Most developers, when choosing a ground floor floor design, consider two options. The first is reinforced concrete slabs.
Second - wooden beams(lags). Many people have no idea that it is possible to make a high-quality and inexpensive floor on the ground.
Meanwhile, this design cannot be called new. It began to be used after its invention artificial stone called concrete.
About what it represents flooring on bulk soil, what its pros and cons are, we will talk in this article.
At its core, a ground floor is a “cushion” of small crushed stone or expanded clay, on which lies a reinforced slab of monolithic concrete. Ballast bedding performs two tasks:
- raises the level of coverage to a given height;
- transfers the weight of the structure to the ground.
The floor is protected from soil moisture and heat loss by insulation laid on a layer of waterproofing.
The load-bearing basis of such a coating is a layer of soil. Therefore, the main risk factors when installing a floor on the ground in a private house are frost heaving and moisture. The first threat is blocked by insulating the foundation base from the outside with sheet foam. It cuts off the cold bridge that causes water to freeze.
It should be noted that when permanent residence in the house, the temperature of the soil underneath never drops below zero degrees. If the building is empty in winter, then the forces of frost heaving can cause cracks in the concrete screed and deform it. In this case, you cannot do without insulating the base.
Protection from soil moisture is a relatively simple measure only when the groundwater level is low (2-3 meters). On raw and marshy areas It is better to refuse the installation of such a coating. The cost of waterproofing and strengthening the foundation in this case increases significantly.
For pile and columnar foundations, a slab on the ground is not The best decision. In this case, the cost of protecting the bedding from frost is higher than when using a foundation “tape”.
Construction technology
There are two ways to install floors on the ground:
- For concrete preparation;
- Without a rough layer of concrete directly onto the compacted base (pillow).
The first method is rarely used today. It was developed at a time when roofing felt was used to protect floors from moisture. To glue it, a layer of concrete preparation (subfloor) was made.
The second option is simpler and cheaper. Modern waterproofing materials can be laid directly on the ballast pad without sticking to a solid base.
The process of installing a concrete floor on the ground begins with pouring the underlying layer. Before this, the installation of water supply and sewerage networks must be completed.
For backfilling, you can use any well-compacted soil. Fine crushed stone (fraction 5-10 mm), coarse river sand or sand-gravel mixture are suitable for this. The pillow is poured in layers of 15 cm, spilling each with water and compacting with a manual or mechanical tamper.
Compacting the bedding with a vibrating rammer
To improve thermal insulation top level pillows can be made from expanded clay gravel(10 cm). The total thickness of the ballast “pie” should be in the range from 30 to 40 cm.
Film waterproofing laid under the insulation needs to be protected from damage by sharp gravel and pressing through expanded clay. Therefore, the backfill is completed with a 5-centimeter layer of compacted sand. The thickness of the film laid on the ground must be at least 0.4 mm.
When laying film insulation, its strips are spread with an overlap of 10-15 cm, fixing them with construction tape. The edges are let down onto the masonry to a height equal to the total thickness of the insulation, concrete screed And finishing coating. A thermal gap 2-3 cm wide is left between the structural “pie” of the floor and the walls and partitions. It is filled with scraps of polyethylene foam or special thermal tape.
To insulate the base, you can use EPS (extruded polystyrene foam), sawdust concrete or perlite concrete. Often, waterproofing is not laid under foam plastic, since it practically does not absorb moisture. It is covered with a polymer film on top. It protects the insulation from the destructive effects of an alkaline environment cement mortar.
Under lightweight concrete on sawdust and perlite, a plastic film is needed. The thickness of the listed heat insulators is not the same. For XPS it is 50 mm. The layer of sawdust and perlite concrete should be at least 10 cm.
Having laid the thermal insulation, a concrete screed is made on its surface using fine-grained filler (fraction 5-10 mm, thickness 10 cm). The work is carried out in two stages. First, pour a layer 5 cm thick and lay it on it steel mesh(cell 10x10 cm, wire diameter 3-4 mm). After this, the thickness of the screed is adjusted to the design level, determined by calculation of the expected loads. Recommended concrete class B12.5.
This is how you get the correct flooring on the ground when the soil water level is low. Rough concrete preparation for rigid insulation is not done. There is no real benefit from it, but an increase in the cost of 1m2 finished design very noticeable.
Installing a heating system (warm floor) changes the technology and sequence of work. In this case, first pour a rough mixture over the compacted cushion. concrete preparation and lay out a layer of waterproofing. Having laid the insulation (EPS), pipes are fixed to it and a leveling screed is made of concrete. The reinforcing mesh is laid over the pipes or heating cable.
In passing, we note that floors on the ground can be made not only in brick, block, but also in wooden houses. With the right approach, ballast backfill does not have any effect negative impact on wood.
One of the options for properly pairing such a structure with chopped walls is shown in the diagram below.
Interface with a wooden wall
At low ground level concrete slab, lying on clay or on a layer of compacted waterproofed bedding, is made in basements. This is a very common option in cottage construction.
Before installing the screed, the area of the room must be divided into strips 80-100 cm wide using steel U-shaped profile or wooden beacon boards placed on edge. The damper tape is attached to the walls before pouring begins so that it protrudes 1.5-2 cm above the design mark of the finishing surface.
Pouring concrete begins from the far end of the room and moves towards front door.
Laying is done in strips, filling the cells slightly above their level. For leveling, use a vibrating screed or metal rule, moving it along the beacons.
After allowing the mixture to dry, the beacons are removed from it, filling the resulting seams fresh concrete. After this, the concrete is covered with film and given 4 weeks to gain strength, periodically moistening it with water.
Pros and cons of the design
When planning to lay a floor on the ground, you need to know what its advantages are over other types of foundations:
- Reasonable cost;
- Readiness of the base for laying any floor coverings;
- There is no need to ventilate the underground space to avoid the appearance of fungus;
- Greater durability compared to wooden and reinforced concrete floors.
The disadvantages of this design include:
- Loss of useful room height (up to 60 cm);
- Labor intensity of waterproofing work at high groundwater level;
- Poor compatibility with columnar and pile foundations;
- High cost of repairing hidden communications.
Floors on the ground are a universal way to create a warm and reliable foundation in the house. And they can be done at any groundwater level and type of foundation. The only limitation is the house is on stilts. In this article we will describe in detail all the layers of the “floor pie” and show how to organize it with your own hands.
Concrete floors on the ground imply the absence of basements or gaps for ventilation in the underground.
At its core, it is a multi-layer cake. Where the lowest layer is the soil, and the topmost is the floor covering. At the same time, the layers have their own purpose and strict sequence.
There are no objective restrictions for organizing the floor on the ground. High groundwater this is not a hindrance. The only thing they weakness– production times and financial expenses. But on such floors you can put brick or block walls, and even heavy equipment.
Correct “floor pie” on the ground
The classic floor pie on the ground implies the presence of 9 layers:
- Prepared clay;
- Sand cushion;
- Crushed stone;
- Polyethylene film;
- Rough concreting;
- Waterproofing;
- Insulation;
- Finish screed;
- Flooring.
We deliberately did not indicate the thickness of each layer, so as not to set any strict restrictions. Below, approximate values and influencing factors will be indicated. But first we would like to point out very important point: The groundwater level can change very seriously in a fairly short period of time.
In our practice, there have been 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. Moreover, this phenomenon was observed not in one individual house, but in an entire block of private buildings (40-60 houses).
Experts explain such phenomena by improper drilling of water wells. Such actions lead to mixing of aquifer lenses, rupture of layers and changes in aquifers. Moreover, they can drill a well quite far from your home. So pay close attention to the purpose of each layer of the floor pie on the ground and do not think that there are unnecessary elements here.
- Prepared clay. The purpose of this layer is to stop groundwater. In general, the three bottom layers of the floor pie are intended for exactly this. Of course, if, while removing the fertile layer, you have reached the clay layer, then you do not need to bring it and fill it up, only a little preparation is required. But more on that in due time.
- Sand. There are no special requirements for sand. You can use any, for example, quarry or even unwashed.
- Crushed stone. 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 rise of water and weakens the pressure upper layers, and crushed stone does not allow water to rise in principle. At the same time, each layer must be compacted. The thickness of each layer is at least 10 cm. Otherwise, there is no point in filling it up. But the maximum height needs to be explained in more detail. The fact is that tamping is most often done homemade devices. The weight of such instruments is 3-5 pounds.
It has already been empirically proven that compacting a layer of crushed stone, sand or clay more than 20 cm. hand tools impossible. Therefore, the thickness of one of the first three layers maximum - 20 cm. But, if you need to make the floor pie higher, then tamping can be carried out in two stages. First, 15-20 cm of sand is poured and compacted well. Then another layer of the same thickness is poured and compacted again.
The order of occurrence of the clay-sand-crushed stone layers cannot be changed. The reason here lies in the fact that if sand is poured on top of crushed stone, then after some time it will seep through it. Which in turn will lead to subsidence and destruction of the concrete layer, and then deformation of the entire floor.
- Polyethylene film. Be sure to take the film with your sleeve and lay it without cutting. That is, there will actually be two layers of polyethylene. It is intended solely to prevent the concrete solution from flowing into the crushed stone.
- Rough concreting. Minimum thickness layer 8 cm. Sand can be taken from a quarry, but it must be 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.
- . If the preliminary work is carried out correctly, ordinary roofing material without powder can handle waterproofing. If in doubt, you can lay roofing felt in two layers.
- Thermal insulation. Here it is recommended to use only Extruded Polystyrene Foam (EPS). Thickness should be determined depending on the region and climatic conditions. But we do not recommend using EPS with a thickness of less than 50 mm.
- Finish screed. Depending on the project, water heated floor pipes or cables can be integrated into it electric heating floors Only river sand is used. 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 floor coverings.
Installing a floor on the ground with your own hands
Before starting work, calculate the excavation depth. The calculation is carried out in reverse order. That is, the threshold of the front door is taken as zero. Then they begin to add up the thickness of each layer. For example:
- Linoleum – 1 cm;
- Finish 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 the minimum values. And each building is individual. Important: add 5 cm of depth to the result obtained for you.
Excavation is carried out to the calculated depth. Of course, the fertile layer will be removed, but clay may not always be below. Therefore, we will describe the process of organizing a floor pie on the ground in full.
Before filling the layers, draw level marks with chalk in 5 cm increments on all corners of the foundation. They will make the task of leveling each layer easier.
Soil compaction
Any clay will do for these purposes. It is scattered in an even layer, and before compacting it is generously moistened with an aqueous solution of liquid glass. The proportions of the solution are 1 part liquid glass and 4 parts water.
For compaction first three layers, you can use a one and a half meter piece of timber 200x200. But the process will be better if you do special device. To do this, to a one and a half meter segment metal pipe, A piece of channel is welded in a T-shape. The lower part of the channel should not have an area of more than 600 cm2 (20 by 30 cm). To make the tamper heavier, sand is poured into the pipe.
The compacted layer of prepared clay is well moistened with cement laitance. To prepare it, 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 cement comes into contact with liquid glass the chemical process of crystallization begins. It goes away quite quickly, but during the day you should not disturb the crystal formation in any way. Therefore, do not walk on clay, but rather leave the 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 sand and step on it. Chemical processes between liquid glass and cement will continue for 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, feel free to step on it and compact it.
Crushed stone. It is scattered in an even layer over the surface of the sand and also compacted. Pay attention to the corners. It is very important that after compacting the surface is as smooth as possible.
Polyethylene film. It is laid with a 10 cm overlap and taped. 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 is not, but only a technological layer to prevent laitance from flowing 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. fiber per 1 cubic meter of concrete. Try to level the freshly poured solution, following the corner marks. On a flatter surface, it will subsequently be more convenient to lay layers of waterproofing and insulation.
48 hours after pouring, the concrete must be reinforced. To do this, you will need 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 bottle. Then thin layer They dust the concrete and immediately begin to rub the cement into the surface. The most convenient way to do this is by grouting.
This procedure increases the strength of concrete by an order of magnitude, and in combination with liquid glass makes it as waterproof as possible. The concrete will mature within one and a half months, but by next stage work can begin within a week.
Insulation and waterproofing
To create a waterproofing layer, the floor surface is cleaned and treated with liquid bitumen. Ruberoid is laid overlapping, with an allowance of 3-5 cm. The joints are carefully soldered using construction hair dryer. Wall allowance 5 cm. IMPORTANT: Make sure that the roofing material fits into the corners and do not leave any voids. The second layer of roofing felt is laid offset by 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 5 cm thick EPS layer replaces 70 cm of expanded clay. And in addition, EPS has a practically zero water absorption coefficient and quite high compressive strength. We recommend laying 3 cm thick EPS in two layers. In this case, the top layer is laid with an offset. This method guarantees the absence of cold bridges and increases the thermal insulation properties of the floor pie. The joints between the EPS boards are glued with special tape.
Proper thermal insulation of the floor pie is an extremely important component for the energy efficiency of the entire house as a whole. Up to 35% of heat escapes through the floors! Even if the floors do not produce heat themselves (warm floors), they should be thermally insulated as much as possible. This will allow you to save quite impressive amounts on heating in the future.
Floor screed
Glue along the room, 15-20 mm thick. In this case, the lower part must be glued to the EPS boards. For reinforcing floors on the ground in residential premises they use masonry mesh with cells 100x100 mm. Wire thickness 3 mm. The mesh must be placed on 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 regular PET bottle caps.
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 mesh, this will require additional costs for fastening and will require violating the integrity of the EPS. And if the fittings are not fixed, then it can easily change the levels of the beacons. Therefore, it will be more convenient to fill this layer and then level it with a self-leveling screed.
For the finishing screed, the solution is diluted in the proportion of 1 part M500 cement + 3 parts. river sand. The work is carried out promptly. To roughly level the surface, you can focus on the corner marks.
After pouring the finishing screed, it should be allowed to gain strength for 3-5 days. With a thickness of 5 cm, the ripening 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, take a roll of dry toilet paper, place it on the floor and cover it with a saucepan 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.
The self-leveling screed is diluted according to the manufacturer's instructions and poured onto the surface of the concrete floor. When the work is carried out scrupulously, height differences do not exceed 8-10 mm. Therefore, a minimal amount of self-leveling screed is required. It dries quite quickly. And after 1-2 days the floor pie on the ground will be completely ready for laying the floor covering.
During the construction of a private house or during major renovation The question of screed reinforcement inevitably arises. Those who want to save money make only a concrete screed, while others want to create a surface “for centuries” using concrete floor reinforcement.
Depending on the purpose and location, the construction of a concrete floor can be divided into several types:
- rough screed resting on the ground or slab;
- leveling screed (self-leveling floor);
- construction, resting on floor slabs;
- screed with layers of heat and sound insulation.
Reinforcing concrete floors is advisable in cases of formation and with a multi-layer screed with a layer of thermal insulation. Reinforcement in such cases is simply necessary, since the floor is not built on a fixed (monolithic) base, and is subject to tensile and bending loads.
Reinforcement can be used to reduce it if calculations suggest its layer is too thick. There are several types of reinforcement. The appropriate one is selected according to the project and operating requirements only after calculations have been completed. Make your own calculations, taking into account everything building codes, is quite difficult, and there is a high probability of error. Therefore, to resolve this issue, it is better to use the help of design organizations.
For reinforcement of concrete floors are used following designs and materials:
- reinforcement frame;
- mesh made of wire rod;
- welded mesh with cells from 50-200 mm;
- fiberglass mesh;
- polymer mesh;
- special additives for fiber concrete.
Regardless of the reinforcement method, strengthening work concrete floors must be carried out in compliance with certain rules.
Types of reinforcement based on the characteristics and purpose of your floor.
- Before pouring, the reinforcement material must be strictly distributed over the surface of the construction site using supports (except for fiberglass additives).
- Reinforcement should not create obstacles in the distribution of concrete.
- The concrete and reinforcement material used must have good adhesion. To do this, avoid contamination with oily substances.
- To avoid corrosion, rotting or oxidation, the concrete must completely cover the reinforcement.
Frame or monolithic reinforcement is necessary in cases where the foundation and floor of the house are a single system for holding the building, or when reinforcement is necessary based on calculations or due to the unreliability of the soils on which the house will rest. In this case, the construction of the entire structure must be carried out taking into account the following indicators:
- thickness of reinforced concrete structure - more than 100 mm;
- the height of the reinforcement frame is more than 50 mm.
Monolithic option
With this method, the reinforcing frame is built from reinforcement. The reinforcement used can have a diameter of 6-40 mm. It depends on the project or the required structural strength. Reinforcement of concrete floors of private houses in most cases is done with reinforcement having a diameter of 10-20 mm.
The reinforcing mesh is “knitted” using steel wire 2-3 mm thick. Moreover, when forming it, cells with dimensions of 100-200 mm are made.
Then several layers of mesh (mostly two) are attached to the lifting ribs. It is better to use whole pieces of reinforcement for work, both in length and width. If the consumption of reinforcement is too high, then scraps can be used, but the fastening is done overlapping with an overlap of at least 0.5 m. Then the reinforced frame is filled with concrete.
Welding can also be used to form a frame from reinforcement. But to do such work with your own hands you need to have welding machine and work experience. Improper work technology often leads to thinning of the reinforcement at the joints.
Reinforcement using meshes
A less complex type of reinforcement of the floor structure is a reinforcing mesh made of wire. In this way, it is possible to strengthen a concrete floor with a thickness of less than 80 mm (used to form a multi-layer base on the ground or to strengthen the floor screed in places subject to special loads, for example, in the bathroom, kitchen, garage or hallway). The reinforcement system is practically no different from monolithic reinforcement. The result is that the mesh installed at a height of 20-30 mm is filled with concrete solution.
The design of the mesh can be either welded or knitted. There are also ready-made metal meshes for reinforcement. It will be enough to lay them in a layer on the floor surface with an overlap of 1-2 cells and tie them with wire. The cost of such a mesh in monetary terms is not much higher than with self-production. But it saves time and increases reliability.
Polymer mesh
The use of polymer mesh is one of the most simple ways reinforcement This method is often used not to strengthen the floor structure, but to prevent concrete from cracking during the drying process and with small deformations. The mesh is installed directly on the base of the floor, especially if it is covered with a film located on the embankment (cushion) or on thermal insulation, to prevent the appearance of cracks with reverse side screeds.
Polymer meshes are widely used to reinforce self-leveling concrete floors. This is due to the ease of installation and technological features self-leveling floors. Formation of floors using polymer mesh significantly reduces the volume required concrete and the thickness of its final layer.
Additives to concrete
Today in construction, the use of fiber fiber, which is polymer fibers with a thickness of about 15 microns, is becoming increasingly popular. When added to concrete, the screed layer is strengthened and the appearance of microcracks during drying is prevented.
Even with minor violations of conditions proper drying and the formation of microcracks is significantly reduced.
Reinforcement of a concrete floor is done when additional reinforcement of the base of the room is required. In industrial construction, reinforcement of floors in workshops and other production premises Necessarily.
The reinforcement improves the resistance of the screed to loads If the project provides for the implementation of a floating screed, then it is reinforced. Reinforcement of the concrete floor is carried out during shrinkage of buildings.
In all these cases, special meshes are used different materials. The reinforced screed resists the destructive effects of vibration, dynamic loads, and also withstands significant static pressure. In this article we will consider the reinforcement of concrete floors with various materials.
When reinforcement of a concrete floor is necessary
When installing a subfloor you cannot do without reinforcement Reinforcement of a concrete base is done only when operating conditions require it:
- The structure of the floating screed necessarily includes a reinforcing mesh. This type of screed is isolated from a fragile base with thermal insulation slabs or backfill of dry floors.
- A rough cement floor laid on the ground must be reinforced with reinforcing mesh. The ground is first backfilled with crushed stone or expanded clay.
- If there is a threat of destructive consequences from swelling of the soil, the concrete screed must be reinforced.
- When installing heated floors, the screed is subject to deformation and cracking due to significant temperature changes. The screed is reinforced over the entire area of the heated floors.
- They strengthen the base of floors in places where heavy objects will be installed, as well as where vibration and dynamic loads may occur.
- The reinforcement is used when laying concrete floors with a thickness of more than 50 mm.
In private households, floor reinforcement is used mainly in garages and rooms with installed heavy equipment (workshops).
Types of reinforcement products
Several types of materials are used to strengthen a concrete floor:
- metal grid;
- polymer and fiberglass reinforcement;
- fiber fiber.
Metal grid
The metal mesh is convenient because the rods are already fixed in it and you don’t have to connect them with your own hands Metal reinforcement makes it possible to obtain a base that is powerful in strength. A layer of concrete floor made from metal reinforcing mesh is used for constructing foundations on the ground in workshops, warehouses and garages.
Metal reinforcement for screeds is steel rods of periodic profile. To strengthen concrete floors, reinforcement with a diameter of 8 to 12 mm is mainly used. In some cases, larger steel rods are used.
The reinforcement is laid on the base of rooms with cell sizes from 50x50 mm to 150x150 mm. The gratings are made using the method spot welding steel rods.
This manufacturing method involves the production of reinforcing bars in a factory. IN special conditions grids of steel rods are formed at the installation site using electric welding.
The rods are connected by welding If more powerful reinforcement is required, then they resort to the option of placing meshes in two layers. The diameter of the rods and the size of the cells are determined based on special technique calculations.
The calculations are based on averaged indicators of static and dynamic loads that will affect the monolithic base of the concrete floor.
In addition to heavy reinforcement, wire mesh is used. They are much lighter than steel rods and are used for subfloors with moderate loads. Wire mesh is made either by spot welding or by simply knitting cells with the same wire.
Wire with a diameter from 2 mm to 6 mm is used to make meshes. Standard sizes cells can be from 50x50 mm to 200x200 mm. Wire mesh is supplied to retail chains in rolls, which is convenient for transportation and installation.
Polymer reinforcement is used when installing dry and semi-dry screeds Polymer and fiberglass mesh spacers are most often used when laying a concrete mixture in the form of a screed over the backfill of dry floors.
Fiberglass and polymer reinforcement are used in floors that can withstand loads of 300 to 400 per 1 m 2. Plastic mesh attracts consumers with the following qualities:
- the lightness of the mesh rolls is light, eliminating any inconvenience during their transportation and storage;
- The polymer material is easy to cut, allowing installation reinforcing mesh in a short time;
- absolutely no threat of material corrosion.
Fiber fiber
Fiber is added to the dry cement mixture before pouring it with water. A hardened layer of concrete with fiber fiber makes it possible to obtain a screed that is resistant to the formation of microcracks in the monolith. 
Polymer mesh and fiber are not used for the device concrete foundations on the ground. This material cannot withstand bending and tensile stresses.
The areas of application of types of floor reinforcement are presented in the table below:
Floor reinforcement with metal mesh
The edges of the mesh must be recessed in the concrete so that the metal is not subject to corrosion processes
Metal mesh laid in the middle of the concrete layer. Thus, the steel rods will be protected from the occurrence of corrosion processes. The reinforcement of a concrete floor is carried out in several stages:
- It is convenient to use light metal profiles as beacons. The profiles are aligned with the markings on the walls using pads. A solution is placed between the guide profiles. The floor surface is leveled according to the rule.
- After the solution has set, the profiles are removed and the depressions are filled with the solution. For more information about base reinforcement, watch this video:
Reinforcing the base of the floor with polymer and fiberglass mesh is done using the same technology as reinforcing floors with metal mesh.
Adding fiber fiber to the cement mortar does not affect the method of laying conventional concrete screed.
Building a house is a long-term process and includes a huge number of works in various directions. This includes the construction of walls, the construction of roofs, and a host of other types of work. One of the required steps is pouring the rough screed. It is necessary to create a primary base, on which the finishing screed or finishing coating will then be laid. A rough screed does not require special qualifications of the builder, but, nevertheless, involves a large number of works associated with its creation.
Creating smooth floors in a new home is not the easiest thing. And it is the construction of a rough screed that is the main step on the way to a level base suitable for laying various types coatings It ensures the reliability of the base and its strength. This is a rather labor-intensive and time-consuming process, but at the same time it is financially quite economical.
As a rule, laying the rough screed on the first floors is done directly on the ground. And most often, ordinary material is used as a base material. concrete mixture made from sand and cement.
However, quite simple process creating a rough screed cannot be called. The fact is that it involves laying several layers various materials and several preparatory stages:
- soil preparation - it must be thoroughly compacted;
- laying sand and gravel mixture;
- flooring waterproofing material, insulation;
- installation of the rough screed itself;
- installation of finishing material.
Thus, the floor consists of several layers. And this design has its own name - floor pie. It may also contain . Reinforcement is necessary to increase the strength of the screed.
Important! A rough screed can only be installed on dry soil. It will not be possible to create a full-fledged one in damp conditions, as problems with waterproofing may arise. Also rough screed can only be installed if groundwater is at least 4 m below the surface.
Also, during the installation of the rough screed, a floor heating system and other communications can be installed inside, if necessary according to the house construction project.
In general, a concrete floor on the ground in private construction is probably the most acceptable option for creating a foundation. It is often installed inside garages, on terraces, verandas, in warehouse premises and others.
On a note! Most often, concrete floors on a soil base are installed where there is no severe cold in winter period, that is, in the middle or southern zone of the Russian Federation. In cold regions, it is recommended to use wood to create the subfloor.
In the photo - crushed stone bedding
Main advantages
If we consider the main advantages of creating a floor on the ground, we can identify the following.
- Simplicity of all work. In general, creating a floor pie with the right approach takes only a few hours.
- High strength and resistance to deformation will ensure a long service life of the floor finish.
- On such a basis good performance heat, hydro and sound insulation. Such a floor will not freeze critically even in cold weather, which will keep the house warm and cozy.
- One of the factors is economy. Arranging a rough screed is not as expensive as it might seem at first glance.
Thanks to all these advantages, many future home owners choose it as a foundation rather than one made from any other materials.
Types of rough screed
Rough, like a regular screed, can be different types. It all depends on the installation technology and materials used. It can be performed using both dry and wet methods.
Dry floor screed- this is a kind of multi-layer cake, where the layers are vapor barrier material (or waterproofing), expanded clay or sand, acting as a dry “pillow”, as well as any leveling material such as chipboard, OSB, plywood or gypsum fiber, depending on the wishes of the owner of the future home. Often the material can be laid not in one, but in two layers, with individual sheets fastened with self-tapping screws.
Wet screed is made on the basis cement-sand mixture, which will be poured on top of previously laid other layers and carefully leveled. A waterproofing layer and insulation can be laid under it, in mandatory- sand cushion.
On a note! There is also a semi-dry screed. If in the previous version the mixture during preparation and use will resemble the consistency of sour cream, then in the version with a semi-dry screed it will look like wet sand.
Schemes of the rough screed device
Depending on the level at which the groundwater lies, as well as depending on the ground level and the position of the screed relative to the foundation, several types are distinguished.
Table. Types of arrangement of rough screed.
| Type of screed | Description |
|---|---|
| Screed below ground level | This method is used if it is planned to arrange food storage rooms or warehouses under the floor. In this case, the screed is located below the ground level, adjacent to the foundation. |
| Screed at ground level | Can be used in both industrial construction and residential construction low-rise buildings. The screed is located at ground level and adjacent to the strip foundation. |
| Screed above ground level | In this case, the screed is mounted above the foundation level; it is most effective and advisable to use it in places where groundwater lies quite close to the surface, in areas where the risk of floods and streams is high. |
In general, there is no universal scheme for arranging a screed - depending on the design of the house, it can be carried out in any of the above options. However, it is important to accurately design the location and level before construction begins. doorways so that you don’t have to correct mistakes later.
Foundation preparation process
All work on arranging a rough screed begins with careful preparation of the soil base. To begin with, it is important to identify the highest and lowest points, taking into account the level of the soil and the evenness of its surface. It will help to determine their values laser level. This procedure is necessary in order to evaluate for yourself the entire scope of work, as well as decide how much building materials may be required.
It is also important to pay attention to thoroughly compacting the soil. For this you can use a special construction equipment– for example, a roller or vibrator. The procedure is necessary so that in the future the soil does not sag significantly and this does not lead to cracking of the rough screed, which will undoubtedly negatively affect the finishing coating floors
After the soil has been thoroughly compacted, a sand and gravel cushion is laid. It can also be made of clean, washed and river sand. The thickness of this layer should not be more than 60 cm. In the latter case, a layer of gravel or expanded clay is also poured on top, which will make it possible to create a more durable base.
Attention! Before the soil is compacted, it is important to cut off the entire fertile layer, if any. It can be found in a more worthy use than burial under the house. The soil layer is removed approximately 35 cm.
It is also recommended to fill the pillow not all at once, but in layers - for example, 20 cm each. In this case, each layer is well compacted separately. The procedure will make the base as dense as possible. Before compacting, the pillow is moistened with water. The thickness of the expanded clay layer can be at least 10 cm. This layer is also compacted separately.
Prices for popular models of electric vibratory rammers
electric vibrating rammer
Layer of rough screed and waterproofing
Another important stage when creating a rough screed, this is its waterproofing. If it is neglected, then the moisture seeping from the soil will “undermine” the concrete screed and as a result the foundation will become unusable and collapse, or at least will last for a very short period of time.
For waterproofing rough screeds it is usually used roll materials– others in this case will be ineffective. Perfect option– use of rolled bitumen material or waterproofing membrane. Less commonly, but still used, dense polyethylene. The material must be laid in one large piece. If it is necessary to form joints (in the case of large areas), then they are carefully sealed - soldered or taped with construction tape so that water has no chance of penetrating to the base.
Attention! The waterproofing material should not have defects - holes, otherwise it will not fulfill its role.
It is important to lay the waterproofing material in such a way that it extends 15-20 cm onto the walls. If necessary, after laying the finishing screed, the excess can be cut off. If waterproofing material cannot be laid for some reason, then the final screed must be processed coating materials, which can resist and retain moisture.
Thermal insulation
In order to make the floors as warm as possible, it is important not to skip the thermal insulation stage. Expanded clay, basalt wool, and extruded polystyrene foam are used as materials that help retain heat. Laying the material is simple - slabs or layers of any of them are mounted end-to-end, without gaps, on a surface insulated from water. In this way, it will be possible to obtain a base that maximally retains the heat that tends to leave the house.
Attention! After laying the insulation material, it is recommended to lay another layer of waterproofing. This will allow you to fill the screed evenly and protect the insulation as much as possible from getting wet in the event of flooding. Wet insulation often loses most of its properties.
The most convenient and simplest option, but not the cheapest, is polystyrene foam. In addition to its thermal insulation functions, it makes floors stronger. Polystyrene foam can also be used as insulation. In this case, for garage and storage facilities The material used is PSB50, and for residential premises - PSB35.
It is important to protect polystyrene foam from contact with cement, which can destroy the material. To do this, the foam must be closed plastic film. But at mineral wool there is one drawback that sometimes scares off builders - it tends to absorb moisture, which is why waterproofing measures must be carried out especially carefully.
Reinforcement
Reinforcement is an additional strengthening of the rough screed by laying a reinforcing mesh in it. This material, created from metal rods or plastic, can significantly strengthen the base and allow it to withstand maximum loads. The mesh is laid on top of the previously installed layers on small supports, so that when pouring the screed, it appears to be inside the cement-sand mixture, and not under it. If the mesh has not been raised, it will not perform its functions of strengthening the base. The approximate height of raising the mesh level is about 2-3 cm. It is recommended to use a mesh with a cell size of no more than 10x10 cm. smaller size cells, the stronger the base will be, this is especially true in relation to plastic mesh, which is also often used in construction.
Fiber fiber for concrete screed - replaces metal mesh reinforcement