in the home. After all, gypsum is endowed with a porous structure, which means it can "breathe". Gypsum screed will both absorb and then release moisture. This property is especially important in a climate characterized by significant temperature differences and high humidity. Semi-dry with fiber- polypropylene fiber is intended for reinforcing the screed. The advantage of additives in cement mortar give it a lot of positive characteristics:

strength and durability;

minimum curing time;

resistance to high and low temperatures,

influence of anti-icing salts;

decrease in water permeability;

resistance to abrasion and mechanical stress;

absence of probable delamination, chips, shrinkage cracks.

Do-it-yourself semi-dry floor screed

Concrete with plasticizer- a highly active additive that increases the fluidity, strength and uniformity of the building mixture, improves heat and sound insulation properties. An effective additive allows you to make the structure of the cement-sand mortar homogeneous. Due to this, the physical and mechanical properties of the liquid composition change. The surface formed with its help becomes absolutely smooth and not subject to mechanical impact. Finishing floor screed- the ties described above are classified as draft. In addition to them, there are also such compounds with which it is possible to solve specific problems of the floor. First of all, we are talking about finishing solutions that aim to bring the floor, as they say, to the ideal. It is also necessary to select the finishing floor screed depending on the mode in which the room will be used. The thickness of the finishing screeds can be no more than a dozen millimeters. These screeds are usually formed by a rather liquid and fluid type of mortar, and after application they do not need additional alignment.

Finishing floor screed

Ties according to the method of coupling

Depending on how the screed is connected to the foundation slab, bonded, floating and separating bases can be distinguished.

Related- is placed on the working surface of the floor, without the use of heat and waterproofing materials. This type is used if it must be very light, the base of the floor does not require leveling, or the area of ​​\u200b\u200bthe room is very large.

On the separating layer separates from thermal insulation and waterproofing and does not come into contact with walls. This design helps to reduce heat loss. It is made on the basis of rather rigid mineral plates. In this way, the floor is most often arranged in bathrooms, a bathroom or on the ground floors of apartments. floating- is installed on an insulating layer, which is a pillow to protect against heat loss, extraneous sounds and high humidity. Most often used when used as a floor covering linoleum, laminate or parquet board. When using parquet will not apply.

Do-it-yourself floating floor screed

Preparation for work

Before you make a floor screed, you need to collect all the necessary fixtures and materials. You will need:

mixing container concrete mix;

a drill with a special nozzle or a construction mixer;

hydraulic level;

rule;

Master OK;

tape measure and marker for marking the area.

If you decide to mix a screed mortar, whether it is a ready-made mixture or you mix cement with sand, there is no turning back. Therefore, carefully prepare the surface on which the screed will be applied. There is nothing special to tell here - the result of the preparatory work should be the floor surface, from which all crumbling and baying areas are removed with the help of a perforator or a jacking tool.

Markup execution

At the highest point of the floor, mark on the wall from the floor a distance equal to the thickness of the future screed and mark. For laying ceramic tiles, the thickness of the screed should be 15 mm, for laminate - 10 mm, and for linoleum this value is 5 mm at all. There will be nothing shameful if you play it safe and, to be sure, add another 5 mm to the required screed thickness.

Further, starting from the mark, draw a horizontal line along the entire perimeter of the walls of the room and, having drawn the full path, return to the starting point. A horizontal line can be drawn using a level, or you can use a horizontal line drawn when searching for the highest point on the floor. Check the distance from the mark of the future floor level to the horizontal line. And now, retreating from the horizontal line along its entire perimeter to this distance, get a line showing the future level of the floor.

Installation of beacons

As lighthouses, the use of even beams, pipes or galvanized profiles for plaster beacons is allowed. Using the line of the future floor, drawn along the entire perimeter of the walls of the room, install beacons on the floor in the room. Align one end of the beacon along the line on the wall, and the other - along the level, achieving a strictly horizontal position of the beacon. Arrange the beacons along the entire length of the room, the distance between the beacons should not exceed the length of the rule (with emphasis on the second syllable), but in general in construction practice this distance ranges from a meter to one and a half. To level the beacons in height, place bricks, stones under them, but in no case wooden blocks or pieces of chipboard or fiberboard, which, when wet, will first increase in volume, and as the screed dries, they will decrease and cause cracking of the surface of the screed. It is very important to place stones under the lighthouses more often in order to prevent them from sagging.

Installation of plaster beacons for floor screed

Beacons are fixed with a solution of alabaster or gypsum, you can also fix them with concrete mortar, but you will have to wait at least a day before the concrete “sets”.

Solution preparation

For screed designed for rigid floor coverings, tile, laminate or parquet, the proportions of the mortar will be as follows: 1 part of cement, 5 parts of sand and 0.8 parts of water. For a screed for soft floor coverings, linoleum or carpet, the mortar recipe will be slightly different: 1 part cement, 4 parts sand and 0.8 parts water. When preparing the solution, it is very important to prevent excess water in it, otherwise cracking of the screed cannot be avoided. Prepare the mortar with the least possible amount of water, and to facilitate the laying of the mortar, add plasticizers to it when kneading.

Mortar laying

Moisten the surface of the old floor with water to increase adhesion to the solution. Using a trowel, manually fill the space under the beacons with mortar to prevent them from sagging during the laying and leveling of the screed.

Start the process of laying the screed from the corner opposite to entrance doors. Bring the containers with the prepared cement-sand mortar into the room and start laying it between the beacons. Use a trowel to distribute and level the solution, achieving a more dense laying, and then take up the rule. Having placed the rule perpendicular to the lines of the lighthouses and moving it away from you at arm's length, press the rule to the profiles of the lighthouses. Shaking the rule to the right and left and without releasing pressure, move it towards you with translational movements along the guide profiles of the lighthouses, as if on rails. In this case, all excess mortar will be removed from the surface of the screed, and the surface itself will become perfectly flat and smooth.

The process of laying a dry floor screed

If, after the first pass with the rule, shells and bumps form on the surface of the screed, apply a little solution to the surface and once again run the rule over the problem area of ​​the screed. If necessary, the guide profiles can be removed after 5-6 hours, and after about a day, the gaps without mortar left by the profiles should be filled with mortar and leveled manually. If plaster beacons were used, there is no need to remove them, let them remain in the solution.

Fresh screed care

On the second day after application, a fresh screed should be covered with plastic wrap. After two weeks, tiles or linoleum can be safely laid on a new screed. But for laminate and parquet, sensitive to moisture, you should withstand the screed for a month under the film, and then another two weeks with air access.

Pouring a screed for the floor in an apartment with your own hands is not such a difficult matter. If you are not afraid of manual labor and want to control the process yourself, consider our simple recommendations and you will achieve a good result. Your floor will be ready for any type of floor covering, whether parquet, laminate or linoleum. A well and properly made screed is a guarantee that your floors will last a long time and will never cause inconvenience.

If you want your floor to be smooth and last for many years, then before laying the selected flooring, carefully prepare its base and, above all, level the floor. The screed is a leveling layer. Consider how to properly make a floor screed in an apartment.

The screed can be made from various materials using different technologies. Depending on these parameters, the following types are distinguished:

1. Concrete. This is a classic type of tie. It is used, as a rule, for the initial leveling of the surface. This method is indispensable if there are large surface drops. The composition of such a mixture includes cement, sand and other fillers. The implementation of such a screed is associated with high labor costs.
2. Self leveling. Such a screed is made from ready-made mixtures. The leveling layer is obtained with a thickness of about three centimeters. It is used as a finishing screed to level all differences and surface irregularities. This perfect option for any type of flooring.
3. Dry. This type of screed can be used if necessary to even out large differences in floor height (from 3 to 12 cm). As a rule, two technologies for performing this type of screed are used:
   • Lag Alignment. Plywood, chipboard and other sheet materials are used as leveling materials.
   • Leveling with gypsum boards. Most often, materials and developed technologies are used to perform the screed in this way. German company KNAUF.

A beautiful floor cannot be made without a quality screed

Which material to choose for the floor screed in the apartment depends, first of all, on the primary state of the floor surface and the choice of the finishing floor covering.

Purpose of the screed

No major floor repair is complete without a screed. Consider what functions the screed performs.

1. The main purpose of the screed is to form a flat surface. Quality styling such flooring as, for example, laminate, linoleum or parquet is impossible without a perfectly flat floor base.
2. It performs the function of strengthening the strength and rigidity of all building structures.
3. It serves as an additional element of sound and heat insulation of the room.
4. With the help of a screed, the floor is raised to the required level.

floor screed requirements

In order for the screed to fully perform its functions, it must meet a number of requirements in its parameters:

1. Possess a certain strength and withstand standard compressive loads.
2. The density of the screed substance must be the same throughout the entire thickness of the surface and the area of ​​​​the room.
3. It should have a layer thickness of more than two centimeters for floor slabs and at least four centimeters if it is poured over a heat and sound insulating layer.
4. It should be 1.5-2 cm thicker than the diameter of the pipes that they want to hide in it.
5. When laying on a layer of sound insulation from the wall, it is necessary to make an indent of 2-5 cm, which is subsequently also filled with sound insulation.
6. A monolithic continuous layer is poured onto waterproofing, which can be taken as a thick polyethylene film or roofing felt. A layer of waterproofing is started by 5 - 10 cm on the walls of the room.
7. The surface of the screed must not contain cracks, potholes or chips.

Necessary preparatory work

The list of work that needs to be done before laying the screed largely depends on its type and the initial state of the floor, but in any case, you will have to perform the following operations:

• carefully examine, partially or completely dismantle the old coating;
• remove all construction debris;
• to remove dust, clean the surface with a vacuum cleaner or a wet brush;
• if there are oil stains, then they must also be removed;
• using a laser level, determine the maximum possible height of the floor in a given room;
• install beacons.

Work technology and features

The correct floor screed will be obtained only if all the requirements for the composition of the mixture, its kneading and installation are met. Depending on the type of screed chosen, the procedure for preparing and laying it will differ significantly.

Laying concrete screed

Despite the fact that this process is quite laborious and long, alignment in this way is the most common.

First of all, the floor surface is completely freed: all furniture and other household items are taken out of the room. The old flooring is removed from the vacant floor, the base is carefully examined and preparatory work. The basis of the concrete screed is cement, sand, plasticizers and other fillers.

Laying concrete screed is a messy and labor intensive process. However, this type of screed is the cheapest and it is still popular.

For work you will need:

• rule;
• level;
• roulette;
• trowel and spatula;
• drill with a nozzle for mixing the solution;
• solution container;
• construction knife;
• beacons.

In ready-made mixtures, the manufacturer has already taken care of the correct ratio of components and useful additives.

Hardware stores offer ready-made cement-sand mixtures for the preparation of concrete mortar. These mixtures already contain sand, cement, as well as additional useful fillers in the right ratio. The solution can be prepared independently, taking the necessary ingredients in certain proportions. Usually for the preparation of the screed, three parts of sand are taken for each part of cement.

Grades and composition of concrete

Plasticizers make the mixture more elastic, increase its curing time and prevent further cracks and chips. If height differences of more than seven centimeters are to be leveled, then it is strongly recommended to add fiber with reinforcing properties to the solution or use a metal mesh when laying concrete.

The floor screed in the apartment with the help of a concrete solution is performed in the following sequence:

In one room, the solution must be laid within one day. For better adhesion of individual flooded areas, thin reinforcement or mesh can be used.

After pouring the entire floor, it is covered with polyethylene or wet rags and left until completely hardened. This helps to avoid crack formation. For the same purpose, drafts and direct sunlight on the floor surface are not allowed in the room.

Depending on the mixture used, it will be possible to walk on such a floor after 3 to 4 days. It is necessary to check the evenness of the floor again with the help of a level and, if necessary, cut off the bumps or wipe them with a special machine.

Should be taken into account! The time of complete drying and hardening of the concrete screed is 28 - 30 days. Until the end of this period, it is impossible to lay the finishing floor covering or the underfloor heating system. The exception is the flooring with ceramic tiles. It can be laid on the screed after 5 days.

Laying a self-levelling screed

Such a screed is used when it is necessary to obtain a perfectly flat floor surface, for example, for further laying laminate, polymer coatings, linoleum and other floor coverings.

Sales outlets offer a large selection of self-leveling compounds that are easy to prepare yourself, following the manufacturer's instructions.
The order of work in this case will be as follows:

1. Construction debris, dirt and dust are carefully removed from the surface. This stage must be approached with all seriousness so that the remaining dust particles and debris do not float on the surface of the fill.
2. The floor surface is primed. If the floor surface is very hygroscopic or highly dusty, then the primer is applied two or three times, allowing each layer to dry completely, according to the instructions on the label.
3. The solution is prepared according to the manufacturer's instructions. To prevent the formation of lumps, the mixture must be added to the liquid, and not vice versa. It is convenient to stir the mixture with a construction mixer or using a special nozzle dressed on a drill. The solution should have the consistency of sour cream of medium density. The prepared mixture for saturation with oxygen stand for 5 - 7 minutes.
4. The prepared mass begins to be poured from the corner farthest to the door along the wall.
5. The thickness of the mixture, and its alignment is carried out using a metal brush and a spiked roller.

The spiked roller helps to remove air bubbles from the mixture and distribute it evenly on the surface.

Such a floor dries much faster than concrete. It will be possible to walk on it after 8-10 hours, and complete hardening occurs within 3-5 days. Drying time depends on room temperature and layer thickness. It is necessary to cover the surface from direct sunlight and protect it from drafts, sudden temperature changes and water ingress.

This is the most new technology floor leveling. Such a screed consists of 2 layers:

• a layer of a special mixture or fine expanded clay sand;
• sheet material.

As sheet material plywood, fiberboard or gypsum fiber sheets are used. Between themselves and to the base, the sheets are fastened with self-tapping screws and glue. The joints are covered with a special putty and then polished.

Dry screed according to Knauf technology

Such a screed not only levels the floor, but also serves good layer heat and sound insulation.

You can see more details about the technology of dry floor screed in the video presented at the end of the article.

We told how to make a floor screed in an apartment. Despite the large amount of work, they are quite capable of being completed. home master. In conclusion, I would like to give advice to strictly follow the technology and use only certified, fresh and quality materials. This will save you from frustration and the need to redo a large amount of time-consuming work.

Video: installation of a dry floor screed

In order to correctly make a floor screed based on cement mortars and concretes, the screed must correspond to the purpose of the room and have the necessary parameters for this.

The screed can become a solid foundation for the floor in any room of the house. Cement screed is not afraid of moisture and it is convenient to use it as a base for floors in wet areas, as well as outside the house - on terraces, in the garage. The device of a heat-insulated floor in rooms also does not do without a coupler.

Screed solutions

Cement - sand mortar for screed

For the installation of screeds, a traditional cement-sand mortar of a grade not lower than M75 is used. To prepare the solution, a mixture is prepared from one part of cement and three parts of sand. The strength of the finished screed is increased if the screed mortar has a thick consistency.

Cement-sand mortar is easier to prepare and easier to lay in a screed than concrete. But the consumption of cement for a screed device of the required strength is greater than for concrete. So, mortar screed is more expensive than concrete.

Lime should not be added to the solution. Although lime increases the plasticity of the solution, it reduces the strength of the screed.

Concrete of normal, thick-plastic consistency

For the installation of screeds, concrete of class B10, B15, B20 is used. Crushed stone, gravel is used as a concrete filler. The size of the filler granules must be at least three times smaller than the thickness of the screed.

Concrete for semi-dry screed (carving)

To prepare concrete for a semi-dry screed, much less water is used than usual. A semi-dry screed has a higher compressive strength (up to 35 MPa) than mortar and plastic concrete screeds. In addition, it is less susceptible to shrinkage, which reduces the risk of cracking in the screed.

Semi-dry screed is suitable for underfloor heating. It is convenient to prepare concrete for a semi-dry screed at the construction site in a special concrete mixer - mixocrete, which prepares concrete and immediately delivers it with a pneumatic pump along flexible pipe to the installation site.

The composition of cement mortars for concrete floor screed

Cement mortars and concretes can be prepared at the construction site. It is recommended to include additives in their composition to increase plasticity, accelerate setting and reduce the water permeability of the screed.

To obtain concrete of the required compressive strength class, It is recommended to use the following grades and quantities of cement:

During storage, the cement loses its activity. The consumption of cement indicated in the table is indicated for cement with a shelf life of no more than two months. Consumption of cement with a shelf life of normal conditions more than 3 months increase by 20%; more than 6 months - by 30-40%.

Cement with a shelf life of more than 12 months is not recommended.

When using stale cement, the mixing time is increased by 2-4 times. It is recommended to introduce additives that accelerate the hardening of concrete.

For the preparation of medium-strength concrete, a mixture of 1 part (by volume) of cement, 2.5 parts of medium-sized sand and 4 parts of aggregate - gravel or crushed stone, is used.

The specified ratio of the ingredients of the mixture is approximate and depends on many factors. For example, the amount of sand in the mixture should be sufficient to fill all the gaps between aggregate granules. With large granule sizes, the amount of sand is slightly increased, and for fine aggregate, on the contrary, it is reduced. Cement consumption is also adjusted depending on its brand, shelf life and required concrete strength (see table above).

The prepared cement mortar must have good plasticity and mobility. Such a solution is easier to level and compact better. To increase plasticity, special additives are used - sulfite-yeast mash (SDB) in an amount of 0.15-0.25% by weight of cement; mylonaft (M1) - 0.1-0.2% by weight of cement, and others. At home, craftsmen often add a small amount of grated laundry soap to the concrete mixer.

The mobility of the concrete mixture also depends on the ratio between sand and crushed stone. The best mobility is achieved at some optimal ratio, at which the thickness of the cement paste layer is maximum. When the sand content in the aggregate mixture exceeds this value, the concrete mixture becomes less mobile, which is explained by the increase in the surface area of ​​the aggregate mixture.

To give the concrete mixture plasticity, much more water is often added to the concrete than necessary (40 ... 70% by weight of cement). Concrete should not be made too liquid, adding a lot of water. A screed made of such concrete will dry for several months, have reduced strength and frost resistance. The risk of significant shrinkage and cracking of the screed increases.

Excess water that has not entered into chemical reaction with cement, remains in concrete in the form of water pores and capillaries or evaporates, leaving air pores. In both cases, the concrete will be weakened by the presence of pores, and the more water, the more pores and thus the less strength and frost resistance of concrete.

Dry mixes for floor screed

The best option, although more expensive, is to use ready-made dry mixes for the screed device. Such mixtures are commercially available on the construction market. The composition of the mixture already includes the necessary additives.

Manufacturers can include microfiber in the mixture - fibers that perform the function of reinforcement. Microfiber screed is more resistant to shrinkage and cracking.

There are mixtures specially designed for underfloor heating screed. This should be indicated on the packaging of the mixture.

There are fast-setting compositions. Floor tiles can be laid on a screed from such a mixture after 24 hours.

The packaging of the dry mix should contain information about which screeds and laying conditions it is intended for, what compressive strength of the screed will ensure the use of the mixture.

For residential premises, the compressive strength of the screed must be at least 12 MPa, for a garage - at least 20 MPa.

Types of floor screeds

By design, screeds can be connected to the base on which they are laid, or laid on a separating layer, or floating.

Ties connected to the base are performed if the base is also made of concrete. For example, a screed on a reinforced concrete floor slab or on a concrete floor preparation. To ensure adhesion of the screed to the base, the surface of the latter is specially prepared - dedusted and primed. The minimum thickness of the screed is 2.5cm.

In screeds on a separating layer a layer is laid between the concrete base (reinforced concrete slab or concrete preparation) and the screed waterproofing film not less than 0.2 mm thick. The edges of the film panels are laid with an overlap of at least 10 cm and sealed with adhesive tape. The edges of the film are wrapped on the walls.

The separating film layer prevents water leakage from the freshly laid concrete. Dehydration of concrete reduces the strength of the screed. The screed concrete must be laid on a separating layer of film in all cases where it is possible for water to leak from the concrete into the screed base.

The minimum thickness of the screed on the separating layer is 3.5 cm.

floating screed laid on a layer of insulation or sound insulation, for example, when installing or Minimum screed thickness 4.5 cm. subject to reinforcement. Floating screed with a thickness of more than 7-8 cm. it is allowed not to reinforce.

Floor screed technology in a private house

The screed is laid at a temperature of the base and air above +5 degrees C. The technology of laying the screed does not change whether cement-sand mortar or concrete is used for laying, including semi-dry consistency.

Work is performed in the following sequence.

Perform the preparation of the base on which the screed will be laid. For the screed associated with the base, the surface of the base is cleaned of debris, dusted with a vacuum cleaner and primed.

For the installation of a screed on the separating layer and floating - a layer of sound and heat insulation is laid, a separating layer of waterproofing film is laid on top.

Styrofoam strips or polyurethane foam edge tape 1-2 thick are fixed to walls and other vertical structures. cm. to create an expansion joint.

Guide rails - beacons - are laid on cakes of fast-setting cement mortar. Beacons are laid over the entire surface of the base in parallel rows with a step of approximately 1.5 m. and at a distance of 20 cm from the walls. Used as lighthouses wooden slats or various metal profiles, pipes.

On sale there are special galvanized steel profiles for beacons. Profiles are convenient in that they do not need to be removed from the screed layer. But such profiles have low mechanical strength, increased flexibility and require careful alignment when mounted on cakes and accuracy when pouring concrete.

The upper surface of the beacons is leveled in one plane. If necessary, provide the required slope of the plane.

The solution prepared in the concrete mixer is fed to the place of work, and moving towards the door, it is evenly distributed between the beacons so that the thickness of the solution is slightly higher than the level of the beacons.

With a grater, the solution is pre-distributed between the beacons and compacted. Finally, the solution is leveled with a wooden or metal rail - as a rule, moving it along the lighthouses in zigzag movements towards itself. If shells remain behind the rail in the screed, then they are filled with mortar and re-aligned with the rule.

After the solution begins to harden and can withstand the weight of the worker, beacons are removed from the screed. Do this in a timely manner until the solution has finally set, and carefully so as not to damage the screed. If a semi-dry screed is laid, then it will be possible to remove the beacons in 3-4 hours.

The gaps in the screed remaining after the removal of the beacons are filled with mortar and leveled with a grater, making circular motions.

Until the solution has completely hardened, furrows are made in certain places of the screed, cutting the solution with a spatula to the required depth. After setting the solution, such grooves will have to be cut with a power tool with a diamond blade.

Expansion joints in the screed

A wall expansion joint separates the screed from walls and other vertical structural elements buildings - columns, stair supports, etc. The seam is necessary in order to exclude the mutual transfer of stresses between the screed and the structures of the house. Stresses can arise as a result of thermal expansion of materials or their shrinkage, as well as as a result of deformations under the action of loads.

In addition, the seam improves the sound insulation of rooms, making it difficult to transmit sounds from walls to floor structures and vice versa.

To arrange a seam along the walls and other elements of the building, an elastic tape with a thickness of 1 cm. to the full height of the screed.

When placed in a screed of underfloor heating pipes with an expansion joint for the entire thickness of the screed, adjacent fields of underfloor heating pipes are separated.

In addition to the expansion joint at the walls, cuts are made in the screed, which divide the screed into smaller rectangular sections. One side of the plot should be no larger than 3-6 m. V narrow corridors compensation incisions are made across the corridor, every 2-2.5 of the corridor width.

In addition, compensation cuts are made at the junction of different floor coverings, as well as at the border of the change in the thickness of the screed, in doorways and in other openings at the border of different rooms of the house.

Compensation cuts are necessary to compensate for the shrinkage of the screed material during drying. Without them, cracking of the screed may occur. Incisions are made to a depth of 1/3 - 1/2 of the thickness of the screed. The width of the cuts depends on the thickness of the screed and the presence of underfloor heating pipes in the screed.

If the screed is reinforced with a mesh, then the expansion cuts should be located above the joints of the individual sheets of the mesh.

If the floor covering along the screed is tile, then the expansion cut must coincide with the joint of the tile.

The expansion slots can remain empty if the flooring is parquet or laminate. The incisions are filled with waterproof silicone sealant if the flooring is tile.

How to properly reinforce the screed

Be sure to reinforce thin screeds with a thickness of 4.5-5 cm on a separating layer of film. Floating screeds, the base of which is a layer of insulation (sound insulation) or compacted soil, are reinforced with a screed thickness of 7-8 cm. and less.

If the screed has a thickness greater than that indicated above, then the need for reinforcement is determined depending on the operational load. For example, a floor screed in a garage for a car or on outdoor terrace on compacted soil, it is recommended to reinforce with a screed thickness of up to 10 cm.

Screeds made from a ready-made dry mix containing microfiber reinforcing fibers in many cases do not require additional reinforcement.

Usually the screed is reinforced with a mesh of steel wire diameter 3-4 mm. The grid must have cells sized 100x100 or 150x150 mm.

The steel mesh is laid on the spacers so that it is approximately in the middle of the screed layer. The protective layer of concrete up to the grid must be at least 2 cm. indoors, and at least 4 cm. when the concrete screed comes into contact with the ground.

On top of the grid, as usual, beacons are installed on the cakes from the solution and leveled.

The thickness and level of the screed in the premises of the house

When choosing the thickness of the screed, the strength of the base on which the screed is laid, the presence or absence of reinforcement of the screed and the operational load are taken into account. In addition, there are restrictions on the minimum thickness different types screeds (see sections of the article above).

V different rooms floors, the thickness of the screed, selected for structural reasons, may be different. For example, the thickness of the screed in rooms with warm floors must be such as to cover the heating tubes with a layer of at least 3 cm.

In the house it is convenient to have floors located in all rooms of the floor on the same level. Only in rooms where water can be spilled on the floor - in the bathroom, toilet, it is recommended to make the floor level lower by 1 cm. than in neighboring rooms.

To make the floors in the rooms at the same level, it must be taken into account that the floor covering that is laid on the screed in the rooms can have different thicknesses. For example, the thickness of porcelain stoneware in the kitchen is different from the thickness of parquet in the living room.

In order to determine the level of the screed surface in the room, first outline the level of coverage of the finished floor on the floor. To do this, choose a room where the total thickness of the screed and flooring is greatest. The level of the finished floor in this room is taken as the level of the finished floor of the floor.

Then, the selected level of the finished floor of the floor is transferred to other rooms. The level of the screed in the room should be lower by the thickness of the floor covering.

In the premises of the floor, the thickness of the screed, selected from design considerations, is adjusted to a given level. If possible, then adjust the level of the base of the screed, for example, change the thickness heat and sound insulation under the screed. Choose the most economical option.

To determine the levels of surfaces when working on the installation of screeds in the house, it is convenient to use a laser device - a level gauge, or a hydraulic level - a transparent tube filled with water. The use of a rail with a bubble level will not provide the necessary accuracy.

Screed laying

Laying the screed in the room is carried out in one go, without interruptions. When planning work, it is taken into account that the traditional solution must be laid within two hours after preparation. The time of suitability for laying solutions prepared from ready-made mixtures is indicated on their packaging.

The solution is placed outside the doorway by a few centimeters, and then the excess is cut off along the border of the expansion joint.

The surface of the screed is rubbed with a trowel 8-10 hours after laying, until the concrete has finally set. Semi-dry concrete screed, laid with a concrete pump, rubbed after 3-4 hours. Smoothing eliminates small roughness on the surface. It is not necessary to rub the screed if tiles will be laid on the screed.

Screed Care

The screed must remain damp for a week after installation. At this time, the screed must not lose moisture, otherwise the strength of the screed will decrease. To prevent the screed from drying out, it is covered with plastic wrap or sprayed daily with water.

After seven days, the film is removed, the room is ventilated and the screed is left to dry. After another three to four weeks, tiles can be laid on the screed. Moisture-sensitive floor coverings are laid on the screed after four to six weeks, when the moisture content of the screed is less than 3%.

Floating screed in the floor on the ceiling

On the reinforced concrete floor between floors arrange a floating floor with a concrete screed. The floor is called floating, because the screed does not have a rigid connection with the structures of the house.

The floating screed is separated from the walls and floors by a layer of elastic mineral wool. This floor design provides sound insulation between the rooms of the house, and also allows the screed to move with changes in temperature and humidity.

If the ceiling is dry, with a humidity of no more than 3%, and the lower room is heated, then soundproofing slabs can be laid directly on the ceiling concrete. Otherwise, a vapor barrier film is laid between the ceiling and the soundproofing slabs.

How to choose material for soundproofing -

Soundproofing layer of slabs mineral wool from above cover with a construction polyethylene film. Film panels are brought onto the walls, to a height of about 20 cm. The strips of film are overlapped. Overlap 20 cm.

The film prevents the penetration of cement laitance from the freshly laid mortar into the sound insulation layer and into the edge tape.

A reinforcing mesh of steel wire with a diameter of 3 - 4 is laid on the film mm. with cells measuring 100 x 100 mm. or 150 x 150 mm.

In the floor screed, you can place heating pipes to radiators, as well as pipes with electrical wiring. Pipes are laid over the reinforcing mesh and attached to it with plastic clamps.

It is recommended to wear corrugated covers on heating pipes and wires. plastic pipe. In covers, heating pipes will be able to move freely when the temperature changes. In addition, corrugated pipes protect the communications laid in the screed from mechanical damage when pouring the cement mixture.

To level the cement mortar in the screed, beacons from pipes or other profiles are laid on the reinforcing mesh. Lighthouse pipes are laid in increments of about 1.5 m. and level it horizontally with a level. The position of the beacons sets the thickness of the screed. The recommended thickness of the screed for residential premises is not more than 6 cm.

A cement mixture is laid in the space between adjacent beacons. Moving along the lighthouses, the rule or edged board distribute the mixture and level the surface.

Eight to ten hours after laying, the surface of the screed is smoothed (rubbed). Grouting can be omitted if ceramic or stone tiles are laid on the screed.

After the cement mixture has hardened, the parts of the edge tape and construction film protruding from the screed are cut off.

Watch the video, which shows in detail how to mark the level and thickness of the screed in the premises.

Features of the screed for underfloor heating

If pipes will be laid in the screed, then it is better to use a ready-made dry mix specially designed for this purpose to prepare the solution. The finished mixture for underfloor heating contains additives that increase the elasticity of the solution.

If the mixture is prepared independently, then an emulsion is added to the solution to increase elasticity. For example, home craftsmen add PVA glue at the rate of 2 l. for 1 m 3 solution.

The screed should cover the underfloor heating pipes with a layer of at least 4-5 cm. Thus, the total thickness (taking into account the diameter of the tubes - 1.6 cm) will be – 6–8 cm.

Care for the warm floor screed for the first three weeks is the same as usual. Before laying the top coat on the screed, the screed must be thoroughly dried. To do this, 21 days after laying the screed, turn on the heating and increase the temperature daily by 5 °C until it reaches the limit - 24 °C.

This temperature should be maintained for 14 days and then lowered daily by 5 °C. Therefore, the heating of the screed lasts another 23–24 days, which should be taken into account when drawing up a schedule for finishing work.

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The most versatile, durable and strong flooring option is cement screed, which can tolerate temperature changes and is resistant to moisture. To achieve an excellent result, it is necessary to strictly observe the technology of work.

Most often, the floor is leveled with the most popular, budget and accessible way- using cement and sand. The cement surface (as seen in the photo of the floor screed) is able to repel fats, acids and conducts heat well.

In order to save budget funds and be sure of the reliability of the work performed, many homeowners are thinking: how to make a floor screed with their own hands?

And this process is not fast, but quite affordable, even for a self-taught master.

What is the screed made of?

This composition is quite simple to knead by yourself, with the following components:

• water (2 parts);
• sand (3 parts);
• cement (1 part).

To make the screed the most dense and reliable, it is worth adding any adhesive substance - a plasticizer - to the solution. Adhesives can be purchased ready-made at any hardware store.

A mortar of cement with sand can be placed on brick, concrete and stone. The solution is laid in a maximum thickness of 10 centimeters. If the layer is less than 3 centimeters, it is better to apply the reinforcement method to avoid cracks.

The main types of cement screed

When screeding the floor in the house, different types of it are used, depending on the goal that needs to be achieved in the end:

• Screed using a floating structure with insulating layers.
• Screed that is connected to the surface of the wall and floor.
• Cement screed, independent of the type of surface.

Preparation for work

Before starting work with a cement screed, it is necessary to properly prepare the work surface. That is, you need to clean the floor in the room and carefully level it before work.

There is a situation when the screed is made directly on the ground. In this case, it must be properly tamped, then pour the bitumen composition to smooth the screed. If this is not done, then cracks may already appear on the finished surface, since the base will sag over time.

The second step is the installation of beacons, that is, measuring the space of the room with a level and installing icons that correspond to the desired height. This ensures the smoothness and evenness of the floor.

Beacons help in the future without any problems to fill a perfectly flat surface. Most often, the columns are placed every 30 centimeters, then beacons - slats - are attached to them.

The cement composition should be poured to the highest level, while it is much easier to calculate the required amount of floor screed mortar in the apartment, that is, to avoid unnecessary unnecessary costs for materials.

Direct work on the floor screed

If the surface is leveled by about 4 centimeters, it is better to make a connected screed. So the fill will connect both the base of the surface and the wall of the room.

The composition of the solution itself should be moderately thick and flow freely (without lumps) just above the level of the beacons. This is necessary because with further drying, the fill will settle a little.

To get rid of excess air (bubbles), after pouring, it is necessary to compact the solution with a vibrating screed.

Note!

At the end of the day, you can remove the beacons, and the traces left from them can be carefully primed and rubbed with a solution.

There is a non-cohesive surface leveling option. The instruction on how to make this screed is quite simple, but you need to take into account that you will need to provide an even and moisture-resistant base. To avoid cracks in the layers, the use of primers and similar substances is not recommended.

Dry floor screed - the most fast way make the most even coating, which can withstand a fairly large load and is suitable for rooms where traffic is increased.

Dry screed can be made from the following materials:

• moisture resistant drywall;
• plywood resistant to moisture;

Usually, a dry screed is made in height from 3 to 5 centimeters, but, if necessary, it can be higher, but reinforcement with an additional layer of plates will be required.

Note!

You will also need a dry filler - expanded clay, that is, special granules of their baked clay, which are light in weight.

For a dry screed, profiles are used that are distributed one and a half meters from each other strictly parallel, starting from the wall. Then sheets are laid on a dry screed, starting strictly from the door.

Still, the most traditional concrete screed, which has been tested by experience and is used for finishing coatings and during the installation of underfloor heating. If necessary, then in this way it is easy to make any desired bias.

When self-screeding the floor, it is important to know that the room should not be heated during the passage of work, as the composition may not dry evenly!

DIY floor screed photo

Note!