Monolithic ceiling on metal beams. Do-it-yourself monolithic ceiling Installation of monolithic floor beams

Monolithic beam ceilings are made in the formwork from monolithic concrete at the construction site, with mandatory reinforcement.

By design, such overlaps are:

Ribbed (consisting of main beams (girders) and auxiliary beams with a monolithic slab;

Caisson in the form of a system of intersecting beams of the same section, monolithically connected to the slab.

Beamless, representing a solid monolithic slab supported on columns with thickened capitals.

Spans between monolithic beams 3-6m (without beam ceilings up to 3m). Thickness 60-100m.

If the main and secondary beams have the same height, then such an overlap is called coffered.

Main disadvantage:

labor intensive

Non-industrial (long lead times)

Beamless ceilings are used for frame buildings with a grid of columns 5 * 5 or 6 * 6; they can be monolithic and prefabricated based on the gimps of the columns.

Figure 3. Monolithic reinforced concrete floors

a- ribbed; b - caisson; c - beamless; 1-plate; 2-auxiliary beams; 3-main beams (girders);

4-columns; 5-cross beams; 6-capital

a) monolithic beamless floors

b) prefabricated beamless ceilings

Theme: Hardwood floors

Wooden floors are mainly used in low-rise buildings and in areas where wood is a local material. This type of overlap is simple in design and has a relatively low cost. The disadvantages of wooden floors include their insufficient durability, flammability, the possibility of decay and relatively low strength.

Wooden floors consist of beams, which are the supporting structure, inter-beam filling, floor structure and ceiling finishing layer (Fig. 1).

Beams (Fig. 2) are made mainly in the form of rectangular bars, the dimensions of which are established by calculation. Most often, the height of the beams is 130, 150, 180 and 200 mm, and the thickness is 75 and 100 mm. The distance between the beams (along the axes) is usually 600 ... 1000 mm.

To support the inter-beam filling, the so-called cranial bars with a section of 40 x 50 mm are nailed to the sides. The depth of support of the ends of the beams in the nests stone walls take 180 mm (Fig. 3, a). Between the end of the beam and the masonry, it is necessary to leave a gap of at least 30 mm so that there is no contact with the masonry and moisture evaporation from the beam is ensured. The ends of the beams are antiseptic with a 3% solution of sodium fluoride to a length of 750 mm, and the side surfaces of the ends of the beams are pasted over with roofing paper in two layers on the resin. To enhance rigidity and stability, the ends of the floor beams are anchored into the walls. A steel anchor is attached to the beam at one end, and the other end is embedded in the masonry.

When supporting beams on internal walls(Fig. 3.6) their ends are antiseptic and wrapped with two layers of roofing paper. The gap between the beams and the walls of the nests is also recommended to be filled with mortar for fire and soundproofing reasons.

The filling between the beams (see Fig. 1) consists of a shield roll, lubrication on the top of the roll with a clay-sand mortar 20 ... 30 mm thick and a sound-proof slag layer. In the attic and basement floors, the backfill is thermal insulation and its thickness is determined by heat engineering calculation.

The construction of the floor on a wooden floor consists of a plank flooring made of planed tongue-and-groove boards, nailed to the logs of plates laid across the beams through 500 ... 700 mm. If the floor is parquet, then the flooring is made of unplaned boards (black floor). Due to the presence of a lag under the floors, a continuous air gap is created under the entire area of the room, which communicates with the air of the room through rooms arranged in the corners. ventilation grates. This ensures ventilation of the underground space and removal of water vapor from it. To reduce the height of the ceiling, the floor is often laid directly on the beams. However, the absence of a lag worsens the sound insulation of the floor.

The lower surface of the wooden floor, which forms the ceiling, is upholstered drywall sheets or plaster over a layer of shreds. For this, lime-gypsum mortar is most often used.

Reinforced concrete floors are used in cottage and industrial construction, they serve as a ceiling for the lower floor and a floor for the upper one. There are two types of reinforced concrete floors: monolithic and prefabricated. Monolithic ones are made directly at the construction site; after pouring, they represent a single horizontal plane. Prefabricated - assembled from factory plates, which are mounted one after the other, the gaps are filled with mortar, the result is a monolithic surface. The length of the plates produced ranges from 2 to 7.2 m, width from 0.8 to 2 m, height up to 22 cm.

Advantages and disadvantages

Monolithic reinforced concrete floors are one of the most reliable and versatile. Their advantages include:

High bearing capacity.
Long service life. In the first 50 years, concrete is only gaining strength, such panels can serve several generations of people.
Possibility of pouring ceilings of any size and shape. The only condition for large rooms is the installation of additional supports.
Fire safety. Concrete does not burn and does not contribute to combustion.
No seams or transitions.
The thickness is less than that of finished boards.

Flaws monolithic floor:

Device complexity. The need to use specialized equipment, which greatly complicates the possibility of self-arrangement.
Heavy weight exerts a strong load on the walls and foundation, which makes it impossible to use in some buildings (wooden houses).
Seasonality of work. At temperatures below 5°C, it is necessary to use antifreeze additives, which significantly increases the cost of the process.
Fill continuity. It is not recommended that "old" and "new" concrete meet, this can lead to cracking.

Often at construction sites they use ready-made ones. These floors have their advantages:

Factory reinforced concrete slabs construction material The used for the overlay.

Comparative cheapness.
Mounting speed.
Strength and durability.
Ease of installation. The slabs can be laid by a truck crane with the help of several slingers.
Noise isolation. The voids in the slabs reduce the noise level.
Reliability. Plates are manufactured in the factory, which guarantees quality.

Disadvantages of precast concrete floors:

The need to attract lifting equipment.
A lower level of rigidity in comparison with a monolithic overlap.
The presence of spans between the plates, which requires additional finishing.

Types

Depending on the principles of the device, reinforced concrete floors can be of several types:

ribbed;
caisson;
beamless.

Pouring a monolithic floor will help reduce the amount of concrete used, reduce pressure on the foundation, walls. It is usually used for arranging industrial buildings when it is necessary to fill large spans.

This monolithic ceiling includes a slab and beams running along it (they can go in one or two directions). There are main beams, which are based on columns, walls, and secondary ones, based on the main ones. The slabs rest on secondary beams. The ribs of the plate lie on the walls or columns. The width of the slabs is from 1.8 to 2.8 m, this allows you to make slabs of minimal thickness (5-8 cm). It should be noted that the installation of formwork for such a structure is more difficult than when pouring flat slabs, and the ceilings are ribbed and require plasterboard sheathing. The thickness of the ribbed floor is 5-6 cm less than usual. The device of floors with ribbed monolithic slabs is 2 times more profitable than the usual one.

Scheme of the caisson floor.

When pouring large areas, coffered ceilings are also popular. In such a ceiling, the beams are placed in two directions (perpendicularly) with a step of up to 1.5 m, a monolithic concrete slab is located on top. The beams must have a height of at least 1/20 of the span, the thickness of the slab must be from 4 cm.

The lightness of the reinforced concrete slab is given by voids between the ribs, which are formed with the help of plastic void-forming molds that perform the function of a removable or fixed formwork. The device of the coffered floor allows you to save up to 55% of the material in comparison with flat slabs. Caisson slabs are also called often-ribbed, often-beamed, or waffle monolithic slabs.

Beamless ceilings are made in rooms with large uniform loads and when they want to get smooth ceilings, convenient for mounting overhead vehicles, wiring communications. It can be multi-storey warehouses, refrigerators, meat processing plants. Beamless ceiling is a flat reinforced concrete continuous panel. It rests on columns or mushroom-shaped capitals. The peculiarity of this design is that the load is transferred through the panel directly to the columns. The grid of columns is made in a square or rectangular shape with a step of 6 m. At the top, the columns expand, forming capitals. Beamless design has a number of advantages: sanitary indicators are improved, room ventilation is facilitated, communications are simplified, the area requiring additional finishing is reduced (ceilings are smooth), the ceiling height is lower than when using ribbed or coffered structures, which saves on building maintenance (heating , cooling).

Manufacturing technology

For pouring monolithic structures, it is necessary to prepare the following materials: reinforcement, cement (grade from M-400), crushed stone, sand, apparatus for welding reinforcement, boards for formwork, power tools (for cutting boards, reinforcement). When the material is ready, you can start assembling the formwork, its bottom can be made of boards 3-4 cm thick, or waterproof plywood 2 cm thick, boards 2-3 cm thick are used for the side walls. If the panels are with slots, they must be covered with a film , this will prevent the solution from escaping.

The first thing to do is to lay the bottom shields; cross beams and supports are used for installation. The distance between the uprights (supports) is 1-1.2 m. After that, the side walls are mounted. The formwork must be strong, be set strictly horizontally, the bottom can be covered with a film or roofing material, this will give a smooth surface, remove minor unevenness of the boards.

The calculation of reinforcement in reinforced concrete floors should be carried out by a specialist. It is advised to use reinforcement with a diameter of 8-14 mm (depending on the expected loads).

Reinforcement is carried out in two balls, the lower one is installed on plastic supports. A mesh is made from reinforcement in increments of 150-200 mm. The reinforcement is attached to the grid with soft wire. The fittings are taken in one piece, if the length is small, then an additional piece is attached with an overlap equal to 40 times the diameter of the rod. The joints are placed in a checkerboard pattern. The meshes are connected at the edges with U-shaped reinforcements. The frame after pouring must be hidden with a concrete ball from 2 cm.

Additional reinforcement is carried out depending on the pour area. It is made by separate pieces of reinforcement 40-200 cm long. The lower mesh must be strengthened in the opening, the upper mesh above the bearing walls. In places of support on columns, reinforcement requires separate volumetric reinforcing elements.

For pouring floors, concrete grade M400 is used (1 part concrete, 2 - sand, crushed stone -4, water). Concrete is poured into the formwork, starting at one corner and ending at the opposite. When laying, you need to use a deep vibrator, this will help remove voids from the concrete. A reinforced concrete slab is poured without interruption, 8-12 cm thick. After pouring, the surface is leveled with devices similar to mops.

The formwork can be removed 2-3 weeks after pouring, then the slab gains 80% of its strength. If the formwork is removed earlier, then the supports are left. The plates can be used after 28 days (after complete drying). To avoid drying out and the appearance of cracks, the first week after pouring, the concrete should be regularly moistened and watered. Sometimes the surface is covered with burlap or film to further retain moisture.

Monolithic reinforced concrete floors are still of limited use due to their high labor intensity. They are used in cases where it is necessary to cover an atypical room with atypical dimensions, as well as in monolithic buildings.

Monolithic floors are made of beams (ribbed) and beamless in the form of a smooth slab (Fig. 5.4).

Fig.5.4. Structural schemes of monolithic reinforced concrete floors:

a - ribbed; b - caisson; in - beamless; 1 - plate; 2 - beams; 3 - columns; 4 - column capital

5.1.4. Ceilings by beams

Beam ceilings are used in low-rise construction (in wooden and stone buildings), in the reconstruction of old buildings by replacing wooden beams with more durable metal or reinforced concrete ones.

According to the material, the beams are divided into wooden, reinforced concrete and metal.

Ceilings on reinforced concrete beams. Ceilings on reinforced concrete beams consist of beams laid on load-bearing walls with a distance in the axes of 600, 800, 1000 mm, inter-beam filling and floor (Fig. 5.5).

The depth of support of the ends of the beams on the walls or girders is taken at least 150 mm. The ends of the beams on the supports are anchored, and the gaps between the beam and the nest walls to a depth of 40-60 mm are sealed with mortar. Inter-beam filling (Fig. 5.6) consists of a run-up, which is a flooring of lightweight concrete slabs and a soundproof (heat-insulating) layer. The seams between the rolling elements and the beams are carefully filled with mortar or glassine is laid on top of the rolling. Soundproofing is usually performed from a layer of slag or sand with a thickness of at least 60 mm. From below, the roll and beams are rubbed with mortar. This design is used for plank floors along the logs. When installing other types of floors, such as cement, requiring a continuous gesture

Fig.5.5. Prefabricated reinforced concrete beams and details of their support:

a - plan for the location of floor beams; b - general form beams; 1 - beam;

2 - steel anchor; 3 - steel structure; 4 - mounting loop; 5 - concrete embedment

After some preparation, the space between the beams is filled with slag, along which a layer of cinder concrete with a thickness of at least 40 mm and a floor are laid (Fig. 5.6d). More appropriate in these cases are rolls of double-hollow lightweight concrete stones - liners that have sufficient soundproofing properties and require only careful filling of the joints with mortar (Fig. 5.6 e).

Ceilings on metal beams. Currently, metal beams are used only in exceptional cases in the repair and reconstruction of buildings.

Steel beams (usually I-beams) are located at a distance of 1-1.5 m from each other. The depth of support of their ends on the walls is 200-250 mm.

Fig.5.6. Prefabricated beam construction

reinforced concrete elements:

a - general view; b - lightweight concrete slab; c - lightweight concrete stone insert; d, e - floor options with mineral floors; 1 - reinforced concrete beam; 2 - reel from lightweight concrete slabs; 3 - waterproofing layer; 4 - sound insulation; 5 - soundproof gasket; 6 - log; 7 - plank floor; 8 - slag; 9 - slag concrete thickness

40 mm; 10 - cement floor 20 mm thick; 11 - grouting with mortar

To increase the area of pressure on the masonry in order to protect it from collapse, concrete pads or steel linings are placed under the ends of the beams. The ends of the beams are anchored into the masonry of the walls and, if necessary, insulated with felt, followed by sealing the gaps around the perimeter of the nest with concrete (Fig. 5.7).

Inter-beam filling can be made of reinforced concrete prefabricated or monolithic slabs, and in some cases from brick vaults.

Fig.5.7. Ceiling construction on steel beams:

a - supporting the ends of the beams on the walls; b - anchor fastening detail; c - overlap with filling with a reinforced concrete monolithic slab; g - the same, brick vaults;

1 - steel beam; 2 - steel anchor; 3 - concrete pad; 4 - bolt; 5 - sealing with cement mortar; 6 - reinforced concrete monolithic slab; 7 - lightweight concrete; 8 - ceramic tiles over a layer of cement mortar; 9 - brick vault; 10 - soundproof layer; 11 - two layers of roofing; 12 - plank floor along the logs; 13 - steel mesh; 14 - plaster with cement mortar

Ceilings on wooden beams. At present, wooden floors are allowed only in low-rise buildings and only in areas where wood is a local building material. Their advantages are the simplicity of the device and the relatively low cost. Disadvantages - combustibility, the possibility of decay and relatively low strength.

All wooden floor elements are made from coniferous forests (pine, larch, spruce, etc.). Beams are made mainly in the form of rectangular bars, the dimensions of which are established by calculation. (Fig. 5.8). The distance between the axes of the beams is taken from 600 to 1000 mm.

To support the inter-beam filling, bars with a section of 40 x 50 mm, called cranial, are nailed to the sides of the beams (Fig. 5.8). The depth of support of the ends of the beams in the sockets of the stone walls must be at least 150 mm (Fig. 5.9). The ends of the beams are antiseptic with a 3% solution of sodium fluoride or coated (except for the ends) with resin, and when embedded in the outer walls, they are additionally wrapped with two layers of roofing paper. On internal walls or girders, two layers of roofing felt on tar mastic are laid under the ends of the beams. The gaps between the walls of the nest and the ends of the beams to a depth of 40-60 mm are tightly sealed with mortar. The location of the wooden floor beams, as well as their anchoring, are similar to reinforced concrete beam-type floors (Fig. 5.1 c).

The filling between the beams (Fig. 5.10) consists of a board board run, lubrication on the top of the run with a clay-sand mortar 20-30 mm thick and a soundproof layer of slag or calcined earth 60 mm thick. The floors are made of boards along the logs with the device in them at the corners of the premises of metal ventilation grilles. Ceilings are plastered with lime-gypsum mortar along the strips or hemmed with sheets of dry plaster.

Fig.5.8. Structural solutions of wooden beams:

1 - bar single beam; 2 - beam composite of two bars of solid wood; 3 - a beam of glued wood; 4 - cranial bar

Rice. 5.9. Details of supporting wooden floor beams on

stone walls:

a - on outer wall; b - on the inside; 1 - external load-bearing wall; 2 - external self-supporting wall; 3 - internal load-bearing wall; 4 - wooden beam; 5 - thermal insert; 6 - two layers of roofing paper on tar mastic or antiseptic zone of the beam; 7 - an anchor made of strip iron; 8 - crutches or nails

Fig.5.10. Floor construction on wooden beams:

a - with a plank shield roll; b - the same, from hollow blocks; c - the same, from lightweight concrete blocks (slabs); d - floors in bathrooms; e - types of rollovers; 1 - beams; 2 - reel (shield); 3 - plaster; 4 - clay lubricant; 5 - backfill; 6 - log; 7 - soundproof gasket; 8 - plank floor; 9 - hollow lightweight concrete block; 10 - cranial bar; 11 - solution; 12 - gypsum board; 13 - ceramic tile floor; 14 - cement screed 20 mm; 15 - concrete preparation; 16 - two layers of roofing material on mastic; 17 - plank floor; 18 - plates; 19 - boards; 20 - false ceiling

In this article we will talk about what are the methods of erecting a monolithic floor, and you will also learn about the advantages and disadvantages of these methods. The article will talk about the basic requirements for the thickness and reinforcement of reinforced concrete floor elements.

Reinforced concrete is an almost eternal material. It creates a multitude structural elements- beams, walls, lintels. One of the most difficult, at first glance, products is overlapping. However, the complexity of the construction is fully offset by the operational properties of the finished product.

Advantages of a monolithic floor:

The highest load-bearing capacity of known materials.
The most durable of widely available materials.
Relatively cheap raw material (for concrete).
To perform the work, high qualification of the entire team is not required (1-2 leading specialists are enough).
Combined functions: the base of the floor of the second floor, the armored belt, the connection of all walls to each other.
Properly arranged monolithic construction eliminates the appearance of deformation defects ("steps", distortions, cracks).

Disadvantages of concrete floors:

Labor intensity of construction. The work is connected with the installation of horizontal formwork of high strength and rigidity.
Accompanying material is involved, which after concreting may become unusable - plywood, flanging board, racks (wooden).
The heavy weight of the structure requires powerful walls and a foundation.
High thermal conductivity of concrete - all areas open from the outside must be insulated.
Concrete flooring is possible only on stone walls.

Reinforced concrete floors are suitable for permanent buildings designed for a long service life, as well as for premises that provide for a significant static and dynamic load - workshops, hotels, hostels (with partitions made of stone material).

In private construction, monolithic floor slabs are usually arranged along brick walls, since concrete walls are much more difficult to erect than brick ones.

The thickness of the monolithic slab

Due to the big specific gravity concrete (2400 kg / m 3), products from it are heavy. The mass of the product can be reduced by reducing the part of the concrete in the structure, that is, simply making it thinner. Rigidity is compensated by reinforcement. Sufficient thickness of reinforced concrete elements:

load-bearing walls - 160 mm
floors - 200 mm
partitions - 100 mm

The thickness of these elements will be considered sufficient only if the rules of reinforcement are observed. Calculations and many years of practice have shown that there is an optimal balance of mass, volume, cross section and bearing capacity w / w elements. Read about this below in the section "Reinforcement of floors". Sufficient thickness brick wall- 380 mm (1.5 bricks).

Floor formwork

Like any reinforced concrete element, the ceiling requires the installation of a form for concrete - formwork. Since the ceiling has a significant area and is at a height, the formwork for it has the form of a table: a solid plane that fills the space between the bearing walls (and columns) on a spatially rigid frame of racks and slopes. There are three types of formwork, but one requirement is invariable for any of them - a reliable foundation.

Inventory formwork

Factory kit, which includes:

Racks - screw retractable jacks, up to 4 m long.
Equipment for racks - “tripods” at the bottom for the stability of a free-standing jack and a “crown” at the top for landing table beams.
wooden beams- factory glued products of an I-profile with a height of 200 mm and a length of up to 4.2 m.
Laminated plywood - sheets of plywood 18-24 mm thick, 1220x2440 mm in size, covered with a stable film, designed to create a floor plane. The coating withstands up to 40 concreting cycles.

Such a set is professional - high-rise residential buildings are built with inventory formwork. It is reliable, comfortable and designed for continuous use. The purchase of a set for the installation of one floor will not justify itself - all steel products are not cheap. Formwork rental can be a solution. The company's specialists will calculate required amount each of the elements for your object.

The undoubted advantages of this approach are the speed of formwork installation and ease of use, as well as the quality of the plane. The disadvantages include the risk of delaying the lease term.

Homemade formwork

All elements of the "table" for overlapping can be made independently from wood and some metal parts.

This method is used when the main elements - racks, beams and plane material (plywood or board) are available. This is the main advantage of the method - the use of improvised material. Obvious disadvantages:

Labor-intensive construction requiring advanced carpenter skills.
Large waste of material - up to 20% will become unusable.
Problematic height adjustment (“horizontal” installation).

Combined method

It provides for the partial use of inventory formwork elements and lumber.

In this case, you can use the factory racks with tripods and crowns, and make the beams and formwork flooring from the board. Or rent laminated plywood, and assemble the frame of the "table" from the wood at hand. There can be many combinations.

Floor reinforcement

For the installation of a reinforcing cage of a hanging reinforced concrete floor with a thickness of 200 mm, a mirror mesh of reinforcement A3 Ø 16 mm with a cell of 150-180 mm is used. When using concrete prepared on site, we recommend reinforcing the frame by using a smaller rod spacing of 150 mm. If the concrete is factory, a step of up to 200 mm is allowed. In places of support and junction of elements (support on a wall, column, capital), we recommend making reinforcements - adding rods.

Floor concreting

There are concreting rules that must be observed unquestioningly so as not to subject the structure to destruction in the future:

The laying of concrete in the ceiling must be done in one go. If the concrete is not placed for a long period of time, the laid concrete may seize and the new concrete will not be able to mix with it. The result is a boundary along which a crack can go.
When concreting in a cool period (0...+5 °C), use special anti-frost additives. Read more about winter concreting in this article.
Be sure to use vibrators - deep or surface. Without vibration, concrete has 40-50% of the design strength. You will find more information about concreting in our article.
The ceiling formwork is dismantled no earlier than 28 days after concrete is laid.

reinforced concrete slabs, monolithic ones are also popular among private developers. Their advantages include not only the solidity and durability inherent in the same plates, but also the ability to cover rooms of any configuration. At the same time, the disadvantages include a large mass of plates, requiring a reinforced base and wall materials of increased strength, and the need to assemble the formwork. Therefore, many self-builders, including the craftsmen of our portal, prefer a lightweight variety - monolithic ceilings on a profiled sheet, which will be discussed in the material. Consider:

What is a monolithic overlap on a profiled sheet.
Technology of the device of steel-reinforced concrete floors.
The experience of the portal participants in the installation of unsupported monolithic ceilings according to the profiled sheet.

Monolithic overlap on a profiled sheet

Initially, NIIZhB (Research Institute of Concrete and Reinforced Concrete) of the USSR State Construction Committee developed a method for pouring monolithic reinforced concrete floors with steel (SPN) for industrial buildings and structures. The first recommendations for the design of monolithic reinforced concrete floors with SPN were developed in 1987, after almost two decades, STO 0047-2005 appeared, in fact, slightly updated version first option. However, for those who want to understand the technology and make calculations on their own, without resorting to the services of a pro, our old-timers are advised to first study the training manual from the Land of the Soviets.

Yury

If you want to understand without extra costs, read the recommendations for the design of monolithic reinforced concrete floors with steel profiled decking, NIIZhB, 1987.

The essence of the technique lies in the fact that the corrugated board serves both as an external reinforcement of the plate, as well as the finishing layer.

When talking about industrial premises, such exterior finish more than enough. According to the developers of the service station, lightweight ceilings along the profile, compared to a conventional monolithic slab, have a number of advantages:

Reducing the amount of steel on beams - by 15%.
Reducing labor costs - by 25-40%.
Reducing the mass of the plate - by 30-50%.
Increasing the rigidity of floors (to horizontal loads).
Simplification of communications wiring - placement of highways in corrugations.
The absence of wooden formwork - an increase in the speed of work.

The use of steel-reinforced concrete floors in the construction of industrial and private buildings is permissible under the following basic conditions:

slightly aggressive and non-aggressive operating environment;
humidity conditions up to 75%;
the temperature in the room is not higher than + 30⁰С;
used concrete without potassium chloride and other chlorine-containing additives.

That is, the main contraindication to this type of flooring is high humidity, which is why they are usually used as interfloor and are not used between the basement and the first floor or the basement and the first floor.

al185 FORUMHOUSE Super Moderator

The profiled sheet in the base will rot, who are interested in the timing, look with a search. On the protection of the wheel arches, galvanized self-tapping screws rust in a couple of months.

For pouring slabs, it is allowed to use both heavy and light concretes, but the compressive strength class for heavy concrete on fine-grained aggregates is from B15 (M200), for lightweight concrete on porous aggregates - from B12.5 (M150). The minimum layer of concrete above the profile flooring is 30 mm, if a finishing screed is provided, if without a screed - from 50 mm. The flooring is made of load-bearing profiled sheets (H), with a corrugation height of 44 mm.

For the reinforcing cage, reinforcing bars of a periodic profile, class A-III, and class Bp wire are used. If it is planned to overlap with a stairwell, then it is necessary to reinforce the reinforcing cage around the perimeter and install side formwork. Steel beams of the load-bearing frame are either rolled or composite profiles.

Technology for the installation of steel-reinforced concrete floors

In the original version, the profiled sheet is laid not only on the walls, but also on the frame of steel beams (girders), which is the carrier. The number and parameters of the beams are calculated individually, based on the dimensions of the overlapped span and the expected loads, the average step is from 1.5 to 3 m, but each sheet should have three support points - in the center and along the edges. Single-layer reinforcement - mesh, wire diameter from 3 mm, pitch 200 × 200 mm, thickness of the protective layer over the mesh is at least 15 mm.

Profiled sheets are laid across the long side of the span, with wide corrugations down, along the length on the overlap runs, at least one wave, butt-to-width. Between themselves, the waves are fixed with rivets or self-tapping screws with a step of no more than 500 mm. In order for the profile and runs to work as one system, the flooring is fixed with rod anchors that are welded to the beams. Next to the load-bearing walls, the anchor must pass through each wave, on intermediate beams through one. In addition, the flooring is fixed to the beams by means of self-tapping screws or dowels.

However, the use of steel beams is not the most attractive option for self-builders, so many of the craftsmen of our portal prefer Alternative option- unsupported monolithic overlap along the profile sheet.

The experience of the portal participants in the installation of unsupported monolithic ceilings according to the profiled sheet

winder

Overlapping along a profiled sheet can be without I-beams or channels.

Instead of a frame, a bearing profiled sheet is used with a wave height of 60 mm or more, a thickness of 0.7 mm, and reinforced reinforcement - lower, upper, transverse and mesh. In this case, the profiled sheet is fixed formwork, and the main load is taken by the reinforced reinforcing cage. The sheets are laid with a narrow corrugation down and, just as in the method with beams, they are oriented in waves across the long side of the span. It turns out a kind of ribbed monolithic overlap, only the ribs are formed not by removable formwork, but by corrugations. Unlike a steel-reinforced concrete slab supported by beams, this slab is not recommended to be poured with lightweight concrete, and the compressive strength class should be increased to B22.5 (M300).

winder

It is reinforced concrete that holds the load, neither foam concrete nor expanded clay concrete have the necessary strength. Strengthening the reinforcement in this case is useless.

When pouring, be sure to thoroughly vibrate the solution. If necessary, props are placed from below, which are removed after the concrete has gained strength.

One of our craftsmen decided to use the profiled sheet not only as a formwork, but also as an additional power frame.

worodew

I make a monolithic ceiling according to the H75 profiled sheet, 0.7 mm thick. In order not to lose its bearing capacity, after pouring, I decided to include it in joint work with concrete. I did this: with a puncher (drill 6 mm) in each ridge I punched holes every meter and inserted pieces of wire 6 mm thick, 10 mm long into them, and instead of stars I put and tied reinforcement on it, plus a mesh on top. Even stiffness has increased, I compare before and after knitting reinforcement.

Spans of 3.6 and 2.0 m, in a wave reinforcement 12 mm, on top - a wire mesh 5 mm thick, with a cell of 100 × 100 mm. From below, the waves were closed with gas block trimmings and sealed the cracks mounting foam, one bottle was enough for 70 m². The flooring rests only on the outer walls and on bearing wall in the middle. The slab was poured with a concrete pump, the ceiling thickness was 130 mm, the area was 76 m², about 7 m³ of mortar (M300) was taken. After a few hours, it was possible to cut off the bumps, focusing on the rule, the next day I moistened the slab and polished it.

The underfloor heating system is usually mounted in a finishing screed, but if desired, you can combine a warm floor and a monolithic ceiling along a profiled sheet.

Toha71

Is it possible to install TP pipes directly into the poured slab? Will the presence of TP pipes in it not weaken such an overlap? And if possible, how much thickness to add under the 20 pipe? As I understand it, the TP must be placed between the layers of reinforcement so that the top layer of reinforcement in concrete is not “drowned” for its normal operation? I would like to try once and pour the concrete evenly so that only the finishing self-leveling floor remains and you do not have to load the slab with an additional screed.

The method has the right to life, subject to an increase in the thickness of the overlap and the presence of certain experience.