Monolithic overlap with your own hands. Calculation, preparation and installation of formwork. Do-it-yourself monolithic concrete floor How to make a formwork for a monolithic floor

H The stronger the floor structure, the more reliable the protection. Concrete slabs are especially good for this. But in order to lay them, a crane is required, which is both expensive and not always possible to use.

An alternative for the floor device would be the use of monolithic concrete. Its laying can be done in relatively small portions, the weight of which allows manual work.

But how to ensure that a self-made monolithic concrete floor has sufficient strength and does not crack or, worse, does not collapse? Is it possible and how to do it without using complex calculations and formulas? Yes, it's possible. But let's go in order...

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How is the concrete floor

To begin with, let's figure out how a concrete floor slab works and how it works. Without this, some points may be incomprehensible.

The strength of concrete, like other stone materials, is not the same depending on the direction of the load. Best of all, it withstands compression, and worst of all, it withstands stretching.

Moreover, the difference is so great that in the calculations of the strength of structures, the tensile strength of concrete is usually not taken into account at all!

But the floor slab rests on the edges, and is loaded over the entire surface. At least its own weight. Obviously, she will tend to bend. If we consider the cross section of such a plate, then in the upper part it is compressed, and in the lower part it is stretched. Moreover, the efforts will be maximum at the top and bottom, and in the middle of the section they will turn out to be zero (see Fig. 1).

Since, as we have already said, concrete is disgustingly resistant to stretching, it is reinforced with metal reinforcement. Without it, an ordinary stove would break even under its own weight.

Reinforcement is needed not only at the bottom of the section. There are other places in the floor slab that experience tension, they also need to be reinforced. How and what stresses arise can be seen in Figure 1.

Interesting: The Parisian gardener Joseph Monier, who invented reinforcement, thus becoming the "father" of reinforced concrete, was nevertheless a complete ignoramus in construction. So, until the end of his days, he was sure that the reinforcement should be laid in center sections of bent structures. In fact, here it is absolutely useless.

We select reinforcement and brand of concrete

The greater the thickness of the slab and the strength of the concrete, the greater the diameter of the reinforcement, the stronger the overlap. But at the same time heavier and more expensive.

For the solid part, we use OSB3 with a thickness of 16 mm. It is cheaper than the waterproof plywood commonly used on a construction site, and then goes for, on, subfloors, etc.

We will find out the layout of beams and racks when using inventory formwork when we rent it. This scheme depends on both the load and the type of equipment.

The ceilings are solid reinforced concrete structures. Their use is relevant for increased weight loads, primarily in multi-storey buildings. In private construction, their main advantages include the ability to reduce installation costs by independently performing individual or all stages of work with minimal involvement of special equipment. The technology is considered time-consuming, to eliminate errors, the calculation of the slab should be entrusted to specialists. The parameters obtained must be taken into account when preparing the main project of the house.

Conventionally, everything is divided into prefabricated (solid or hollow, manufactured at the factory), often ribbed (cellular type with sections of lightweight material or empty blocks) and monolithic. The latter are valued primarily for the absence of seams, this option is chosen when concreting multi-storey buildings, pouring floors or delimiting floors in individual buildings. Depending on the design and installation method, they are divided into: beamed, beamless (the most popular variety with a smooth surface in the construction of private houses), with fixed formwork (at the same time it acts as a heat-insulating layer) and laid on steel decking. The latter are valued for reducing labor intensity and the possibility of reducing thickness and weight.

Features and benefits of a monolithic floor

The pluses include:

1. Strength and solidity (lack of seams), and, as a result, ensuring a uniform load on the foundation and load-bearing walls.

2. Possibility of leaning on columns. This gives more freedom in the planning process compared to the option of laying prefabricated floor slabs from standard size prefabricated elements.

3. Safe arrangement of the balcony without the need for additional supports due to the solidity of the main horizontal structure.

Calculation of the slab, drawing up a reinforcement scheme

Ideally, the design is entrusted to specialists, they will help you choose the option with correctly distributed loads, which is optimal in terms of “reliability-cost of building materials”. The initial data for self-calculation are the dimensions of the floor with the obligatory consideration of the width of the supporting platforms. The thickness of the monolith is selected based on the maximum value of the longitudinal span (the ratio recommended for beamless structures is 1:30, but not less than 15 cm). For floors within 6 m, the minimum is 20 cm, over 6, options are considered with their reinforcement with stiffeners. In varieties of the beam type, the step of the supports is taken into account (respectively, the minimum height is found by dividing it by 30).

The calculation of the slab begins with determining its own weight: the average (2500 kg / m3) is multiplied by the thickness of the floor. The rate of live load (weight of furniture, equipment and people) for residential buildings is 150 kg / m2, taking into account 30% of the reserve, it is increased to 195-200. The total, maximum possible load is obtained by adding these values.

To check the section of the reinforcement, the maximum bending moment is calculated, the formula depends on the way the weight is distributed. For a standard beamless floor supported by two load-bearing walls М max = (q l2)/ 8, where q is the total load, kg/cm2, l2 is the span width. This formula is the simplest, in the absence of reinforcement in the zones of maximum compression of concrete or uneven distribution of weight, it becomes more complicated.

To check the cross section of the reinforcement, a coefficient is calculated that takes into account the design resistance of building materials (reference values ​​depend on the selected mortar strength class and steel grade). The obtained value corresponds to the minimum allowable metal area in the cross section of the plate. It is compared with the preliminary one; if it is exceeded, the circuit needs to be strengthened (reducing the cell pitch or using rods with a larger diameter).

Due to the complexity of the calculation, specialists are usually trusted; when passing it, a chess pattern is selected from two grids (lower and upper) with a cell pitch of 20 × 20 cm and a rod thickness of 10-14 mm (hot-rolled steel). Both reinforcement is provided in the center of the monolithic slab, areas with increased loads and places of contact with supports, as well as a margin for overlapping walls (depending on the strength of building materials - from 150 mm for brick to 250 for cellular concrete). Longitudinal and transverse rods, if possible, are laid inseparably, if this condition is violated, they overlap - at least 40 cm.

The main stages of installation

Laying begins with the calculation and purchase of building materials (ideally, project data is used). Formwork structures are being prepared: panels made of thick moisture-resistant plywood, metal or plastic, beams and telescopic supports (1 pc / m2), equipment for preparing, supplying and compacting concrete, a tool for bending reinforcement and special stands. If necessary, an armored belt is laid along the perimeter of the load-bearing walls, such a need arises when erecting ceilings in a house made of aerated concrete.

The main steps include:

• Assembly and installation of formwork.
• Placement of the armored carcass.
• Filling a monolithic slab with concrete, compaction and leveling.
• Moisture maintenance of the solution, covering, dismantling of the formwork after 28 days.

1. Requirements for supports and shields.

Installation involves pouring concrete into a sealed horizontal formwork, preference is given to special collapsible structures. In principle, it is easy to make shields yourself from plywood with a thickness of at least 20 mm (it is better not to use boards due to difficulties in fitting). A prerequisite is the installation of telescopic metal racks (when erecting the floor of the first floor of the house, they are replaced by stationary supports). In their absence, replacement with logs with a diameter of at least 8 cm is allowed, but one should be prepared for problems when adjusting the level.

To support the shields, a crossbar is laid - a longitudinal beam with a cross section of at least 10 × 10 cm, if necessary, the formwork is reinforced with transverse elements (this situation most often occurs when working with homemade products). The shields are laid without gaps, the edges tightly rest against the wall. When mounting vertical structures, the value of the approach to the carrier systems is taken into account. To eliminate the risk of leakage, the bottom is covered with a film, sealed factory reusable varieties are lubricated to facilitate the removal process. The stage ends with a level check, deviations are not allowed.

2. What should be taken into account when reinforcing?

Reinforcement with metal is the main requirement of the technology. The distance from the edge of the concrete to the metal is at least 25 mm. The joints are tied with wire with a cross section of 1.2-1.5 mm, welding is not allowed. For meshing, pre-prepared clamps are used: made of steel with a thickness of at least 10 mm, with an interval of up to 1 m, similar elements are placed at the ends. Reinforcement of a monolithic reinforced concrete floor is completed with the laying of connectors that ensure uniform load perception on the entire system - after 40 cm near the walls, after 70 from it, with a subsequent step of 20.

3. Nuances of concreting.

The main requirement of the technology is the continuity of the process; ideally, the solution is ordered at factories and poured using the appropriate equipment. The recommended thickness of the concrete layer is 20 cm, which in most cases coincides with the height of the floor itself. The minimum grade is M200, in order to enhance the thermal insulation properties and lighten the weight, part of the coarse-grained high-strength filler can be replaced with expanded clay, but this method requires approval by specialists (strength testing).

Holes for the supply of communications and ventilation ducts are laid before the start of pouring, drilling of a frozen monolithic slab is a violation. The stage ends with the obligatory compaction of concrete using internal vibrators. The rules for caring for the surface are generally standard, but it is impossible to water the structure abundantly with water, unlike the foundation or vertical walls, it is wetted more accurately.

Rates

The cost of filling when contacting professional firms varies from 4,000 to 9,000 rubles / m3 (subject to the use of the customer's formwork). The total cost depends on the chosen reinforcement scheme, the height of the future slab (from the ground level or from the mark of the previous horizontal support) and its thickness, the method of placement (on columns or load-bearing walls), and the total amount of work. The list of services of construction companies includes the installation and dismantling of formwork structures, assembly of the reinforcement cage according to a project prepared in advance (paid separately), continuous concreting and care of the laid mixture: watering, covering, and, if necessary, warming up. The advantage of turning to professionals is the mandatory quality control carried out at the end of curing.

The advantages of laying flooring with your own hands include a reduction in the cost of paying for work - up to 30% at least. For pouring, simple building materials are used - concrete and reinforcement, saving on them is unacceptable. The volume of the solution is calculated based on the thickness and area of ​​​​the slab, the length and weight of the metal - according to the reinforcement scheme drawn up in advance. Renting formwork structures is expensive: the minimum price per m2 is 400 rubles per month (you can’t rent it earlier).

Additional costs when doing do-it-yourself work include the need for special equipment and containers for raising the solution up (bucket shoes and a crane or concrete pump). This is not a problem when arranging solid floors on the basement floors of a house, but in other cases, you cannot do without the appropriate equipment. This is due to the main requirement of the technology - a continuous process of concreting, monolithic ceilings with individual patches, frozen on different days, are inferior in quality to those poured at a time. The minimum costs for performing all stages on their own are 3200 rubles per 1 m2 with a plate thickness of 20 cm.

Do-it-yourself interfloor overlapping is important to install correctly, gradually applying construction technology. It is necessary to delve into all the details of the construction of buildings.

At the first stage, it is important to determine the thickness of the main load-bearing walls of the first and second floors; the thickness of the future floor will depend on this. According to the standard for houses made of brick or aerated concrete, the interfloor ceiling can be set from 15 to 20 cm, in houses made of more fragile materials, the thickness decreases. Interfloor technology depends on the selected materials, the height of the future structure and the weight of the entire structure.

Formwork and formwork installation

start with the formation of formwork. It is installed between floors, designed for stable fastening of the transverse beams. If there are old wooden boards, their use will be appropriate. Initially, having formed a coating of boards, it is necessary to install a support. Often used stable logs. A layer of waterproof plywood is laid over the formed structure. Next, check the quality of the structure for sagging. When eliminating shortcomings and bends, you must immediately eliminate them. In the future, the design must be stable, withstand the additional load of furniture, distributing the load.

The device of interfloor overlapping is divided into several main types:

• Reinforced concrete;
• Monolithic;
• prefabricated;

Do-it-yourself reinforced concrete flooring is popular in stone and brick buildings. A design feature is the laying of hollow panels. When seams are formed, they are completely filled with mortar. The disadvantage of forming reinforced concrete type floors is their massive weight and the need to use lifting equipment. In addition, the plates have a standard size. With a house perimeter that differs from the typical project, it will be difficult to correctly install the support of each slab.

Do-it-yourself wooden interfloor ceiling built if you want to save money and time for construction. At the same time, it is important to correctly determine the type of overlap and the ability to carry out installation without the involvement of additional equipment, renting forklifts and a team of specialists.

Monolithic cover. Main characteristics

The device of interfloor overlapping monolithic type is a homogeneous solid structure, the mass of which is distributed on the load-bearing walls. The use of a monolith has an undeniable advantage in the absence of the need to use construction equipment. This coating is effective in that it makes it possible to implement modern architectural solutions created by oneself at no additional cost. Before starting installation, it is advised to prepare building beams that will serve as a support. The steel surfaces of the beams are mounted on wooden partitions.

Typical formwork includes the presence of elements:

• Special telescopic racks;
• Holding tripods;
• Flooring;
• Main moisture resistant plywood;
• Frame and fittings.

The nuances of laying reinforcement with your own hands

Installation of interfloor ceilings carried out as far as possible without touching the surface of the formwork. The dimensions of the reinforcement range from 6 to 12 mm. At the same time, the structure is fixed with certain clamps. The formed frame leaves cells 10 * 10 cm. A wire is used to tightly bind the frame to the cells. Beams can be used in various types from wooden to aluminum. Further, the entire surface of the layer is densely filled with mortar, forming a uniform surface.

It is quite difficult to completely fill the ceiling with your own hands. The main nuance is in the implementation of the casting layer no more than 10-12 hours from the previous one. To create a uniform layer, the solution must not be allowed to dry completely. The technology of interfloor overlappings makes it possible to obtain reliable adhesion of the monolith to the surface of the overlapping and mortar, fastening the entire structure. This way of creating an overlap with your own hands is the most reliable, safe and easy to install. Complete solidification of the entire layer occurs no earlier than 28 days after the last pour. Uneven drying leads to the subsequent destruction of the surface, the formation of chips, cracks and additional dust. If it is necessary to eliminate the resulting defects, it is important to simultaneously fill the entire surface with a small amount of water and leave to dry completely.

Overlappings of prefabricated monolithic type and their differences

The prefabricated-monolithic type of flooring is the most relevant and in demand in the cottage-type construction market. The combination of support beams on one side and hollow blocks on the other has many advantages. The device of beams of interfloor ceilings must be evenly poured with concrete and the interfloor structure is ready. The weight of a typical design is quite low and is no more than 19 kg per square meter. It is somewhat more difficult to make a prefabricated monolithic floor in time, however, it is not required to rent lifting equipment and all stages can be carried out independently. Wire reinforcement of the entire structure is created no more than 6 mm in diameter.

Removal of formwork and installation of interfloor ceilings

When mounting the main floors, the formwork is removed. Removal of the side surfaces is permitted when the main floor is completely frozen and has formed a solid structure. It is necessary to carefully check the entire surface from all sides.

The strength of a concrete structure is determined by the indicators:

• Bearing elements whose span is less than 2 meters make up 50%.
• Slabs with a span of 6 meters or more - 70%.
• Reinforced types of structures no more than 25%.

How to determine the strength of the hardened concrete of the installed floor slab?

The concrete surface increases the strength of the coating from the moment the last layer is poured over time:

• Day 3 strength is about 30%.
• Day 7 increases to 60%.
• Day 14 is 80% or more.
• Day 28 is about 100%.
• The 90th day is increased by 30%.

The duration of hardening of the concrete floor depends on the air temperature and the level of humidity of the environment. There are special additives that help speed up the process of hardening of concrete on the floor surface.

Installation of interfloor ceilings can be time-consuming, in case of difficulties, InnovaStroy specialists recommend contacting experienced craftsmen.

Do-it-yourself wooden interfloor ceiling

The wooden ceiling structure is responsible for the formation of a stable floor covering of the upper floor and an even, reliable ceiling of the lower floor. The main mass is taken by the bearing walls of the building. The device of wooden floors is the most popular and in demand in the modern construction of country houses. Due to the ease of construction, the quality of the resulting floor, environmentally friendly materials and economical costs. Wooden blocks tightly bind the elements of the structure, horizontally carrying out the load on all the main supporting walls.

Benefits of installing wooden floors

• Increased level of thermal insulation;
• Preservation of the acoustic properties of the room (if necessary);
• Simplicity and ease of installation with your own hands;
• Carrying out work in all weather conditions;
• The use of any type of ceiling: basement, interfloor, attic, attic.

When using wooden floors in areas prone to moisture accumulation (bathroom, basement, pool area, baths, etc.), it is recommended to use an additional level of waterproofing material.

General characteristics and arrangement of wooden floors

The device of interfloor overlapping on wooden beams requires attention to the possibility of bearing weight. The own weight of the wooden covering is about 250 kg, while the weight of the additional load is taken into account at least 200 kg.

When choosing the dimensions of the beams, it is necessary to clearly determine:

• The thickness of the beam (according to the standard, at least 5 cm);
• Height 15 cm or more;
• When laying wooden beams with a step of 50 meters or more, it is necessary to use a mineral-type insulating material.

The list of necessary tools for the installation of ceilings with your own hands:

• The presence of anchor bolts;
• Keys;
• Staples;
• A hammer;
• Screwdriver;
• Keys;
• Strong rope;
• Nails;
• Hacksaw for wood;
• Roulette;
• Axe;
• Rigid construction cord.

Possessing the stages of technology, the necessary tool, the installation of an interfloor ceiling is quite easy. The installation of wooden floors begins with the laying of a bar. Professionals advise using a glued look with a length of 12 meters or more.

Differences of a wooden ceiling:

• Used when creating individual design of cottages .
• The cross section of the material used depends on the width of the opening and the weight of the future structure, the ability to hold the load of the building foundation.
• When purchasing material for the formation of interfloor ceilings, it is important to pay attention to the quality of the timber. Additional drying for more than 4 months and antiseptic treatment will keep the original quality for a long time.
• In the event of suppuration of wood, the formation of chips and cracks, it is forbidden to use timber!
• All dimensions must be checked and adjusted to the required. The use of beams and bars of various levels is not recommended.
• The fire safety of wood flooring requires additional processing to form a sustainable effect of open fire.

Sometimes masters recommend using rough bars, which are installed on the edges of the beam elements. Next, a roll is formed and a dense rough coating is formed. Arrangement of ventilation also plays a significant role in creating a cozy interfloor overlap. Free circulation of air flows between floors allows you to maintain a comfortable climate inside the building.

The company InnovaStroy specializes in the construction of houses for individual orders on a turnkey basis. High-quality interfloor ceilings are the main task of creating comfortable multi-level housing.

Do-it-yourself video of existing types of interfloor ceilings, offered for viewing by InnovaStroy.

Thank you.

Concrete was ordered M300. Supplier - titanbeton. en
Two drivers who visited me do not understand Russian, do not have maps, do not know the area. The first one had to be fished out in a neighboring town, according to his unintelligible tips, something like "I'm standing at the store, I don't remember what I was passing through." Basically, it got on my nerves. They carry 5 m3. Well, if there really was 4.5 m3.

Separately, a few words about the concrete pump. Initial price - 18 tr. Arrow 32m, poured through the fence without any problems without leaving the asphalt. The driver is a good man, although at the end he asked for 2tr more than what was allegedly claimed for the "move", but he explained and told everything about the filling process itself. The unit itself is very difficult to work with. Although the carrier tried to supply concrete intermittently with one “pumping” of the pump, the pressure and flow rate required great efforts to turn the sleeve back and forth, directing everything inside such a narrow formwork, evenly distributing concrete in layers of 30 cm.

In total, 17 cubic meters of concrete were ordered, the possible refusal of the last mixer at RBU was agreed in advance, payment was made on the spot. After pouring 2.5 mixers, that is, 3/4 of the total volume, after thinking and thinking, we decided to hang up on the concrete unit, we were afraid that the formwork would not survive. They began to vibrate in the old fashioned way, with reinforcement bars - for the same reason. As it turned out, not in vain.
The concrete ran out, the last mixer left. In the receiver of the concrete pump, as expected, there are 200-250 liters of concrete left. The carrier said to point the sleeve somewhere in order to swing something else. Throwing the sleeve on the thin wall of the partition, we did not expect that in a couple of seconds he would spit out another 70-90 liters there almost to the top. And then the formwork cracked ... everyone froze. On M10 studs of medium height, washers with a diameter of 30 mm by 0.5-1 cm were pressed into wooden racks on each side and, as it turned out, a nut was torn off on one of the studs. Thus, the formwork has become wider by these centimeter and a half. There was no further destruction, I exhaled. Geometry violations are not critical. After removing the formwork, they are not noticeable at all.
The remaining concrete was poured onto the platform next to the gate onto the bedding film. We also dragged this concrete into the formwork in buckets, leveling the level more or less everywhere, just up to the windows. Having done everything once more, they parted on this.

The next couple of days, periodically pouring concrete, on the ground closer to the pit, a formwork was assembled that could accept a 5-cube mixer. According to estimates, a volume of 4.8-4.9 m3 was needed. Having agreed with four working crests nearby, I made an order in TitanBeton. I made several portable ladders around the formwork, through which concrete could be poured immediately from the wheelbarrow. The mixer arrived and unloaded. We started to carry. Two people are constantly raking concrete with shovels, one carries it on a wheelbarrow, two more stand inside and pass buckets to each other. I don't remember exactly how long it took. But the concrete did not have time to rise. 2.5-3 hours, I think we managed. However, the concrete was not enough and well. All vibrated. I drove to the market for cement, leaving myself one assistant, they made about 9 more batches of 400 liters. I ran great. Covered everything with a film, left.

After waiting a few days, I began to slowly disassemble everything. I dismantled the trough for concrete, scaffolding, tore off the film. The weather was rainy, so I was not afraid for the concrete to dry out.

When building a house with their own hands, each person is faced with the need to make, which will be found on every floor from the basement to the attic.

There are three options for such overlaps, each of which has its own nuances:

• wood (round timber and timber);
• slabs (reinforced concrete and hollow);
• monolith (full-fledged and on metal beams).

The most difficult and expensive is considered to be a monolithic floor, because. it takes a lot of time (about a month), money and labor to make it. However, in the end, the design justifies itself 100%, because. it is the most durable, has the best insulating properties, and almost never even requires cosmetic repairs.

In order to make a monolithic ceiling, you should decide in advance which type you will like, because. they have significant differences in all respects.

Differences will include reinforcement, concrete (thickness), support system and preparation time.

A full-fledged monolith will cost much more, its construction will require much more effort and time, but the structure will stand for centuries. The thickness of the concrete in it will be twice the same characteristic of the colleague. But this option is not suitable for every floor. For example, it makes no sense to put it at the level of the basement, because. concrete will be poured just like that.

If interfloor ceilings are installed on iron beams, each of them will be twice as thin, but its second half will be compensated by the strength of the metal. In this case, the design will not stand idle less than the previous one, but it will be much easier to create something from it. This type will suit any modern design. In addition, concrete, reinforcing rod and plywood will take much less.

Preparation for work

• sheet A3;
• pencil with eraser;
• plywood laminated;
• hammer with nails;
• only;
• supporting system (wooden beams 100 * 100 and metal spacers from 2 mm thick).

This concrete floor is installed exclusively as reinforced concrete slabs between the first and second floors, but not at the level of the basement or attic. The fact is that it makes no sense to put it at the basement level, and when installed above the second floor, it will already turn out to be excessively heavy. But in order for the results of the work to be of high quality, it is necessary to follow the order and a clear sequence in each step.

1. Drawing up a work plan. At this stage, the device of the future scene of action looms, all load-bearing walls are determined and a selection of materials is made. But, as a rule, the set is standard, and everything is calculated so that you can make a purchase in advance. For the perimeter of the scene, you should take the outer side of the wall of the floor, because. the floor must be firmly on its base. Do not allow deviations, tk. they can result in insufficient strength when the concrete is already poured. Concrete should always be taken of the same brand and in no case should it interfere. This rule is independent of the level.
2. Formwork manufacturing. In its manufacture, first of all, it should be taken into account that the arrangement of all joints must be perfect. Each mm must be in a horizontal plane. The side panels will rise 0.3 m above the formwork level. In no case should you nail the side panels to the edge of the pallet, because. a solution of concrete under pressure can tear them out and all work will have to be started over again. All fastenings occur exclusively in the vertical part of the slab.
3. At this stage, a support system will be installed, consisting of wooden beams and metal braces, which can be interchanged if desired. Wooden beams are laid at the rate of 1 pc per 1 m², while spacers - 1 pc per 2 m². With this ratio, you can not be afraid that the ceiling will collapse. Do not forget that the pressure on each of them will be about 500 kg, and even more at the time of pouring (due to the impact energy when concrete falls). After the entire system is installed, you should go to each individual beam and check it again for stability. After that, you need to climb the formwork itself and walk along it with a firm step. There should be no reaction, as if it were a walk down the street. If deviations are felt, then they must be found and redone, otherwise the concrete will make its way down.
4. If all is well, then you can proceed to the last part of the preparation. Waterproofing is carried out in two ways: using roofing felt or plastic film. The material is laid on the formwork, leveled and pressed with something massive, so that it not only does not fly away, but does not even change its shape. Under concrete, it is better to use roofing felt, because. it has great strength and insulation parameters.

Slab reinforcement

• reinforcing rod А500С;
• soft wire;
• roulette.

At this stage, work will be done on reinforcement.

1. The first step is to decide on the reinforcing rod. It must be strong enough, but at the same time not have an excessively large weight, so that the reinforced concrete structures are kept at a height. The best option is A500S. When calculating, it must be taken into account that a double crate is laid, which significantly increases material costs. It is produced as follows: the rods are laid out end-to-end to the wall in parallel with a step of exactly 0.5 m, after which exactly the same level of rods is laid perpendicular to them. Each of their intersections is tightly connected with a soft wire. The work is very long, but necessary.
2. After the first crate is completed, the second is done in exactly the same way, but you should not tie them together. It is also worth remembering that each of them has a level. The lower one should be 25 mm above the formwork level, and the upper one should be exactly the same below the upper pouring bar. To do this, improvised brackets should be bent from the same rod, which will be installed in the amount of 1 piece per 4 m², and all reinforcement will be tied up on them.
3. Once the installation is complete, you can start testing. The process will not take long, but you will need to check each rod for stability, and then shake all the reinforcement. If nothing has moved, we can assume that the work has been done in good faith, but if deviations appear, they should be immediately eliminated and only then concrete should be poured.

Pouring concrete for a slab

• concrete grade 400 and above;
• automixer with hose;
• supporting system (wooden beams 100 * 100 and metal spacers from 2 mm thick);
• only;
• shovel;
• bayonet shovel;
• polyethylene film;
• water;

1. Before you start pouring, you should remember that you should not even start preparing concrete yourself, because. for a 10 * 10 slab, 28.5 m³ will be required, and it will be difficult even for a whole team of builders to do it with their own hands in a day. Here, automixers with a hose for concrete supply are called to the rescue. When ordering, you should know in advance what the volume of the drum is (most often it is 8-9 m³). With this knowledge, it will be easier for you to calculate the amount of material needed.
2. This step may require the help of 1-2 people. In this case, the filling will occur quickly and without stops. During the pouring of the floor, one person must continuously move along the formwork and direct the concrete in different directions. This is required in order to make the pressure on the formwork uniform. If there are no assistants, then from time to time you will have to stop the pouring process and take up the shovel yourself. Each layer should be plowed to release the collected air. This will have a very positive effect on the quality of the filled plate. The lowest level must be plowed very carefully, otherwise the waterproofing material may be damaged. It will be great to interfere during the process, because. he will have to constantly step over so as not to stumble.
3. When the concrete is poured, you should cover everything with plastic wrap and leave it like that for 27-29 days. During half of this time, one should not forget about wetting the plate with water so that it can fully gain its strength.
4. After the specified time, the supporting system is removed, the polyethylene is removed, and the formwork is dismantled with a crowbar. The result is a perfectly smooth surface on the underside and a slightly uneven top. This is corrected later on immediately. With the right approach, such reinforced concrete slabs will not have a single deviation.

Monolith installation technology

• beams (I-beams);
• concrete grade 400 and above;
• laminated plywood 20 mm and thicker;
• roulette;
• reinforcing rod А500С;
• soft wire;
• roulette;
• automixer with hose;
• shovel;
• bayonet shovel;
• polyethylene film;
• water;
• hammer with nails.

This technology allows you to install the slab not only between the 1st and 2nd floors, but also on top of the basement. It is lighter and thinner, but no longer has the same strength parameters, although it has a number of other advantages. Partially the scheme will be similar.

1. In this case, the first step will not be the formwork for concrete, but the beams. They are mounted whenever possible through the narrow parts of the room, if it is not square. During installation, it should be borne in mind that, on average, the length of one beam is 6-8 m, and this can create significant discomfort if you do not insure yourself in advance with an additional load-bearing partition. Each subsequent I-beam technology prescribes to be located at a distance of 1 m from the previous one.
2. Formwork is installed on the beams, the height of which is not 0.3 m, but 0.15-0.2 m. This is due to the fact that at this stage the basic supporting structure already exists.
3. The second difference will be the supporting system of the future floor, which will now require 1.5 times less, i.e. for every 1.5 m one wooden beam, and for 3 m one metal spacer.
4. The third significant difference is reinforcement. The reinforcement lies with just one crate exactly in the center. All connections occur in exactly the same way.
5. Then everything ends in the same way as a full-fledged monolith, regardless of whether it is the level of the fourth floor or the basement. It is important to pour the concrete carefully as even though the future is reinforced with I-beams, the flow of concrete can break through.

Beams can be used for your personal purposes - wiring, niches or anything else where space may be required. From below it is convenient to sheathe them with plasterboard, because. they are basically on the same level and profile guides are no longer required. Under the condition of the basement from below, through the beams, it is best to carry out lighting that fits perfectly into these conditions.

Device calculation methods

The volume of concrete is considered the easiest - area * height-5% (reinforcement). For a slab mounted on beams, the formula is completely similar. Based on the results, 100 * 0.3-5% \u003d 28.5 m³. Based on average automixers - 4 pcs. The concrete solution itself is mixed in the ratio of 1 part concrete, 3 parts sand and as much water as needed.

Beams are more difficult to calculate than concrete, because often they have to be joined. But if we approach the calculation relatively roughly and imagine that the joints turned out with zero losses, but with an additional spread outside the building, then it is ideal to use 6 m each. In this case, it turns out that it is necessary to calculate prefabricated double beams, then the formula will come out 10 * 6 * 2=120 m (10 beams, each of which consists of two 6 m each).

Modern technologies make it possible to calculate the construction of a concrete slab down to the last nail. So, in the manufacture of formwork, nails are driven in pairs every 0.5 m along the entire perimeter. The vertical formwork is only 0.3 m, but, nevertheless, this place will require additional strength, because of which 2 pairs will be driven into each rib. In total, the construction of formwork for one floor will require 40 * 2 * 2 + 4 * 4 \u003d 176 pieces.

Filling a monolithic floor slab is not the easiest, but a truly universal and time-tested method. In this article, we will talk about the main structural features and stages of the floor installation, as well as the types of formwork, including fixed formwork.

Building typology and scope

The main scope of monolithic ceilings are buildings with load-bearing walls made of brick, block masonry or concrete panels, as well as domed houses. The requirements for the solidity of the overlap may be due to:

• non-standard building plan;
• the need to significantly increase the bearing capacity of the floor;
• increased requirements for hydro and noise insulation;
• the need to provide free planning;
• reducing the cost of interior decoration.

Filling is carried out, as a rule, after the completion of the construction of the walls of the first floor. However, there are options for pouring monolithic ceilings already in buildings with a roof, if weather or other conditions so require. In this case, I-beams are mounted on the masonry of the lower floor and a crown is poured along the perimeter of the bearing walls to the height of the ceiling. Also, to strengthen the mechanical bonds, embedded reinforcement is released from the inside of the crown by 40–50 cm. Its total cross section cannot be less than 0.4% of the cross section of the longitudinal section of the crown.

Design calculations of the supporting structure

When choosing the span length, it should be related to the thickness of the slab as 30:1. However, with independent design, there is practically no point in making an overlap thicker than 400 mm, since the bearing capacity of the structure increases along with its own weight and static stresses. Therefore, the permissible load on makeshift floors rarely exceeds 1500–2000 kg / m 2.

The situation can be corrected by including in the supporting structure I-beams steel beams laid on a concrete-leveled masonry surface of the bearing walls. Another way to increase the length of the span while maintaining relative freedom of layout is to support the ceiling on columns. With a thickness of a monolithic structure up to 400 mm and a span in four directions from columns up to 12 meters, the cross-sectional area of ​​\u200b\u200bthe support is 1–1.35 m 2, provided that the cross section of the embedded reinforcement in the column is at least 1.4%.

Calculation of reinforcement of a monolithic slab

In general, the thickness of the plate is determined by the amount of reinforcing steel that is embedded in it. The reinforcement density, in turn, depends on the maximum allowable load and resistance to cracking. Avoiding special cases, we can give a general example of a design that demonstrates full compliance with regulatory requirements with a sufficiently high margin of safety.

In private construction, reinforced concrete is reinforced with reinforcement with a periodic profile of class A400, aka A-III.

Diameter of rods in slabs thick:

• up to 150 mm - not less than 10-12 mm;
• from 150 to 250 mm - not less than 12–14 mm;
• from 250 to 400 mm - not less than 14–16 mm.

The reinforcement is laid in two meshes with a mesh size of 120–160 mm, the thickness of the concrete protective layer from the edges of the slab is at least 80–120 mm, and at least 40 mm above and below. The direction of laying four rows of reinforcement, starting from the bottom: along, across, across, along. For ligation, galvanized wire with a thickness of at least 2 mm is used.

Installation of formwork of various types

The formwork must withstand a load of 500–1100 kg/m2, including the dynamic impact of falling concrete. To create a formwork plane, you can use:

1. Plastic sheets of reusable formwork.
2. Moisture resistant plywood 17–23 mm thick.
3. OSB 20–26 mm thick.

The edges of the slabs should fit snugly against the walls; it is not allowed to use formwork with gaps at the joints of more than 2 mm, unless it is planned to cover the surface with a waterproofing film.

Sometimes it is reasonable to make the formwork fixed, using profiled sheets for this, orienting them with a narrow shelf down. They are placed along the slab so that the waves form numerous stiffeners during pouring. The calculation of the thickness is carried out from the lower edge, thus saving the concrete mixture is 20-25%. In this case, the height of the ridge should not exceed a third of the total thickness of the slab. If the formwork is not planned to be removed, self-tapping screws with a rubber washer are screwed into it and tied with a thin wire to the reinforcement.

Formwork installation begins with the placement of racks: these can be either steel telescopic racks with a tripod and a unifork, or wood without defects with a cross section of at least 100 cm 2. Each post must be connected to two adjacent inch board slanted braces. Racks are mounted along the lines of the beams, the distance between which, depending on the thickness of the plate 150–400 mm, is:

• 190–240 cm with plywood thickness up to 20 mm;
• 210–260 cm with plywood thickness from 21 cm.

In this case, the distance between the uprights of one beam, depending on the gap between them, is:

• from 140 to 200 cm with a span of up to 150 cm;
• from 120 to 180 cm with a span of 160–210 cm;
• from 100 to 140 cm with a span of 210–250 cm.

The main beams, as a rule, are made of timber 100x100 mm. On them across with a step of 500–650 cm, secondary beams are laid, which have a cross section of 50% of the main ones. If the formwork is made of profiled sheet, the step of the secondary beams is equal to 3.5 distances between the waves.

Vertical formwork is mounted from retaining panels attached to the outer wall of the building. Often, aerated concrete blocks 80–100 mm thick are laid around the perimeter to hide the floor belt.

Reinforcement and strapping

After the formwork is installed, it is lubricated with an anti-adhesive compound and the laying of the reinforcement begins. On the crowns and supporting ribs, the rods are tied into a square, keeping the minimum allowable protective layer on all sides. The main array of overlap is reinforced with mesh. The bottom layer is laid on plastic "crackers" that control the preservation of the lower protective layer. The mesh is tied up at the intersection of every third rod.

After tying the lower mesh, intermediate clamps are installed on it every 100 cm in a checkerboard pattern. To strengthen the support on the walls, end clamps are mounted. These elements help maintain the design distance between two reinforcement planes.

The mounted upper mesh is connected to the lower connecting brackets. After completion of the installation, the reinforcing structure should be as one piece and easily take the load from people walking on it.

Pouring concrete

Monolithic floors are poured with concrete grade B20-B30, prepared in factory conditions. Filling monolithic ceilings should be carried out in one stage, so filling the space with small doses is not recommended. If it is impossible to perform the entire amount of work at once, sections of the slab must be cut with a mesh with a cell of 8–10 mm.

The supply of the mixture to the ceiling can be carried out by a concrete pump or a bulk bucket lifted by a crane. After feeding to the top, the mixture is evenly distributed, seated by vibration and left to harden.

Further actions

Concrete gains sufficient strength after 4 weeks, all this time it needs periodic wetting and protection from rain for the first 2 days. After drying, the formwork can be removed and the walls can be erected.

• Preparation for work
• Stages of pouring a monolithic floor slab
• Summing up the work on the installation of the plate

When building a private house, each person faces a number of difficulties that have to be overcome.

To date, a monolithic ceiling is the best way to make a partition between the floors of a house under construction.

One of the biggest difficulties is pouring a monolithic floor slab after the construction of the first floor.

For a monolithic slab, you must first install the formwork.

There are, of course, alternative options, but the plates are not durable, and the tree is not durable. This is what serves as a weighty argument in the direction of a more expensive and painstaking version of the work yourself.

On average, the actual production time is 40 days, 30 of which are passive and 10 are active. But if several people work at the same time, then the active period of pouring the slab can be reduced by 3-4 days. When doing this kind of work, you need to clearly follow a step-by-step action plan and not deviate from it even for a day - this will save time and money.

Preparation for work

• sheet A3;
• pencil and eraser;
• ruler;
• roulette;
• laminated plywood 20 mm or thicker;
• nails not shorter than 50 mm;
• a hammer;
• supporting system - metal spacers, wooden beams not less than 100 * 100;
• only polyethylene.

To begin with, it is worth preparing on all fronts for work and purchasing everything you need, and getting what you already have from the storerooms.