Water heated floor on sand. Warm concrete floor on the ground - professional advice Recommendations for installing a water heated floor on the ground Pouring a warm floor on the ground with fiber

Such a screed is made in private houses, garages, outbuildings, industrial and warehouse premises, in large trading floors, at bus stations, etc.

The method is considered universal, it is used on all types of soil, regardless of the location zone ground water. For pouring, concrete of grade not lower than M300 is used, if the loads on the floor are large and the physical characteristics of the soil are unsatisfactory, then the grade of concrete increases and a reinforcing mesh is necessarily used.

All indicators for the thickness and characteristics of materials are prescribed in the design and estimate documentation. If it is not there, then the calculations must be done independently, while taking into account all the factors that affect the operating conditions of the floor coverings.

The rough screed is located below the ground, adjacent to strip foundation at the ribbon extension level. Such a scheme is used if there are underground rooms under the house for storing food or other needs.
The rough floor screed on the ground is located approximately at ground level and is adjacent to the side inner wall of the strip foundation. The most widespread situation is used not only in housing, but also in industrial construction.
The rough floor screed is located above the foundation tape. It is used during the construction of buildings on waterlogged soils, in areas with flood risks, etc.

There are no universal recommendations for the location of the rough screed, it all depends on the operating conditions and architectural features at home. The only requirement is position door frame you need to plan even before the start of the rough screed, the level of the finished floor should be located at the level of the threshold.

Options for arranging a rough screed on the ground

The specific option is chosen by the builders, taking into account the maximum load on the structure and the proximity of groundwater. Classic Solution- compacted soil, a layer of sand and gravel different thickness, polyethylene film and rough screed with or without reinforcement.

This method is recommended in cases where groundwater is located closer than two meters to the surface. Groundwater is much lower - you can simplify the construction scheme. It is allowed to fill rough screed directly on the ground, use only sand or gravel as backfill. In some cases, it is possible to pour a subfloor directly onto the ground without using a plastic film. For a rough floor screed, the film is used not so much for waterproofing (concrete is not afraid of moisture, on the contrary, in conditions high humidity it increases the strength indicators), how much to delay in a mixture of cement laitance. Without a film, it will quickly leave the concrete, which will have a very negative effect on strength.

What factors affect the construction technology of the rough screed

If they come closer than two meters to the surface, then be sure to backfill with sand and gravel. The backfill serves to prevent moisture from being drawn in by soil capillaries. If there is a backfill, then the use of a film to retain cement laitance is required. If a rough screed is made immediately on the ground, then the film can not be laid.

Important. The location of groundwater must be determined in the spring, it is during this period that they rise the most.

If the floor structure assumes the placement of heat carriers, then the rough screed should have compensation gap between the foundation. Such designs eliminate the negative impact of thermal expansion and exclude the possibility of cracking or swelling of the rough screed.

If the planned load on the floor can exceed 200 kg / m2, then reinforcement is mandatory. Reinforcement parameters are selected individually for each case. The same approach is needed in cases where it is planned to put on the floor interior partitions. You should not rely only on the reinforcement of the finishing screed, its physical characteristics do not allow it to withstand heavy loads.

A few frequently asked questions about the rough screed

Inexperienced builders often try to save money or improve performance characteristics replace the recommended materials for adding a rough screed with others.

Is it advisable to replace the crushed stone bedding with expanded clay bedding for a black screed? At first glance it might seem that this original solution allowing you to insulate the floor at the same time. Professional builders recommend using this material only for those cases when groundwater is low, expanded clay is excluded from getting wet.
Can gravel be replaced with broken bricks and other construction waste? Absolutely not for several reasons. Firstly, the brick draws in water, when wet, it quickly collapses, the base of the rough screed loses its strength and stability. Secondly, waste and broken brick have different linear dimensions, it is impossible to carefully compact them because of this.
Is it possible to put waterproof protection only under the rough screed and not use it anymore? No. We have already mentioned that the polyethylene film performs other tasks - it does not allow cement laitance to leave the solution. Over time, waterproofing breaks its tightness, under the influence of uneven and point loads she's bound to break.
Is it possible to do a spill instead of a rough floor screed? Quite a difficult question. First you need to define what a spill is. Pouring - a layer of liquid solution, which is poured over the bedding under the rough screed. The thickness of the pouring depends not only on the thickness of the bedding layers, but also on the quality of their compaction. If the bedding is dense, then the liquid solution will not penetrate deeper than 4–6 centimeters. As a result, the bearing performance of the base for the floor is significantly reduced. Conclusion. The decision should be made taking into account the loads on the floor.

Now that we have dealt with most of the questions on the features of the rough screed device technology, we can give step by step instructions its filling.

Instructions for the manufacture of a rough screed for the floor on the ground

Consider the most complex and time-consuming option using all layers of backfill.

Step 1. Make measurements. First, on the foundation tape, you need to designate the level of the finished floor.

To do this, use a laser or hydro level. The size is determined according to the design and technical documentation or working drawings for the object. Further down, you need to put marks on the thickness of the floor, depending on its design, the thickness of the finishing screed, rough screed, gravel and sand layer.

Step 2 Remove the soil to the estimated depth, clean the site, prepare for backfilling with sand. Tamp loose soil or carefully clean the base with a shovel.

Step 3 Pour in the sand. As a rule, the thickness of the layer varies within ten centimeters. If required a large number of sand, then it must be poured in stages, each layer should be rammed separately. The quality of ramming will improve significantly if the work is carried out using special mechanisms: vibrorammers or vibrocompactors. During tamping, care must be taken that the sand has a more or less even and horizontal surface.

Ramming - very milestone arranging a rough screed on the ground, there is no need to rush. All the pits are filled and rammed again, the tubercles are cut off.

Step 4 Pour a layer of crushed stone with a thickness of ≈ 5–10 cm, carefully compact it. Crushed stone is better to take several fractions of op sizes. A larger one is poured onto the sand, and a fine one under the rough screed. In this way, the bearing characteristics of the base are improved. Part engineering communications can be hidden in layers of backfill or directly in the rough screed. No need to strive to install all the pipes there and Electricity of the net, in case of occurrence emergencies it is very difficult to get to them for repair work.

Independent production of concrete mix

You can do it yourself using a concrete mixer or order it ready from construction companies. You need to choose yourself, both options can be optimal under certain conditions. It is recommended to calculate the cost of materials in both cases, evaluate your material possibilities and physical forces, the number of workers.

Concrete mixture should be below average in density. Such indicators allow concrete to independently spill over the floor area. One of the advantages of using liquid concrete– no need to install beacons and perform labor-intensive work on its alignment with manual rules.

Workers only need to slightly correct the level in the places where the material is poured. If reinforcement is required, then a mesh is placed at the same time. Building regulations it is required to install it in such a way that the thickness of the concrete on all sides exceeds five centimeters. Otherwise, the structure will not work as a whole, the actual strength of the reinforced concrete will be much less than the calculated one. The consequences can be the saddest.

What will be the final floor chooses the developer. Regardless of the option chosen, builders recommend that you do it from above reliable waterproofing and put in insulation. On top of these structures finishing screed under tiled floor or stacked wooden logs for other floor finishes. Such schemes make the floors warm, which is very important given the modern prices for heat carriers. Simultaneous implementation of recommendations professional builders significantly increases the service life of floor coverings.

Is it profitable to make a rough concrete screed on the ground

The issue worries all developers without exception, it should be considered more carefully. We will compare with the use case for these purposes factory reinforced concrete slabs.

Installation of slabs with a truck crane

The simplest calculations, taking into account the cost of plates and additional work and materials and rough screeds on the ground show savings of up to 25%. And this is only the most approximate calculations. Payment for expensive loading / unloading equipment, delivery shoulder, etc. were not taken into account.

Video - Rough floor screed on the ground

When planning to make a warm floor in the house on the ground, it is advisable to make the structure in two stages: first, pour a rough screed onto the lower layers, and only after it has matured, lay all the other layers on it.

The fact is that the soil and, accordingly, all layers above it can sag. Even if the soil is compacted, even if it is rammed, there will be movements. He lay simply, without load. If you lay a warm floor cake on top, and it weighs a lot, drawdowns will begin, cracks will appear. It can even break the elements of the warm floor. Then all the money will be thrown to the wind. That is why experts advise first to make a rough floor according to all the rules, and then lay a water floor on top. So much more reliable.

Yes, many have a warm floor on the ground without a screed, and nothing sags. But not for everyone and not always. So think carefully. A warm concrete floor on the ground will be more reliable with a rough screed. If you still decide to do without this layer, install at least two reinforcing frames: the first under the heat insulator, and the second in the screed. Then, with careful ramming, everything can stand well.

An example of a floor heating pie on the ground

First of all, we determine the level to which you need to remove the soil. The soil must be removed. If the humus layer or plant residues are not removed, they will begin to decompose and “smell”. Therefore, you will make a draft floor or not, but you need to remove all unnecessary. Moreover, the fertile layer is usually the loosest, and it will definitely settle and can pull all the layers lying above with it. The rocks lying below are denser, firstly because they experience heavy loads, and secondly, because living beings and microorganisms live there less.

For the whole cake of a warm floor on the ground, it can take from 20 cm or more (in some regions - much more). Therefore, you need to start marking from the zero level - where the final floor will be located. Mark it, and then consider how deep you need to go. It is advisable to mark the level of each layer: then it will be easier to navigate.

Warm floor on the ground is quite possible to do it yourself

The correct design of a warm floor on the ground is as follows:

Take off fertile soil remove all rubbish and stones. Level and compact the remaining soil. This must be done very carefully, and verified by the level. This is the basis for all subsequent materials.
A layer of compacted sand (level). Any sand is taken for filling. The main thing is to compact it well and level it again.
A layer of expanded clay or crushed stone (crushed stone is preferable due to lower thermal conductivity). Fraction - small or medium. We compact for a long time and persistently until it becomes almost a monolith.
Pre-stretch. There are two options here:
- Spill crushed stone and sand with a liquid solution (sand + cement in a ratio of 2: 1).
- Fill in the black screed. The desired thickness of this layer is 5-7cm. And for reliability, lay a reinforcing mesh of metal wire 3 mm, with a cell of 10 * 10 cm. Such a draft floor is more reliable. It will withstand heavy loads.
After everything has set and the concrete has hardened, a layer of waterproofing is laid. If the primer is dry, this is usually a polyethylene film, preferably 200 mn in two coats.
Styrofoam plates (glue the joints with adhesive tape so that the solution does not leak).
A layer of metallized waterproofing (not foil, but metallized).
Underfloor heating fixing system and heating tubes, cables, etc.
Underfloor heating screed, preferably reinforced.

Read about solutions and additives for underfloor heating here.

The thickness of all layers of the underfloor heating cake on the ground depends on the region: the colder, the more. In the south, it can be 2-5 cm, but the further north, the more massive layers are required. Each of them is well compacted and leveled. Can be used manual rammers, but mechanical ones are much more efficient.

Particular attention should be paid to the heat insulator. It is recommended to use expanded polystyrene in plates, its density is not lower than 35 kg / m3. For the northern regions, it can be 10 cm or more. If the thickness of the thermal insulation is large (extruded polystyrene foam), it is advisable to use two layers of boards. And lay them so that the seams of the lower layer overlap with the slab lying on top. Glue the joints of each layer with tape.

To protect against dampness, do not forget to carry out waterproofing work with the foundation before starting all work. It is also important not to forget to isolate the foundation from the entire underfloor heating structure. It is necessary to put the same polystyrene foam in plates along the perimeter. In general, the idea behind hydro and thermal insulation is this: to reduce heat loss, you need to isolate your floor from everything but indoor air. Then the heating will be economical, and the rooms will be warm.

Choice of thermal insulation key moment in the organization of a warm floor

Process technology at high groundwater levels

If the groundwater is high, correct sequence layers is not everything. You need to get the water out somehow.

If the depth of laying the underfloor heating layers turned out to be lower than the level of soil water, drainage is necessary. For him, at least 30 cm lower required level making a drainage system. It is advisable to pour river sand, but such volumes cost a lot, so you can use other rocks, but not peat or black soil. As an option - excavated soil mixed with crushed stone.

When laying heat-insulating plates, their joints must be glued with adhesive tape - so the solution will not flow into the cracks

The selected material is poured in layers of 10 cm, each of which is compacted and spilled with water. Layers are usually made three, but more can be. On compacted sand or soil with crushed stone, we lay a layer of geotextile. it modern material, which will pass water down and will not mix different materials. It is not damaged by insects and animals, has high tensile strength. Also, geotextiles additionally equalize the mechanical loads that the floor will experience.

At the same stage, you need to take care of both the hydro and thermal insulation of the floor from the foundation. Can be used for this purpose bituminous mastic or other modern and reliable waterproofing materials and impregnations. And the thermal insulation is standard: the inner perimeter of the foundation is covered with expanded polystyrene plates.

Then there are layers of sand and gravel, and a rough screed is poured on them. Spilling with a liquid cement-sand composition in this case is undesirable. A rough screed is needed for reliability. After it dries, a layer of waterproofing should be applied. At high level groundwater it is better to use not polyethylene, but welded waterproofing or polymer membranes. They are more reliable, although they are more expensive.

Underfloor heating construction on the ground

Further, all the layers, as previously recommended: a heat insulator, a metal-coated hydrobarrier, and fasteners with underfloor heating pipes (or heating cables, for example). All this is covered with a metal reinforcing mesh and filled with another layer of mortar. And then - depending on the used finish coat for underfloor heating.

Results

Warm floor in the house on the ground - quite complex structure. In order for it to be reliable, a rough screed is needed. If for some reason it is not possible to make a screed, you can, in extreme cases, get by with tamping the layers.

Photo gallery (7 photos):

Your question, it almost always arises when installing both a simple floor and a warm floor on the ground. The question is basically whether it is possible to lay waterproofing and all subsequent layers (epps, etc.) on the backfill, or necessarily on the subfloor. Look, a lot of opinions for what is possible. But here we thought for a long time, and consulted, and came to the conclusion that it’s better to still lay the waterproofing (and subsequent layers) either on a rough screed, or pour it on it as well. Let me explain what we are based on. You have soil inside the box, although it was caked, but it just lay, without load. Now you will add more layers, and they are also not hard, but bulk. That is, the waterproofing will be between the hard eps and the bulk (albeit rammed) layer. Any movement of the layer under the waterproofing will cause the waterproofing to be somehow unevenly located. Following micromovements of waterproofing, there may be micromovements of eps. I understand that all your top ties will be reinforced, and they will "keep" the ties from moving. But still, why these extra loads? And I can not guarantee that nothing will ever move in the layers under the waterproofing :-).

By the way, you have waterproofing in the text description, but not in the picture. If your groundwater is lower than 2 meters from the floor mark, then there may not be waterproofing. Just put eps and so on. But everything I wrote above is still valid. Without a rigid layer under the eps, any movement under it will create additional loads on the upper layers.

sand filling 50mm thick, level
dumping of crushed stone or expanded clay with a thickness of 100 mm, and on it, or pouring a layer of crushed stone / expanded clay with liquid cement-sand mortar((2 parts of sand per 1 part of cement), or a rough screed. In total, the thickness of the crushed stone / expanded clay already spilled with a solution will be 10-12 cm. see Let the mortar harden and lay the waterproofing and subsequent layers on top of it.
waterproofing
laying blocks of expanded polystyrene, a layer of 50mm blocks, 20mm blocks on it, so that the total is 70mm
top waterproofing with foil
fittings and pipes for underfloor heating, poured into concrete screed 100mm thick
topcoat (tile), about 20mm on it.

As for the fact that the upper 100 mm of soil must be removed for the crushed stone dumping device, this requirement, apparently, in order to arrange the dumping on better packed layers (not on the surface). You can do this, it will only benefit.

Arrangement of the floor is one of the most important points in the repair or construction. And if we are talking about a private house, this issue becomes even more acute. In many house projects, floors are often designed on the ground, this is quite reliable and one of the most practical and inexpensive options. Currently, underfloor heating is becoming more and more popular and popular every day, so many people prefer this particular type of heating in the house. Reliable thermal insulation of the floor will provide warmth and comfort in it, as well as significantly reduce the cost of its maintenance. After all, warm floors perfectly retain heat in the house, create comfortable conditions for living, and in some cases replace central heating.

What is a floor heating cake on the ground

Arranging floors on the ground, the obligatory moment is their thermal insulation, thanks to this, a multilayer structure is obtained, which is often called a warm floor cake. This design in many ways it resembles a layer cake, as it consists of several layers. I would like to say that the construction of the floor on the ground largely depends on the condition of the soil. It must meet certain requirements. For example, the groundwater level should be at a depth of 5-6 meters, soils should not be loose, for example, sandy or black earth. In addition, it is necessary take into account the load on the floor. It should be noted that the warm floor cake should provide:

thermal insulation of the room;
groundwater protection;
soundproofing in the house;
prevent the accumulation of water vapor inside the floor;
provide comfortable living conditions.

What does a floor heating pie consist of on the ground

By its design, the floor heating cake on the ground consists of several layers, the laying of each layer occurs in stages.

Depending on the design features floor and some other important factors, the floor heating cake on the ground may have a different composition and different thickness.

Advantages and disadvantages of underfloor heating on the ground

Advantages:

Flaws:

underfloor heating, depending on the design features, can significantly reduce room height;
in the event of a malfunction of this system, it is very difficult and expensive to dismantle the layers of the floor;
sometimes it rather lengthy and complicated procedure, which is desirable to perform during the construction of the house;
need to take into account groundwater position.

Options for laying a warm floor cake

There are several options for laying a warm floor cake on the ground. This may depend on the level of groundwater penetration, operational loads on the floor, type of underfloor heating and some other factors. The above option can be considered the main one, where as the main underlying layer is concrete layer. The cake is being laid in another way, where the concrete layer replaces sand cushion, its thickness is 100-150 mm. The sequence is the same, although it is much more difficult to ensure an even base than with a concrete screed.

Depending on the thermal insulation materials, can also be various options warm floor cake. Choosing as a heater polystyrene foam, the laying of the pie will be as follows:

Excellent insulation - mineral wool boards, which have high density, resistant to deformation and durable. This material It is recommended to apply in two layers. For less moisture absorption, they are treated with a water-repellent composition. Used as an insulating layer in a warm floor cake and expanded clay. It is quite simple and inexpensive option. When laying the cake using expanded clay, as a heater, you can not lay additional waterproofing, also expanded clay replaces a layer of gravel and screed. There are also quite a few effective ways laying a warm floor cake using some other heat-insulating materials.

Underfloor heating pie installation technology

Ground flooring is one of the most good options, which the reduces construction costs saves time and labor costs. A well-equipped floor heating pie will provide warmth, comfort and coziness in the house for many years.

Floors on the ground - universal way devices of a warm and reliable foundation in the house. And you can do them at any level of groundwater and the type of foundation. The only limitation is the house on stilts. In this article, we will describe in detail all the layers of the "floor pie" and show how to organize it yourself.

Concrete floors on the ground, imply no basements or gaps for ventilation in the underground.

At its core, this is a multi-layer cake. Where the bottom layer is soil and the top layer is flooring. At the same time, the layers have their purpose and a strict sequence.

There are no objective restrictions for organizing the floor on the ground. High groundwater is not a hindrance in this. Their only weakness– production time and financial costs. But on such floors you can put brick or block walls and even heavy equipment.

The correct "floor cake" on the ground

The classic floor cake on the ground implies the presence of 9 layers:

prepared clay;
sand cushion;
crushed stone;
Polyethylene film;
Rough concreting;
Waterproofing;
insulation;
Finishing screed;
Flooring.

We deliberately did not indicate the thickness of each layer, so as not to set any strict restrictions. Below, approximate values \u200b\u200band the factors influencing it will be indicated. But first we would like to point out the very important point: groundwater levels can change dramatically in a relatively short period of time.

In our practice, there were cases when, within 5-7 years, dry semi-basements and cellars in private houses had to be filled up, because groundwater completely flooded the underground premises. At the same time, such a phenomenon was observed not in one separate house, but immediately in the whole block of private buildings (40-60 houses).

Experts explain such phenomena by improper drilling of wells under water. Such actions lead to mixing of aquifer lenses, fracturing and alteration of aquifers. Moreover, they can drill a well far enough from your home. So be careful about the purpose of each layer of the floor cake on the ground and do not think that there are extra elements here.

prepared clay. The purpose of this layer is to stop groundwater. In general, the three lower layers of the floor cake are for this purpose. Of course, if you, removing the fertile layer, have reached the layer of clay, then you don’t need to bring and fill it up, only a little preparation is required. But more about that in due time.
Sand. To the sand special requirements no. You can use any, for example career and not even washed.
Rubble. Large, fraction 40-60 mm.

These three layers are responsible for cutting off the capillary rise of water. A layer of clay cuts off the main access, sand weakens the capillary water rise and relieves pressure upper layers, and crushed stone does not allow water to rise in principle. At the same time, each layer must be rammed. The thickness of each layer is at least 10 cm. Otherwise, it makes no sense to fill it up. But according to maximum height need to be explained in more detail. The fact is that tamping is most often done makeshift gadgets. The weight of such instruments is 3-5 pounds.

It has already been empirically proven that to compact a layer of rubble, sand or clay more than 20 cm. hand tool impossible. Therefore, the thickness of one of the first three layers is maximum - 20 cm. But, if you need to make the floor cake higher, then tamping can be carried out in two stages. First, 15-20 cm of sand are poured and rammed well. Then another layer of the same thickness is poured, and rammed again.

The order of occurrence of clay-sand-gravel layers cannot be changed. The reason here lies in the fact that if sand is poured on top of rubble, then after some time it will seep through it. Which in turn will lead to subsidence and destruction of the concrete layer, and then the deformation of the entire floor.

Polyethylene film. Be sure to take the film with a sleeve, and fit without cutting. That is, there will actually be two layers of polyethylene. It is intended solely to prevent the solution from draining from concrete into rubble.
Rough concreting. Minimum Thickness layer 8 cm. Sand can be taken from a quarry, but always washed. But crushed stone is required with a fraction of 10-20 mm. This layer will be the basis for the final part of the floor on the ground. Dispersed steel fiber reinforcement is recommended.
. With properly carried out preliminary work, ordinary roofing material without powder can cope with waterproofing. If in doubt, you can lay the roofing material in two layers.
Thermal insulation. It is recommended to use only Extruded Polystyrene Foam (EPS) here. The thickness should be determined according to the region and climatic conditions. But we do not recommend the use of XPS with a thickness of less than 50 mm.
Finishing stitch. Depending on the project, water floor heating pipes or cables can be integrated into it electric heating floors. Sand is used only river. This layer must be reinforced. Dispersed reinforcement with steel fiber is possible. The thickness of the screed is at least 50 mm.
Flooring. Concrete floors on the ground, organized in a private house in this way, have no restrictions on the use of flooring.

Do-it-yourself flooring on the ground

Before starting work, calculate the depth of excavation. The calculation is carried out in reverse order. That is, the threshold is taken as zero front door. Then begin to summarize the thickness of each layer. For example:

Linoleum - 1 cm;
Finishing screed - 5 cm;
Insulation - 6 cm;
Rough screed - 8 cm;
Crushed stone - 15 cm;
Sand - 15 cm;
Prepared clay - 10 cm.

The total depth turned out to be 60 cm. But keep in mind that we took minimum values. And each building is different. Important: add 5 cm of depth to the result obtained for you.

Excavation is carried out to the estimated depth. Of course, that the fertile layer will be removed, but clay may not always be at the bottom. Therefore, we will describe the process of organizing a floor cake on the ground in full.

Before filling the layers, draw with chalk, at all corners of the foundation, level marks in 5 cm increments. They will facilitate the task of leveling each layer.

Soil compaction

For these purposes, any clay will do. It crumbles in an even layer, and before tamping it is abundantly moistened with an aqueous solution of liquid glass. The proportions of the solution are 1 tsp of liquid glass and 4 tsp of water.

For compacting the first three layers, you can use a one and a half meter piece of timber 200x200. But the process will be better if you make a special fixture. For this, to a one and a half meter segment metal pipe, T-shaped weld a piece of the channel. The lower part of the channel should not have an area of more than 600 cm 2 (20 by 30 cm). To make the rammer heavier, sand is poured into the pipe.

The compacted layer of prepared clay is well moistened with cement milk. For its preparation, 2 kg of cement is dissolved in 10 liters of water. Make sure that no puddles form on the surface of the clay. That is, it should be fairly even.

Almost immediately after the contact of the cement with liquid glass the chemical process of crystallization begins. It passes quickly enough, but during the day it should not be disturbed in any way crystal formation. Therefore, do not walk on clay, but rather leave work for a day for a technological break.

The main layers of the "floor pie"

Sand. After a day, you should start filling the sand. At the same time, try not to walk on the first layer. Pour in the sand and step on it. Chemical processes between liquid glass and cement will go another week and a half. But air access is no longer needed for this, and water is present in the clay. Having poured a layer of 15 cm, boldly step on it and tamp.

Rubble. Spreads evenly over the surface of the sand and is also rammed. Pay attention to the corners. It is very important that after tamping the surface is as even as possible.

Polyethylene film. Laid with an overlap of 10 cm and glued with adhesive tape. A small, 2-3 cm bend on the walls is allowed. You can walk on the film in soft shoes with extreme caution. remember, that polyethylene film, this is not, but only a technological layer to prevent the flow of cement laitance into crushed stone.

Rough concreting.“Skinny concrete” is being prepared in the following proportion: cement M500 - 1 hour + sand 3 hours + crushed stone 4 hours. For dispersed reinforcement, steel fiber should be added at the rate of 1 kg. fibers per 1 cube of concrete. Try to level the freshly poured mortar, guided by the corner marks. For more flat surface, subsequently it will be more convenient to lay layers of waterproofing and insulation.

48 hours after pouring, the concrete must be hardened. This will require a solution of liquid glass in water (1:10) and cement. First, the solution is passed over the entire surface. You can use a roller, or you can use a spray gun. Then concrete is powdered with a thin layer and immediately begins to be rubbed into the cement into the surface. It is most convenient to do this with grout.

This procedure increases the strength of concrete by an order of magnitude, and in combination with liquid glass makes it as waterproof as possible. Concrete will mature within one and a half months, but by next step You can start working within a week.

Warming and waterproofing

To create a waterproofing layer, the floor surface is cleaned and treated with liquid bitumen. The roofing material is overlapped, with an allowance of 3-5 cm. The joints are carefully soldered with building hair dryer. Wall allowance 5 cm. IMPORTANT: Make sure that the roofing material adheres to the corners, do not leave voids. The second layer of roofing material is laid with an offset of half the width of the roll. During waterproofing work, it is best to walk on the surface in shoes with soft soles (sneakers, galoshes).

For thermal insulation, the most the best option- extruded polystyrene foam. A layer of XPS 5 cm thick replaces 70 cm of expanded clay. And additionally, XPS has a practically zero water absorption coefficient and a rather high compressive strength. We recommend laying 3 cm thick XPS in two layers. In this case, the laying of the top layer is carried out with an offset. This method guarantees the absence of cold bridges and increases the heat-insulating properties of the floor cake. The joints between the XPS boards are glued with special adhesive tape.

Proper thermal insulation of the floor cake is an extremely important component for the energy efficiency of the whole house as a whole. Up to 35% of heat escapes through the floors! Even if the floors themselves will not produce heat (warm floors), they must be thermally insulated as much as possible. This will allow you to save on heating in the future quite impressive amounts.

Floor screed

Glue along the room, 15-20 mm thick. Wherein lower part must be glued to the XPS boards. To reinforce the floor on the ground in residential premises, a masonry mesh with cells of 100x100 mm is used. Wire thickness 3 mm. The grid must be placed on the supports so that it is approximately in the middle of the screed layer. To do this, it is placed on special stands. But you can use ordinary corks from PET bottles.

The installation of beacons is possible, but in combination with reinforcing mesh, this will create a rather bulky and extremely fragile structure. After all, if you rigidly fasten the grid, it will require additional costs on fasteners and it will be necessary to violate the integrity of the XPS. And if the reinforcement is not fixed, then it can easily change the levels of the beacons. Therefore, it will be more convenient to pour this layer and then level it with a self-leveling screed.

For the final screed, the solution is diluted in the proportion of 1 tsp of M500 cement + 3 tsp. river sand. Work is carried out promptly. For rough leveling of the surface, you can focus on the corner marks.

After pouring the finishing screed, it must be allowed to gain strength within 3-5 days. With a thickness of 5 cm, the maturation period of this layer will be 4-5 weeks. During this time, regular wetting of the surface with water is required.

Acceleration of the cement hydration process is unacceptable! After about a month, you can check the degree of readiness. To do this, in the evening they take a roll of dry toilet paper, put it on the floor and cover it with a pan on top. If in the morning toilet paper will be dry, or slightly damp, then the layer is ready. You can level the floor with a self-leveling screed.

Self-leveling screed is spread according to the manufacturer's instructions and poured onto the surface of the concrete floor. With scrupulous performance of work, height differences do not exceed 8-10 mm. Therefore, a minimum amount of self-levelling screed is required. It dries pretty quickly. And after 1-2 days, the floor cake on the ground will be completely ready for laying the flooring.