How to make a concrete floor with your own hands. Do-it-yourself monolithic concrete floor Make a monolithic floor in a finished house

The construction of a house and a number of other buildings involves the mandatory arrangement of interfloor or attic floors. Often, wood is used to implement this task. Wooden floors easy to install, but if you need to provide high-quality insulation and sound insulation of the room, give preference to concrete floors. A monolithic concrete floor can be made independently. Read the instructions and get started.

Before starting any work, it will be useful to familiarize yourself with the rules for laying monolithic slabs. The main recommendations are as follows:

• the span length can be no more than 900 cm. This is the maximum allowable length of one monolithic slab;
• to lift the slabs, you must use special equipment. In accordance with this requirement, hinges must be mounted in the slab, by hooking on which the crane can lift the product to the desired height. Relevant for those situations when the plates are bought in ready-made either they are made independently, but on the ground;

  

• slabs can only be laid on pre-leveled walls. There should not be any significant distortions and differences;
• from each edge, the plate should rest on the wall by 9-15 cm;
• the slabs are laid with the obligatory sealing of technological seams and, in general, all cracks with a mortar. "Dry" laying is unacceptable;
• during the installation of the plates, it is necessary to constantly monitor the evenness of their laying. Plumb and level are used for checking;
• boards may only be laid on bearing walls. All kinds of piers are erected strictly after the completion of the arrangement of the floors;

  

• if a hatch needs to be made in a monolithic ceiling, it is allowed to cut it out only at the junction of two concrete slabs. The arrangement of the hatch in one reinforced concrete product is unacceptable;
• slabs are laid with a 2-3 cm gap.

  

If the length of one slab is not enough to cover the entire span, you can use one of the two available options:

• lay the slabs back to back, leaving gaps at the edges of the room. At the end, the gaps will need to be filled with concrete blocks;
• lay the plates not close, but at regular intervals (20-30 mm). At the end, seal the gaps with concrete, having previously fixed the formwork under the ceilings so that building mixture did not fall down.

Formwork installation

The technology of arranging the ceiling implies the mandatory use of horizontal formwork. You can rent a ready-made formwork from a specialized company, or you can assemble the necessary structure with your own hands.

The first option is simpler and more convenient. Ready-made factory formwork comes with telescopic supports, which allows you to further save time on the manufacture of props.

The second option is more budgetary. For self assembly formwork, use an edged board with a thickness of at least 2.5-3.5 cm. You can use moisture-resistant plywood with a thickness of 2 cm or more.

Boards should be knocked down as tightly as possible. If there are noticeable gaps between the boards, the formwork must be covered with a waterproofing film.

Formwork set

Prepare the following fixtures for formwork assembly:

• boards;
• plywood;
• beam;
• a hammer;
• hacksaw;
• level;
• nails;
• axe.

Formwork installation

First step. Install the vertical supports. The best option– adjustable telescopic metal poles. In their absence, wooden logs with a diameter of 80 mm or more are also suitable.

Install racks in meter increments. The distance between the walls and the posts closest to them must be at least 200 mm.

Second step. Lay crossbars over the support posts. This is a longitudinal beam, due to which the entire structure placed above will be supported.

Third step. Install the formwork on top of the crossbars. First, lay the transverse bars on the longitudinal bars. wooden beams, on them - boards or plywood.

Select the dimensions of the formwork so that its extreme edges rest against the walls without the formation of cracks.

Fourth step. The upper edge of the formwork structure must be strictly on the same level with the upper edge of the lined wall. To meet this requirement, adjust the height of the support legs.

Fifth step. Install vertical structural elements. Since the edges of the floor slab must extend into the wall, place the vertical railing at an appropriate distance from the inner edges of the walls.

Sixth step. Check the evenness of the formwork with a level. Correct deviations if found.

To connect the formwork elements, use convenient fasteners, for example, dowels or nails.

For the convenience of carrying out subsequent work, the formwork can be covered with waterproofing material.

Telescopic stands are preferred over their wooden counterparts for the reason that metal is much more durable than wood. Each telescopic pole is capable of withstanding a load of up to 2000 kg without the appearance of deformations and cracks, as can happen with a wooden beam.

Video - Installation of slab formwork

Reinforcement order

A monolithic floor slab is subject to mandatory reinforcement.

First step. Prepare armature. Select the appropriate diameter of the bars in accordance with the calculated loads. In most cases, rods with a diameter of 1.2-1.4 cm are used.

Second step. Lay the first reinforcing mesh at the bottom of the future monolithic slab. First lay the longitudinal, and then the transverse bars. The optimal cell size of such a grid is 120-150 mm. If the cover has small area, you can increase the mesh size up to 200 mm.

Third step. Tie the joints of the bars with steel wire.

Fourth step. Lay a second reinforcing mesh on top, similar to the first. Tie both meshes with wire.

If the length of one rod is not enough, tie an additional rod with an overlap equal to at least 40 reinforcement diameters. That is, if you use rods with a diameter of 12 mm, the overlap should be at least 480 mm.

concrete preparation

A standard concrete mortar is prepared for the initial pour. The recipe is the following:

• 2 parts of sifted clean sand;
• 1 part coarse aggregate - both crushed stone and gravel can be used;
• 1 part of cement M400-M500;
• water.

Add enough water so that the consistency of the solution is close to the consistency of liquid sour cream. A thin solution will perfectly fill all the internal cavities and cracks, so that the slab will become truly monolithic.

The solution is most conveniently prepared in a concrete mixer. First, load the dry and solid ingredients, and then gradually, without ceasing to stir, add water.

In the absence of a concrete mixer, you can prepare a solution in a large trough, but this is too long and rather difficult, especially if there are no assistants.

Slab pouring

The process of pouring a monolithic ceiling can be divided into 2 stages: pouring and finishing pouring.

spilling

At this stage, the initial layer of concrete is poured. Pour the solution measuredly and slowly, sudden movements are unacceptable, because of this the formwork may warp.

Don't make the bleed too thick. The main task of this layer is to fill all the existing cavities.

“Smooth” the finished filling with a shovel over the entire surface. Do it smoothly and carefully. So you remove excess air and finally fill even the smallest cavities.

Finishing fill

At this stage, you need to prepare a separate solution. The recipe is the same as in the previous case. The only difference is that you need to take less water to make the concrete thicker.

First step. Pour a layer of concrete of such thickness that about 20-30 mm remain until the calculated thickness of the finished monolithic slab. Pour slowly and evenly.

Second step. Level the fill with a shovel as in the previous part of the instructions. Leave the concrete for a couple of days and proceed to the next step.

Third step. Prepare a mortar of 1 part cement and 3 parts sand. Large aggregate at this stage is not needed. Add water to obtain a solution of medium density.

Fourth step. Fill the stove to the end with the solution prepared in the previous step. In the process of pouring, level the slab with a rule until a perfectly smooth surface is obtained.

This completes the pouring of the monolithic floor. You will only have to monitor the state of the pour for some time so that the concrete hardens and gains strength without any problems.

Concrete care after pouring

During the curing process, the concrete will release a large number of heat, under the influence of which intensive evaporation of moisture will begin. Lack of moisture will cause the concrete to crack. Therefore, during the first few days after pouring, you will need to regularly moisten the slab with water.

You can pour water in buckets (2-3 buckets per run) or through a hose with a sprayer. You can first lay old rags (preferably burlap) on dried concrete and pour water on them. In hot weather, cover poured concrete with polyethylene, because. Too fast drying may cause the board to crack.

Formwork can be removed approximately 10 days after the last wetting. In general, the plate will gain strength in 3-5 weeks. After this period, it will be possible to proceed to the implementation of further planned construction work.

Thus, it is possible to independently equip a monolithic ceiling. At the same time, you will spend much less money on arranging the necessary structures than in the case of buying ready-made prefabricated slabs. Follow the instructions and you'll be fine.

Successful work!

Video - Do-it-yourself monolithic overlap

Concrete flooring is a durable and reliable element, which is indispensable in the construction of multi-storey buildings and structures. Installation of a monolithic ceiling does not require lifting mechanisms, which saves on equipment and additional labor costs. The use of interfloor partitions in the construction reduces the time for work and allows you to build structures with your own hands. The production of concrete floors is an easy process, but in order to make a high quality material with its main advantages, it is necessary to follow the sequence of work and calculate the main parameters of the building element.

Purpose

Concrete floors are one of the main building elements in the construction of buildings. They are designed to connect:

• basement with rooms;
• the first floor with the second;
• roofs with a house.

They are also used for horizontal screeding of buildings and structures.

Cover requirements

The following requirements are put forward for concrete floors:

• the presence of the necessary strength;
• must not contain deformations and must have rigidity and a long service life;
• an important property in a concrete floor is its maximum fire resistance, water resistance and the inability to penetrate air;
• the concrete structure between the floors must have sound and heat insulation.

Kinds

The scheme of interfloor overlapping of concrete.

There are the following types of concrete floors:

• attic;
• basement;
• interfloor.

Concrete flooring also happens:

• hollow, which is often used in construction, where interfloor overlap is required for houses made of concrete, blocks and bricks;
• ribbed, used in the manufacture of the roof of industrial buildings, where there is no heating of the premises;
• monolithic, which is a reinforced concrete element and is characterized by increased strength, is used in the construction of buildings and structures with a large number of storeys.

Materials and tools for manufacturing

When working with concrete floors with their own hands, prepare the following tools and materials:

• concrete pump;
• capacity;
• buckets;
• jack;
• building level;
• plywood with moisture resistance property;
• boards;
• steel fittings;
• wire;
• concrete mortar or components for its preparation by one's own hands: sand, water, cement and various additives to increase the strength of the mortar.

How to calculate parameters?

Scheme of a monolithic reinforced floor.

When working with concrete floors, it is important to purchase high quality materials. When preparing a building mixture, which will be used to fill the structure, concrete grades 250 and 400 are used, which include heavy fillers. To make partitions with your own hands, it is important to thoroughly calculate the main parameters of the material. The calculation is based on a comparison of two main properties:

• strength of the reinforcing structure;

Plate calculations are based on the following indicators:

• intensity of constant loads;
• efforts in sections with a large load;
• axle stiffness.

The calculation of monolithic floors consists of determining their individual components. First you need to make a formwork from plywood of great thickness, then install it from steel rods tied with wire. The calculation of partitions is carried out by special computer programs and designers.

The definition of strength is obtained from factors such as: load and strength.

To find out the maximum bending of the slab, use the following data:

• design resistance of reinforcement and concrete;
• fittings A400 C class.

The definition of parameters includes the following calculations:

• working reinforcement area;
• required moment of resistance;
• the maximum moment in the section of the beams.

Formulas and constants are in the collection of building codes and regulations.

Formwork device for overlapping

Formwork construction technology includes the installation of plywood on horizontal supports. To choose the right amount of materials, you need to know the area and volume of the planned floor. The thickness of the structure depends on the possible loads and the dimensions of the span. Thus, the formwork is made of increased strength without allowing deformations, so that it can bear the weight of reinforced concrete for a long time.

When choosing boards for formwork, you should pay attention to their strength and thickness. Before installation, the structure is measured by the construction laser level span height and floor bottom. In the process of installing home-made racks, they are adjusted in length to the height of the structure on which the first layer of the beam will be built.

It is important to observe the distance, which should be more than one cubic meter. Place the racks on the floor with a flat surface and high strength. After that, the transverse beam is laid in increments of about half a meter and then the formwork is installed. After the formwork is installed, the top of the structure is checked for horizontality using the building level.

When using boards instead of a plywood sheet, they are laid to each other without gaps and a moisture-proof material is laid on top. On all edges of the formwork, boards are installed, which are fixed at the corners of the structure so that they do not deform from the solution.

When installing the formwork yourself, it is important to remember a few rules:

• exclude the formation of holes, cracks through which the mortar can flow out of the concrete during the pouring process;
• check the strength of the jacks installed under the formwork;
• moisture-resistant plywood is used for the construction of formwork;
• formwork should be as strong as possible, because the quality of the structure being built depends on it;
• formwork should be installed both over the area and around the perimeter of the room, which will protect against leakage of the concrete mix.

Reinforcement

Partitions between floors need reinforcement, which can be started after the formwork has been installed. Reinforcement of structures is carried out with reinforcement in one or two layers per formwork. A reinforcing mesh measuring twenty by twenty centimeters is installed, while the first row is laid on protective layer, which provides uniform distribution concrete mix for reinforcement.

If necessary, connect the reinforcing elements, an overlap of at least seventy centimeters should be made. To maintain the proportion, it is necessary to install a second layer on top of the first row of the reinforcing mesh with the same step (twenty centimeters), only ensuring perpendicularity. At the intersection of the reinforcing bars, they are fixed with steel wire and a special hook designed to connect the reinforcement. In the manufacture of a two-layer frame based on segments of reinforcing bars, a similar sequence is carried out for the first layer and the second is laid, while maintaining a distance between layers of at least three centimeters.

During the construction of the house, you can not do without installing the ceiling. This design limits the height of the room, insulates it from the penetration of cold air in winter, and takes on the load from the roof or upper floor. AT modern technologies most often use a plate reinforced with reinforcement.

Description of types, design features, technical requirements

Depending on location and functional purpose concrete floors are of several types:

• basement;
• interfloor;
• attic;
• attic.

According to another classification, they are divided into solid and prefabricated. The first are made independently, pouring the mixture onto the prepared reinforcing cage. This method does not require the use of a crane to lift the slabs, but additional hands will be needed to install the formwork, tie the frame, and pour the concrete.

Prefabricated systems are obtained by laying standard panels right size. By execution, they are of three types: monolithic, ribbed, hollow. In private construction, the third option is more often used. Product dimensions: length - up to 7 m, width - 1.5, height - 0.22.

Considering the operating conditions, the following requirements are imposed:

• strength and rigidity exceeding the calculated load (it is defined as the total weight of the slab itself, screed, furniture, and other things);
• high level of sound insulation;
• fire resistance;
• wall thickness under concrete blocks not less than 200 mm.

Concrete has a high thermal conductivity, to reduce which it is recommended to insulate, for example, with mineral wool.

Installation instructions

Do-it-yourself pre-preparation of the structure and slabs helps to lay the finished concrete floor with your own hands.

Scheme of preparatory work

1. To ensure that the panels are in the same plane, the upper end of the load-bearing walls is checked for horizontality. This can be done in this order: 30-40 cm before the end of the masonry, markers are applied to the wall using a laser or liquid level, and then the finishing brick rows are checked with a tape measure. The top row is positioned so that the bricks are oriented inside the room.

2. Most often, the edge of the box is aligned differently - the perimeter of the upper edge of the walls with reinforcement is concreted. Due to this, the brick or block structure is additionally strengthened. At a certain level, the masonry leaves an unfilled space for the armored belt. The depth of support (overlap) of the ceiling depends on the total thickness of the slab together with the thermal insulation. Usually the panel goes into the wall by 70-120 mm.

The scheme of pouring the armored belt is similar to laying the foundation: the formwork is mounted, inside it a frame is made of reinforcing bars by welding, the mixture is poured without crushed stone. The design of the belt for the plinth is made faster: they simply put additional formwork along the outer edge of the foundation.

3. Before installing the plates, the voids in their ends must be closed. If this is not done, placing the top floor wall on the edge of the floor may cause it to collapse. Concreting of inter-slab joints will not work: the mixture will flow into the holes. It is not difficult to close the cavity - a half-brick is inserted into it and sealed with a solution.

4. Prepare a platform for lifting equipment. This is a site with dense soil, otherwise the crane will get stuck in soft soil. To ensure its stability, temporary placement of road panels on the site is practiced. It is advisable not to install a crane near the pit in order to prevent the collapse of the soil or the sliding of heavy equipment.

Laying technology

It will not be possible to install the ceiling yourself; three installers usually participate in the process. One worker connects the plates, the other two correct them when lowered.

1. A sufficiently thick concrete mixture is applied to the reinforced belt (layer thickness of at least 2 cm).

2. The crane operator lowers the panel, holding it by pulling on the sling ropes. In a suspended position, it is easily moved in the right direction with the help of a crowbar.

3. Compensation propyl. It is necessary if several spans are covered with one slab. Conventional structures work in bending and must rest on two short ends. If intermediate supports are placed, tensile stresses occur in the upper part of the floors. Since there is no reinforcement there, cracks can appear. To relieve stress, a groove is sawn with a grinder, placing it above the intermediate support. Subsequently, a crack will appear at the site of the slot.

4. Anchoring. This is a firmware with reinforcing wire: it is threaded through the mounting eyes, pulled together, and then welded. The scheme is usually laid down in the project, if it is not there, apply standard version. Load-bearing walls have at least 1 anchor for every 3 running meters, on non-bearing anchors are removed from all extreme loops. The end plates are sewn with diagonal anchors.

Inter-tile cracks (rusts) are poured concrete mortar, due to which the structure becomes monolithic and durable.

During installation, sometimes you have to adjust the dimensions. The optimal overlap on the wall is no more than 120 mm, and the maximum allowable value is 250. With an increase in this parameter, the scheme of operation of the floor changes, as a result, cracks may appear on it. The panels are shortened in the following way:

• they outline the cutting line, put a bar under it - its thickness should be such that the edge to be separated is in weight;
• according to the marking, an incision is made with a grinder, concrete is split with a sledgehammer above and below the voids;
• break barriers;
• the metal reinforcement is cut with a grinder, leaving a couple of millimeters - this residue is smashed with a sledgehammer (otherwise the stressed reinforcement may pinch the grinder's disc).

If the size is insufficient, the gap near the wall is bricked up.

How to make your own cover?

The frame is made from edged boards (thickness 25-35 mm), plywood (thickness from 20 mm) or rented.

1. Install the formwork. Its dimensions should be such that the edges rest against the walls without gaps. The position of the structure is checked using a level. Cover it up waterproofing film.

2. Reinforce. Usually, rods with a diameter of 12-14 mm are taken for the frame. First, longitudinal and then transverse elements are laid (cell 12-15 cm), tied with wire. In the same order, the upper mesh of the frame is made, the joints of the bars are staggered, the ends of the rods are placed on the supporting beams.

3. Preparation of concrete. Volumetric proportions of its components:

• sifted sand - 2 parts;
• crushed stone (gravel) - 1 part;
• cement M400 (500) - 1 part;
• water.

Water is poured so much that the solution resembles liquid sour cream in density.

4. Fill. Carefully fill all cavities with the mixture, “stroke” with a shovel, removing air. For finishing pouring, a thicker mixture is made, laid down. The thickness of the layer is 2-3 cm less than the final size of the overlap. After a couple of days, the set composition is covered cement-sand mortar medium density, align the rule to an ideal plane.

The hardening monolith is periodically watered with water, covered with a film in the heat. On the 10th day, the formwork is removed, allowed to gain strength within 3-5 weeks. After that, you can proceed to the next stage of construction.

Do-it-yourself remodeling or building can usually save you a decent amount of money, as long as everything is done in compliance with building codes and regulations.

Scheme of floor slab insulation.

Do-it-yourself formwork will help not only save a certain amount of money, but also guarantee quality. This requires certain knowledge that will help you fill the floors with your own hands. The only downside to this case- this is that the formwork will have to be installed over the entire area of ​​\u200b\u200bthe house.

Do-it-yourself formwork is also a way out of a situation where it is impossible or extremely difficult to call a crane and lay a factory slab, for example, if construction is going far outside the city.

Scheme of monolithic overlap.

A monolithic floor has a number of advantages: in addition to being stronger than wood, it can be made without standard sizes, support for it can be not only walls, but also columns.

At the same time, it is best to order a ready-made concrete solution that has passed quality control and contains appropriate fillers that improve the very quality of concrete and prevent it from delamination at the factory. In this case, it is necessary to use the strength class with the brand B20-B30 (M-250, M-400), frost resistance is not lower than F50.

If a monolithic ceiling is made for the second or third floor, then you can’t do without a concrete pump, throwing concrete with a shovel or through the gutters is not only a tedious task, but it will also affect the quality of the ceiling.

When pouring concrete on a floor slab with your own hands, it should be noted that the formwork must be strong and reliable. The weight of wet concrete with fillers is about 500 kg per 1 sq. m., therefore, depends on how strong the formwork is. appearance overlap, and its quality. Also required wooden bars with a section of 10 by 10 cm as spacers, racks, beams.

In order for the ceiling to turn out to be of high quality, when making formwork with your own hands, it is worth using laminated plywood, which will later be easy to clean.

Formwork is made from wooden planks, which are located in a horizontal plane, while the boards must be lubricated with a special lubricant that will help remove the protective film from the boards.

The formwork must support the entire weight without visible deformation.

Reinforcement of floor slabs

Floor reinforcement scheme.

Reinforcement is best done with iron reinforcement - in addition to greater strength, this design will also be more fire resistant.

Reinforcement involves the use of profile reinforcement A III, A400-500. It is necessary to use four rows of reinforcement: along and across the span - lower, along and across the span - upper.

If the plate thickness is less than 150 mm, then reinforcement in one layer is possible, if more, then two layers are necessary. In this case, the mesh is placed on both sides, above and below the floor slab, and connected with a wire. Cells 150 by 150 or 200 by 200 mm are created, while it is necessary to use rods of the same section.

Additional reinforcement is made in places of holes or accumulation of large loads and stresses. Rods with a length of 400 to 1500 mm are used, it all depends on the size of the hole or the length of the span, the formwork must be made to the full length.

The calculation of the strength of the floor slab consists in comparing two factors:

1. Forces acting in the plate.
2. Strength of reinforced sections in the slab itself.

The second point must be greater than the first.

Let's calculate the permanent loads of the floor slab:

Slab 200 mm with a load of 550 kg per m3.

Curb weight 2.5 t/m3 x1.2 = 2.75 t/m3

The weight of the floor itself with a thickness of 100 mm of the screed is 2.2 tons per 1 m2 x 1.2 = 2.64 per m3.

With a floor thickness of 50 mm - 110 kg per 1 m3.

building requirements

Scheme of prefabricated-monolithic overlap.

A monolithic slab must be made quite strong, it must withstand not only its own load, but also furniture, walls, equipment and people. It should be sufficiently rigid and not give deflections.

When installing a monolithic slab, sound insulation must be provided, which is established by special norms and rules for this type of buildings and structures.

A monolithic ceiling, which will serve as a separator between two rooms with a temperature difference of 10 degrees, must comply with the requirements of thermal protection. This requires the use of heat-shielding materials when concreting the slab with your own hands.

Calculation of the strength of floor slabs

It is necessary to bring to the area of ​​the partition slab, for example, made of brick:

One linear m 3 m high weighs 0.12 m x 1.2 x 1.8 t per m3 = 0.78 t / m.

With a step of partitions, for example, 4 m, we get 0.78 / 4 \u003d 0.2 / m2. We take the reduced weight of the partitions equal to 300 kg / m2.

Housing, taking into account the reliability factor, we accept 1.3 for the first group of limit states - 150 kg / m3.

Temporary \u003d 150 x 1.3 \u003d 195 kg / m2.

Total full load is 550+110+300+195=1150 kg/m2.

For draft calculations, we accept a load equal to 1.2 t/m2.

Scheme of installation of floor slabs.

Considering everything is extreme permissible loads, you can choose the fittings of the required diameter, which will affect both the cost of construction and the reliability of the structure. However, it will be good if all calculations are made by a specialist, since it is necessary to take into account a lot of factors, for example, to ensure the limitation of cracking.

It is necessary to take into account the bending moments, since they determine 95% of the reinforcement of the slabs at the bend. The most loaded sections are the center of the slab, the middle of the span.

You can find out the values ​​for some special cases. To do this, consider each of the directions, taking X, Y, and get MX = MY=gi 2/23.

Slab with dimensions 6x6 - MX = MY = 1.9 t/m.

Slab with dimensions 5x5 - MX = MY = 1.3 t/m.

These are the forces acting on the plate along and across, therefore, mutually perpendicular sections should be checked for strength.

It is necessary to check the strength of the normal section to the longitudinal axis in terms of bending moment. Steam, compressed concrete and tension reinforcement from below, perceive the instantaneous reinforcement that comes to it. Let's take the height of this pair equal to 0.8h, with the height of the section of the plate - h.

NX (Y) \u003d MX (Y) / (0.8h) - force in the reinforcement.

It turns out for 1 m of the width of the slab section, with the dimensions of the slab - 6x6 - 11.9 t, for a slab with a size of 5x5 - 8.2 t, for the slab 4x4 = 5 t. Under these conditions, the corresponding reinforcement of the third class (A400) is selected - periodic profile.

The design rupture resistance of the reinforcement, the cross-sectional area of ​​the reinforcing bar with the resulting diameter are taken, and the bearing capacity of the bar is calculated. We get the step of reinforcement in each of the directions, that is, a reinforced mesh stretched in concrete.

pouring concrete

The pouring and concreting of a monolithic floor slab is usually carried out using a concrete pump, especially if the slab is located on the second or third floor. You can do it yourself, but the game is not worth the candle, because you will have to hire assistants, which will “eat up” all the savings.

To compact concrete, a deep or surface vibrator is used, while not forgetting that excessive vibration can lead to the opposite effect, and the concrete will delaminate.

Internal vibrators should be installed with a step not exceeding the radius of its one and a half action. The time of vibration at each step should ensure the compaction of the concrete mixture, one of the signs is the cessation of settling and the release of bubbles.

When performing work, it should be taken into account that fast drying concrete shrinks and microcracks form. Therefore, after pouring concrete with your own hands, the entire structure should be watered with water for at least three days.

Scheme of a monolithic reinforced concrete floor.

In winter, it is necessary to order concrete with antifreeze additives, which, although they have Negative influence on reinforcement, but this is acceptable if the additive is factory-made. By the way, it also affects the curing time of concrete, which should be taken into account when carrying out winter work.

Crushed stone must be added to the concrete, otherwise the strength will be low, the reinforcement must be tied with a knitting wire, welding of the reinforcement will not give such strength as a bundle. It is not recommended to add gravel, its surface is even, which will make the grip fragile.

The monolith of the slab must be durable, this requires not only high-quality material, but also compliance with the technology. It is not recommended to pour concrete into winter time even taking into account frost-resistant impurities, all work is best done in the warm season.

Rules and technology for performing work

Before starting the process of concreting a monolithic ceiling with your own hands, preparatory work should be carried out:

• take measures for the safe conduct of work;
• install formwork over the entire area;
• mount the void formers for wiring and embedded parts.

All structural elements that will be closed during the concreting process, as well as the installed and fixed formwork and its supporting elements, must comply with SNiP 3.01.01-85.

It is necessary to use removable lighthouse rails or install spatial fixators, which will indicate the level of the top of the concrete.

When concreting, it is allowed to walk on boards with supports that rest on the ceiling formwork.

The concrete mixture should be laid only in horizontal layers, the thickness should be the same, without gaps. Laying with a consistent direction is done in one direction in all layers.

The next layer of the concrete mixture must be laid before the setting of the previous layer, the time must be determined in the laboratory. Otherwise, a production seam will form.

In places where the concreting will be broken, slats should be installed, and the surface of the working seam should be located perpendicular to the surface of the slab.

If the concreting has been interrupted, then the next stage of concreting can be carried out only when the setting process is over, which is approximately 24 to 36 hours.

It is not allowed to rest the vibrator on the fittings or on the embedded parts of the structure included in the monolith.

As soon as the concrete has acquired the necessary strength, the formwork should be removed, which over time will come into contact with the concrete more and more, even if special emulsions are used.

As soon as concrete acquires the necessary strength, it can be loaded with permissible loads.

Before proceeding with the installation of floor slabs with your own hands, you should take into account all the pros and cons of this event. You will need to calculate what time it will cost to call a concrete pump, use vibrators, order concrete mix.

In houses made of brick, concrete or concrete blocks, floors are usually made of reinforced concrete. They provide exceptional strength and seismic resistance of the structure, and are also very durable and do not burn, which is important. There are several ways to arrange reinforced concrete floors. The most common and versatile is laying prefabricated floor slabs. Such slabs are ordered at reinforced concrete factories, and then mounted with a crane and a team of workers. In those cases where the use of 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 equipped. In fact, you can pour a monolithic slab not only when there are indications for this, 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 at the construction site.

Do-it-yourself monolithic floor slab

A monolithic floor has a number of advantages compared to a floor made of prefabricated reinforced concrete slabs. Firstly, the construction is solid and monolithic without a single seam, which provides a uniform load on the walls and foundation. Secondly, a monolithic fill allows you to make the layout of the house more free, as it can be based on columns. Also, the layout can include as many corners and nooks as you like, for which it would be difficult to pick up 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 equip 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 save on materials.

Like everything related to construction, a monolithic ceiling begins with a project. It is advisable to order the calculation of a monolithic floor slab in the design office and not save on it. It usually includes the calculation of the cross section of the plate for the action of the bending moment at maximum load. As a result you will get optimal dimensions for a floor slab specifically in your home, instructions on which reinforcement to use and what grade of concrete. If you want to try to perform the calculations yourself, then an example of calculating a monolithic floor slab can be found on the Internet. We will not focus on this. Consider the option when an ordinary country house is being built 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 a monolithic floor slab:

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

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

1. Calculation of the floor slab, if the span is more than 7 m, or the project involves the support of the slab on the column / columns.
2. Installation of formwork type "deck".
3. Reinforcement of the slab with steel bars.
4. Pouring concrete.
5. Compaction of concrete.

So, after the walls are driven to the required height, and their level is almost perfectly aligned, you can proceed to the arrangement of a monolithic floor slab.

The device of a monolithic floor slab assumes that the concrete will be poured into a horizontal formwork. Sometimes horizontal formwork is also called a "deck". There are several options for its arrangement. The first - rental of ready-made removable formwork from metal or plastic. Second - making formwork on site using wooden boards 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 on the same level.

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

Formwork is installed in this way:

• Vertical poles are installed. These 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 posts should be 1 m. The posts closest to the wall should be located at a distance of at least 20 cm from the wall.
• Crossbars are laid 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 not ready-made formwork is used, but self-made, then on top of the longitudinal bars are laid cross beams on which sheets of moisture-resistant plywood are placed on top. The dimensions of the horizontal formwork must be perfectly adjusted so that its edges rest against the wall without leaving gaps.
• The height of the support-racks 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 should be such that its edges go onto the walls by 150 mm, it is necessary to make a vertical fence at exactly this distance from the inner edge of the wall.
• For the last time, the horizontal and even arrangement 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 props for formwork is preferable wooden poles, as they are reliable, each of them can withstand a weight of up to 2 tons, microcracks do not form on their surface, as can happen with wooden log or a bar. Renting such racks will cost about 2.5 - 3 USD. per 1 m2 of area.

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

The reinforcing mesh should go onto the walls at least 150 mm if the walls are made of brick, and 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 plate. The second - top - should be located 20 - 25 mm below the top edge of the plate.

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

The thickness of a 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 thickness of the slab 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 the thickness of the slab of 200 mm we subtract two gaps of 20 mm and subtract 4 thicknesses of reinforcing bars).

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

The next step - end stop. It is installed with a step of 400 mm at the ends of the reinforcing cage. Serves to strengthen the support of the plate on the wall.

Another important element - upper and lower mesh connector. How it looks, you can see in the photo. It is necessary so that the spaced grids perceive the load as a whole. The installation step of this connector is 400 mm, and in the zone of support on the wall, within 700 mm from it, with a step of 200 mm.

pouring concrete

Concrete is best ordered directly from the factory. This greatly simplifies the task. In addition, pouring the mortar from the mixer in an even layer will ensure exceptional strength of the slab. What can not be said about the stove, which was poured by hand with breaks to prepare a new portion of the solution. So it is better to pour concrete immediately with a layer of 200 mm, without interruptions. Before pouring concrete into the formwork, it is necessary to install a frame or boxes 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. 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, formwork rental and the order of a mixer machine, as well as a concrete pump. In fact, it comes out to about 50 - 55 USD. per m2 of flooring. How the floor slab is poured with concrete can be seen in the video demonstrating the installation of floor slabs.

How to properly lay floor slabs

The use of factory-made monolithic reinforced concrete floor slabs is considered more traditional. PC slabs are more popular - 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 seeming simplicity of the task, there are a number of nuances and rules that must be observed when working with floor slabs.

Rules for laying floor slabs

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

• The span should not be more than 9 m. It is this length of the slab that is the largest.
• Unloading and lifting of plates is carried out with the help of special equipment provided by the project. To do this, there are mounting loops in the plates, for 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.
• It is impossible to lay the slabs dry, all cracks and technological seams must be sealed with mortar.
• The location of the plates must be constantly monitored relative to the walls and supporting surfaces.
• Plates are laid only on load-bearing walls, all piers are equipped only after the installation of ceilings.
• If you want to cut a hatch in the ceiling, then it must be cut at the junction of two plates, and not in one plate.
• The slabs should be placed as close as possible to each other, but with a gap of 2 - 3 cm. This will ensure seismic resistance.

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

Floor slab laying technology

In the process of laying floor slabs, there should be clear coordination between the crane operator and the team receiving the slab. To avoid injuries at the construction site, as well as to comply with the entire technological process and the rules described in SNiPs, the foreman at the construction site must have routing floor slab installation. It indicates the sequence of work, the number and location of equipment, special equipment and tools.

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

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

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

Do not forget that safety precautions must be observed. It is not allowed to carry out work with a crane in open area with a wind of 15 m / s, as well as with ice, thunderstorms and fog. During the movement of the slab with a crane, the assembly team should be away from the path along which the slab will be moved, from the side opposite to the feed. Despite the fact that using the services of a professional foreman and a team of installers significantly increase the cost of installing floor slabs, this is not the case when you can save. The foreman must provide a project.

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

Preparatory work before laying floor slabs

First - flat support surface. The horizon should be almost perfect, 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 a concrete mortar. Subsequent work can be done only after the concrete has gained maximum strength.

Second - ensure the strength of the support zone. If the walls are built of 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 plates, it is necessary to fill in the armored belt. Proper styling floor slabs implies that the bearing 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, a formwork is installed around the entire perimeter of the building, a reinforcing cage made of a rod of 8–12 mm is inserted into it, and then everything is poured with concrete with a layer of 15–20 mm. Further work can be continued only after the concrete has dried.

Third - install mounting towers. Telescopic supports, as described in the section on the installation of 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 from its place. After installation, these towers are removed.

Installation of hollow core slabs with a crane

After the freshly poured concrete has taken on sufficient strength and dried, the installation of floor slabs can begin directly. 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:

• A concrete solution is applied to the bearing surface with a layer of 2 - 3 cm. 150 mm. If the plate is supported by 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. Directly laying the plates can begin when the solution gains 50% of its strength.

• While the mortar dries, the crane operator can hook the slings onto the slab fasteners.
• When the signal is given to the crane operator that it is possible to feed the slab, the team of workers must move away from the place where the slab is moving. When the slab is already very close, the workers hook it with hooks and unfold it, while damping the oscillatory movements.

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

• If there is a need to move the plate, you can use a crowbar. It is possible to align its location only along the laying zone, it is impossible to move the plate across the walls, otherwise the walls may collapse. Then the slings are removed, and a signal is given to the crane operator to pick them up.
• The procedure is repeated for all plates without exception. The rules for installing floor slabs suggest that the alignment of the slabs should be carried out 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 it is necessary to lay reinforcement in the support area of ​​\u200b\u200bthe slab. Proponents of this method say that it is more convenient and easier to move the stove. In fact, putting anything other than concrete mortar under the slab is prohibited by the technical card. Otherwise, the slab can easily move out of the support zone, as it will slide over the reinforcement. In addition, the load will be distributed unevenly.

Laying floor slabs on the foundation is practically no different from laying floors. The technology is exactly the same. Only the foundation surface must be carefully 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 done without a specialist.

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

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

Also, the plate must be connected to the wall. Why is reinforcement embedded in the wall.

The second way - ring anchor. In fact, it looks like an armored belt. A formwork is arranged along the perimeter of the slab, reinforcement is installed in it and concrete is poured. This method slightly increases the cost of laying floor slabs. But it's worth it - the plates are clamped from all sides.

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

All modern stoves with round voids are produced with already filled ends. If you purchased plates with open holes, then they must be filled with something 25 - 30 cm deep. Otherwise, the plate will freeze. You can fill in 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 rely on internal walls.

The price for laying floor slabs depends on the amount of work, the area of ​​\u200b\u200bthe house and the cost of materials. For example, the cost of only PC floor slabs is approximately 27 - 30 USD. per m2. The rest is related materials, crane rental and hiring workers, as well as the cost of shipping plates. Professional teams for the installation of floor slabs have a variety of prices 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