Reinforcement of the subfloor along the ground. Rough floor screed: types, advantages and step-by-step process of rough floor screed on the ground

If earlier concrete floors on the ground were used only for unheated rooms, then the emergence of new building materials and technology has significantly expanded the scope of their use. Now such floors are installed in all rooms, and the degree of protection against heat losses in concrete floors is almost as good as structures made of traditional materials... And in terms of durability, concrete floors are unmatched. Another advantage of such structures is that they can serve as the basis for all types of finishing flooring.

Concrete floors can have several varieties, but the same ones are presented to all. requirements. Regulatory guidance the design and construction of concrete floors are prescribed in the provisions of SNiP 2.03.13-88. Compliance with these provisions guarantees the durability of the structures.

SNiP 2.03.13-88. Floors. Download file (click on the link to open the PDF file in a new window).

Table. The main regulatory requirements to concrete floors.

Indicator name	Regulatory Requirements
	The physical characteristics of soils should prevent the possibility of deformation of the concrete floor due to natural subsidence or seasonal expansion of the wet earth. In living quarters, it is taken into account that the temperature does not fall below zero. It is forbidden to use soils as a base for floors that are not compacted in accordance with SNiP 3.02.01-87.
	Backfills can only be used after careful mechanical ramming, the concrete base layer must have a concrete class ≥ B 22.5. The parameters of the underlying layer in terms of thickness are selected taking into account the maximum possible loads. Deviations of the bottom bedding from horizontal is not ≤ 15 cm per 2 m floor length. Backfilling is done with sand or gravel.
	Provided for underlying, used in cases where the floor is located in the zone of capillary waters. In this case, the height of the rise of moisture along the capillaries is taken in the parameters of 0.3 m for sand of a coarse fraction, 0.5 m for a fine fraction and 2.0 m for clay. The height of the groundwater, as many amateurs say, does not have any effect on the height of the capillary waters.
	Insulation thickness concrete structures governed by the provisions of SNiP and depends on the specific purpose of the premises. Concrete floors on the ground, installed in heated rooms, must have a heat-insulating gasket around the perimeter of the abutment to the foundation or walls. This gasket additionally compensates for thermal expansion of the structures.
	Provided when it is necessary to level the surface of the concrete layer, to cover various engineering networks, lowering the thermal conductivity and creating slopes (if necessary). The thickness by 15-20 mm should be more than the diameter of the engineering pipelines. For bulk coatings with polymers, the screed is made of concrete ≥ B15, the strength of light (semi-dry) concrete ≥ 10 MPa. With increasing loads on the floor in individual areas, the thickness of the screed is calculated taking into account the elimination of deformation and loss of integrity.

Taking into account the characteristics of the room and project documentation technical requirements adjusted.

Step-by-step instructions for the construction of concrete floors on the ground

For example, consider the option of arranging a concrete floor in a residential area. To save building materials, it is recommended to install a water protection.

Step 1. Calculation of parameters and the number of layers of concrete floor. Before starting work, you need to decide on the zero level. If the house is being built according to the project, this parameter is indicated on the drawings. Zero level - level finishing coating floor, everything below this level is indicated on construction drawings with a minus sign, everything above - with a plus sign. In most cases, the floor is located at the level of the foundation, but there may be deviations.

If you do not have a project, which is very bad, then we recommend equipping the concrete floor in such a way that the concrete surface is in the same plane with the foundation. Now you need to make the calculations of the pie.

Sand layer. For a private house, it is enough to make a pillow with a thickness of about 10-15 cm. Gravel can not be used, the load on the floor in living quarters is not so high.
A layer of primary concrete under the base. The thickness is about 10 cm. If you wish, you can reinforce the primary layer with a metal mesh with a mesh size of up to 10 cm and a wire diameter of up to 3 mm.
Insulation. It is recommended to use modern extruded polystyrene foam. It can withstand significant loads, does not absorb moisture, and is not afraid of rodents. The thickness of the insulation is within 10 cm, it is impractical to do less due to low efficiency.
Top screed for concrete floor. The parameter depends on the load, in our case the screed should be more than 7 cm.

The thickness of the waterproofing layers is not taken into account. Now add up these dimensions - this is the distance from the ground to the upper plane of the foundation tape.

Step 2. Leveling the ground. Measure the level of the soil under the floor, decide how much you need to throw away or add according to the previously made calculations. If there is a lot of earth, then it should be removed, you will have to dig with a bayonet shovel, no equipment can work in the perimeter of the strip foundation. If there is not enough land, then the missing amount should be added. Check the ground level regularly.

Loose soil must be rammed. This can be done with a mechanical unit (frog, vibrating plate) or manually. The first option is much better - the work is noticeably accelerated, and the quality of ramming improves.

Practical advice. If you do not have a vibratory plate, then experienced builders it is strongly advised to water the compacted soil abundantly with water and leave it for several days for natural shrinkage. The formed grooves after shrinkage are additionally leveled and re-tamped. If the ground is loose, then uneven shrinkage of the concrete floor cannot be avoided, and this is an extremely unpleasant phenomenon.

You can independently make the simplest device for compaction of soil. Take a beam of 100 × 100 mm, approximately 1 m long.Nail to the bottom end wooden platform from trimming a board with a side of a square about 20-30 cm, fix the handles to the upper end. You should not make a large platform: the larger it is, the less tamping effort, you will only trim upper layer earth, and do not compact it. If the layer of earth exceeds 10 cm, then you need to ram in several stages, after each of them a fresh backfill is made.

Step 2. Along the inner perimeter of the foundation tape, mark the location of the sand layer, insulation and the finishing concrete layer. During work, do not allow deviations from the marks made by more than 2 cm.

Step 3. Fill in sand, level and tamp each layer constantly. Once again, we remind you that the stability of the concrete floor largely depends on the quality of the ramming of the base of the concrete floor.

Step 4. When the sand bed is at the design thickness, the first layer of concrete can be poured. The material is prepared on the basis of one part of cement grade M 400, two parts of sand and three parts of gravel. Gravel and sand should not contain clay, it greatly degrades the properties of concrete. Calculate the approximate amount of material. First, determine the cubic capacity of the layer, it is not difficult to do this. Then use the practical data. For one cubic meter of M100 concrete, you need about 3 bags of M400 cement, for M150 concrete you need 4 bags of cement. Accordingly, you will need twice as much sand and three times as much gravel. The calculations are approximate, but in practice, no one measures fillers up to a kilogram. Concrete can be prepared using a concrete mixer or by hand. Let's briefly describe the technology of both methods.

Making concrete with a concrete mixer

It is not worth buying a large concrete mixer, for private construction it is quite enough to have a unit with a bowl volume of 0.5–0.75 m 3. Store sand, gravel and cement next to the concrete mixer, place the materials in such a way that it is convenient to throw them into the bowl. Water is always poured first; for a mixer with a volume of 0.75 m 3, at least three buckets are needed. Then you need to throw about 8-10 shovels of gravel into the water and pour cement. The gravel breaks down all small lumps of cement to a homogeneous mass. When the cement is completely dissolved in the water, you can throw sand and gravel until you get the right grade of concrete. Water is added as needed. Initially, the tilt of the bowl should be approximately 30 °, then, as it fills, it can be raised. But do not increase the angle too much - the larger it is, the worse the ingredients mix.

Electric concrete mixer prices

electric concrete mixer

Making concrete by hand

This is hard physical work that requires certain practical skills, but for small volumes, you can prepare the material in this way. How to prepare concrete by hand?

Prepare a flat, solid area of about 2 x 2 m. For the base, it is best to use steel sheet if it is not there, then you can make a wooden box with low sides. The height of the sides is within 20 cm.
Place sand, gravel, and cement on one pyramid-shaped pile. When filling the pyramid, alternate all materials, the amount should correspond to the recommended proportions.
Use a shovel to throw the pyramid with ingredients to a new place and back again. Double crossover will ensure uniform mixing of cement with sand and gravel.
In the center of the pyramid, make a funnel deep to the bottom, pour water into it. Take the prepared ingredients in small portions with a shovel and mix them with water. Drive in a circle, making sure that the barrier roll of dry material does not break. Water is also added as needed.

The concrete must be prepared in portions, taking into account the speed of its placement.

Step 5. Pour concrete on the surface of the compacted sand in portions. Control the height using the lines made on the foundation. The concrete is leveled first shovel and then the rule. There is no need to make lighthouses, only last layer concrete floor. Level the mass with a long rule, check the flatness of the coating periodically with a level. Upon detection of significant deviations from horizontal problem areas should be corrected immediately.

Practical advice. Professional builders recommend making the first layer of the floor from a semi-dry mass. It has several advantages: significantly less thermal conductivity than ordinary one, manufacturability and ease of installation. In terms of strength, the semi-dry mass is inferior to the wet mass, but this is not critical for the floors in the house. A semi-dry mass is prepared in the same way as a wet one. The only difference is that the amount of water decreases.

Step 6. Install waterproofing, work can be started after the concrete has set, this will take at least 48 hours. If the concrete layer was made in dry and hot weather, then it must be abundantly moistened with water at least twice a day. Earlier in this article, we have already mentioned that waterproofing for concrete floors on the ground in houses is not always considered a prerequisite. If the thickness sand pillow is sufficient to interrupt the capillary absorption of moisture, then waterproofing is not needed. In addition, waterproofing is also not required on all gravel bases. The gravel does not draw water through the capillaries. But for reinsurance, waterproofing can be done, use for this an ordinary plastic film with a thickness of about 60 microns. This material is inexpensive, and in terms of efficiency it is in no way inferior to expensive modern nonwovens.

Step 7. Insulation layer. Extruded polystyrene foam is recommended. It has excellent performance in all respects. The only drawback is the high cost. For decreasing estimated cost concrete floors, expanded clay or slag can be used as insulation.

Important. These heaters react extremely negatively to increased humidity. For them, the presence of waterproofing is a prerequisite. Moreover, waterproofing should be done both from above and below.

Step 8. Cover the concrete surface with expanded polystyrene sheets. Do not allow gaps between the sheets, insert them lightly. The material is perfectly springy and, when the load is removed, eliminates cracks on its own. Expanded polystyrene is well cut with an assembly knife. You need to cut it on a flat surface under a ruler or a flat rail. If you have an electric cutter, great, if not, then work by hand. First, the sheet is cut on one side, then exactly along the cut line on the other. After a slight bending force, the notched sheet breaks. Styrofoam can also be cut with a fine-toothed wood hacksaw.

Step 8. Normative acts do not provide for the need for waterproofing polystyrene foam, but practitioners advise not to skip this stage of the work and cover it plastic wrap or another type of waterproofing agent.

Step 9. Install a soft heat insulator along the inner perimeter of the foundation strip. These can be strips of polystyrene about one centimeter thick or special foam strips. The heat insulator performs two tasks: it eliminates the possibility of heat leakage from the concrete floor to the foundation strip and compensates for linear expansion of the concrete floor.

Step 10. Install beacons. Finishing layer concrete must have a flat surface. Beacons can be installed different ways, but the fastest and easiest way to do it from metal rods.

Sketch a few small piles on the surface cement-sand mixture... In order for it to set faster, you need to increase the amount of cement by one and a half times. The distance between the piles is about 50-60 cm, the main criterion is that the rods should not bend under their own weight. The distance between the lines of beacons should be 20-30 cm less than the length of the rule.
Place the two outermost beacons under the level. Carefully check their position, the top plane of the beacons should coincide with the plane of the foundation tape.

Practical advice. In order to speed up the setting of the cement-sand mixture, sprinkle it with dry cement several times. Remove the wet cement and sprinkle the piles under the rods again. Cement very intensively absorbs moisture, after such procedures, you can continue to work without waiting for the complete hardening of the solution.

Pull the ropes between the two extreme beacons and do the rest along them. Do not forget to check the position, it is very difficult to correct mistakes in the future.

After all the lighthouses are exposed, start making the top layer of the concrete floor.

Step 11. Throw concrete between the beacons in small portions. First level the material with a shovel and trowel, and then with a rule. Work carefully, do not allow grooves to appear. To improve the performance of the top layer of concrete, add plasticizers during preparation. The specific brand doesn't matter, they all work great. The main thing is to observe the proportions and technologies recommended by the manufacturers. For the top layer, add four parts sand to one part of the cement.

This completes the work, allow time for the screed to completely harden and then proceed to topcoat concrete floor. You can use lumber as a finishing floor, ceramic tiles, linoleum, etc. We have considered the simplest concrete floor, but there are options with electric or water heating, it will take much more time and knowledge to equip such structures.

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

The method is considered universal, it is applied on all types of soils, regardless of the zone of location of groundwater. For pouring, concrete of a grade not lower than M300 is used, if the loads on the floor are large, and the physical indicators of the soils 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 flooring.

The rough screed is located below the ground, adjacent to strip foundation at the level of the ribbon expansion. Such a scheme is used if there are underground rooms under the house for storing food or other needs.
A rough floor screed along 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 starting the rough screed, the level of the finished floor should be 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. The classic solution is compacted soil, a layer of sand and gravel of various thicknesses, plastic wrap and a rough screed with or without reinforcement.

This method is recommended for use in cases where groundwater are located closer than two meters to the surface. Groundwater is much lower - you can simplify the construction scheme. It is allowed to pour a rough screed directly on the ground, use only sand or crushed stone as a backfill. In some cases, the sub-floor can be poured directly onto the ground without the use of plastic wrap. 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 for the delay in the mixture of cement milk. Without a film, it will quickly leave the concrete, which will have a very negative effect on strength.

What factors affect the technology of construction of a rough screed

If they come closer than two meters to the surface, then be sure to backfill with sand and gravel. The bedding serves to exclude moisture absorption by soil capillaries. If there is a bedding, then the use of a film to delay cement milk is required. If the rough screed is done immediately on the ground, then the film can be skipped.

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

If the placement of heat carriers is supposed to be in the floor structure, then the rough screed must have compensating gap between the foundation. Such structures eliminate the negative effect of thermal expansions 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 required. 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 indicators 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 filling the rough screed with others.

Is it advisable for a black screed to replace the filling with crushed stone with expanded clay? At first glance, it may seem that this original solution, allowing you to simultaneously insulate the floor. Professional builders recommend using this material only for those cases where the groundwater is low, and expanded clay is excluded from getting wet.
Can gravel be replaced with broken bricks and other construction waste? It is categorically impossible for several reasons. Firstly, the brick draws in water, in a wet state it quickly collapses, the base of the rough screed loses its strength and stability. Secondly, waste and broken brick have different linear dimensions, because of this it is impossible to tamp them thoroughly.
Is it possible to put the waterproofing protection only under the rough screed and not use it again? No. We have already mentioned that the plastic film performs other tasks - it does not allow the cement laitance to leave the solution. Over time, the waterproofing breaks its tightness, under the influence of uneven and point loads, it will surely break.
Is it possible to pour it instead of a rough floor screed? Enough complex issue... First you need to define what a shedding is. Spillage - 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 backfill layers, but also on the quality of their ramming. If the bedding is dense, then the liquid solution will not penetrate deeper than 4-6 centimeters. As a result, the load-bearing characteristics of the sub-floor are significantly reduced. Output. The decision should be made taking into account the loads on the floor.

Now that we have figured out most of the questions about the features of the technology of the rough screed device, we can give step by step instructions its filling.

Instructions for making a rough floor screed on the ground

Consider the most difficult and time-consuming option using all layers of bedding.

Step 1. Take measurements. First, you need to mark the level of the finished floor on the foundation strip.

To do this, you should 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 final screed, rough screed, a layer of gravel and sand.

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

Step 3. Add sand. As a rule, the thickness of the layer fluctuates within ten centimeters. If a large amount of sand is required, then it must be poured in stages, each layer separately tamped. The quality of ramming will significantly improve if the work is performed using special mechanisms: vibratory rammers or vibrating compactors. During tamping, you need to ensure that the sand has a more or less even and horizontal surface.

Rammer - very important stage arrangement of a rough screed on the ground, there is no need to rush. All the holes are poured in and again rammed, the tubercles are cut off.

Step 4. Pour a layer of crushed stone about 5–10 cm thick, tamp it thoroughly. It is better to take crushed stone of several fractions in sizes. A larger one is poured onto the sand, fine under the rough screed. In this way, the bearing characteristics of the base are improved. Some of the utilities can be hidden in the backfill layers or directly in the rough screed. There is no need to strive to install all pipes there and Electricity of the net, in case of emergencies, it is very difficult to get to them to carry out repair work.

Self-production of concrete mix

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

The concrete mixture should be below average in density. Such indicators allow the concrete to spill independently over the floor area. One of the advantages of using liquid concrete is that there is no need to install beacons and perform laborious work to level it using manual rules.

Workers only need to slightly adjust the level at the places where the material is poured. If reinforcement is required, then the mesh is placed at the same time. Building regulations require it to be installed 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, actual strength reinforced concrete will become much less than the calculated one. The consequences can be the most dire.

What kind of finish the floor will be chosen by the developer. Regardless of the option chosen, builders recommend that you do it from above. reliable waterproofing and put insulation. On top of these structures, a final screed is made under the tiled floor or laid wooden logs for other options for finishing flooring. Such schemes make the floors warm, which is very important given the modern prices for heat carriers. At the same time, the implementation of the recommendations professional builders significantly increases the operating time of floor coverings.

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

The question 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 slabs and additional work and materials and rough screeds on the ground, show savings in the range of 25%. And this is only by the most approximate calculations. Payment for expensive loading / unloading equipment, delivery leverage, etc. was not taken into account.

Video - Rough floor screed on the ground

Reinforcement of a concrete floor is done when additional reinforcement of the base of the room is required. In industrial construction, floor reinforcement in workshops and other industrial premises is mandatory.

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 performed when the buildings are shrinking.

In all these cases, special meshes are used from 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 concrete floor reinforcement is necessary

When installing the subfloor, you cannot do without reinforcement

Reinforcement concrete base do only when required by the operating conditions:

The structure of the floating screed necessarily includes reinforcing mesh... A screed of this type is insulated from a fragile base with thermal insulation plates or backfilling of dry floors.
A rough cement floor laid on the ground must be reinforced with a reinforcing mesh. Previously, a backfill is made of crushed stone or expanded clay on the ground.
With the threat of the appearance of destructive consequences from the swelling of the soil, the concrete screed must be reinforced.
When installing underfloor heating, the screed is subject to deformation and cracking due to significant temperature changes. The screed is reinforced over the entire area of the underfloor heating.
Reinforce the base of the floors in those places where heavy objects will be installed, as well as where vibration and dynamic loads may occur.
The reinforcement is used when laying a concrete floor 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 the concrete floor:

metal grid;
polymer and fiberglass reinforcement;
fiberglass.

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 fittings make it possible to obtain a strong base. A layer of concrete floor made of a metal reinforcing mesh is used for the construction of foundations on the ground, in workshops, warehouses and garages.

Metal fittings for screeds are steel rods with a 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 a mesh size from 50x50 mm to 150x150 mm. Lattices are made by the method spot welding steel rods.

This manufacturing method implies the production of reinforcing grilles in the factory. Under special conditions, steel bar gratings 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 the grids in two layers. The diameter of the rods and the size of the cells are determined on the basis of a special calculation method.

The calculation is based on the average values 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 sub-floors with moderate loads. Wire meshes are made both by spot welding and by simple knitting of cells with the same wire.

For the manufacture of meshes, a wire with a diameter of 2 mm to 6 mm is used. Standard sizes cells can be from 50x50 mm to 200x200 mm. Wire nets are supplied to the retail network in rolls, which is convenient for transportation and installation.

Polymer reinforcement is used for the installation of dry and semi-dry screeds.

Polymer and fiberglass mesh pads are most often used when laying concrete mix in the form of a screed over the backfill of dry floors.

Fiberglass and polymer reinforcement are used in floors that can withstand loads from 300 to 400 per 1m 2. Plastic mesh attracts the consumer with such qualities:

the lightness of mesh rolls is light, eliminating any inconvenience during their transportation and storage;
polymer material is easy to cut, which allows you to lay the reinforcement mesh in a short time;
absolute absence of the threat of corrosion of the material.

Fiberglass

Fiber is added to dry cement mix before filling it with water. The hardened layer of concrete with fiberglass 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 construction of 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 following table:

Floor reinforcement with metal mesh

The edges of the mesh must be recessed into the concrete so that the metal does not corrode.

The metal mesh is laid in the middle of the concrete layer. Thus, the steel rods will be protected from corrosion processes. The concrete floor reinforcement device is carried out in several stages:

It is convenient to use light metal profiles as beacons. The profiles are aligned with the lining to the level of the markings on the walls. A solution is placed between the guide profiles. The floor surface is leveled by the rule.
After the mortar has set, the profiles are removed, and the cavities are filled with mortar. For more information on base reinforcement, see this video:

Reinforcement of the sub-floor with polymer and fiberglass nets is carried out using the same technology as the reinforcement of floors with metal mesh.

Adding to the composition cement mortar the fiberglass does not affect the way conventional concrete screeds are laid.

A rough floor screed on the ground is laid under the finishing one, therefore, flaws are allowed with it and it may not have an absolutely flat surface. The rough screed is poured to level the differences in the base of the floor over the ground and to prepare the finishing one. A finished floor on the ground without screed is the first coating that serves the same purpose.

Floor device.

How to make a rough screed with your own hands

To correctly make a rough floor screed on the ground, you must follow the instructions:

first of all, the highest point is determined and beacons are placed along it;
the floor is being prepared for pouring;
preparation of the solution is in progress;
the solution is poured;
when the rough screed is ready, you need to monitor it until it hardens.

Beacon installation rules

Rough wet floor on a screed.

Before starting work, debris should be removed from the territory. After that, you can start installing beacons according to the following sequence:

heaps of cement mortar are placed along the wall on one line with a step of 0.5-1 m from each other;
then beacons are installed on the piles, it can be a metal profile or a pipe;
putting the profile on the heap cement composition, it is slightly pressed to the ground, sinking in a solution; bringing the level to the desired height, that is, until a single plane is formed, the lighthouse is fixed with several more portions of cement;
required height of the lighthouse - when its highest point is on the same level with the screed;
to make the alignment of the first beacon easier, two self-tapping screws are screwed into the place of their connection and a fishing line is pulled over them; on this line, you can straighten subsequent beacons.

After installing the first beacon, all the others are set in the same order. If the installation was correct, then the last profile should be opposite the first.

Preparatory stage

Types of sub-floor device.

In order for the adhesion of the screed to the base of the floor to be sufficient, a number of preparatory measures should be taken.

The first stage of preparation is alignment. If there are cracks, holes, irregularities at the base, then they are sealed with a solution.
The second stage is cleaning. The place where the screed will be laid is cleared of debris and dirt.
After cleaning, the surface is primed for better adhesion.

While the screed is being laid, all holes must be sealed with plugs. Before hiding pipelines and other engineering Communication, they should be attached to the floor with dowels, wrapping isolon in front of this. Rough floor screed on the ground is an economical design. The components of the solution itself are inexpensive.

Completion of the rough screed

Scheme of the construction of the subfloor on a combined screed.

Usually the solution is prepared in a ratio of 1 to 3 (cement and sand, respectively). For 1 kg of dry mixture, 0.5 liters of water is usually taken. If you do not observe the specified proportions, then the composition will not come out as strong as required. Subject to all the rules, the consistency mixture should be homogeneous and plastic. To prepare it, you need the following tools:

shovel;
buckets;
suitable capacity;
concrete mixer;
robe.

Next, the process of laying the screed begins. The space between two nearby beacons is filled with mortar using a shovel. When the profiles are covered with the mixture, it is necessary to take the rail and, putting it on the beacons with both ends, remove the top layer of the mortar to the place of the mark with wave-like movements towards yourself. If voids begin to form under the rail or the rule, then the solution is reported in them and again leveled. There are several professional tricks to make your screed smoother:

in order to avoid displacement of the lighthouses during flooding under them, all empty spaces must be filled in advance with a solution;
it is better to prepare cement in several passes in order to have time to fully use it before it hardens;
It is better to fill the screed in one day so that the surface is homogeneous, without cold bridges.

How to monitor the screed in the early days

Installation of a dry sub-floor on the joists along the floor slab.

During the drying time, the screed shrinks, so you need to look after it. For the first days of drying, do not walk on it. The room where the screed is laid should be darkened and closed to prevent drafts. All measures are aimed at creating the same microclimate throughout the room, so that the evaporated liquid is distributed evenly everywhere. After a day, the screed is covered with a film and wait for its complete hardening. This will take 2 to 5 days. It all depends on the thickness of the layer.

If a rough screed is used to level the floor along the ground, then some irregularities are allowed. If the floor on the ground is planned to be warm, then the rough screed should be leveled. This is due to the fact that a heating element the floor is placed on the ground between the screeds, and if the rough screed is not leveled, then the main screed of the floor will turn out with height differences at various points, that is, the heating of the room will be uneven.

A rough floor screed on the ground is an economical option, but very laborious, that is, the materials for such work are inexpensive and it is not a problem to buy them, but the process of work itself is long and rather difficult. When laying a layer of cement-sand mortar, sand is poured under it and rammed. After tamping, the floors are covered with rubble. If you pour the screed onto a layer of rubble, then it will not settle and crack over time.

Concrete parameters

Comparative characteristics of base concrete.

Ground floor is designed mainly for country houses and cottages, as it is believed that this is the most economical and reliable option... In the context of the floor on the ground, it looks like a layer cake. First, a layer of ground cleared of grass is taken and the sole is prepared from it. Sand is poured onto it, a waterproofing film is installed, a rough screed is poured, which includes a reinforced metal mesh. After that, the materials for insulation are laid, then the film is again installed to protect against moisture and, finally, a cement-sand screed, on which the floor will rest. Different conditions mean different Constructive decisions, which entails an increase or decrease in the number of layers.

If the project of the building was conceived with heating with a liquid heat carrier, then in this case a rough concrete screed with a thickness of 80-100 mm is made on the ground. Wherein cement strainer will have a thickness of 50-70 mm. Floor on the ground with a warm floor system does not differ from a warm floor, but has a thinner screed.

It is believed that a rough concrete or cement-sand screed must be reinforced. In construction terminology, this layer is called the underlying layer. In construction guides, there are several points about the underlying layer:

Non-rigid underlays of floors made of asphalt concrete, stone materials, selected compositions of earth, slag, crushed stone or gravel require mandatory mechanical compaction.
Rigid underlying layer - concrete, reinforced concrete, reinforced concrete - can be made of concrete of class B22.5. If the floors have increased loads directed to the sub-base, then it is allowed to use concrete of class B7.5. In this case, the screed is made with B12.5 concrete.
The thickness of the underlying floor layer is determined by calculating the loads acting on it in millimeters, for example, for sand - 60 mm, for slag, gravel, crushed stone - 80 mm, for concrete in residential premises - 75 mm; the same in production conditions - 100 mm.
If the concrete sub-base is used as a covering without screed, its thickness should be increased by 20-30 mm.

Usually, there are no direct instructions for reinforcing the floor over the ground. But in the list of materials, there is a reinforced floor on the ground with both concrete and rough screed. This issue is being addressed by design organizations and bureaus.

In addition to the rough screed, the floor on the ground has two types of finishing screed device. Before proceeding with the laying of the final floor screed on the ground, you need to install it zero level... Usually the floor is leveled on the ground using a laser level gauge.

In private housing construction, the technology of installing a concrete floor on the ground is widely used. This type of floor is the most demanded because of its simplicity of execution, strength, low cost and general availability of concrete. Concrete flooring on the ground is usually performed in utility rooms, less often in residential ones. In order to cope with this task with your own hands, you need to understand what layers the pie of this building structure consists of.

Layers of the concrete floor structure on the ground:

Underlying layer;
Waterproofing;
Thermal insulation;
Concrete base plate;
Screed;
Floor covering.

In order for the concrete floor on the ground to serve in the house for many years, you need to properly operate it - make sure that the air in the building is warm. In the absence of heating in the house for a long time, the floor structure may deform, with the appearance of cracks and ruptures due to the receipt of a large load from the frozen soils on the floor cake.

Ground floor technology

First you need to set a zero level in the room. For this, marks are put down along the perimeter of the walls in the lower part of the entire room, focusing on the bottom doorways... Thus, lowering or raising this line, it will be possible to make required thickness pirogue. The thickness of the concrete is controlled by means of a rope pulled over nails, which serves as a level.

To prepare the subsoil, we remove the vegetative layer of the soil, clean it with our own hands from debris and tamp it. We level the surface as much as possible.

Typically, a concrete floor cake is about 350mm thick. Therefore, it is necessary to dig the soil to this thickness from the zero line. If the soil level is below 350mm, then it is necessary to remove the layer of fertile soil, tamp and fill in dry sand to the required level with its subsequent compaction. After that, tamping and leveling of the surface is carried out. For this the best tool is a special vibrating plate. In its absence, tamping is carried out with your own hands and for this you can do with a simple log or flat board, to which handles are attached for convenience of work. Concrete flooring on the ground is a technology that requires the most leveled surface at the stage of laying each layer.

For additional waterproofing of the future structure, you can first make a layer of clay. If the clay is dry, it is necessary to spill it with water, tamp it with your own hands, cover it with sand, followed by its compaction. In addition, clay makes the substrate warmer.

Advice! To indicate the required backfill height, several pegs of the required length can be driven into the ground. The main thing is that they should be marked clearly in level. After all dry layers have been covered, the pegs will need to be removed before pouring the concrete.

The first layer (thickness 50-100 mm) is filled with gravel, followed by pouring with water and tamping. The second layer (about 100mm) is filled with sand, also followed by tamping. As a result, we will have a warm cushion for the concrete base of the floor pie in the house.

Hydro and thermal insulation device

To create waterproofing, use various technologies, where often used is the filling with heated bitumen and polymer membranes). We recommend making waterproofing using a special waterproofing polymer membrane, but if you want to save money, you can do it yourself with an ordinary plastic cake film with a thickness of 200 microns or more. The film is laid with an overlap of 10-15 cm, and the joints must be sealed and glued with tape.

Important! Waterproofing should be performed over the area of the entire room of the house, the edges adjacent to the walls should be bent along the wall a few centimeters above the zero line.

The modern construction market has a huge number of different types thermal insulation materials, for example:

expanded clay;
mineral wool;
Styrofoam;
extruded polystyrene foam;
isolon.

Each type of insulation has its own laying technology, the observance of which will make it possible to get a warm floor in the house.

Reinforcement of the concrete floor structure along the ground

In order to give the floor structure strength and protect it from destruction during operation, it is necessary to perform its reinforcement. For this purpose, you can use plastic or metal reinforcing mesh or reinforcing bars. If we use rods, then they must first be fastened with a flexible steel wire into a mesh with a mesh from 100 to 200 mm (the higher the load on the floor, the smaller the mesh size should be). For the reinforcement to work effectively, it is necessary that the reinforcement on both sides be protected with a layer of concrete - for this, the reinforcement mesh must be laid on supports with a height of about 20-30 mm. It is not difficult to do this with your own hands, it is enough to put bars under the grid and raise it to the desired height.

Creation of formwork and guides

Planks, beams, metal profiles, reinforcement rods, etc. can be used as guides. Using the guides, we divide the surface into several areas with a width of about 2m. It is important that the guides are stacked at the same level. We fix the guides with lime-cement mortar or in another way.

To make the formwork, you can use boards or moisture-resistant plywood. Place the formwork for pouring concrete between the guides. As a result, cells are formed - the so-called "cards", which must be filled with concrete. These guides can also serve as beacons for leveling cement when pouring. Throughout the entire process of installing a concrete floor, it is important to ensure that the surface is even, the guides and formwork must also be checked with building level before you start pouring. The unevenness of the formwork is eliminated either by cutting off the upper part of the boards or by placing remnants of bars, plywood, etc. under them.

Before pouring the concrete, do not forget to treat the formwork with oil - this will make it easy to remove wooden elements from hardened concrete.

Pouring concrete

Pouring concrete followed by a rough concrete screed. To prepare a concrete solution, we use the following ratio of components:

cement grades M400-500 -1 part;
sand - 2 parts;
crushed stone - 4 parts;
water - 0.5 parts.

We mix all the components using a concrete mixer, or manually and fill in concrete mortar uniform consistency in several "cards" at the same time in 1 reception, at least in 2, helping yourself with a shovel in more even distribution on the surface.

Advice! Fill concrete mix should be performed from the corner of the wall opposite front door so you don't have to walk on concrete.

After filling in a few maps, you can start the rough alignment. To do this, we use a rule of about two meters long. Moving the rule towards us along the guides like on rails, we distribute the concrete into the "cards", thus removing the excess concrete mass and filling the voids.

When the entire area of the room has been processed in this way, you need to give the concrete time to harden (about a month), covering it with plastic wrap. To prevent cracking of the concrete, be sure to spray it with water periodically.

The video clearly illustrates the technology of the rough screed device:

Fine concrete screed

The installation of a concrete floor on the ground is completed with the stage of creating a finishing concrete screed. The most effective option is to use self-leveling screeds based on gypsum or cement and special additives.

An important parameter the screed is its weight. Therefore, if you need to reduce the load on the floor, use lightweight screeds - self-leveling floors. A feature of such a coating is the speed of installation - it can be done in 1 day, well suited for hidden communications and underfloor heating devices.