Installation of wooden and monolithic floors. Reinforced concrete floors. Floors on metal beams

In this article we will look at the main types of floors and the materials from which these floors are constructed. So, what are overlaps? Floors are a structure that divides adjacent rooms in height, that is, it forms floors and separates them from attics and basements.

Basic requirements for floors

The floors must have sufficient strength to withstand the load both from its own weight and useful (furniture, equipment, people in the room, etc.).The value of the payload per 1 m2 of flooring is set depending on the purpose of the room and the nature of its equipment. For attic floors, the payload should be no more than 105 kg/m2, and for basement and interfloor floors 210 kg/m2.
The ceiling must be rigid, that is, under the influence of loads it must not deflect (the permissible value is from 1/200 for attic floors to 1/250 of the span for interfloor floors).
When installing the floor, a sufficient degree of sound insulation must be provided, the amount of which is established by standards or special recommendations for the design of buildings for a particular purpose. To do this, it is necessary to carefully close the gaps in the places where the material joins, in order to avoid the transfer of sound from neighboring premises located above or below.
Floors separating rooms with a temperature difference of 10 °C (for example, separating a cold basement from the first floor or an attic from the first floor) must meet the requirements of thermal protection, that is, it is necessary to increase the layer of thermal insulation.
No floor structure, especially wood, can withstand prolonged exposure to fire, but each material has its own fire resistance limit. The fire resistance limit of reinforced concrete floors is 60 minutes; wooden floors with backfill and lower plastered surface - 45 minutes; wooden floors protected with plaster, about 15 minutes; There are even fewer wooden floors not protected by fireproof materials.

Types of house floors

interfloor (separating residential floors, including the attic),
basement (separating the basement from the residential floor),
basement (separating the residential floor from the cold underground),
attic (separating the residential floor from the unheated attic).

In my own way constructive solution The load-bearing part of the floors can be divided into:

beams, consisting of a load-bearing part (beams) and filling;
beamless, made from homogeneous elements (flooring slabs or flooring panels).

Types of floors for the home

Beam floors

In beam ceilings load-bearing base consist of beams located at the same distance from each other, on which filling elements that perform enclosing functions are laid. Beams can be wooden, reinforced concrete or metal.

Floors made of wooden beams

In private housing construction, the most popular are wooden beam floors, usually used in wooden and frame houses.

For wooden beams there is a limitation on the width of the span (room). They can be used for:

interfloor ceilings - with a span width of 5 meters;
for attic floors (with an unused attic space) with a span width of up to 6 meters. Metal beams can be used for any span width.

The wooden floor is made from wooden beams of coniferous and hardwood. On the upper side of the beams there is a flooring, which also serves as the floor. The structure of the beam floor consists of the beams themselves, the run-up, the floor and the insulation.

With a rectangular house plan, it is advisable to block the span along the short wall.

Scheme for laying floor slabs along a short wall

To prevent beams from bending under the weight of the floor, they must be placed at a certain distance (see table). The section of the beam is determined based on the load falling on it.

For example: You need to build a floor measuring 3.0 * 4.0 m. We lay wooden beams (section 6x20) along a wall equal to 3.0 meters. If the ceiling is between floors, the beams are laid at a distance of 1.25 m from each other, if the attic floor is 1.85 m. That is, the larger the span of the future floor, the smaller the distance between the beams will be, since a larger area of flooring accounts for more loads

The distance between the beams is also affected by the thickness of the floor boards. If they are 28 mm or less thick, the distance between the beams should not exceed 50 cm.

Advantages of wooden flooring:

The main advantage is that a wooden floor can be quickly and easily installed in any (even difficult) place, without the use of any special means, that is, you can do without a crane or other equipment. The wooden floor is light and relatively inexpensive.

Disadvantages of wooden floors:

The main disadvantage of wooden floors is the increased flammability, sometimes the possibility of rotting and infection with bark beetles.

Wooden floor installation technology:

Installation of beams: Before installing the beam, it must be processed antiseptic solution. If the beams rest on stone or concrete wall, then its ends must be wrapped in two layers of roofing felt. The beam is inserted into the nest prepared during the construction of the wall. When inserted into the nest, the beam should not reach back wall by 2-3 cm. The end of the beam is made beveled.

Beam installation diagram

(1 - beam, 2 - roofing felt, 3 - insulation, 4 - mortar).

The remaining free space in the nest is filled with insulation; you can fill it with polyurethane foam.

Installation of rewind: Bars (section 4x4 or 5x5), which are called cranial, are nailed to the side faces of the beams.

Scheme of rolling wooden panels

(1 - wooden beam, 2 - cranial block, 3 - roll-up shield, 4 - vapor barrier, 5 - insulation, 6 - finished floor finishing, 7 - ceiling finishing).

A roll of wooden panels is attached to these bars. The roll-up is made from boards made of longitudinal boards or boards from transverse boards. The knurling plates must be pressed tightly against each other. They are attached to the cranial block with self-tapping screws. The roll-up serves as preparation for attaching the “clean” ceiling.

Insulation gasket: An integral part of a wooden beam floor is insulation, which primarily performs the role of sound insulation in the interfloor ceiling, and also serves as thermal insulation in the attic floor. First of all, you need to decide what material to use. The insulation material can be mineral wool, polystyrene foam, slag, perlite, expanded clay, as well as dry sand, sawdust, shavings, straw, and wood leaves. Mineral wool - light material, easy to use, unlike foam plastic, it “breathes”, has sufficient heat and sound insulation, in general, in most cases, cotton wool is suitable for both insulating interfloor and attic floors. Expanded clay (fraction 5-10 mm) is a heavier material than mineral wool, which makes the structure heavier (the weight of 1 m2 of expanded clay ranges from 270-360 kg).

After fixing the roll, a layer of thermal insulation is placed on top of it. First, a layer of roofing felt, glassine or vapor barrier film is laid between the beams, bending it about 5 cm onto the beams and moving on to thermal insulation. The thickness of any insulation for an interfloor floor should be at least 100 mm, and for an attic floor, that is, between a cold and heated room - 200-250 mm.

Cost and consumption of materials: The consumption of timber for traditional wooden floors is approximately 0.1 m3 per 1 m2 of flooring at a depth of 400 cm. The average cost of a cubic meter of wooden beams is from 145 dollars (or 14 dollars per linear meter). And the cost of the boards will cost you about $200 per cubic meter. Costs for 1 square meter of flooring using wooden beams range from $70 and above.

Floors on metal beams

Compared to wooden ones, they are quite reliable and more durable, and also have a smaller thickness (save space), but such floors are rarely erected. To fill the openings between the beams, you can use lightweight concrete inserts, lightweight reinforced concrete slabs, wooden panels or wooden slabs. The weight of 1 m2 of such flooring often exceeds 400 kg.

Advantages:

A metal beam can cover large spans (4-6 meters or more).

The metal beam is non-flammable and resistant to biological influences (rot, etc.).

But the overlap metal beams are not without drawbacks:

in places high humidity Corrosion forms on the metal.

In addition, such floors have reduced heat and sound insulation qualities. To mitigate this disadvantage, the ends of the metal beams are wrapped in felt. In such floors, the load-bearing element is a rolled profile: I-beam, channel, corners.

Rolling profile

Prefabricated reinforced concrete hollow slabs 9 cm thick are laid between the beams. A layer of slag and reinforced concrete screed 8-10 cm thick is applied over the reinforced concrete slabs. Steel consumption is high - 25-30 kg/m2, depending on the grade of steel from which the beams are made.

Scheme of the design of a prefabricated reinforced concrete floor slab on metal beams

1 - “clean” floor; 2 - boardwalk; 3 - beam; 4 - prefabricated reinforced concrete slab; 5 - waterproofing; 6 - plaster mesh; 7 - plaster.

Material cost: Price steel profile ranges from 7 to 18 dollars/linear meter. The cost of lightweight reinforced concrete slabs is from $110 per piece. For 1 square meter of flooring on metal beams you will spend from $100 and more.

Floors made of reinforced concrete beams

They are installed on spans from 3 m to 7.5 meters. The work is complicated by the need to use lifting equipment. The weight of such beams is 175 - 400 kg.

Advantages:

With the help of reinforced concrete beams you can span larger spans than with wooden ones.

Flaws:

For installation of ceilings according to reinforced concrete beams lifting equipment must be used.

Installation: Reinforced concrete beams are laid at a distance of 600-1000 mm. The filling of the interbeam space is arranged in the form of lightweight concrete slabs or hollow lightweight concrete blocks (if plank floors or parquet floors, slabs are used, and for linoleum or parquet floors on a concrete base, hollow blocks are used).

Scheme of the design of a lightweight concrete slab on reinforced concrete beams

(1 - reinforced concrete beam, 2 - lightweight concrete slab, 3 - cement screed and substrate, 4 - parquet, laminate)

Scheme of the design of a floor slab made of hollow blocks on reinforced concrete beams

(1 - reinforced concrete beam, 2 - hollow blocks, 3 - cement screed, 4 - linoleum)

The seams between the beams and slabs are filled with cement mortar and rubbed. Attic floors must be insulated, interfloor floors must be soundproofed, and basement floors must also be insulated.

Floor slabs made of hollow blocks on reinforced concrete beams

Cost: For one linear meter of beam you will have to pay from 25 dollars. The price for one lightweight concrete block is from 1.5 dollars. As a result, for 1 square meter of flooring on reinforced concrete beams you will spend from 65 dollars.

Beamless floors

They are homogeneous elements (slabs or panels) laid close to each other or a solid monolithic slab, which simultaneously serve as load-bearing and enclosing structures. Depending on the manufacturing technology, beamless floors can be prefabricated, monolithic or prefabricated monolithic.

Prefabricated reinforced concrete floors

The most popular, especially in brick houses. To install reinforced concrete floors, two types of panels are used: solid (they are made mainly from lightweight concrete) and hollow-core. The latter have round holes kind of “stiffening ribs”. Panels are selected depending on the width of the span to be covered and load-bearing capacity.

Advantages:

Reinforced concrete slabs have high strength and are designed for a payload of over 200 kg/m2.

Unlike wood, concrete is not afraid of dampness and does not require any maintenance.

Flaws:

When installing floors made of reinforced concrete slabs, lifting equipment is required.

Buy ready-made slabs the right size not always possible, since they are made in standard sizes at the factory.

Scheme of a beamless floor for a house

Installation: Floor slabs are laid on a layer cement mortar grade 100. The support of the slabs on the walls (walls more than 250 mm thick) must be at least 100 mm. The seams between the slabs must be cleared of debris and thoroughly filled with cement mortar.

Approximate cost of the material: The cost of one floor slab starts from $110. For 1 square meter of flooring made of reinforced concrete slabs you will spend at least 35-40 dollars.

Monolithic reinforced concrete floors

There may be various shapes. Monolithic reinforced concrete floors are a continuous monolithic slab 8-12 cm thick made of grade 200 concrete, supported on load-bearing walls. The weight of a square meter of a monolithic floor with a thickness of 200 mm is 480-500 kg.

Photo of reinforcement of a monolithic reinforced concrete floor

Installation of monolithic floors is carried out in four stages:

Installation of steel load-bearing beams in prepared places;
Installation of suspended wooden formwork from unedged boards(suspended from steel beams);

Installation of suspended wooden formwork from unedged boards

U masonry reinforcement (diameter 6-12 mm);
Concreting the floor slab with M200 concrete.

Advantages of a monolith:

No expensive loading and unloading operations and more high quality concrete surface that does not require sealing joints, as well as the ability to implement complex architectural and planning solutions.

The disadvantages of monolithic floors include the need to install wooden formwork over almost the entire area of the future floor. However, this does not mean that the formwork needs to be installed all at once. The overlap can be done in separate spans, moving the formwork as the concrete sets.

Installation: Before proceeding with the installation of the ceiling, it is necessary to construct the formwork (it can be purchased ready-made or rented), which consists of telescopic racks, tripods, uniforks, beams, flooring and plywood. Formwork made of wooden and aluminum beams allows you to form floors of any configuration - rectangular, cantilever and even round. Sheets of plywood are placed on the upper wooden part of the beam to form the formwork for pouring concrete. Next, the reinforcement frame is installed and secured. The ends of steel rods 60-80 cm long are bent and tied with wire and reinforcement. Then concreting is carried out over the entire area of the ceiling to a height of 10-30 cm. Complete adhesion of the concrete occurs after 28 days.

Formwork for a monolithic floor slab made of wood flooring and plywood

Installation of a reinforcement cage in the formwork for the construction of a monolithic reinforced concrete slab

Approximate cost of material: The cost of floor formwork, with wooden and aluminum beams, starts from $40. The approximate consumption of reinforcement for the floor is 75-100 kg/m3 of concrete. The cost of 1 ton of reinforcement is $650. The cost of 1 cubic meter of ready-made concrete is from $130. As a result, the price for 1 square meter of monolithic flooring will cost you from $45 and above (without the cost of formwork).

Prefabricated monolithic floor

More modern solution on the installation of floors. The bottom line is that the space between the floor beams is filled with hollow blocks, after which the entire structure is poured on top with a layer of concrete.

Prefabricated monolithic flooring for a house

Advantages:

Installation without application lifting mechanisms, improvement of thermal insulation properties, the possibility of constructing floors of complex shapes, reducing construction time.

Flaws:

The disadvantages include that the prefabricated monolithic structure has a labor-intensive (manual) installation process, which is not advisable when building a house with 2-3 floors.

Installation: During installation, prefabricated monolithic floor beams are laid on the walls at intervals of 600 mm. The weight of a linear meter of beam does not exceed 19 kg. This allows, in most cases, the installation of beams without the use of a crane. Hollow blocks are laid manually on the beams. The weight of the expanded clay concrete block is 14 kg, the polystyrene concrete block is 5.5 kg. As a result, the dead weight of one square meter of the original floor structures is 140 kg for expanded clay concrete blocks and 80 kg for polystyrene concrete blocks.

The floor structure prepared in this way performs the function of permanent formwork on which a layer is laid monolithic concrete class B15 (M200).

Before pouring concrete, it is necessary to reinforce the structure with reinforcing mesh with cells measuring 100x100 mm made of wire with a diameter of 5-6 mm.

The weight of one square meter of finished flooring is 370-390 kg for expanded clay concrete blocks and 290-300 kg for polystyrene concrete blocks.

Expanded clay concrete block for prefabricated monolithic flooring

Approximate cost: The cost of prefabricated monolithic floor structures (beams and blocks) will cost you 40-50 dollars/m2. The cost of finished floor structures (beams + blocks + mesh + concrete) is 70-75 dollars/m2.

Thermal and sound insulation of floors:

The thermal protection of the ceiling must be such that the temperature on the floor surface is close to the internal air temperature and does not fall below it by more than 2°C. To avoid dampness between heated and unheated rooms, a layer of glassine should be placed above the thermal insulation to protect the insulation layer from moisture.

Laying scheme for heat and soundproofing materials into the ceiling

(1 - wooden beam, 2 - skull block, 3 - roll, 4 - layer of insulation, 5 - vapor barrier film or glassine, 6 - boards)

In addition to good thermal protection, floors must also provide sufficient sound insulation of the premises. In accordance with current standards (data for the Russian Federation), the insulation index Rw must be equal to or greater than 49 dB.

For hollow-core reinforced concrete slabs with a thickness of 220 mm, the insulation index is Rw = 52 dB.

For wooden floors (280 mm insulation layer + one 12 mm layer of plasterboard) the sound insulation index is 47 dB.

Now a little about insulation. Ready-made mineral wool slabs performed well as thermal insulation. In addition to the well-known insulation with ready-made mineral wool slabs, there are alternative options, carried out on site. For example: You can pour slag or ordinary sawdust. By the way, they are 4 times lighter than slag and at the same time provide 3 times better thermal insulation with the same layer thickness. So, at a winter temperature of -20°C, the backfill of slag should be 16 cm thick, shavings - 7, and sawdust - only 5 cm.

You can make sawdust concrete slabs for the same purpose yourself. To do this, you can take 1 volume part of sawdust, 1.5 parts of lime mortar or 4 parts of clay, 0.3 parts of cement and from 2 to 2.5 parts of water. The finished slabs are dried in the shade, laid on a roofing felt pad, the seams are sealed with clay or lime mortar. Square meter such a slab weighs about 5-6 kg with a thickness of 10 cm.

What kind of flooring should you choose for your home? It all depends on the type of house, as well as on the installation technology and price of this ceiling. To conclude this article, I will provide a table in which you can compare different types floors and choose the most suitable one for yourself.

Attention: Prices in this article are presented for the period of 2008. Be careful!

It is impossible to imagine buildings without floors, for the manufacture of which concrete mixtures and reinforcement are used. Floors have increased strength and can withstand high stresses. Reinforced concrete structural elements are installed various methods. In some cases, installation is carried out using reinforced concrete products manufactured at reinforced concrete factories. Using another technology, a monolithic floor slab is constructed, the basis of which is concrete mortar and reinforcement with a diameter of 8-12 mm. Consider the installation of a solid slab. Let's figure out how to take the first step correctly.

Prefabricated and monolithic floor slab - design options

When constructing residential and industrial buildings, builders construct various types of reinforced concrete floors:

prefabricated For their manufacture, the required number of standard reinforced concrete panels, manufactured under production conditions. The length of the slab is selected taking into account required distance between main walls. After laying using lifting equipment finished products they are anchored and the working seam between the ends of the panels is sealed;
prefabricated monolithic. The technology for forming prefabricated monolithic type floors is similar to the method for arranging prefabricated structures. The finished slabs are laid on supports, the function of which is performed by the load-bearing walls of the building. After fixing the laid slabs with reinforcement, a concrete layer with a thickness of at least 100 mm is poured. The ceiling height includes the thickness of the slab and the height of the concrete poured on top;

One of the most reliable and expensive floors in construction is a monolithic floor

monolithic. To construct a single slab, no lifting equipment is required. The process of constructing a solid structure involves installing panel formwork, assembling and placing a reinforcement cage inside it, as well as subsequent pouring of concrete mortar. It is important to correctly calculate the formwork taking into account the planned load on the floor. Having mastered the installation technology, it is easy to carry out all the work on your own.

Private developers prefer monolithic structures due to their simplicity, the possibility of independent construction, and the absence of the need to use lifting equipment. It is not necessary to construct panel formwork from wood if you decide to form. In this case, the lower surface of the ceiling, formed by the metal profile, does not require additional finishing. When choosing a type of reinforced concrete slab, follow the requirements of the design documentation and take into account the structure of the building.

Advantages and disadvantages of laying monolithic type floors

When planning the installation of a monolithic floor for your own home or cottage, you should study in detail the advantages of a monolithic structure compared to a prefabricated and precast-monolithic option and analyze its weaknesses.

The main advantages of a solid reinforced concrete floor slab:

increased strength of monolithic reinforced concrete. In the design of a solid reinforced concrete base there are no seams and a joining zone, which are present in the prefabricated version of the floor;
balancing the forces created by the weight of the building elements on the building box and foundation. The load is evenly transmitted along the entire perimeter of the supporting surface;
the possibility of constructing floors of various shapes for the implementation of non-standard projects of original buildings. In this case, columns and load-bearing walls can be used as supporting elements;

In houses made of brick, concrete or concrete blocks, the floors are usually made of reinforced concrete

the possibility of implementing architects' plans related to the construction of remote-type balconies on a reinforced concrete ceiling console. An increased safety margin of such structures is guaranteed;
the rigidity of a monolithic slab formed between the floors of a building. The one-piece structure does not have the ability to move in the transverse plane and longitudinal direction;
the ability to carry out installation work with your own hands. There is no need to use crane equipment to lift heavy reinforced concrete slabs to the installation site.

The undeniable advantages of the one-piece design also include durability. The service life of a properly concreted floor exceeds a century.

Along with a set of advantages, there are a number of disadvantages:

an increase in the duration of construction work associated with the long-term increase in operational strength of the concrete mass;
the need to use increased volumes of concrete mixture, which should preferably be poured in one go using a concrete pump.

An analysis of the advantages of the design and a study of the shortcomings allows us to assert that the monolithic floor is superior to the prefabricated version in most respects.

Installation of a monolithic ceiling - step-by-step technology

Installation work between floors of a building should be started only after a thorough study of the technology, which provides for the following stages of work:

Monolithic ceiling has a number of advantages compared to floors made of ready-made reinforced concrete slabs

Performing strength calculations of reinforced concrete slabs.
Preparation of necessary building materials, tools and equipment.
Assembling the formwork structure and ensuring its tightness.
Manufacturing a reinforcement cage and placing it inside the formwork.
Preparation of concrete mixture and filling with ready-made formwork solution.

Each of these stages of work has its own characteristics. Let us dwell in more detail on the specifics of performing the main stages.

Perform load capacity calculations

All loads that act on monolithic reinforced concrete during operation are divided into the following types:

ongoing efforts. These include loads that are created by the weight of the building box, the mass of the partitions inside the building, as well as the roof structure;
variable loads. Their size is determined by weight utility networks, a mass of finishing elements, furniture. The amount of temporary loads also depends on the number of people inside the building.

The load capacity of monolithic slabs depends on the thickness of the reinforced concrete mass. To ensure the required safety margin of the slab at a load of 500 kg per 1 sq. m it is necessary to maintain a thickness of the reinforced concrete mass equal to 0.2 m, determined on the basis of special calculations. It is important to take into account the operating conditions of the slabs to prevent them from cracking.

Like everything related to construction, monolithic flooring begins with a project

The accuracy of strength calculations is affected by the following factors:

the size of the design forces acting per unit area of the floor;
marking of the concrete solution used;
thickness of the formed reinforced concrete slab;
the length and width of the structure spanning the space between floors.

Based on the calculations, the cross-sectional size of the reinforcement is determined, which dampens bending moments and tensile forces. Without special engineering training, performing calculations on your own is problematic. Entrust the calculation operations to professional builders or perform the calculations online using a special calculator posted on professional websites.

How a panel frame is formed using permanent formwork

Formwork for a monolithic floor slab is made on the basis of the following building materials:

moisture-resistant plywood, the thickness of which is 2-2.5 cm. The laminated coating of the plywood will facilitate its dismantling after the solution has hardened;
smooth boards made from durable lumber. To assemble the shields, use boards whose thickness is 4-5 cm and width 18-20 cm;
telescopic metal supports or ordinary logs with a diameter of 15 cm. Racks are used to ensure the immobility of the formwork;
wooden beams used to support the formwork frame. The beams perform the function of transverse elements of the formwork structure.

To assemble the formwork, also prepare hardware and the necessary carpentry tools. Do not forget about the building level, which allows you to check the horizontalness of the structure.

The construction of a monolithic floor slab assumes that concrete will be poured into horizontal formwork

When assembling the formwork, follow the sequence of operations:

Draw the level of placement of formwork panels on the wall surface.
Install the supporting elements with an interval of 100 cm between them.
Place metal profiles or cross bars on vertical supports.
Lay out plywood sheets or prepared boards and secure them firmly.
Nail a vertical edging along the contour of the formwork structure.
Check for horizontal alignment and seal the joint areas.

The formwork structure must be dismantled 4 weeks after concreting.

How to properly reinforce a monolithic floor slab

You should prepare in advance for carrying out reinforcement work. The following materials will be required:

special linings that ensure a fixed position of steel reinforcement relative to the outer surface of the concrete mass;
corrugated reinforcement with a bar cross-sectional diameter of up to 12 mm, increasing the ability of concrete to absorb loads;
a knitting device and annealed wire, allowing you to quickly fix the elements of the reinforcement frame.

To facilitate bending operations, a special device will be required. Cut the workpieces using a grinder equipped with a cutting wheel for metal.

After the formwork is arranged, a reinforcement frame made of two meshes is installed in it

Produce the reinforcement grid according to the given algorithm:

Cut the steel reinforcement into bars of the specified length.
Place the longitudinal blanks on the clamps in increments of 15-20 cm.
Bind cross bars, observing the specified interval.
Tie vertical reinforcement to the connected lattice every 100 cm.
Tie the top level mesh and secure it carefully to the supports.

When connecting reinforcement to the ceiling, maintain an overlap of 35 times the diameter of the rods.

How to pour slabs onto load-bearing walls of a house

The monolithic floor slab is poured with a concrete mixture prepared from the following ingredients:

Portland cement marked M400;
gravel or crushed stone up to 3 cm in size;
purified sand.

All components of the solution are mixed with water until a creamy concrete is obtained. To increase the efficiency of mixing, a concrete mixer is used. However, given the need for an increased volume of the mixture, it is worth buying ready-made concrete, which is delivered to the work site in a special mixer.

The concreting process includes the following steps:

Supplying the concrete mixture into the formwork with reinforcement.
Uniform distribution of concrete over the area of the future floor.
Compacting a concrete mass using a mechanical vibrator.

At the final stage, the surface is leveled. Concrete gains operational strength within one month and requires additional moisture. After all, during the hardening process of concrete, moisture gradually evaporates. To maintain constant humidity and prevent cracking, the surface is covered with plastic film and regularly moistened.

Conclusion

Having familiarized yourself in detail with the features of the technology, it is not difficult to install a monolithic ceiling for a private house, cottage or summer house on your own. Significant savings can be achieved by doing the work yourself cash. It is important to use a high-quality concrete mixture and correctly reinforce the floor. Before starting construction activities, it is advisable to consult with professional builders who will always help with advice.

Any developer would like to build a reliable ceiling in a country house for minimal money. Usually, when asked what you will use to cover the span in a two-story stone cottage, the homeowner says that it will be reinforced concrete slabs. Or wooden beams, or, which is more expensive, pour a monolithic reinforced concrete floor. It is much less common to hear that a prefabricated monolithic floor (PCM) will be installed. This is due to the lower prevalence of this technology, as well as the traditional inertia of thinking inherent in the domestic construction market. Most people believe that conventional slabs, in the combination of “price, load-bearing capacity, ease of use for builders and speed of installation,” have no equal, and SMP is too expensive and difficult to make.

In this article we will tell you if this is true and answer the following questions:

What are the features of a prefabricated monolithic floor?
How much does it cost to install 1 sq. m of such overlap.
What nuances need to be taken into account.

Features of prefabricated monolithic flooring

To understand what SMP is, just study the following picture.

As can be seen from the photo above, a prefabricated monolithic floor consists of factory-made beams with a triangular reinforcement frame (so-called trigons), mounted on a concrete base. Aerated concrete blocks are laid between the beams, which act as permanent formwork.

A reinforcing mesh is also laid on top of the blocks, always with a gap, or a frame with a cell of 10x10, 15x15 cm is knitted from “eight” or “tens” reinforcement.

The beams are supported from below with wooden supports or telescopic posts, and then concrete is poured.

After the concrete has gained strength, the racks are removed and further construction and finishing work is carried out.

It seems that this technology is inferior to the standard and familiar one, when reinforced concrete floor slabs are quickly laid on the walls by crane. And in terms of the degree of manufacturability, i.e. number of preparatory operations, similar to conventional pouring of a monolithic floor. The question arises: what are the advantages of the NSR then? To answer this, we need to consider key features slab and monolithic flooring.

Let's take an example of a house made of aerated concrete. To mount concrete floor slabs on such a “box”, it is necessary to pour an armored belt around the perimeter of the walls, which will evenly redistribute the load from the slabs to the blocks.

This technology has been well developed for a long time and usually does not cause difficulties for builders. But it is difficult or impossible to cover long unsupported spans of 8, 9, 12 or more meters with slabs. In addition, the geometry of modern country houses is far from a simple square or rectangle, and the standard length of ordinary floor slabs is 6 m. That is, if the house has bay windows, ledges, curved sections, the “box” has a complex configuration, then you will have to either cut the slabs or rack your brains, how combine floor slabs with monolithic sections.

Under the flight of stairs.

To install the slabs, you need good access roads and the possibility of unhindered operation of the crane that will lay them. Not at all suburban areas it's possible.

Now let's go over the monolithic floor. For its installation, in the same aerated concrete house, there is no need to fill a separate armored belt, because The monolithic floor itself is a rigidity disk that redistributes the load. But for a monolith, it is necessary to install formwork over the entire area of the covered room from corrugated sheets or laminated plywood and install supports. High-quality connection of the spatial reinforcement frame.

Making a monolithic ceiling on long spans, over 7 meters, is not always cost-effective, because it will turn out very heavy, and will actually “eat” itself.

To all of the above, we add that if it is necessary to reconstruct a stone house, if the customer wants to replace old and rotten wooden floors, the option with slabs immediately disappears, and the mass of the monolith may simply not be supported by the foundation and soil foundation.

Let's move on to the prefabricated monolithic floor. As mentioned above, the basis of this floor is beams. The base - the “core” of the beams, in which the reinforcement cage is installed, can be made of concrete.

Weight 1 linear m of such a beam is about 17 kg.

victorborisov User FORUMHOUSE

I built one-story house made of aerated concrete with flat roof. The ceiling is prefabricated and monolithic. During its installation, a problem arose about how to raise the beams with a concrete base. If a beam with a length of 3500 mm and a weight of 60 kg can be thrown by two people onto a wall 3 m high, then with beams with a length of 6500 mm and a weight of 110 kg this will no longer work. We need helpers, or better yet, a crane, which will have to be rented.

To install SMP based on concrete beams, special T-shaped blocks are required, i.e. blocks with a chamfer at the bottom.

This version of beams is already outdated, and some manufacturers offer lighter beams based on a galvanized steel profile on which the reinforcing cage is mounted.

Weight 1 linear m of such a beam is approximately 6 kg.

Those. Such a beam can be lifted and mounted manually, without the use of lifting equipment.

The final weight of such a beam is also affected by the number of rods of additional longitudinal reinforcement. Its diameter and number of rods are selected based on the design calculation of the load-bearing capacity of the prefabricated monolithic floor.

Another advantage of SMP is the ability to flexibly select the load-bearing capacity of the floor depending on the expected operational loads.

The filler (permanent formwork) between metal beams can be ordinary, relatively light ordinary ones, and not special T-shaped ones, aerated concrete, polystyrene concrete, expanded clay concrete blocks, as well as blocks made of warm ceramics.

You can reduce the weight of a prefabricated monolithic floor even more by using liners made of dense foam.

The question arises about the fire hazard of this covering option, but in Europe such filler is often found even in the construction of multi-storey buildings.

Note that SMP with aerated concrete liners, according to test results, have a high degree of fire resistance.

A prefabricated monolithic floor has less weight than a monolithic one. This, in turn, reduces the load on the walls, foundation and soil. Therefore, SMP can be used when renovating buildings and replacing old and weakened floors in residential buildings.

With an equal floor thickness of 25 cm, the weight of the monolith is approximately 500 kg/sq. m, and for SMP - 300 kg/sq. m.

Beams can be of different lengths, they can be joined at an angle, which makes it possible to cover rooms with complex configurations.

Let us add that SPM has a high bearing capacity. By increasing the height of the beam section and using additional longitudinal reinforcement, it becomes possible to span unsupported spans up to 16 meters long.

Triangular frames made industrially, have a height of 10, 15, 20, 25 and 30 cm.

Another advantage of a prefabricated monolithic floor is that there is no need to install an armored belt, because it is poured simultaneously with the ceiling, which also simplifies and reduces the cost of work. You can immediately embed heated floor pipes into the ceiling.

By stretching the concrete along pre-installed “beacons”, you will immediately obtain a flat surface, ready for laying the finished floor covering.

Prefabricated monolithic flooring: practical information

Although the SMP cannot be called a new product, and its installation according to the design principle does not cause difficulties even for beginners, many users of the portal have questions: what to use as temporary supports for beams with laid blocks: boards, beams or telescopic racks?

E_I_A Member FORUMHOUSE

I think it’s easier to buy one and a half boards of not the highest grade and use them for supports than to rent racks for a month. The boards can then be used for something else on the rafter system.

Tagan1 User FORUMHOUSE

I have been professionally involved in monolithic work for many years and I can say that metal telescopic racks are superior to board supports in all respects. The stands are installed in a few minutes. By moving the stand up and down, millimeter precision of installation under the beams is achieved. With the boards, you will have to catch centimeters, drive in wedges to securely support them, fasten them with jibs, then disassemble it all, and this is a waste of time, and therefore money.

The price of renting racks in terms of the cost of the entire construction is scanty.

The racks are placed at an average distance of 1.5 m from each other. Important point : When installing the racks, we immediately think about what they will stand on. For support you need a solid base with good load-bearing capacity. If it is not compacted soil or a slab foundation, then there is a danger of the post being pushed down by the weight of the concrete, even if the post is on a board pad.

At independent device prefabricated monolithic floor, you need to pay attention to the following point - the need to install a concrete diaphragm.

Tiberius User FORUMHOUSE

In houses made of brick, concrete or concrete blocks, the floors are usually made of reinforced concrete. They provide exceptional strength and earthquake resistance to the structure, and are also very durable and do not burn, which is important. There are several ways to construct reinforced concrete floors. The most common and universal is laying factory-made floor slabs. Such slabs are ordered from concrete factories and then installed using a crane and a team of workers. In cases where using a crane on a construction site is difficult, or when the house has a non-standard layout and it is difficult to lay out finished slabs, a monolithic floor slab is installed. In fact, you can fill a monolithic slab not only when there is evidence for it, but also simply because you consider it more appropriate. In this article we will tell you how to lay floor slabs and how to pour a monolithic slab. Not all work can be done independently, but it is still worth familiarizing yourself with the technology, if only in order to control the process on the construction site.

DIY monolithic floor slab

Monolithic flooring has a number of advantages compared to flooring made from ready-made reinforced concrete slabs. Firstly, the structure is strong and monolithic without a single seam, which ensures an even load on the walls and foundation. Secondly, monolithic filling allows you to make the layout of the house more free, since it can rest on columns. Also, the layout can involve any number of corners and crannies for which it would be difficult to select floor slabs of standard sizes. Thirdly, it is possible to safely equip a balcony without an additional support plate, since the structure is monolithic.

You can install a monolithic floor slab yourself; you don’t need crane or a large team of workers. The main thing is to follow the technology and not skimp on materials.

Like everything related to construction, monolithic flooring begins with a project. It is advisable to order the calculation of a monolithic floor slab from a design office and not save on it. It usually includes a calculation cross section slabs under the influence of bending moment at maximum load. As a result, you will receive the optimal dimensions for the floor slab specifically in your home, instructions on what reinforcement to use and what class of concrete. If you want to try to perform the calculations yourself, an example of calculating a monolithic floor slab can be found on the Internet. We will not focus on this. Let's consider the option of building an ordinary country house with a span of no more than 7 m, so we will make a monolithic floor slab of the most popular recommended size: from 180 to 200 mm thick.

Materials for the manufacture of monolithic floor slabs:

Formwork.
Supports for supporting the formwork at the rate of 1 support per 1 m2.
Steel reinforcement with a diameter of 10 mm or 12 mm.
Concrete grade M 350 or separately cement, sand and crushed stone.
Bending device for reinforcement.
Plastic supports for fittings (clamps).

Technology for pouring a monolithic floor slab includes the following steps:

Calculation of the floor slab if the span is more than 7 m, or the project involves supporting the slab on a column/columns.
Installation of deck type formwork.
Reinforcement of the slab with steel rods.
Pouring concrete.
Compacting concrete.

So, after the walls have been kicked out required height, and their level is almost perfectly level, you can begin arranging a monolithic floor slab.

The construction of a monolithic floor slab assumes that concrete will be poured into horizontal formwork. Sometimes horizontal formwork is also called “deck”. There are several options for its arrangement. First - rental of ready-made removable formwork made of metal or plastic. Second - production of formwork on site using wooden planks or sheets of moisture-resistant plywood. Of course, the first option is simpler and preferable. Firstly, the formwork is collapsible. Secondly, it offers telescopic supports, which are needed to support the formwork at the same level.

If you prefer to make the formwork yourself, please note that the thickness plywood sheets should be 20 mm, and the thickness of the edged boards 25 - 35 mm. If you knock down panels from edged boards, then they need to be tightly adjusted to each other. If gaps are visible between the boards, then the surface of the formwork should be covered with waterproofing film.

Installation of formwork is carried out in this way:

Vertical support posts are installed. It can be telescopic metal racks, the height of which can be adjusted. But you can also use wooden logs with a diameter of 8 - 15 cm. The step between the racks should be 1 m. The racks closest to the wall should be located at least 20 cm from the wall.
Crossbars are placed on top of the racks (a longitudinal beam that will hold the formwork, an I-beam, a channel).
Horizontal formwork is laid on the crossbars. If you are not using ready-made formwork, but home-made one, then lay on top of the longitudinal beams cross beams, on which sheets of moisture-resistant plywood are placed on top. The dimensions of the horizontal formwork must be adjusted perfectly so that its edges rest against the wall without leaving gaps.
The height of the pillar supports is adjusted so that the upper edge of the horizontal formwork coincides with the upper edge of the wall masonry.
Vertical formwork elements are installed. Taking into account the fact that the dimensions of a monolithic floor slab must be such that its edges extend 150 mm onto the walls, it is necessary to construct a vertical fence exactly at this distance from the inner edge of the wall.
The last time the horizontal and even position of the formwork is checked using a level.

Sometimes, for the convenience of further work, the surface of the formwork is covered with a waterproofing film or, if it is made of metal, lubricated with machine oil. In this case, the formwork can be easily removed, and the surface of the concrete slab will be perfectly flat. The use of telescopic racks for formwork is preferable to wooden supports, since they are reliable, each of them can withstand a weight of up to 2 tons, and microcracks do not form on their surface, as can happen with a wooden log or beam. Renting such racks will cost approximately 2.5 - 3 USD. per 1 m2 of area.

After arranging the formwork, a reinforcement frame made of two meshes is installed in it. For the manufacture of the reinforcement frame, steel reinforcement A-500C with a diameter of 10 - 12 mm is used. These rods are used to knit a mesh with a mesh size of 200 mm. To connect longitudinal and transverse rods, 1.2 - 1.5 mm knitting wire is used. Most often, the length of one reinforcing rod is not enough to cover the entire span, so the rods will have to be connected to each other lengthwise. To make the structure strong, the rods must be connected with an overlap of 40 cm.

The reinforcing mesh should extend onto the walls by at least 150 mm if the walls are made of brick, and by 250 mm if the walls are made of aerated concrete. The ends of the rods should not reach the vertical formwork along the perimeter by 25 mm.

Reinforcement of a monolithic floor slab is carried out using two reinforcing meshes. One of them - the bottom one - should be located at a height of 20 - 25 mm from the bottom edge of the slab. The second - the top - should be located 20 - 25 mm below the top edge of the slab.

In order for the lower mesh to be located at the required distance, special plastic clips. They are installed in increments of 1 - 1.2 m at the intersection of the rods.

The thickness of the monolithic floor slab is taken at the rate of 1:30, where 1 is the thickness of the slab, and 30 is the span length. For example, if the span is 6 m, then the slab thickness will be 200 mm. Considering that the grids should be located at a distance from the edges of the slab, the distance between the grids should be 120 - 125 mm (from a slab thickness of 200 mm we subtract two gaps of 20 mm and subtract 4 thicknesses of reinforcing rods).

To space the meshes at a certain distance from each other, they are made from 10 mm reinforcing rod using a special bending tool. special clamps - stands as in the photo. The upper and lower flanges of the clamp are 350 mm. The vertical size of the clamp is 120 mm. The installation step of the vertical clamps is 1 m, the rows should be staggered.

Next step - end clamp. It is installed in increments of 400 mm at the ends of the reinforcement cage. Serves to strengthen the support of the slab on the wall.

Another important element - connector of upper and lower mesh. You can see what it looks like in the photo. It is necessary so that the spaced grids perceive the load as one whole. The installation step of this connector is 400 mm, and in the area of support on the wall, within 700 mm from it, in steps of 200 mm.

Pouring concrete

It is better to order concrete directly from the factory. This makes the task much easier. In addition, pouring the mortar from a mixer in an even layer will ensure exceptional strength of the slab. The same cannot be said about the slab, which was poured manually with breaks to prepare a new portion of the solution. So it is better to pour concrete immediately in a layer of 200 mm, without interruptions. Before pouring concrete into the formwork, it is necessary to install a frame or box for technological openings, for example, a chimney or ventilation duct. After pouring, it must be vibrated with a deep vibrator. Then leave to dry and gain strength for 28 days. For the first week, the surface must be moistened with water, only moistened, and not filled with water. After a month, the formwork can be removed. The monolithic floor slab is ready. For the installation of floor slabs, the price includes the cost of reinforcement, concrete, rental of formwork and ordering a mixer machine, as well as a concrete pump. In fact, it comes out to about 50 - 55 USD. per m2 of flooring. You can see how the floor slab is poured with concrete in the video demonstrating the installation of floor slabs.

How to lay floor slabs correctly

The use of factory-made monolithic reinforced concrete floor slabs is considered more traditional. The most popular are PC slabs - slabs with round voids. The weight of such slabs starts from 1.5 tons, so laying floor slabs with your own hands is impossible. A crane is required. Despite the apparent simplicity of the task, there are a number of nuances and rules that must be followed when working with floor slabs.

Rules for laying floor slabs

The prefabricated floor slab is already reinforced at the factory and does not require additional reinforcement or formwork. They are simply laid in a span supported on the walls, following some rules:

The span should not be more than 9 m. This is the length of the slabs that are the largest.
Unloading and lifting of slabs is carried out using special equipment provided by the project. For this purpose, the slabs have mounting loops to which the mounting slings are hooked.
Before laying floor slabs, the surface of the walls on which they will be laid must be leveled. Large height differences and distortions are not allowed.
The slabs should rest on the walls by 90 - 150 mm.
The slabs must not be laid dry; all cracks and technological seams must be sealed with mortar.
The position of the slabs must be constantly monitored in relation to the walls and supporting surfaces.
The slabs are laid only on load-bearing walls; all partitions are installed only after the installation of the floors.
If you need to cut a hatch in the ceiling, then it must be cut at the junction of two slabs, and not in one slab.
The plates should be located as close to each other as possible, but with a gap of 2 - 3 cm. This will ensure earthquake resistance.

If there are not enough floor slabs to cover the entire span, and there remains, for example, 500 mm, then there are different ways laying floor slabs in this case. The first is to lay the slabs end to end, leaving gaps along the edges of the room, then seal the gaps with concrete or cinder blocks. The second is laying slabs with uniform gaps, which are then sealed concrete mortar. To prevent the solution from falling down, formwork is installed under the gap (a board is tied up).

Floor slab laying technology

During the process of laying floor slabs, there must be clear coordination of actions between the crane operator and the team receiving the slab. To avoid injury on a construction site and to comply with all process and the rules described in SNiPs, the foreman at a construction site must have a technological map for the installation of floor slabs. It indicates the sequence of work, the quantity and location of equipment, special equipment and tools.

It is necessary to start laying floor slabs from the flight of stairs. After laying the slabs, their position is checked. The slabs are laid well if:

The difference between the lower surfaces of the plates does not exceed 2 mm.
The height difference between the upper surfaces of the slabs does not exceed 4 mm.
The height difference within the site should not exceed 10 mm.

As the installation diagram of floor slabs demonstrates, after laying the slabs, they must be connected to each other and to the walls using metal connecting parts. Work on connecting embedded parts and connecting parts is carried out by welding.

Don't forget to follow safety precautions. It is not allowed to carry out work using a crane in an open area with a wind of 15 m/s, as well as during ice, thunderstorms and fog. When moving the slab using a crane, the installation team should be away from the path along which the slab will move, on the opposite side of the feed. Despite the fact that using the services of a professional foreman and a team of installers significantly increases the cost of installing floor slabs, this is still not the case when you can save money. The foreman must provide the project.

Before ordering slabs from the factory, it is necessary to carry out preparatory work. It is better to coordinate the delivery time of the machine with slabs and the crane at the same time, so as not to overpay for downtime of special equipment. In this case, the installation of the slabs can be carried out without unloading, directly from the vehicle.

Preparatory work before laying floor slabs

First - flat supporting surface. The horizon should be almost ideal; a height difference of 4 - 5 cm is unacceptable. First of all, we check the surface of the walls, then, if necessary, level it with concrete mortar. Subsequent work can be carried out only after the concrete has acquired maximum strength.

Second - ensure the strength of the support area. If the walls are built from brick, concrete or concrete blocks, then no additional measures need to be taken. If the walls are built from foam blocks or gas blocks, then before laying the slabs it is necessary to fill in the reinforced belt. Correct styling floor slabs assumes that the supporting surface must be strong enough to support the weight of the slab and not deform along the abutment line. Neither aerated concrete nor foam concrete have the necessary strength. Therefore, formwork is installed along the entire perimeter of the building, a reinforcement frame made of 8 - 12 mm rod is installed in it, and then everything is filled with concrete with a layer of 15 - 20 mm. Further work You can continue only after the concrete has dried.

Third - install mounting towers. Telescopic supports, as described in the section on installing a monolithic floor slab, are installed in increments of 1.5 m. They are designed to take on the weight of the slab if it suddenly slips out of its place. After installation, these towers are removed.

Installation of hollow core slabs using a crane

After the freshly poured concrete has acquired sufficient strength and has dried, the installation of the floor slabs can begin. For this, a crane is used, the lifting capacity of which depends on the size and weight of the slab; cranes of 3 - 7 tons are most often useful.

Stages of work:

Concrete mortar is applied to the supporting surface in a layer of 2 - 3 cm. The depth of application of the mortar is equal to the depth of support of the slab, i.e. 150 mm. If the slab rests on two opposite walls, then the solution is applied only to two walls. If the slab rests on three walls, then on the surface of three walls. You can begin laying the slabs directly when the mortar reaches 50% of its strength.

While the solution dries, the crane operator can hook the slings onto the slab fasteners.
When the crane operator is given a signal that the slab can be moved, the team of workers must move away from the place where the slab is moving. When the slab is very close, the workers hook it with hooks and turn it around, thereby dampening the oscillatory movements.

The plate is sent to right place, one person should stand on one wall and the other on the opposite wall. The slab is laid so that its edges rest on the wall at least 120 mm, preferably 150 mm. After installation, the slab will squeeze out excess mortar and evenly distribute the load.

If there is a need to move the slab, you can use a crowbar. Its position can only be aligned along the laying area; the slab cannot be moved across the walls, otherwise the walls may collapse. The slings are then removed and a signal is given to the crane operator to pick them up.
The procedure is repeated for all slabs without exception. The rules for installing floor slabs suggest that the alignment of the slabs should be done along the bottom edge, since it is the bottom surface that will be the ceiling in the room. Therefore, the slab is laid with the wider side down and the narrower side up.

You may come across a recommendation that reinforcement must be placed in the area where the slab is supported. Proponents of this method say that it is more convenient and easier to move the stove. In fact, placing anything other than concrete mortar under the slab is prohibited by the technical map. Otherwise, the slab can easily move out of the support area, as it will slide along the reinforcement. In addition, the load will be distributed unevenly.

Laying floor slabs on the foundation is practically no different from laying interfloor slabs. The technology is exactly the same. Only the surface of the foundation must be thoroughly waterproofed before laying the slabs. If the project provides for non-standard support of floor slabs, then special steel elements are used for this. Such work should not be carried out without a specialist.

Anchoring - tying the slabs together - can be done in two ways, depending on the project.

First - tying slabs with reinforcement. Reinforcing rods with a diameter of 12 mm are welded to the fastening embedded elements on the slab. For slabs from different manufacturers, the location of these elements may be different: in the longitudinal end of the slab or on its surface. The strongest connection is considered to be a diagonal connection, when the plates are connected to each other with an offset.

The slab must also be connected to the wall. Why is reinforcement built into the wall?

Second way - ring anchor. In fact, it looks like an armored belt. Formwork is installed around the perimeter of the slab, reinforcement is installed into it and concrete is poured. This method slightly increases the cost of laying floor slabs. But it's worth it - the slabs end up clamped on all sides.

After anchoring, you can begin to seal the cracks. The gaps between the floor slabs are called rustications. They are filled with concrete grade M150. If the gaps are large, then a board is tied from below, which serves as formwork. If the gaps are small, then the floor slab will be able to withstand the maximum load the very next day. Otherwise you need to wait a week.

All modern slabs with round voids are produced with the ends already filled. If you purchased slabs with open holes, then they need to be filled with something 25 - 30 cm deep. Otherwise the slab will freeze. You can fill the voids mineral wool, concrete plugs or simply fill with concrete mortar. A similar procedure must be performed not only on those ends that face the street, but also on those that rest on the internal walls.

The price for laying floor slabs depends on the scope of work, the area of the house and the cost of materials. For example, the cost of PC floor slabs alone is approximately 27 - 30 USD. per m2. The rest - related materials, renting a crane and hiring workers, as well as the cost of delivering slabs. Professional teams have very different prices for installation of floor slabs, from 10 to 25 USD. per m2, maybe more depending on the region. As a result, the cost will be the same as for pouring a monolithic floor slab.

Laying floor slabs: video example

Most often in country houses Of course, wooden floors are installed. But in cottages with 2-3 floors, this structural element of the building can also be poured from concrete. Such floors can withstand heavy loads and at the same time are reliable. However, the construction of such structures, in comparison with wooden ones, is, of course, more expensive. In addition, the technology itself for arranging floors of this type is considered relatively complex. Concrete structures of this type can be poured, for example, using a profiled sheet.

Characteristics

Monolithic floors can be erected using corrugated sheets not only in private homes, but also, for example, in industrial buildings, garages, warehouses, etc. Such structures are quite heavy in weight. But since in this case corrugated sheeting is used as formwork, it takes less concrete to fill them than to install a conventional monolithic slab. Consequently, the weight of the ceiling is reduced. Accordingly, such a slab puts less load on the supports.

The advantages of such structures, in comparison with conventional monolithic ones, also include:

no need to use multi-row reinforcement;

possibility of installing the ceiling in short terms;

no need to dismantle the formwork.

In industrial premises, the ceiling filled in this way is usually not even further finished. The profiled sheet looks quite aesthetically pleasing.

Design

Before you start constructing a monolithic floor using corrugated sheets, of course, you should draw up a detailed drawing of it and do everything necessary calculations. Designing such structures is a very complex and responsible matter. Errors in the calculations of monolithic floors can lead to their rise in cost, shortened service life, and in some cases even to the collapse of the structure.

Therefore, the design of such slabs is usually entrusted to specialists. The owner of a house can independently calculate a monolithic floor using corrugated sheets only if he has special education. You can also create a project for such a slab using software developed for this purpose.

Requirements for floors

In most cases, I-beams are used as beams for such slabs. When designing a monolithic floor using corrugated sheets, the following factors are taken into account, among other things:

each sheet must rest on at least three beams - at the edges and in the center;

beams should be laid at a distance of 1.5-3 m from each other;

along the length, the sheets can be mounted end-to-end when assembling formwork for floors;

the width is overlapped by at least 1 wave;

the layer of concrete mixture after pouring should rise above the waves of material by at least 5 cm;

The reinforcement frame for such a slab should be knitted from 12-8 mm rod.

The surface of the finished slab can be 3 cm vertically away from the edge of the sheet waves. However, pouring in this way is allowed only if a screed is subsequently intended to be poured on it.

Concrete floors, including corrugated flooring, are installed only in buildings with heavy walls. It is allowed to support slabs on metal sheets only on brick or block enclosing structures. Equip structures of this type in wooden structures it is forbidden.

Installation of monolithic flooring on corrugated sheets: installation technology

Corrugated ones are laid on I-beams in such a way that their waves are perpendicular to the latter. Most often used for pouring floors roofing material, marked N. It is believed that a sheet with a not too high wave is best suited for the installation of such structures. It is advisable to use such corrugated sheeting under a monolithic floor, primarily because in this case it turns out to be the most durable.

Ribbed ones are fixed metal sheets on I-beams when installing formwork with reinforced self-tapping screws. When using such fasteners, there is no need to pre-drill holes in the decking and beams. Screw in the screws with a drill at low speeds in increments of about 30 cm. The width of the corrugated sheet overlaps is usually additionally secured with rivets.

Attic passage

After the entire opening of the building is closed, vertical formwork walls made of boards are installed along the edges of the future slab. The same elements are installed where it is planned to make an exit to the attic in the future. Before assembly, experts advise covering the boards with plastic film. This will make dismantling them much easier later.

After removing the boards from the finished slab, at the point where the attic exits, the corrugated sheeting is simply cut with metal scissors. The operation is very simple and can be performed in a few minutes.

Reinforcement

At the next stage, reinforcement is installed on the formwork made from corrugated sheets and boards. When knitting it, a thicker rod of 12 mm is usually placed parallel to the waves. Perpendicular elements are made from 6-8 mm reinforcement. If desired, you can also purchase a ready-made reinforcing mesh for such an overlap. However, pouring the slab in this case will, of course, cost a little more.

Of course, after pouring the monolithic floor over the corrugated sheet, the frame should be in its thickness. Therefore, the associated reinforcement is lifted above the sheet using special plastic clamps. According to the standards, the connected mesh should be located above the bottom of the metal formwork at a height of at least 1.5 cm. This will allow for a fairly reliable and durable floor to be poured.

When installing a slab on a corrugated sheet, both self-made and purchased reinforcement cages are mounted using the same technology. For knitting mesh with your own hands, you should use strong wire, 1.2-1.4 mm thick.

Additional supports

After the reinforcement frame is connected and installed, the actual pouring of the slab begins. Previously, if necessary, additional steel or wooden vertical supports are installed under the sheets between the beams. Such structures are used if the distance between the I-beams was chosen to be large enough when drawing up the project for a monolithic floor on corrugated sheets. After the slab hardens, the additional supports are simply dismantled.

Pouring the slab

Concrete mix To build monolithic floors on corrugated sheets with your own hands, in the vast majority of cases, they use ready-made purchased ones. The fact is that such structures must be poured in one step. Concrete is placed in parts into the formwork, mainly only when installing large ceilings, for example, production workshops.

Of course, cook it yourself right away large number cement mortar and pouring it onto the sheets will be extremely problematic. Therefore, concrete is laid when installing monolithic floors on corrugated sheets, usually using the following technology:

a concrete truck is ordered to the work site;

feed the solution into the formwork from a steel hose;

As the mixture spreads, all resulting defects are smoothed out manually.

Also, during the pouring process, it is advisable to pierce the concrete with a shovel from time to time. This will avoid the appearance of voids in the finished slab, reducing its strength.

Final stage

Monolithic floors on corrugated sheets, like any other concrete structures, take quite a long time to harden. The slab will gain sufficient strength only 4 weeks after pouring. At this point, you can remove additional supports from under them and begin, for example, building a roof.

While the slab is hardening, you need to carry out proper care. For the first two weeks, the ceiling should be watered at least once a day. Otherwise, surface cracks may form on the slab. And this will certainly lead to crumbling of the top layer in the future. For reliability, the wetted slab can also be covered with plastic film. It is especially important to carry out this procedure in hot weather.

What you need to know

Interfloor ceilings should only be poured at above-zero temperatures. Otherwise, such a design will not turn out to be too strong. Sometimes concrete slabs are made on corrugated sheets in winter. However, in this case, a mixture of a special composition is used for filling, which increases the cost of the work.

Monolithic ceiling on corrugated sheets: manual pouring guide

During the production of slabs, concrete is supplied to the formwork, thus, in most cases, from a tank using a hose. However, there is a technology for self-filling such structures. In this case, additional sectional adjustable formwork is installed above the corrugated sheet.

In this case, each part of such a structure should be filled at a time. The sections must be positioned across the I-beams in such a way that each individual slab is subsequently supported by at least three beams.

The cutting walls of such formworks are not statically attached to the main frame. After pouring each section, the board is simply rearranged to the same distance. This formwork element is configured in such a way that adjacent finished slabs, after pouring, are interlocked using the tenon/groove lock principle.

Do you need a screed?

The technology for installing a monolithic floor on corrugated sheets is therefore relatively simple. Compared to concrete structures, slabs cast on metal ribbed sheets are usually thinner. After all, in this case formwork gives them additional strength. However, when using a hose to supply the solution, the surface of such ceilings, unfortunately, is usually not particularly smooth. After all, it can be quite difficult for builders to correct it during pouring.

Therefore, after the slab has hardened, in most cases, a concrete screed. You can prepare the mixture for such a leveling coating yourself. Concrete mixed in a cement/sand ratio of 1/3 is usually used to fill the screed. The minimum permissible thickness of such a leveling coating is 3 cm.

Operating rules

The service life of monolithic ceilings, including those cast on a profiled sheet, corresponds to the durability of the main load-bearing elements Houses. That is, you will never have to change this design in the future. However, such floors can last so long, of course, only if they are used correctly.

The service life of structures of this type may be reduced due to:

exposure to aggressive environments;

frequent changes in humidity.

To ensure that such a monolithic ceiling on corrugated sheets does not have to be repaired or dismantled in the future, communications - heating and water supply pipes - should be laid in the attic in strict compliance with all required technologies. This is especially true for slabs that serve as floors or ceilings for bathrooms, steam rooms, etc. Any leaks over such floors must be repaired immediately.