Floor slab reinforcement, reinforcement: materials, diagram, drawing

A floor slab is a horizontal protective load-bearing structure that is located inside a building, separating all adjacent rooms by height. When constructing private houses, attic, basement and interfloor slabs are used, made using monolithic reinforced concrete construction technology.

Basic installation errors

When strengthening a slab foundation, the reinforcement scheme is drawn up in strict accordance with technology.
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If necessary, this scheme may involve an uneven distribution of rods. Places where it is planned to install load-bearing interior partitions and columns (pressure zones) are subject to additional reinforcement.

The reinforcement is laid in one layer if the thickness of the slab does not exceed fifteen centimeters. In other cases, it is recommended to install a reinforcement cage.

Calculations for a slab-pile foundation are performed separately, taking into account the location of the pile supports and the material from which they are made. In each case of slab reinforcement, the drawing is drawn up according to preliminary calculation data.

Slab parameters

Most often, the reinforcement is laid in two rows, the joint actions of which are ensured by vertical rods. The distance between the rods should be equal to the pitch of the main metal structure. Reinforcement at the ends of the slab is performed with U-shaped clamps; their minimum length is equal to two parameters of the base thickness.

All rows must be covered with rod strapping to ensure reliable perception of torque at the edges of the foundation and to be able to anchor the ends of the longitudinal rods.

Punching zones

At the support points of vertical structures, rods are laid out with a reduced reinforcement pitch. If the rods are laid out across the entire width of the foundation slab in increments of twenty centimeters, then in places where partitions are placed it is recommended to reduce this distance to ten. This will prevent the occurrence of cracks and dents.

When reinforcing a monolithic foundation, the frame elements of the slabs and walls should be tied together. When concreting the base, it is necessary to leave parts of vertically placed rods, which later act as connecting links. Such ends are launched into the base, the edges are bent at the level of two dimensions of the slab height, then they are tied to the main frame.

To provide the foundation with the necessary properties and protect it from destruction, it is necessary to strictly adhere to the reinforcement technology. As a rule, inexperienced builders make common mistakes:

Do not stretch polyethylene material over the poured concrete solution. The laitance leaks out and cracks appear on the surface;

Having filled a cushion of sand and crushed stone, many neglect to compact it. The foundation shrinks and cracks form;
on the installed formwork, the cracks through which the mortar mixture flows are not sealed, which leads to the appearance of unevenness;
poor insulation of the slab from the soil surface will lead to premature destruction of the foundation, and restoration work will be quite expensive;
It is a mistake to use stones as spacers;
during installation work, reinforcing bars are fixed in the soil layer, the metal corrodes and quickly collapses;
Before laying the foundation, a cushion of sand-crushed stone mixture is not poured, which reduces the strength of the slab. Another typical mistake is that only crushed stone is used to construct the cushion, but the minimum percentage of sand content in the cushion under the foundation slab before its reinforcement should be within forty;
the spacing of the mesh rods exceeds the permissible maximum limit of forty centimeters, or does not at all correspond to the calculated data on load effects;
there is no protective layer of concrete mortar on the side of the reinforcement ends, and the metal is subject to corrosion ahead of time;
There are no vertical reinforcing bars under the installation of walls and columns, and the load forces are distributed unevenly.

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These are the most serious errors that can clearly have a negative impact on the performance of the foundation. There are also more unobvious features that only experienced specialists can tell you about.

Materials

Reinforcement is the strengthening of a concrete block from the inside using various materials. Rods or fibers can be used that, when the block is stretched, do not allow it to crack.

In practice, reinforcement materials can be divided into 3 groups:

metal rods,
composite reinforcement,
fiber.

Steel bars

The standard length of a steel bar for reinforcing concrete structures is 11.75 m. The reinforcement can have different diameters and grades. Depending on the marking, the rods are joined into a reinforcing frame by welding or knitted with wire.

In the mass of concrete, the connection between the steel rods and the mortar is quite strong due to the corrugation on the rod. The steel frame inside the monolith redistributes the loads and keeps the concrete from cracking, since the metal has greater tensile strength. At the same time, concrete, in turn, protects the metal from corrosion.

Steel reinforcing frame

Composite material

Such fittings have a fairly wide range of source materials, increasing almost every year. To date, fiberglass and basalt plastic rods with spiral wrapping, simulating the periodicity of the steel reinforcement profile, are more or less used.

In addition, the construction market offers polyethylene rephthalate and hydrocarbon fittings, which have not yet received widespread popularity. The undeniable advantage of the composite is its low weight. But when constructing foundations or retaining walls, this advantage is of little importance, but the strength characteristics are very important.

Composite reinforcement is usually used in horizontal building elements supported on the ground

Fiber fiber

Fine material (fiber) is added to the solution at the mixing stage. Moreover, the fiber itself can have different diameters and lengths.

Fiber is made from fiber based on:

become,
glass,
polypropylene compounds,
basalt.

Fiber fiber to enhance the tensile strength of concrete

Material selection

Depending on the complexity and main characteristics, there are several types of reinforcement. You need to know which one to use in a particular case. There are rigid and flexible fittings. The cross section distinguishes between heavy and light. It can be smooth or ribbed. The latter is usually used with large quantities of concrete to create a solid monolithic slab.

The fittings are produced by large metalworking enterprises. The first stage is the acceptance of steel, which is then processed by deformation, rolling or drawing. The last method is the most labor-intensive. Rolling is more economical, since the waste here is minimal. After cleaning, the reinforcement is cut on special machines.

Reinforcement is mainly intended to strengthen concrete structures. The rigid type of reinforcement is used in the construction of frames and corners. Flexible is used for the manufacture of various meshes, rods, frames. With the help of reinforcement, the structure takes on shape and integrity, and the service life increases if the selection is carried out correctly.

Today, with the active development of private construction, the popularity of reinforcement for floors and flat monolithic slabs is increasingly growing. When using such building materials, it is important to correctly calculate the parameters of the slab and the diameter of the reinforcement, and draw a diagram of the reinforcement of the floor slab. The size of the span affects the thickness of the slab. For example, if the span between load-bearing walls is 6 meters, you need to use a slab with a thickness of at least 20 cm. If you reduce the concrete layer, the consumption of rolled metal will increase.

Requirements for floors

Floors are one of the main structural elements of buildings, dividing them into floors. Their purpose is to perceive and transmit permanent and temporary loads on walls and columns, as well as to isolate rooms from each other and from the external environment. Floors are classified according to:

Location: interfloor, attic, above-basement.
Structures: beam (the main load-bearing element is beams), slab (load-bearing slabs and decking).
Load-bearing elements: reinforced concrete, wood, steel.
Method of construction: monolithic, ribbed and hollow.

READ Features of pouring concrete floors in a private house
Prefabricated floors are used in frame construction systems.

Reinforcement of hollow and multi-hollow slabs can be done without constructing formwork, since they are very light. Reinforcement of a monolithic floor, due to its heaviness, requires a two-layer bond. They will need formwork and methods of additional reinforcement.

Floor slab reinforcement drawing:

Reinforcement of a ribbed floor slab is carried out only on one side, taking into account the characteristics of the building. When reinforcing a floor in a private house, you need to strengthen the side that will be the ceiling or floor. Store-bought products always have markings that indicate the permissible load.

The structure of the floors consists of load-bearing and insulating elements, floor and ceiling. Each of the floors is subject to force: its own weight, the mass of partitions and various engineering systems. These impacts create deformation and stress, which manifest themselves in deflections. Non-force influences also exist. These are people walking, objects falling, loud conversations, radio, TV, etc.

The following requirements apply to floors:

Floors must be consistent with the durability of the building.
Possess a high degree of fire resistance.
Must be easy to use.
Don't miss the cold.
Provide sufficient sound insulation.
Have architectural expressiveness.
Comply with economic feasibility.

Depending on what the building is intended for, it must be subject to separate requirements. The type of structure and the height of the structure depend on the size of the interfloor spans and the degree of load. The architect's goal is to limit the amount of deflection of the floor. Floors of residential buildings should be designed with a height of about 300 mm.

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Construction of formwork

In some cases, developers reinforce floor slabs on their own.
Similar decisions are made when a construction project has incorrect geometry. This makes it possible to bypass standards and approach certain types of work in your own way. Reinforcement is done according to special rules. All materials are purchased only from reliable companies, since a marriage here can cost people’s lives. When drawing up a slab reinforcement scheme, it is necessary to take into account the auxiliary reinforcement that will be needed to strengthen individual sections:

in the central part of the slab;
in places where the slab will come into contact with columns or walls;
where the loads are most concentrated (installation of a fireplace, heavy furniture or household appliances).

Before installing the formwork, it is a good idea to make calculations using a special computer program. Accurate calculation is needed to distribute pressure evenly across the supports. The longitudinal pitch for the racks must be at least two meters with a laying pitch of 62 cm. The cross beam lies vertically. The distance from the wall to the stand must be at least 25 cm. First, removable formwork is made where the working reinforcement will be located.

For its construction, materials are usually used that can then be used for other purposes. To do this, use ordinary edged boards. If you need to ensure a perfectly flat surface, use sheets of laminated plywood with a thickness of at least 25 mm. But it won't be cheap. This method is much more accessible: first the same boards, and then lay regular plywood on top.

All this is done around the entire perimeter of the object. If the future slab will be used as a ceiling, then it is better to replace the side boards with bricks or foam blocks, the height of which should correspond to the thickness of the concrete. After the concrete hardens, the formwork does not break, but is carefully dismantled in parts so as not to damage the slab.

There is another technology for constructing a floor using corrugated sheets, which is used as permanent formwork. Less reinforcement is required and concrete is saved. This filling increases the strength of the structure several times.

How to avoid mistakes when creating a reinforcing frame

Mistakes can be made at any stage of construction; foundation reinforcement is no exception in this case. Even the slightest defects can contribute to the destruction of the slab base or complicate the concreting process. Therefore, it is necessary to learn in more detail what mistakes are made at the reinforcement stage in order to completely avoid them or minimize them.

The most important mistake when reinforcing a foundation slab can be called incorrect calculations of the expected load on the foundation or their absence. Indeed, on the basis of these data, the dimensions of the reinforcing bars are selected and the layout of the reinforcement is determined.
The reinforcement bars are connected end-to-end. This method cannot guarantee the strength of the structure, so it is recommended to overlap the elements; the length should be at least 15 diameters.
During the process of laying the reinforcing frame, the rods are located in close proximity to the soil or stuck into it. As a result of heaving or movement of the soil, the reinforcement becomes embedded in the ground, which leads to the formation of corrosion on the rods. This phenomenon reduces the strength of the frame and the entire base.
Failure to comply with the rules for the location of rods can also cause destruction of the slab. The recommended distance between the rods should be no more than 40 cm, and in some situations this parameter is reduced to 20 cm.
If the ends of the reinforcement do not have a protective coating, then corrosion of the elements may occur under the influence of moisture from the concrete solution.
Proper reinforcement under load-bearing walls and in the corners of the building is of great importance.
The installation of the frame is carried out not on clamps, but on wooden blocks or other non-standard elements. They not only violate the integrity of concrete, but also promote the penetration of moisture into metal elements.

Foundation slab reinforcement

Reinforcing the foundation slab is a very important and complex stage. But if you follow the rules and accurately carry out the calculations, you can carry out this process yourself.

Advantages and disadvantages of monolithic frame technology

Monolithic reinforced walls have the following advantages:

the one-piece construction without seams is strong and reliable, it does not blow through, and temperature bridges do not form;
a smooth, even surface allows you to begin finishing work without prior preparation;
building construction in a short time;
monolithic houses have an open layout;
increased service life of reinforced concrete structures;
complex architectural curved elements and arches are made quite easily.

Disadvantages of monolithic walls:

low sound insulation;
mandatory wall insulation;
the ability of concrete to conduct vibrations.

Rules for reinforcing a slab foundation

The basic requirements for a monolithic slab are given in 52-101-2003. They contain recommendations on the location and knitting of reinforcing mesh, and what supports to use to provide a lower protective layer. The use of rods with flaking rust is not allowed.

The periodic cross-section rods provide high adhesion, and the binding wire is more reliable than plastic clamps. However, reinforcement should begin in stages: choosing a rational scheme, calculating the cross-section of the rods, fixing the frames in space using special elements.

Reinforcement schemes

The recommendations of SP 63.13330 for reinforced concrete structures have a special section on the manufacture of main load-bearing structures (10.4). In particular, the following requirements are specified for a slab foundation:

the reinforcement is laid in two directions (mesh with a maximum cell size of 30 x 30 cm), connected by wire knitting or welding;
the meshes are placed as close as possible to the top and bottom edges, taking into account a protective layer of 3 cm;
Using U-shaped clamps, the mesh rods are tied together at the ends;
in places where monolithic walls and columns are installed, vertical rods are released or anchored with hooks to strengthen the slab;
under load-bearing walls, the cell pitch decreases compared to the rest of the slab;
It is allowed to discharge the mesh cell in the central part to the minimum permissible percentage of reinforcement (0.3%).

The grids can be positioned correctly taking into account the lateral protective layers (minimum 4 cm between the rod and the formwork), the location of the communication input nodes (relevant for non-buried slabs).

In practice, for low-rise cottages the following scheme is used:

mesh of 8 mm reinforcement in the top layer;
similar mesh in the bottom layer;
reinforcement of USP ribs or a smooth slab (thickness 30 cm or more) with frames around the perimeter of 10 - 14 mm periodic cross-section rods.

This is due to the absence of heaving forces when using a warm blind area, ring drainage around the foundation, replacing soil with non-metallic materials to a depth of 40 cm. The recommended cell size in the discharged part is no more than 1.5 of the slab thickness, under walls 10 x 10 - 20 x 20 cm In the absence of a footing, the lower protective layer increases to 5 - 7 cm.

Openings

In non-buried slabs it is impossible to do without openings in the monolithic structure for the entry of utility systems. This issue is very poorly described in the specialized literature. An individual developer should refer to the design guidelines for reinforced concrete buildings:

cutting holes in welded mesh with bending the rods upward;
edging of openings larger than 30 cm with rods 10 - 14 mm diagonally located to the mesh cells;
There is no need to reinforce the perimeter of holes smaller than 15 cm.

In deep slabs there are no communication entry nodes by default. To increase the maintainability of engineering systems, sewerage and water supply are run through the basement walls.

Plate/tape interface

It is possible to correctly install reinforcement bars in the formwork of a buried slab foundation with a basement, taking into account the following conditions:

walls on a recessed slab are prohibited from being placed close to its edges; the minimum perimeter offset is equal to the thickness of the foundation strip (from 10 to 40 cm);
The anchoring scheme for the interface between the tape and the monolithic basement wall has several options.

Reinforcement outlets in the slab under the walls.

For example, a U-shaped clamp can be extended upward from the slab, the distance between the rods of which corresponds to the size of the tape frame, in order to subsequently connect these two structures. In addition, you can tie rods bent at right angles to the lower and upper mesh of the slab and extend them 40 - 60 cm outwards in the same way as the previous option.

If the project does not have a rigid connection between the tape and the wall with a deep slab, in these places the mesh is reinforced with U-shaped clamps to avoid pushing through.

Design features

Reinforced concrete products combine the properties of solid concrete (stone) and metal, which has elasticity. Concrete is better able to withstand compressive loads, while metal is better able to withstand tensile loads. In building structures, the load on the floors in all cases will be directed vertically downward and generally distributed evenly over the entire area. The load consists of its own weight and all objects, structures, and people that will be there.

Double reinforcement of the floor: 1. working rods of the lower zone; 2. rods of the upper zone (their diameter is assumed to be less than or equal to the diameter of the rods of the lower zone); 3. reinforcement that redistributes loads; 4. wire rod stands.

The floors bend and are reinforced in such a way as to withstand just such a load. It always contains two meshes of reinforcement, upper and lower. Reinforcement bars in meshes are placed along the span and across the span. The reinforcement spacing (the distance between parallel bars) in industry is determined using engineering calculations based on the design loads. In individual construction, when making the floor yourself, the pitch is usually 150-200 mm.

The reinforcing mesh should be located in the thickness of the concrete at a distance of 25-30 mm from the surface. The reinforcement bars are tied together with tying wire at all intersections. You can also use ready-made welded reinforcement mesh. Independent reinforcement of a monolithic floor using welding is not recommended, since stress concentrations are formed at the welding points, which will subsequently lead to ruptures. In production conditions, welded mesh is subjected to a technological operation to relieve stress.

Components of a monolithic floor: concrete, supporting reinforcement, crown, floor.

Separators are installed between the upper and lower reinforcing mesh - vertical reinforcement elements (a kind of clamps) designed to ensure that the distance between the upper and lower reinforcing mesh is the same in all directions. The mesh separator can be of various types: a bent hook, a loop - whatever your imagination allows. They must be located with a certain step. The drawing presented here shows a schematic distribution of reinforcement.

The edges of the ceiling must be reinforced with additional reinforcement - U-shaped and L-shaped elements (see drawing). They especially require strengthening of the support area. If the slab is supported along the entire contour, then reinforcement must be done along the entire perimeter.

Let's look at the section drawing. The upper part will work in compression, and the lower part will work in tension. The main tensile load falls on the lower reinforcement, so it needs to be made thicker than the upper one.

Drawing diagram of the reinforcement of a monolithic floor.

The larger the span, that is, the distance between the supports, the greater the requirements for its strength characteristics. The recommended span is up to 6 m. Above this size, additional reinforcement will most likely be needed. It is possible to say more accurately whether they are needed or not only after strength calculations. But there is a general pattern: directly above the support the upper layer of reinforcement is strengthened, and in the middle between the supports the lower layer of reinforcement is strengthened. The principle of arrangement of reinforcements is reflected in the presented drawing.

Reinforcement bars must be continuous. If they consist of separate elements, then the overlap must be at least 40*d, where d is the diameter of the reinforcement. For example, for reinforcement with a diameter of 10 mm, the overlap should be 400 mm. For floor slabs, hot-rolled steel reinforcement, class A3, is used. The recommended diameter is from 8 to 14 mm. By taking these guidelines into account, you can refine your drawing.

For residential premises with a span of up to 6 m, supported along the contour, at any aspect ratio, we can recommend a slab thickness of 200 mm, reinforcement spacing of 200 x 200, diameter of the lower mesh rods 12 mm, diameter of the upper mesh rods 8 mm.

Basic installation errors

Do not stretch polyethylene material over the poured concrete solution. The laitance leaks out and cracks appear on the surface;

Having filled a cushion of sand and crushed stone, many neglect to compact it. The foundation shrinks and cracks form;
on the installed formwork, the cracks through which the mortar mixture flows are not sealed, which leads to the appearance of unevenness;
poor insulation of the slab from the soil surface will lead to premature destruction of the foundation, and restoration work will be quite expensive;
It is a mistake to use stones as spacers;
during installation work, reinforcing bars are fixed in the soil layer, the metal corrodes and quickly collapses;
Before laying the foundation, a cushion of sand-crushed stone mixture is not poured, which reduces the strength of the slab. Another typical mistake is that only crushed stone is used to construct the cushion, but the minimum percentage of sand content in the cushion under the foundation slab before its reinforcement should be within forty;
the spacing of the mesh rods exceeds the permissible maximum limit of forty centimeters, or does not at all correspond to the calculated data on load effects;
there is no protective layer of concrete mortar on the side of the reinforcement ends, and the metal is subject to corrosion ahead of time;
There are no vertical reinforcing bars under the installation of walls and columns, and the load forces are distributed unevenly.

Selection of fittings

Three types of reinforcement are used for construction work:

Reinforcement with a smooth surface (A240), used for reinforcement in the vertical plane. Not recommended for strengthening monolithic slabs;
Brand A300 (diameter within 10-12 mm). The surface of the rods is covered with ring notches;
Brand A400. The rods have a crescent-shaped profile. Thanks to the increased working diameter, it is best suited for reinforcing slabs.

Before reinforcing a monolithic foundation, it is necessary to calculate the optimal cross-section of the rods. The reinforcement mesh consists of two layers, the elements of which are located at right angles to each other. The lower and upper rows are connected by means of vertical clamps. Knowing the cross-section of the concrete slab, you can calculate the cross-section of the reinforcing mesh bars running in one direction: it should be about 0.3% of the total area of the monolithic slab.

If the width of one of the sides of the foundation is less than 3 meters, the minimum diameter of one rod is 10 mm. For more massive slabs, it is often sufficient to use reinforcement with a diameter of 12 mm. The maximum diameter of the rod for the plate is 40 mm.

Scheme of reinforcement of a monolithic slab

The slab reinforcement diagram allows you to get a clear picture of the location of all structural elements. The drawing contains parameters for the placement of the upper and lower chords of the system and the distance that is formed between them, the design thickness of the concrete layer, reinforcement pitch and other values . Spatial diagrams additionally display the location of telescopic racks, formwork and crossbars.

The design reinforcement scheme depends on the type and profile of the slab: beam, flat, hollow, ribbed, etc.:

For beam-type slabs (support is provided on three walls, the load occurs mainly in one direction from top to bottom, for example, in interfloor ceilings), up to 6.0x8.0 m in size, single-span reinforcement and a continuous fill profile are used;
For slabs with large spans supported by columns, multi-span reinforcement (usually two layers) is suitable. Before work, a load calculation is carried out.

If it is necessary to carry out reliable reinforcement of the floor slab (SNiP), the load is calculated as follows:

useful (house equipment, etc.) – 200 kg/m²;
from partitions – 150 kg/m²;
from the floor – 100 kg/m².

Thus, the average load for a residential building will be 450 kg/m², that is, the floor slab must withstand exactly this load, preferably slightly more than 500 kg/m² .

It is advisable to entrust the development of complex schemes to professional designers, who will provide a drawing and a sectional drawing for the reinforcement of a monolithic floor slab.

Common mistakes when reinforcing

There are frequent cases of errors leading to disruption of technology and reduction of operating time. These include:

there is no polyethylene protective film on the surface of the erected monolithic slab (due to the outflow of water when the concrete hardens, the surface of the base dries out excessively, as a result of which cracks form);
the prepared sand and gravel substrate is not compacted (distortions and cracks);
when forming the formwork system, cracks are not sealed, which leads to leakage of the concrete mixture and a reduction in the optimal water level in the solution;
there is no waterproofing over the equipped substrate (reduction of the water level in the poured solution);
reinforcement bars are placed directly into the ground (corrosion of the material occurs in the shortest possible time, violating the integrity of the structure and the purpose of reinforcing the base);
non-compliance with recommendations on the dimensions of fractions of reinforced frames (voids are formed);
when arranging column elements, the reinforced frames are not fastened to the rods of the columns, which leads to an uneven distribution of loads on the constructed foundation;
lack of a protective layer (premature corrosion of metal elements).

Watch the video on how to avoid mistakes when laying reinforcement and further pouring the foundation.

https://youtube.com/watch?v=GLqVVVe0yrM%3F

Excavation

The soil is marked according to design standards, increasing its perimeter by 50 cm on each side for the installation of a drainage system

The soil is marked according to design standards, increasing its perimeter by 50 cm on each side for the installation of a drainage system. It is worth remembering that the slab itself should protrude beyond the walls of the future house by 10 cm on each side.
Pegs are driven into the ground and a marking cord is pulled. The axes of the future slab should also be drawn.
The soil is removed from the pit to a depth of 60 cm. At the same time, you should carefully monitor the quality of the soil being removed. If early digging of soil is observed on a building site, then the loosened soil must be removed layer by layer until you reach layers untouched by a shovel. Here, according to the instructions, you will have to remove layers of soil around the entire perimeter of the pit in order to completely level it. After this, the bottom of the pit is compacted and filled with sand to the design level of the pit. If this is not done and the foundation is mounted on soft soil, then the force of the house’s pressure on the slab will simply break it over time precisely in the place of loose soil.

A drainage system is laid around the design base area in the form of special perforated pipes with their slope towards the storage well or central storm drain.
Then you should lay a layer of crushed stone 20 cm thick and carefully compact it according to the principle of laying a sand cushion.
Now we install the formwork from high-quality wooden panels. Their height should be at least 40 cm. It is advisable to clean the inner walls of the formwork. The formwork is fastened with bolts, screws or self-tapping screws. From the outside, the wooden frame can be supported with wedges for greater stability.

What is the need for reinforcement?

In order to increase the strength of concrete and reduce its quantity, reinforcement is used. In theory, any material can act as reinforcement. But in practice, steel and composite are most often used.

A composite is a complex of materials. The basis can be basalt or carbon fibers, which are filled with polymer. Such fittings are lightweight and not subject to corrosion.

Steel, compared to composites, has much greater strength and relatively low cost. In the process of reinforcing monolithic walls, channels, angles, I-beams, corrugated and smooth rods are used. In the case of creating complex building structures, metal mesh is used for reinforcement.

Reinforcement comes in different shapes. But most often you can find the rod one on sale. In the construction of low-rise buildings, corrugated rods are usually used. They have a low price and excellent adhesion to concrete, which makes them very popular among buyers. Steel rods, which are used in the construction of monolithic structures, usually have a diameter in the range of 12-16 mm.

Floor slab reinforcement, drawing

Due to the relatively low cost of the design and ease of installation, a home craftsman can carry out all the work with his own hands. Before construction begins, it is necessary to draw a drawing and strictly follow it during the construction process.

The following parameters are taken into account during operation:

slab thickness - calculated according to the proportion 1:30. For example, for a slab with a length and width of 4x6 m, the thickness is taken to be 20 cm;
scale (sizes of all elements in plan);
features of the reinforcement frame (single-layer, two-layer);
reinforcement pitch;
the presence of enhancements and their location.

If the slab will be located on load-bearing walls, the support depth should be 80 mm.

Floor slab components:

concrete - the minimum thickness is 6.0 cm, the thicker the slab, the higher the strength and sound insulation properties, however, the actual parameters depend on the specific conditions of the object;
supporting reinforcement – blocks cracking in the wall zone;
crown - passes through all load-bearing walls of the object. Reinforcing bars are inserted into the crown.

What reinforcement is needed for a slab foundation

Any rod used in the foundation frame must comply with the requirements of GOST 5781 of 1982. However, reinforcement, like most structural materials, has a classification:

AIII – corresponds to the markings A400 and A500, has a variable cross-section, popularly called “corrugated”;
AII – corresponds to the current class A300, the cross-section is periodic, discharged;
AI – new A240 marking, smooth profile.

For the foundation, reinforcement A400 (AIII) is used, it has a crescent-shaped profile.

On sale you will most often find rods of class A500C (for welded mesh, frames) or A500. Reinforcement with index C at the end is suitable for welding and knitting, without index - only for knitting.

We recommend reading in more detail: What reinforcement is needed for the foundation.

Due to the complexity of calculations and the small dimensions of buildings in low-rise construction, a simplified scheme is recommended. Two grids at a distance of 10 cm vertically with at least identical cells. If the developer wants to save on pouring the slab, the calculation should be ordered from specialists who will calculate the minimum required reinforcement, use thin reinforcement in the center of the foundation, strengthen the perimeter, and the places where the internal walls pass.

If the foundation dimensions are more than 3 m on any side of the slab, it is recommended to use rods of at least 12 mm. To determine the minimum possible cross-section, the following method is used:

calculation of the slab cross-section - length multiplied by thickness (for example, 6 m x 0.3 m);
calculation of the minimum allowable cross-sectional area of the rod - the previous figure is divided by the minimum percentage of reinforcement (0.3% for concrete B20, 0.15% for grade B22.5, 0.1% for grade B15), for this example 1.8 m²/0 .15 = 27 cm²;
calculation of the reinforcement area in each row - the result obtained is divided in half (in the example 27/2 = 13.5 cm²);
determination of the minimum permissible cross-section of a rod depending on the mesh pitch (13.5 cm² / 31 rods every 20 cm for a slab 6 m long = 0.42 cm²;

GOST 5781 contains a table of assortments with reinforcement sections of different diameters. For example, for rod diameters 14 mm, 12 mm, 10 mm, this value will be 1.54 cm², 1.13 cm², 0.785 cm², respectively. Thus, even 10 mm reinforcement provides twice the reinforcement percentage compared to the minimum. Mating is done in the building spot after laying out in rows.

Template for laying reinforcement.

Then it is necessary to correctly calculate the total number of rolled metal products of each diameter. The rods are sold in 11.7 m lengths; the overlap for longitudinal anchoring is 40 reinforcement diameters. The length of the workpiece for each U-shaped clamp is equal to 5 dimensions of the slab thickness, their number coincides with the total number of longitudinal and transverse rods in one mesh. You can convert the length into kilograms using tables from the same GOST, but each construction market has similar conversion tables.

The upper mesh is laid on supports; the most popular in private construction are:

spider - a U-shaped clamp with legs curved in opposite directions;
the supporting frame is a lattice curved at a right angle.

The length of each of them is calculated individually, taking into account 2 pcs/m².

The spider is made of reinforcement with a diameter of 8 mm; such elements must be made in advance for laying the upper mesh.

DWG nodes

Projects

DWG

Nodes in DWG for buildings with load-bearing walls (up to 6 points) (ATR 3.2 2017)

ATP nodes BGB 3.2-2017

Nodes in DWG for buildings with load-bearing walls up to 3 floors inclusive (7, 8, 9 points) (ATR 3.1 2015)

Album of technical solutions and recommendations sheets in the model Album of technical solutions and recommendations with sheets l.17 Fragment plan l.18 Prefabricated floor plan l.19 Monolithic floor plan l.20 Development along the A-axis l.21 Development along the 3-axis l.22 Section 1-1 l.23 Dressing scheme for walls 400 mm l.24 Dressing scheme for walls 500 mm l.25 С-1 for walls 400 mm l.26 С-1 for walls 400 mm l.27 с-1 for walls 500 mm l.28 S-1 for walls 600 mm l.29 S-1 for walls 400 mm l.30 S-1 for walls 500 mm l.31 S-1 for walls 600 mm l.32 S-2 for walls 400 mm l.33 S-2 for walls 500 mm l.34 S-2 for walls 600 mm l.35 S-3 for walls 400, 500 mm l.36 S-3 for walls 600 mm.S-4 for walls 400 mm l.37 S-3 for walls 500,600 mm l.38 S-5, S-6 l.39 S-7 l.40 S-8 l.41 S-9 l.42 S-10 l.43 S- 10 l.44 S-10 l.45 S-11 l.46 S-11 l.47 S-11 l.48 S-12 for walls 400 mm l.49 S-12 for walls 400 mm l.50 S- 12 for walls 500 mm l.51 С-12 for walls 500 mm l.52 С-12 for walls 600 mm l.53 С-12 for walls 600 mm l.54 С-13 section А-А for walls 400 mm l .55 C-13 section A-A for walls 500, 600 mm l.56 C-13 section B-B l.57 C-14 for walls 400,500 mm l.58 C-14 for walls 600 mm. S-15 for walls 400 mm l.59 S-14 for walls 500, 600 mm l.60 S-16 l.61 S-16 l.62 S-17, S-18 l.63 S-19 l.64 S-20 l.65 S-21 l.66 S-22, S-23, S-24 l.67 S-25 for walls 400, 500 mm l.68 S-25 for walls 600 mm. Section A-A l.69 K-1 l.70 K-1 l.71 K-2 l.72 K-3 l.73 Partition fastening diagram

Nodes in DWG for frame buildings (up to 6 points) (ATR 4.2 2015)

Node I

Scheme I-1(m 1k10) Scheme I-2(b-m) Scheme I-Ob-A(m 1k10) Scheme I-Ob-B(m 1k10)

Node II

Scheme II-1-A(m 1k10) Scheme II-1-B(m 1k20) Scheme II-1-B(m 1k10) Scheme II-2-A(m 1k10) Scheme II-2-B(m 1k10) Scheme II-2-B(m 1k10) Scheme II-2-G(m 1k10)

Node III

Scheme III-1 (M 1k10) Scheme III-2-A (M 1k10) Scheme III-2-B (m 1k10) Scheme III-3 (m 1k10) Scheme III-4 (m 1k10) Scheme III-5-A (m 1k10) Scheme III-5-B (m 1k10) Scheme III-6-A (m 1k10) Scheme III-6-B (m 1k10)

Node IV

Scheme IV-1(M 1k10) Scheme IV-Ob-A(m 1k10) Scheme IV-Ob-B(m 1k10) Scheme IV-Ob-B(m 1k10)

Node V

Scheme V-1(m 1k10) Scheme V-2(m 1k10) Scheme V-3(m 1k10) Scheme V-4(m 1k10) Scheme V-5(m 1k10)

Node VI

Scheme VI-1-A (M 1k10) Scheme VI-1-B (M 1k20) Scheme VI-2-A (M 1k20) Scheme VI-2-B (M 1k20) Scheme VI-3 (M 1k10)

Node VII

Scheme VII-1-A(m 1k10) Scheme VII-1-B(m 1k10) Scheme VII-2(m 1k10)

Node VIII

Scheme VIII-1-A (m 1k10) Scheme VIII-1-B (m 1k10) Scheme VIII-2 (m 1k20)

Node IX

Scheme IX-1(m 1k10) Scheme IX-2(m 1k10) Scheme IX-3(m 1k10) Scheme IX-4(m 1k10)

Node X

Scheme X-1-A(b-m) Scheme X-1-B(m 1k10) Scheme X-2-A(b-m) Scheme X-2-B(m 1k10)

Node XI

Scheme XI-1(b-m) Scheme XI-2(b-m) Scheme XI-3(b-m) Scheme XI-4(b-m) Scheme XI-5(b-m)

Knot XII

Scheme XII-1-A(m 1k20) Scheme XII-1-B(m 1k10) Scheme XII-1-B(m 1k10) Scheme XII-1-G(m 1k10) Scheme XII-2-A(m 1k20) Scheme XII-2-B(m 1k10) Scheme XII-3-A(m 1k20) Scheme XII-3-B(m 1k10) Scheme XII-3-B(m 1k10) Scheme XII-4(m 1k20) Scheme XII -5-A(b-m) Scheme XII-5-B(b-m) Scheme XII-5-B(m 1k10)

Node XIII

Scheme XIII-1-A(m 1k20) Scheme XIII-1-B(m 1k10) Scheme XIII-2-A(b-m) Scheme XIII-2-B(b-m) Scheme XIII-2-B(b -m)

Knot XIV

Scheme XIV-1-A(m 1k10) Scheme XIV-1-B(m 1k10) Scheme XIV-1-B(m 1k10) Scheme XIV-1-G(m 1k10) Scheme XIV-2-A(m 1k10) Scheme XIV-2-B(m 1k10) Scheme XIV-2-B(m 1k10) Scheme XIV-2-G(m 1k10) Scheme XIV-3-A(m 1k10) Scheme XIV-3-B(m 1k10) Scheme XIV-3-B(m 1k10) Scheme XIV-3-G(m 1k10) Scheme XIV-3-D(m 1k10)

Details

Part D-1(m 1k1) Part D-2(m 1k4) Part D-3(m 1k2) Part D-4(m 1k4) Part D-5(m 1k1) Part D-6(b-m) Part D-7(m 1k1) Column F-1(m 1k10)

Nodes in DWG for frame buildings (7, 8, 9 points) (ATP 4.1 2015)

Node I

Scheme I-1 (m 1k10) Scheme I-2 (m 1k20) Scheme I-Ob-A (m 1k10) Scheme I-Ob-B (m 1k10)

Node II

Scheme II-1-A(m 1k10) Scheme II-1-B(m 1k20) Scheme II-2-A(m 1k10) Scheme II-2-B(b-m) Scheme II-3-A(m 1k10 ) Scheme II-3-B (m 1k20) Scheme II-3-B (m 1k20) Scheme II-4 (m 1k10) Scheme II-5 (m 1k10) Scheme II-6-A (m 1k10) Scheme II- 6-B(m 1k10) Scheme II-6-B(m 1k10) Scheme II-6-G(m 1k10)

Node III

Scheme III-1(M 1k10) Scheme III-10-A(M 1k10) Scheme III-10-B(M 1k10) Scheme III-2-A(M 1k10) Scheme III-2-B(b-m) Scheme III-3(M 1k10) Scheme III-4(m1K10) Scheme III-5-A(m 1K10) Scheme III-5-B(m 1K10) Scheme III-5-B(M 1k20) Scheme III-6(M 1k10) Scheme III-7 (M 1k10) Scheme III-8 (M 1k10) Scheme III-9-A (M 1k10) Scheme III-9-B (M 1k10)

Node IV

Scheme IV-1 (M 1k10) Scheme IV-2 (M 1k10) Scheme IV-3 (M 1k10) Scheme IV-4 (M 1k10) Scheme IV-5 (M 1k10) Scheme IV-Ob (M 1k10)

Node V

Scheme V-Ob(M 1k10)

Node VI

Scheme VI-1-A (M 1k10) Scheme VI-1-B (M 1k20) Scheme VI-2-A (M 1k10) Scheme VI-2-B (M 1k20) Scheme VI-2-B (M 1k20) Scheme VI-3(M 1k10) Scheme VI-4-A(M 1k10) Scheme VI-4-B(M 1k10) Scheme VI-4-B(M 1k20) Scheme VI-5(M 1K10)

Node VII

Scheme VII-1-A(m 1k10) Scheme VII-1-B(m 1k10) Scheme VII-2-A(m 1k10) Scheme VII-2-B(m 1k10) Scheme VII-3-A(m 1k10) Scheme VII-3-B(m 1k10)

Node VIII

Scheme VIII-1-A(m 1k10) Scheme VIII-1-B(m 1k10) Scheme VIII-2-A(m 1k10) Scheme VIII-2-B(m 1k10) Scheme VIII-3-A(m 1k10) Scheme VIII-3-B(m 1k10)

Node IX

Scheme IX-1(m 1k10) Scheme IX-2(m 1k10) Scheme IX-3(m 1k10) Scheme IX-4(m 1k10)

Node X

Scheme X-1-A(m 1k10) Scheme X-1-B(m 1k10) Scheme X-1-B(m 1k10) Scheme X-1-G(m 1k10) Scheme X-2-A(m 1k10) Scheme X-2-B(m 1k10) Scheme X-3-A(m 1k10) Scheme X-3-B(m 1k10) Scheme X-4-A(m 1k10) Scheme X-4-B(m 1k10) Scheme X-5-A(m 1k10) Scheme X-5-B(m 1k10) Scheme X-Ob-A(b-m) Scheme X-Ob-B(b-m)

Node XI

Scheme XI-1-A(b-m) Scheme XI-1-B(m 1k10) Scheme XI-1-B(m 1k10)

Knot XII

Scheme XII-1-A(m 1k10) Scheme XII-1-B(m 1k10) Scheme XII-2-A(m 1k10) Scheme XII-2-B(m 1k10) Scheme XII-3(m 1k10) Scheme XII -4(m 1k10) Scheme XII-5(m 1k10) Scheme XII-6(m 1k10) Scheme XII-Ob(b-m)

Node XIII

Scheme XIII-1-A(b-m) Scheme XIII-1-B(m 1k10) Scheme XIII-2-A(b-m) Scheme XIII-2-B(m 1k10)

Knot XIV

Scheme XIV-1(b-m) Scheme XIV-2(b-m) Scheme XIV-3(b-m) Scheme XIV-4(b-m) Scheme XIV-5(b-m)

Knot XV

Scheme XV-1-A(m 1k20) Scheme XV-1-B(m 1k10) Scheme XV-1-B(m 1k10) Scheme XV-1-G(m 1k10) Scheme XV-2-A(m 1k20) Scheme XV-2-B(m 1k10) Scheme XV-3-A(m 1k20) Scheme XV-3-B(m 1k20) Scheme XV-3-B(m 1k10) Scheme XV-4(m 1 k20) Scheme XV-5-A(b-m) Scheme XV-5-B(b-m) Scheme XV-5-B(m 1k10)

Knot XVI

Scheme XVI-1(M 1K10) Scheme XVI-2(M 1K10) Scheme XVI-3-A(b-m) Scheme XVI-3-B(b-m) Scheme XVI-3-B(b-m) Scheme XVI-O(m 1k20)

Knot XVII

Scheme XVII-1-A(m 1k10) Scheme XVII-1-B(m 1k10) Scheme XVII-1-B(m 1k10) Scheme XVII-1-G(m 1k10) Scheme XVII-2-A(m 1k10) Scheme XVII-2-B(m 1k10) Scheme XVII-2-B(m 1k10) Scheme XVII-2-G(m 1k10) Scheme XVII-3-A(m 1k10) Scheme XVII-3-B(m 1k10) Scheme XVII-3-B(m 1k10) Scheme XVII-3-G(m 1k10) Scheme XVII-3-D(m 1k10)

Details

Detail MS-1(m 1k1) Detail MS-10(m 1k4) Detail MS-11(m 1k5) Detail MS-12(m 1k5) Detail MS-13(m 1k2) Detail MS-14(m 1k5) Detail MS -15(m 1k5) Detail MS-16(m 1k1) Detail MS-17(b-m) Detail MS-2(m 1k2) Detail MS-3(m 1k2) Detail MS-4(m 1k2) Detail MS- 5(m 1k2) Detail MS-6(m 1k4) Detail MS-7(m 1k5) Detail MS-8(m 1k2) Detail MS-9(m 1k2) Column F-1(m 1k10) Column F-2( m 1k20)

Mounting unit for façade cladding made of bricks to a wall made of aerated concrete blocks. Multi-storey construction DWG | PDF

Partition attachment to frame elements DWG | PDF

Assembly of the partition to the frame elements (solution No. 2) DWG | PDF

Solution for protecting a window unit from blowing DWG | PDF

Solution for installing autoclaved aerated concrete walls for a bathhouse DWG | PDF

Installation of an anti-seismic belt in the attic floor DWG | PDF

Assembly for fastening brick façade cladding to a wall made of aerated concrete blocks using fiberglass flexible DWG connections | PDF

Mounting unit for façade cladding made of bricks to a wall made of aerated concrete blocks using a Z-anchor DWG | PDF

Assembly for fastening brick façade cladding to a wall made of aerated concrete blocks using DWG punched tape | PDF

Node for attaching non-load-bearing partitions to load-bearing walls DWG | PDF

Order of reinforcement and filling

Formwork installation

Reinforcement of floors begins with the installation of formwork. The following requirements are imposed on the formwork: it must withstand the weight of the raw mixture without visually deforming. This is a fairly large load; with a layer of concrete of 200 mm it will be 500 kg per square meter. Therefore, the formwork design must be quite impressive. For panels you can use plywood with a thickness of 18...20 mm, for beams, racks, crossbars you can use timber with a section of 100x100 mm.

You can use professional formwork. Its advantages are that it is designed for high loads; it includes telescopic stands that can withstand significant weight and allow you to adjust the level. This is quite expensive equipment, but now you can find a company that rents out both formwork and racks.

The formwork assembly diagram is easy to find in the literature, and if you take professional formwork, then instructions are attached to it. The main thing is to check the horizontal position after assembly using a level or other available means.

Installation of fittings

Plastic clamps are necessary to create a protective layer of reinforcement in the lower part of the ceiling.
The reinforcement is done in this way: we lay the bottom row on clamps - special plastic supports 25-30 mm high to create a protective layer. We place the rods with the same spacing, parallel to each other. We place the next row on them at an angle of 90? and tie with knitting wire at each intersection. Then we install the mesh separators, bend them, and tie them with the same spacing. The drawing given here will tell you which one. The reinforcement of the floor at the edges is supplemented with reinforcements. Longitudinal and then transverse reinforcement bars are laid on the separators and U-shaped reinforcements. The upper level of the finished reinforcement should be 25-30 mm below the upper plane of the formwork. The assembled reinforcement should be a fairly rigid frame that can withstand the weight of a person without much deformation.

Fill

After the reinforcement is completed, you can begin pouring. This work is best done using a concrete pump, making sure to compact the mixture using a special deep vibrator. It is advisable to fill it in one go. As concrete hardens, it shrinks. The faster the drying, the greater the shrinkage, which can lead to the appearance of microcracks. To prevent this from happening, you need to wet the surface of the hardening slab with water for 2-3 days. This is best done by spraying. But you shouldn’t pour it on a rainy day either; it is recommended to protect the fresh mixture from precipitation. The slab must dry for 30 days, only after which the formwork can be removed.

An example of reinforcement of a house floor slab 6 x 6 m

The thickness of the monolithic concrete floor is calculated from a ratio of 1 to 30 in relation to the span length. If the span exceeds 6 m, load calculations must be carried out by specialists. Therefore, you can consider a reinforcement device for a house with a 6 x 6 m floor - for such parameters you can use standard solutions:

We use reinforcement with periodic profiles of grades A-III, A400 or A500.
The span refers to the distance between the walls on which the ceiling rests. If it is rectangular, then the span is calculated along the short side.
We lay the bottom row of reinforcement along the span, the diameter of the rods is 12 mm. Since the parameters of a 6 x 6 house are indicated along the axes, the length of the rods will be 6 m each for a brick (stone, monolithic) house. If the walls are made of porous blocks, then the overlap of the reinforced mesh on the walls should be at least 20 cm. We calculate it based on brick walls. The distance between parallel reinforcement for all mesh layers is 20 cm.
We place 30 mm high crackers under it, providing a lower protective concrete layer.
The next row is the lower transverse one, the diameter is the same.
We tie with wire with a diameter of 0.8 - 1.4 mm at all intersections.
Mesh separators are installed on the lower mesh. You can make them yourself from similar fittings. The step of the stands is also arbitrary - the upper mesh should not sag when a person’s weight is applied to it. After the final installation of the frame, you can add stands if necessary.
The upper transverse reinforcement is placed on the dividers and connected to them.
Next is the top layer of reinforcement along the span. The diameter of the rods is 8 mm. Connects at all intersections.
At the ends of the frame along each row, U-shaped reinforcement products are installed, connecting the top and bottom of the frame into a single structure.

Thus, for a monolithic floor reinforcement device you will need:

reinforcement with a diameter of 12 mm – 372 m;
on the upper mesh - 8 mm reinforcement - 372 m;
for the manufacture of mesh separators and U-shaped elements, the need for 8 mm reinforcement is approximately 10% of the total length of all rods - 75 m.

You can make complementary frame elements yourself using a simple pipe bender, or buy them as finished products. You can convert the length to weight using the tables, and also when purchasing reinforcement, it is sold by weight. Reinforcing the main mesh for a 6 x 6 m monolithic slab is usually not required.

General recommendations for reinforcement

In order to carry out high-quality reinforcement of a concrete structure, general rules must be followed, taking into account construction technology and the properties of the materials involved. In private construction, they are often neglected, without accurate calculations and drawing up a detailed design, since one- and two-story houses do not place serious loads on the foundation. The reinforcement is laid according to schemes already used earlier, which saves time. In such cases, it is sufficient to comply with the minimum requirements specified in SNiP.

A monolithic reinforced foundation has a sufficient level of strength for the construction of multi-story structures. True, to create the foundation for a high-rise building, a more complex technology is used, which involves the use of several types of reinforcement, accurate calculations of slab dimensions and soil characteristics.

Reinforcement of a monolithic slab

Features of the work are as follows:

all actions are carried out after installation of the formwork;
Between the lower and upper reinforcing mesh, separators are laid - vertically located elements. In private construction, the term “putting reinforcement on a stool” appears. They help maintain an equal distance over the entire surface. To do this, you can use loops, bent hooks or purchased metal parts;
At the edges and in places of support, the overlap is reinforced with L-shaped and U-shaped elements. If the slab is supported along the entire perimeter, reinforcement is carried out along the entire contour;
the main tensile load is transferred to the bottom layer of reinforcement, that is, it must be thicker than the top;
The greater the distance between the supports (span), the stronger the slab should be. the optimal distance between spans is up to 6.0 m;
if the distance is not maintained, the upper reinforcement belt must be reinforced directly above the support, and the lower one in the middle between the supports;
it is good if the rods are inseparable. When using individual elements, the amount of overlap is calculated as follows: 40*d (rod diameter). For example, for reinforcement 10.0 mm in diameter, the overlap is 400 mm;
The recommended diameter of the rods is 8-14 mm.

Reinforced concrete slabs help reduce loads on foundations and wall structures, allowing for additional economic benefits

Taking into account all the recommendations presented, we can understand the following. For arranging a living space with a span of up to 6.0 m, with support along the contour, we can recommend a slab thickness of 20 cm, with a reinforcement pitch of 20x20 cm, with d rods of 12.0 mm for the lower chord and 8.0 mm for the upper . Reinforcement of a monolithic floor slab (dwg drawing) can be done with your own hands.

Laying reinforcement in the pit

Many owners prefer to carry out all reinforcement work directly in the prepared pit. This is, of course, advisable if you look at it from the point of view of saving time. This way you won’t have to move the prepared reinforcement structure from the work site and lay it in the foundation.

But such operations often damage the compacted pad and the waterproofing of the base itself, allowing moisture from the soil to gradually destroy the entire foundation of the structure.

It is better to lay the prepared lower chord with connected supports in a pit, and there, in place, make a solid frame, connecting the upper ends of the supports and the outer reinforcement belt.

In this case, before laying the lower chord, it is worth equipping the sides of the pit with formwork so that the reinforcement is immediately carried out firmly. And the metal frame of such a foundation will not require additional modifications in the form of alignment or displacement.

The principle of operation of reinforcement in the ceiling

Monolithic structures are most often used in the construction of various types of beams. The ceiling is the same beam, but wider and thinner. The calculation of such a structure is carried out in a section along a given span. The upper part of the slab is compressed in the span. The lower part is stretched. The load-bearing lower reinforcing rod prevents the slab from collapsing. On supports, everything works the other way around. If the support of the slab on the supports is not pinched, then the tension above it is insignificant.

The task of designers and performers of floor slab reinforcement is to involve the majority of the structure in the work to ensure resistance to the slightest deformation. This is a general simplified principle of operation of a reinforced frame in a monolithic floor. Sometimes a simple understanding of this principle is enough for high-quality production of a floor frame in a small private house.