Methods of laying floor slabs on the wall. Floor slabs: preparation of the base, sequence of installation work and increasing load-bearing capacity. Preparing the work surface

electric welding machine;

fittings;

concrete solution;

container for mixing the solution;

jackhammers;

scrap;

four-leg sling;

mortar shovel;

Required personnel for slab installation work:

assembler, installing slabs, senior in the team;

installer, mont lining plates;

worker engaged in rigging work.

Installation process

Before installation of floor slabs, the support points are carefully verified

vertically and horizontally and apply cement mortar to the design mark.

Install the slabs over a layer of freshly laid cement-sand mortar M100.

The thickness of the layer of plastic mortar under the supporting parts must be at least 20mm.

Hollow-core floor slabs supported on external walls made of

bricks, lay on a leveled, freshly laid layer of TsPS M100 20mm thick.

2. The size of the slab embedded in brick walls is 90-240mm.

3. All floor slabs must have factory sealed end voids

reinforced concrete liners.

4. The row of masonry under the supporting part of the slabs should be done in a bonded manner.

5. In prefabricated support units reinforced concrete slabs needs to be installed on walls

anchor connections.

6. Anchor walls and ceilings immediately after installing the slabs

overlaps on the mortar and checking the correctness of their position.

7. The distance between anchors should be no more than 3 m, location. brand and details

Installation of anchors should be carried out in accordance with the project drawings.

8. Carefully seal the recesses in the slabs near the mounting loops after installation.

concrete B7.5 according to GOST 26633-91*.

9. The seams between the floor slabs are cleaned and carefully sealed.

Seams should be sealed after installing the connecting elements.

concrete B15 with fine aggregate.

10. For the passage of vertical communications in a hollow-core flooring, it is allowed

drilling holes up to 140mm in voids without violating the integrity of the ribs, punching

holes with impact tools are not allowed. For holes from 140 to 300mm

It is allowed to drill out one of the longitudinal ribs together with the reinforcement.

11. When holes larger than 300 mm are formed, it is necessary to make monolithic sections.

12. When laying out floor slabs, the outermost longitudinal rib may be inserted

into the wall no more than 25mm.

13. It is mandatory to install tie meshes under the floor slabs in places

intersections of load-bearing and self-supporting walls.

14. All installation work must be carried out in accordance with the requirements

SNiP 3.09.01-85 "Production of prefabricated reinforced concrete structures and products",

SNiP 3.03.01-87 "Load-bearing and enclosing structures", SNiP III-4-80 "Safety in construction", as well as the requirements of the series 2.140-1 issue. 1 and the requirements given in the working drawings and in the work design GOST 23118-99 "Steel construction structures".

15. Corrosion protection:

All metal anchors and connections must be protected with a layer of enamel

PF-133 (GOST926-82*) over a layer of soil GF-020 (GOST18186-79) or a layer

masonry cement-sand mortar GOST28013-98* thickness

not less than 20mm;

The surfaces of metal embedded parts must be galvanized;

Anti-corrosion coatings damaged during the work process

must be restored using one of the methods listed above.

16. After installation and welding, protect anchors and ties with B15 concrete

on fine aggregate 40mm thick.

17. Welding should be carried out using E42A electrodes in accordance with GOST 9467-75, thickness

seams 6 mm, but not more than the thickness of the elements being welded.

18. Create a 600mm high fence along the perimeter of the roof

(total height of the fence with parapet is 900mm).

All fencing elements should be painted 2 times with PF-115 enamel

over the GF-021 soil layer.

Do-it-yourself installation of floor slabs.

Currently, in our country, the most popular are three methods of constructing floors in a house. This is the installation of floor slabs, the installation of a monolithic reinforced concrete floor and installation of ceilings on wooden (less often metal) beams. We will definitely talk about all these methods and more. And the first technology we will consider is the installation of ready-made floor slabs.

First, a little about the floor slabs themselves. Depending on their shape, all slabs can be divided into flat and ribbed. Flat ones, in turn, are divided into solid and hollow. We are now interested in empty ones, because... It is this type of slab that is used mainly in low-rise construction.

Hollow core slabs, in turn, are also classified according to various parameters, such as the shape and size of the voids, the thickness of the slabs, the manufacturing technology of the slabs, and the method of reinforcement.

I will not delve into the topic of classification. It is better to look for this information on the websites of manufacturers of reinforced concrete products (reinforced concrete products). We'd better talk directly about installation.

The very first point that you need to pay attention to even at the stage of designing your future home is the opportunity to purchase in your area exactly the slabs of the sizes that are included in the project. Each manufacturer has its own specific range of products and it is always limited. This is really important and I am surprised that very often developers forget about this recommendation and then they have to either cut one or several slabs or make a monolithic section on the floor. We'll talk more about this below.

Storing floor slabs at a construction site.

Of course, it’s great if you have the opportunity to lay floor slabs immediately when they are delivered directly from the truck that brought them. But most often this does not happen. Or the driver insists that you unload the slabs as quickly as possible, because... he is in a hurry for the next order, or the slabs are not laid on the machine in the order in which you need, or you simply bought them in advance and are not going to lay them yet. In all these cases, the slabs will need to be stored on your site.

Try to choose a flat surface for this. Never place slabs directly on the ground. Be sure to put something under the edges of the slab, for example, scraps of wooden beams. There should be only two pads, at a distance of approximately 25-40 cm from the edges. Pads cannot be placed under the middle of the slab.

The slabs can be stored in stacks up to 2.5 meters high. Make the shims for the first slab higher so that if they are possibly pressed into the ground when laying subsequent slabs, the first slab should never touch the ground, otherwise it could easily break. It is enough to make all subsequent linings even from an inch (2.5 cm). They must be stacked strictly one above the other.

Preparation for installation of floor slabs.

Preparation begins at the moment when the masons cast out the last rows of masonry. The slabs will lie flat and without differences if the upper rows of load-bearing walls are level and in the same horizontal plane.

To achieve this, there must be horizontal level marks in all corners of the room being covered. They are placed during the construction of walls using a level, or a laser level, or a hydraulic level. And when the last row of masonry is done, the distance from the marks to the top of the walls is controlled with a tape measure. It should be the same in all corners. From my experience I can tell you for sure that some masons neglect this, especially when they do backfill masonry at the same time as the face masonry, which is done “under the rod”.

Top row brickwork load-bearing walls must be bonded. That is, if you look from the inside of the covered room, then on the load-bearing walls (on which the floor slabs rest) in the very top row of the masonry, only the pokes should be visible.

If the slabs are placed on a load-bearing partition 1.5 bricks thick (that is, the slabs rest on it on both sides), then the top row of such a partition is laid out in one of two ways:

Before laying floor slabs on walls made of various blocks (foam concrete, gas silicate, slag, etc.), it is necessary to make a reinforced concrete belt (usually about 15-20 cm thick). Such a belt is made either by pouring concrete into the formwork, or using special U-shaped blocks along the entire perimeter of the house box, i.e. not only on load-bearing walls, but also on non-load-bearing ones.

When installing hollow core slabs, the holes in them must be sealed. It is much more convenient to do this in advance, while the slabs are still on the ground. In general, SNiP prescribes that voids must be sealed on the side of the slab that rests on the outer wall (to reduce the likelihood of freezing of the slab), and on the side that rests on the internal partition, only starting from the third floor from the top of the house and below (to increase strength). That is, if, for example, the house has a basement floor, a floor between the 1st and 2nd floors and an attic floor above the 2nd floor, then it is necessary to seal the voids on the side load-bearing partitions only in the basement.

I will say that we always seal holes when laying slabs. Moreover, recently, more and more often, round-hollow slabs come from factories with the holes already sealed. It's convenient. If the holes are not sealed, we insert a one-and-a-half brick (you can even use half) into them and fill the remaining cracks with mortar.

Also, before installing the slabs, it is necessary to prepare the site for the crane in advance. It’s good if in the place where the crane will stand the soil is, as they say, compacted. It's worse when the soil is bulky. If you have a basement, you should not place the faucet too close to the house, in order to avoid what is shown in the figure below:

In such cases, it is better to order a truck crane with a longer boom. Also, sometimes in the place where the crane will stand, you first have to put several road slabs (usually used ones are found somewhere). Often this has to be done in the fall in rainy and slushy weather, when the area is so “broken” that the crane simply gets stuck on it.

Three people are enough to install floor slabs. One hooks the slabs, two lay them down. If you want, you can do it together, although not always. It happens that when covering, for example, the second floor, the installers and the crane operator do not see each other. Then, at the top, in addition to the 2 people directly laying the slab, there must be another person who will give commands to the crane operator.

Laying begins from the wall on a layer of mortar no more than 2 cm. The mortar should be thick enough so that the slab does not squeeze it completely out of the seam. After the crane operator places the slab on the walls, he first leaves the slings taut. At the same time, using a crowbar, if necessary, it is not difficult to move the slab a little. If the upper surfaces of the load-bearing walls were made smooth, then the slabs will lie evenly, without differences, as they say, “from the first approach.”

Regarding the amount of support of the slabs on the walls, I will give an extract from the document “Manual for the design of residential buildings. Vol. 3 (to SNiP 2.08.01-85) 6. COLORS:

Paragraph 6.16.: The depth of support of prefabricated slabs on walls, depending on the nature of their support, is recommended to be no less than, mm: when supported along the contour, as well as two long and one short sides - 40; when supported on two sides and the span of slabs is 4.2 m or less, as well as on two short and one long sides - 50; when supported on two sides and the span of the slabs is more than 4.2 m - 70.

When assigning the depth of support for floor slabs, you should also take into account the requirements of SNiP 2.03.01-84 for anchoring reinforcement on supports.

In our practice, we try to make the support no less than 12 cm, fortunately now it is possible to purchase exactly the slabs that are needed. The step of their lengths is 10 cm.

I often hear arguments about whether it is possible to support hollow-core floor slabs on three sides (two short and one long) and how far the long side of the slab can be placed on the wall. From what is written above, it follows that it is possible to support the slabs this way. But this is not entirely true. If you read the specified SNiP, it says that slabs that rest on three sides have a different reinforcement pattern than those that rest on only two sides.

The vast majority of hollow core slabs that are currently produced by concrete factories are designed specifically to be supported on two short sides, so it is not recommended to place them on the wall with their long side. Under a certain load, this can lead to cracking of the slab. The reinforcement scheme and, therefore, the possibility of supporting the slab on a third side must be clarified with the manufacturer.

Another mistake associated with improper loading of the slab is covering two spans at once (see figure below):

Under certain unfavorable conditions the slab can crack, and the location where the crack appears is completely unpredictable. If you still use such a scheme, use a grinder to make a cut (to the depth of the disk) on the upper surface of the slab strictly above the middle partition. Thus, if something happens, the crack will pass precisely along this cut, which, in principle, is no longer scary.

Of course, it’s good if we manage to cover ourselves exclusively with whole slabs. But circumstances are different and yet sometimes some slab (or even more than one) has to be cut lengthwise or crosswise. To do this you will need a grinder with a diamond disc for concrete, a sledgehammer, a crowbar and not the weakest guy at a construction site.

To make work easier, it is better to place the slab on a lining. Moreover, this lining is placed exactly under the cut line. At a certain moment, the slab will simply break along this line from its own weight.

First of all, we make a cut on the upper surface of the slab with a grinder along the cut line. Then, striking with a sledgehammer from above, we cut a strip along the top of the slab. It is quite easy to penetrate concrete in void areas. Next, we use a crowbar to break through the lower part of the slab (also through the voids). When cutting a slab lengthwise (we always cut along the hole in the slab), it breaks quite quickly. When chopping across, if the slab does not break after breaking the lower part with a crowbar, a sledgehammer is used to strike the vertical partitions of the slab from the side until the victory is achieved.

During the cutting process, we cut the reinforcement that comes across. You can use a grinder, but it’s safer to weld or cutting torch, especially when the reinforcement in the slab is prestressed. The grinder disc can bite. To prevent this from happening, do not cut the reinforcement completely, leave a couple of millimeters and then tear it apart with a blow from the same sledgehammer.

Several times in our practice we had the opportunity to cut slabs lengthwise. But we have never used, so to speak, “stumps” less than 60 cm wide (less than 3 holes remain), and I do not advise you to. In general, when deciding to cut a slab, you take full responsibility for the possible consequences, because not a single manufacturer will officially tell you that cutting a slab is possible.

Let's now see what can be done if you still don't have enough slabs to completely cover the room:

Method 1- we place the first or last (maybe both) slabs without bringing the long side to the wall. We fill the remaining gap with bricks or blocks, hanging them no more than half from the wall (see figure):

Method 2- we make the so-called “monolithic section”. Plywood formwork is placed underneath the slabs, a reinforcement frame is made (see figure below) and the area between the slabs is filled with concrete.

Anchoring of floor slabs.

After all the slabs are laid, they are anchored. In general, if the construction of a house is carried out according to a project, then it must contain an anchoring scheme. When there is no project, we usually use the circuit shown in the figure:

The anchor is made by bending the end into a loop that clings to the mounting loop of the slab. Before welding the anchors to each other and to the mounting loops, they must be tensioned as much as possible.

After anchoring, we immediately seal all mounting eyes in the slabs and rustications (seams between the slabs) with mortar. Try not to delay this so as not to get rusted construction waste, and water did not pour into the eyelets during rain and snow. If you suspect that water has gotten into the slabs (for example, you bought slabs with voids already filled, and rainwater could have gotten in even while being stored at the factory), it is better to let it out. To do this, after installation, simply drill one small hole in the slabs from below with a hammer drill, into the voids where the mounting lugs are located.

It is especially dangerous to find water in voids in winter time when the house is not yet heated (or not completed at all) and the slabs freeze below zero. Water saturates the bottom layer of concrete, and with repeated freezing-thawing cycles, the slab simply begins to collapse.

Another way to secure the slabs is to construct a so-called concrete ring anchor. This is a kind of the same monolithic reinforced belt, only it is not made under the slabs, but in the same plane with them, also around the entire perimeter of the house. More often this method is used on houses made of aerated concrete, foam concrete and other blocks.

Let me make a reservation right away that we have never used it because it is much more labor intensive. I think a ring anchor is justified in more earthquake-prone regions than our Nizhny Novgorod region.

Do-it-yourself installation of floor slabs, HOME

We are considering issues related to the installation of floor slabs. How to store slabs? How to prepare walls for ceiling installation? How to lay and fasten the slabs?

During the construction of any structure, floors are used to ensure structural strength and impart rigidity to multi-level buildings. Builders typically use three main methods to install them. Installation must be carried out by experienced specialists with the necessary knowledge in the field of construction.

Peculiarities

As already written above, the most reliable are three options for constructing floors:

installation of monolithic reinforced concrete slabs;
installation of conventional slabs;
laying timber beams.

It should be noted that all floors differ in shape, structure and technical characteristics. The shape of concrete slabs can be flat or ribbed. The first, in turn, are divided into monolithic and hollow.

When constructing residential buildings, hollow-core concrete floors are often used because they are cheaper, lighter and have a higher sound insulation rate than monolithic ones. In addition, internal holes are used for laying various communication networks.

During construction, it is extremely important to decide already at the design stage on the choice of type of floors, taking into account all technical factors.

Each manufacturer produces slabs of a certain range, their quantity is limited. Therefore, changing the material during the installation process is extremely imprudent and costly.

When using slabs, certain rules must be observed on the construction site.

It is better to store purchased floors in an area specially designated for this purpose. Its surface must be smooth. The first slab should be laid on wooden supports - bars 5 to 10 cm thick so that it does not come into contact with the ground. Between subsequent products, there are enough blocks of 2.5 cm in height. They are placed only along the edges, there is no need to do this in the middle. The stack should not exceed 2.5 meters for safety reasons.
If you plan to use long and heavy beams during construction, you should take care of auxiliary construction equipment in advance.
All work must be carried out in accordance with the project, which must be drawn up taking into account the requirements of SNiP.
Installation is permitted only to adult workers who have permission and relevant documents confirming their qualifications.
When installing floors of multi-level structures, climatic conditions should be taken into account. SNiP standards regulate wind speed and visibility restrictions.

Preparation

Any construction has its own project, which is created on the basis of several regulatory documents. Main sections of the project.

Budget plan, describing all costs and deadlines.
Technological map indicating all processes at the facility, describing the labor intensity of each stage and the requirements for the resources used. It should provide instructions for performing specific tasks, indicating effective methods of carrying out work, as well as compliance with safety measures. The map is the main regulatory act of any project.
Executive scheme. Its sample is regulated by GOST. It contains information about the actual performance design work. It includes all changes made to the project during construction, as well as agreements with contractors for installation. The diagram reflects how correctly the structure was erected, whether it complies with accepted standards (GESN, GOST, SNiP), whether safety measures were observed, etc.

Before laying the floors, leveling should be done, that is, make sure that the supporting horizontal plane is ideal. To do this, use a level or hydraulic level. Professionals sometimes use a laser level option.

The difference according to SNiP is no more than 5-10 mm. To perform leveling, it is enough to lay a long block on the opposite walls, on which it is installed meter. This establishes horizontal accuracy. Similarly, measure the height in the corners. The obtained values are written directly on the walls with chalk or marker. After identifying the outermost points above and below, leveling is carried out using cement.

Before installing the floors, formwork is performed. You can do it yourself or use the factory version. Ready-made purchased formwork has detailed instructions that describe the entire installation process, right down to height adjustment.

During construction wooden floors no formwork is needed; the existing supports are sufficient.

If the walls are built from gas silicate materials or foam concrete, then before installing the floors they need to be further strengthened. For these purposes, a reinforced belt or formwork is used. If the structure is brick, then the last row before the ceiling needs to be made into joints.

In preparation for construction and installation work You should prepare the components for the solution in advance - cement with sand and water. You will also need expanded clay or crushed stone to fill the holes before rough finishing.

In hollow-core floors, according to SNiP, it is necessary to seal the holes on the side of the outer wall. This is done to prevent it from freezing. It is also prescribed to close the openings with inside, starting from the third floor and below, thereby ensuring the strength of the structure. Recently, manufacturers have been producing products with already sealed voids.

If lifting equipment is required for construction, then preparatory stage it is necessary to provide a special platform for it. The soil must be compacted to avoid crumbling. Sometimes builders place road slabs under the crane.

Before installation, the floors must be cleaned of dirt, especially if there are traces of old concrete left on them. If this is not done, the quality of the installation will suffer.

At the preparatory stage, the waterproofing of the foundation is checked for the absence of breaks and defects.

Installation

To install the slabs, three people will be required: the first one hangs the part from the crane, the other two install it on site. Sometimes during large-scale construction a fourth person is used to correct the work of the crane operator from the outside.

Installation work of floor slabs is carried out in accordance with the technology regulated by SNiP standards, as well as in accordance with the drawing and layout agreed upon in the project.

The thickness of the partition is calculated depending on the designed load. If reinforced concrete slabs are used, they must be at least 10 centimeters wide, for ribbed options - from 29 cm.

The concrete mixture is prepared immediately before installation. It is better to order it from specialized companies so that it has brand strength. The solution consumption rate is determined at the rate of 2-6 buckets for laying one slab.

Installation begins from the wall, where a sand-cement mixture 2 cm thick is laid out on a brick or block support. Its consistency should be such that after installation of the ceiling it is not completely squeezed out.

In order to place the slab correctly and accurately, it does not need to be immediately unhooked from the crane slings. To begin with, with the suspensions tense, the ceiling is leveled, and then lowered completely. Next, builders check the height difference using a level. If a certain evenness cannot be achieved, then you will have to raise the slab again and adjust the height of the concrete solution.

Experts warn that It is better to install hollow core slabs on two short sides. In addition, you should not cover several spans with one ceiling, as it may burst in an unexpected place. If, however, the scheme provides for one slab for 2 spans, then several runs should be made with a grinder in the places of the jumpers. That is, an incision is made along the upper surface above the central partition. This ensures the direction of the crack in the event of a future split.

Prefabricated monolithic or hollow core floors have a standard length. Sometimes other dimensions are needed for construction, so they are divided with a saw with a diamond blade. It is important to remember that it is impossible to cut round hollow-core and flat slabs lengthwise, which is due to the location of the reinforcement in the support zones. But monoliths can be divided in any direction. Section of a monolithic concrete block may require the use of tools for cutting metal reinforcement and a sledgehammer.

First you need to make a cut on the top surface along the intended line. Then use a sledgehammer to break through the concrete in the void area and break it bottom part slabs During work, a special lining is placed under the cut line, then at a certain depth of the hole made, a fracture will occur under its own weight. If the part is cut lengthwise, then it is better to do it along the hole. Internal reinforcing bars are cut with a gas tool or safe welding.

Professionals advise not to cut the reinforcement with a grinder until the very end; it is better to leave a few millimeters and break them with a crowbar or sledgehammer, since otherwise the disc may get stuck and break.

No manufacturer takes responsibility for a cut slab, since this procedure violates its integrity, and therefore technical specifications. Therefore, during installation it is still better to avoid cutting and use intact parts.

If the width of the slab is not enough, then it is proposed to make monolithic concrete screeds. Plywood formwork is installed below two adjacent slabs. U-shaped reinforcement is placed in it, the base of which lies in the recess, and the ends extend onto the floors. The structure is filled with concrete. After it dries, a general screed is made on top.

When the installation of the ceiling is completed, the process of laying the reinforcement begins. Anchoring is provided to fix the slabs and impart rigidity to the entire structure.

Anchoring

The anchoring procedure is carried out after the ceiling is installed. Anchors fasten the slabs to the walls and to each other. This technology helps enhance the rigidity and strength of the structure. Fasteners are made of metal alloys, often galvanized or stainless steel.

Methods of interfloor connections depend on the presence of special loops.

For slinging high-density elements, fastenings in the shape of the letter “L” are used. Their bend length ranges from 30 to 40 centimeters. Such parts are installed 3 meters from each other. Adjacent slabs are fastened transversely, the outer ones - diagonally.

The algorithm for anchoring is as follows:

the fastener is bent on one side under the eye in the slab;
adjacent anchors are tightened to the limit, after which they are welded to the mounting loop;
interpanel seams are closed with mortar.

For hollow products, slinging is carried out similarly, but an additional reinforced concrete row is laid around the perimeter. It is called a ring one. The fastener is a frame with reinforcement filled with concrete. It additionally fastens the floors to the walls.

Anchoring can be done by two workers.

Safety precautions

When performing installation and preparatory work, certain safety regulations must be observed to prevent accidents. They are prescribed in all construction regulations.

All preparatory and organizational activities in the field of construction are prescribed in SNiP. Among the main ones we can list the following.

All employees must have the necessary permits and other documents allowing them to carry out such activities. Engineering and technical personnel must be instructed and familiarized with safety precautions. Crane operators and welders are required to have special training confirmed by certificates.
The construction site must be fenced off from outsiders to avoid misunderstandings and injuries.
The project must obtain all permits and approvals from government regulatory agencies and other inspection organizations. These include, in particular, surveyors, firefighters, technical supervision, cadastral services, etc.
The construction of the upper levels of a multi-story building is possible only after complete installation lower structures must be completed and rigidly fixed.
If it is not possible to give signals to the crane operator visually (for example, during the construction of large objects), a light and sound alarm system, communication by radio or telephone should be installed.
Cleaning of floors is carried out before they are lifted into place.
Installation is required established scheme layouts.
If there are no mounting loops, the part does not participate in lifting. They are either discarded or used for other work that does not require transportation.
Prefabricated parts must be stored separately.
When constructing multi-storey structures, rules for working at height are mandatory.
Standing on the stove while it is being transported is strictly prohibited.
Providing workers with personal protective equipment is the responsibility of the employer. You cannot be on the court without a helmet.
Removing products from the slings is possible only after they are firmly secured to the working surface.

It's just basic rules. SNiP contains many more conditions for safe implementation construction work when laying floors.

Modern builders use only three methods of constructing floors, which are very popular all over the world. The main types include the installation of wooden beams (metal beams are used somewhat less frequently), installation monolithic slab reinforced concrete floors and installation of conventional floor slabs. We suggest we talk about each of the methods in more detail. First of all, we should consider the most popular technology, which involves laying ready-made floor slabs as a method of installing multi-level structures. But first you need to understand what the plates themselves are.

Prices for construction crews can be very different. Before laying floor slabs, you should understand that they are all divided into ribbed and flat, depending on their shape. Flat can be divided into solid and solid. The technology for laying floor slabs may differ, but only hollow-core ones are usually used in the construction of private houses and small structures.

Their classification can take place according to the following parameters:

reinforcement method;
technology used in their manufacture;
thickness;
dimensions of voids;
form.

It makes no sense to consider the classifications in more detail, since all the necessary information can be easily found on the manufacturer’s website, including SNIP. First, we should talk about the upcoming installation work ah (ENIR which can be found in the public domain). First of all, you should get clarification regarding the order and transportation of slabs of exactly the same dimensions that were included in the main project. The location of the warehouse will play an important role, since the cost of transportation will depend on the distance. Each manufacturer has its own range and, unfortunately, it is quite limited.

Before laying the base material in a horizontal structure, you should decide which type of slabs is preferable to use.

In price lists or in warehouses they can be found in this form:

products with longitudinal ribs;
multi-hollow;
tent panels, in which the ribs are located clearly along the perimeter;
flat.

The most common designs

Multi-hollow structures are often used. Depending on the manufacturing method, two types of materials are distinguished:

Round-hollow.
Continuous formation.

Round-hollow, high-quality, durable and time-tested structures, which are most often used for the construction of small buildings and structures residential type. Many GESN, TTK and other regulatory documents have been created especially for them. Their thickness is about 22 cm. A stumbling block in individual construction can be the presence of exclusively serial sizes of products, which will undoubtedly cause a number of inconveniences. In their production, reusable molds are used. High-quality formwork should be prepared before non-standard structures are made. Moreover, their cost will be significantly higher than standard structures, whose length is 2.7-9 m, in increments of 30 cm.

How wide can the structure be for proper installation?

The width of the structure can be:

1.8 meters;
1.5 meters;
1.2 meters;
or meter.

Products whose width is 1.8 m are not in special demand. Their weight is quite noticeable, so installation is complicated. Continuously formed beams are also used. At the same time, their manufacturing technology is somewhat different, which allows you to create structures of any length. Their thickness will be about 22 cm, while the width will be the same as in previous PCs. Significant shortcomings include too little experience working with similar products and obvious errors in the preparation of GESN and other documentation.

Flatter PTs are often used as additional equipment, provided that hollow-core structures are installed. Their dimensions are standardized: thickness 8-12 cm. There are also thinner products that allow you to cover such small spaces like a corridor, toilet or balcony.

A little about theory

There are not many varieties of floor slabs and they all have uniform state designations. This is how you can use:

hollow-core structures;
tent roofs, which have ribs along the contour in the form of a cornice. One such slab is laid over the entire room;
prestressed ribbed elements, the length of which can reach fifteen meters;
Solid layered structures are not often used, as are monolithic reinforced concrete devices.

Correct calculation allows you to save money

This is primarily due to the prohibitively high cost of monolithic structures, which is several times higher than prefabricated models. Their assembly also takes longer than any other structure. You can make a more accurate calculation yourself by comparing the cost of individual elements. Plates allow you to immediately cover an entire floor, while for monolithic ones it is necessary to additionally use concrete mixtures, fittings and formwork. Hollow ones are irregular and oval in shape.

Advantages of using round-hollow products:

A high-quality, and most importantly free, thermal insulation layer, which is formed due to the existing voids.
Relatively light weight of the main structure.
Free soundproofing layer due to the same voids.

Leaning slabs

Laying floor slabs is possible only after creating and signing a diagram or construction project according to which the structures are laid out. All components should be selected in such a way that their support on a wall made of brick or expanded clay is ensured as tightly as possible. In addition, possible gaps in width should be excluded.

Minimum support indicators:

7 cm for products whose length is no more than 4 m;
9 cm for products whose length exceeds the 4 m mark.

The optimal indicator for support on the wall is 12 cm, and all designers and coating designers adhere to it. This value is a kind of guarantee of reliability in the event that minor deviations were identified during installation. Regarding load-bearing walls, you should think about it in advance, since the distance between them should be sufficient for laying the slabs used.

To calculate the required distance, you need to take the standard length of the slabs and subtract 24 cm. When using the PB or PC series, you should use only supports on the short sides, without calculating intermediate support points.

For example, you can take a floor slab of 4.44 m, from which we subtract 240 mm. Thus, we come to the conclusion that the distance between load-bearing structures should be at least 4.2 m. Only in this case can the product be provided with the best support coefficient. When using the PT series, the support indicator is 800 mm, and the location of the support points can be on all sides. It is worth paying attention to possible irregularities in the location of ventilation ducts. The optimal thickness of load-bearing brick walls is considered to be 38 cm, then 12 cm will go on each side of the house. In this case, another 14 cm will remain in the middle for optimal ventilation channel.

In this case, installation should not be carried out with errors. If a displacement of the laid slabs occurs, this will lead to a significant reduction in ventilation holes, which will lead to a reduction in the cross-section and poor ventilation of the room.

What should you pay attention to when laying floor slabs?

The layout plan for all elements should include the location of ventilation ducts, the features and configurations of the structure, the range of the nearest manufacturer and the existing interfloor openings. But monolithic sections must be indicated separately, since they are poured directly at the site of construction and installation work. It is customary to use semi-trailers for delivery only if the length of the products does not exceed 3.2 meters. Otherwise, you will have to worry about renting panel trucks.

Stick to the plan

Rules to follow:

Anchoring must be carried out between the panels using load-bearing structures. Their layout will depend on the chosen project.
Depending on the location of the elements and the availability of access to the ends of the structures, concrete plugs for voids are installed after or in front of the slabs. More detailed information can be obtained by reading the GESN.
The necessary adjustments are made using a crowbar in the first minutes and using tensioned slings.
The mortar pastel should have a thickness of 1.5 - 2 cm. In this case, longitudinal reinforcement is mandatory. For this, rods with a round cross-section of 1-1.2 cm, model A240, are used.
The technological map indicates that the support on a reinforced concrete structure should be 60 mm, and for brick 125 mm.
If the initial calculation was made correctly, then there should be no height differences. If this happens, then an indicator less than or equal to 50 mm can be leveled using conventional concrete screed. If the indicator is higher, then it is additionally necessary to use a reinforced belt, which is poured directly into the formwork.
The panels are laid exclusively on a prepared and leveled foundation base.

To level the lower plane (basement ceiling), the use of crushed stone or broken brick is prohibited. Before adding mortar or sand, they must be thoroughly sifted.

Preparatory work

The necessary preparatory work must begin while the masons are laying the last course of masonry. The permissible deflection of the slab will be minimized if the level of the load-bearing walls is as level as possible and at the same time located in a single horizontal plane. In order to achieve a similar result, special level marks should be used, which should be placed in all corners of the workroom. To install them, you will need a level, even at the stage of wall construction. A hydraulic level or laser level, however, it is too expensive.

Important points

The laying of floor slabs must be done on a perfectly flat surface, therefore, when erecting the last row of masonry, you should regularly use a tape measure, which will allow you to measure the exact distance from the selected mark to the top of the walls. The indicator for each angle should be the same. Based on centuries-old practice, we can confidently say that most builders neglect this rule, especially if the front and backfill masonry is carried out simultaneously. In this case, no additional calculations are made. Anchoring of floor slabs is carried out in any case.

What you should pay special attention to

It should be noted that the very last row of masonry (brick) should be the bond row. This implies the presence exclusively of butts in the top row of masonry load-bearing walls, when viewed from the inside work room. If the thickness of the load-bearing wall is only one and a half bricks, then the very last row should be made in one of two ways. It is recommended to use a reinforced belt immediately before laying the mounted floor slabs on the walls. The blocks can be made of slag, gas silicate or foam concrete. The thickness of this layer is 150-200 mm. To do this, either the concrete solution is poured directly into the formwork, or it involves the use of special blocks that have a U-shape along the entire perimeter of the box. This means not only load-bearing walls, but also ordinary walls.

When using void-based structures, all holes should be sealed. This should be done before they are installed and while they are lying chaotically on the ground. Based on the GESN, we can say with confidence that only the side that rests on the outer part of the wall needs to be sealed, which will reduce the risk of freezing of the structure used. Also, similar manipulations should be carried out with the side that rests on the internal partition; this must be done to increase the strength of the structure. More detailed technological map must be with the workers.

Trust people's experience in this matter

Based on experience, I would like to note that all holes must be sealed. It is also possible to purchase round-hollow products with already filled holes. But this aspect is not often provided by manufacturers, although it is very convenient. If there are voids, then half bricks should be used to fill them. While the remaining space is sealed with mortar. Installation of floor slabs requires the presence of a pre-prepared site for the crane. If the surface consists of ordinary soil, then everything is fine, but if it is bulk, then difficulties may arise. Up close basements installing a tap is prohibited. If necessary, it is recommended to rent a crane with a longer boom.

Preparing the work surface

The load-bearing capacity of floor slabs is in no way connected with the correctness of their installation. Before laying them, the surface to be used should be cleaned of dirt, old concrete and mortar residues. For correct implementation necessary work builders will need scaffolding, ladders, scaffolding and stepladders. Based on the GESN, when using prefabricated floor models, there is no need for such elements. Before starting installation work, you should check the top layer of the foundation for the presence of a high-quality waterproofing layer. Whether it is a roll or film layer, it must be continuous and represent a kind of continuation of the external or internal vertical waterproofing.

Don’t forget to prepare the solution in advance

Depending on the dimensions of the slabs used, a solution is prepared at the rate of 2-6 buckets per slab. Otherwise, you should order a solution in advance that would have such indicators as grade strength. So how to lay floor slabs correctly? Depending on some factors, the pastel will be laid for several or one panel:

Given monolithic areas, most professionals simultaneously apply pastel to several products ( exact quantity will directly depend on experience and skill);
The surrounding climate will also play an important role. If the weather is hot, the solution will quickly dry out and lose its properties, and in cold weather it will simply freeze.

The working surface is considered to be the bottom edge of the slab. To control the horizontal level, one person is used, who is located below with a bubble level. Control must be carried out simultaneously in two directions, taking into account the levels between panels and floors. If necessary, the top layer of the foundation is dismantled and a new and more even one is created.

We install panels

Elements are mounted either from the side of the walls where they are located ventilation ducts, or from the nearest corner from the tap. Slinging requires the presence of only two installers. All necessary manipulations are performed from a machine that delivers the structures to the construction site, which can significantly reduce the time allotted for unloading. The installers themselves know how to properly install the delivered PC products. The design support must be observed in any case, and for this, the length of all spans is pre-measured using a tape measure.

We do everything step by step

TTK maps indicate correct installation all elements of the slabs onto the surface of the foundation, while we are talking about minimal time costs:

fastening is carried out using loops with sling hooks or special load-handling devices;
transportation of the product to the place of its installation is carried out by workers who must be on safe distance. The panel unfolds using hooks, and all manipulations are performed when the product is in a canopy;
after the pastel is completely leveled, longitudinal reinforcement is recessed into it (for masonry this figure is 60 mm, for reinforced concrete only 30 mm from the edge). The slab is leveled on both sides and then carefully lowered onto the base. All this time the lines remain taut.

If necessary, adjustments are made using crowbars, but only during the first few minutes and only relative to the axis of the wall. Only after this the strobes can be weakened, while control is carried out by one worker horizontally in all directions. The technology for installing floor slabs must be indicated before installation work begins.

The use of the solution is only possible when the slab is lifted by all the hinges, and not just by one. If you lift the product by only two loops, it may happen that it moves spontaneously, thereby squeezing out part of the solution from the opposite edge.

Follow safety precautions

During the installation of the first slab, walking on the surface of the foundation is prohibited, regardless of the width of the tape. To move, use scaffolding, stepladders or scaffolding. Prefabricated elements should not be stored in one place, since their installation may not coincide with their location. Installation is carried out according to the layout diagram, with all elemental components stacked extremely tightly to each other with long edges. PPS or concrete plugs should be installed in the voids after installation and assembly of the basement floors.

Tying with reinforcement

Anchoring floor slabs involves carrying out work according to the following schemes:

the presence of longitudinal connections between the floor elements, which in turn rest on inner part load-bearing wall using smooth reinforcement of a centimeter;
a wall or slab with an L-shaped anchor, which has a bend of 300-400 mm;
adjacent panels in such buildings are U-shaped jumpers with smooth reinforcement one centimeter (A240);
the outer plates are tied with 0.3-0.5 cm wire.

Adhering to existing standards, you can create a prefabricated horizontal disc of the floor, the spatial rigidity of which will be slightly higher, as well as the connection with brick walls and blocks made of concrete.

The support, based on the standards, should be 60-125 mm. In the event of the slightest seismic activity, the anchors will prevent individual slabs from collapsing, thereby allowing people to leave the building. In this case, one should take into account fundamental points that are associated with the basic characteristics of the technical underground.

Joints and their thermal insulation

After installing the slab, leveling is done using brickwork. This material is used as a kind of bridge for the cold. Therefore, it is recommended to additionally lay extruded polystyrene foam or more conventional mineral wool between them. Such materials are estimated, so they will not become unexpected costs. This is the only way to reduce the expected heat loss to a minimum. It is possible to use pieces of insulating material or solid strips. Laying is done along the wall. Existing cracks are sealed using polyurethane foam, which has characteristics similar to insulating material. Estimate programs will allow you to resolve the issue regarding the total cost of materials and necessary work.

Seal the joints

Such thermal insulation material is necessary only for insulating the outer perimeter of buildings and structures. It is worth noting that reinforced concrete products have longitudinal edges, so seams are formed in any case. The width of load-bearing walls is often greater than the adjacent slabs of maximum width. Joints can be sealed using M100. Otherwise, you will have to connect the existing floor slabs together, but for this you will need concrete grade B12.5 or higher.

In certain areas of internal load-bearing structures, ventilation ducts can be located, which originate from underground level. Before using the mixture in this case, it is necessary to first extend the existing channels for pipes to the next floor, making masonry under them.

The use of this technology will allow the PC to be laid on a prepared foundation in a short time, without reducing the strength of the horizontal floor disc. This will ensure a strong connection between the supporting structures, thereby making the building safer in the event of a natural disaster. Installation of loggia floor slabs is done according to the same principle.

We cut the round-hollow slab correctly

A slab 1.2 m wide can be easily cut in just forty minutes, with a fist, a grinder and a crowbar. Most people do not think that such manipulations will be necessary, because there is always the opportunity to order a product of a slightly smaller size. Unfortunately, not everyone has such an opportunity, but storing slabs at home different diameters It's simply not profitable. In any case, you will need to file somewhere and trim somewhere during the installation process.

Cut across

Often during the installation process there is a need to slightly shorten the reinforced concrete product. To do this, the stove must be on the ground and stand on special pads. Chalk can be used as a limiter that will indicate to us the required size. The top of the slab is cut with a grinder, and a special wheel should be used for working with concrete. The chalk mark must completely coincide with the one located under the slab. If you plan to cut only 25 cm, then in addition to the chalk line, the bottom wooden lining on which the slab is located should also move 25 cm from the edge.

Not big tricks when cutting slabs

If this rule is not followed, the concrete will become licked during cutting. After the line has been outlined with a grinder, this cut is tapped with a cam in the immediate place of the cut. The blow should fall on the pipe, and not on the rib. It breaks through with the fourth blow, after which the unnecessary section can be dismantled. This should be done with all pipes. After they have been pierced, the ribs are pierced, but from the side.

At this stage, the weight of the slab should play into your hands, and it should already sag, which will facilitate further manipulations. At this stage it is necessary to use a crowbar. With its help, the entire lower part of the pipe is broken through, right down to the fittings. It is cleared of concrete and cut with a grinder. To do this, use a metal disc. It is better to place the torn side in a brick “house”, and then carefully cover it with mortar to strengthen it.

Cut lengthwise

It is much easier to cut a slab lengthwise than crosswise. However, this will take a little longer, since the length of the product can be only six meters, but the cross-section will be one and a half meters. You should chop according to the same principle as described for cutting across. With a fist we hit the surface of the pipe along the entire length. For a better result (a smoother edge), you should make a small cut using a grinder, and only then hit it with your fist. The bottom of the pipes is broken through with a crowbar (along the entire length). Throughout the entire felling there will be a mesh that can be easily cut with a grinder.

What points should you pay attention to when laying PP?

In order to prevent the dismantling of floor slabs due to mistakes made, the entire installation scheme should be depicted schematically. For such calculations you will need some experience and a regular calculator. Subject to availability only correct scheme can be accurately called required quantity slabs, as well as their exact dimensions, avoiding large gaps in advance. Small gaps are sealed using a concrete-based solution, but for large cracks a cinder block is used. When using hollow-core structures, they should be laid so that the smooth side faces down.

Let's sum it up

Their location should be as close to each other as possible. Every effort should be made to avoid large gaps, as subsequent disassembly may be time consuming. Place them aligned along the bottom edge. You should first consider the location of the communication. To improve the strength of the foundation to be covered, all elements are firmly connected to each other. For this, it is recommended to use 1.2 cm rods or wire rod. All slabs cannot be connected at once. Only two slabs can be secured at a time. WITH outside fastening is done using an anchor. A preliminary calculation regarding transportation will help to initially select the correct equipment that will be used for the subsequent installation of individual elements of a reinforced concrete structure.

It would seem that laying floor slabs could be so complicated, but here, as in almost any technology, there are some peculiarities that should be paid attention to. If you have never encountered floor installation before, it is better to familiarize yourself with these features in advance so as not to make mistakes during the construction process.

Do-it-yourself laying (installation) of floor slabs

So, what do you need to know to properly install floor slabs?

Here is a list of those actions that ensure reliable and durable installation:

the actual installation of the slabs;
competent hammering of rustications;
filling small gaps between slabs;
sealing the ends of the slabs to protect against freezing;
punching a hatch or hole in the slab to access the attic;
receiving the right size slabs by cutting;
safe use of cracked slabs in construction and prevention of cracks.

First, let's look at the theory. Various types of flooring can be used in houses. structural elements:

hollow-core panels;
ribbed prestressed panels in standard sizes;
tent panels having ribs located around the perimeter. Typically, such panels completely cover the entire room;
laminated solid panels;
monolithic ceiling.

Each covering option has its pros and cons. For example, a monolithic floor requires a lot of time to install and is not cheap at all. Ribbed slabs, having standard sizes, are not always suitable for covering rooms whose dimensions are not multiples of their dimensions.

In private construction, the most common are floors made of reinforced concrete round-hollow slabs. The voids in them can have different shapes: from oval to irregular.

Their popularity is explained by a number of advantages in comparison with other types of floors:

due to the voids filled with air, such slabs perfectly retain heat, being heat insulators, and also significantly increase sound insulation;
Compared to other slabs, they have much less weight, reducing the load on supporting structures.

How to shorten a hollow core slab?

Round hollow-core slabs are available to order in any size, but there are times when it becomes necessary to reduce their length or width, cut out the desired shape, for example for a bay window, or make a hole in the slabs to access the attic. In such cases, the slab needs to be chopped using a grinder, a crowbar and a cam. Despite the fairly high strength characteristics of the slab, it is cut quite easily - 40 minutes is enough to cut off the extra centimeters of a 1.2 m wide slab.

How to do this? Let's consider options for cutting the slab crosswise and lengthwise. To cut a slab crosswise, you need to position it horizontally, placing linings under it and drawing lines on it along which it will be shortened. The pads should be located exactly under the marking line, and not along the edges. For example, you need to cut off half a meter of slab. To do this, at a distance of 500 mm from the edge, a chalk line is drawn on the surface of the slab, and a lining is installed exactly under it. If the lining is not under the markings, but next to it, when cutting, the concrete surface will be what is called “licked”.

Along the marked line, the slab is cut with a grinder and a concrete disc. After this, you need to tap on the voids near the cut line with your fist. The cam strikes should be aimed precisely at the voids, and not at the ribs. Usually the plate is broken through with 3-4 blows of the cam. These actions are repeated across the entire width of the slab. To cut the ribs, they are struck with the same fist, only from the side, and not from above. An unnecessary piece of slab, deprived of support from below, will sag under the weight of its own, which will speed up and facilitate the cutting process. Next, using a crowbar, the bottom wall of the pipe is broken through, under which the fittings are located. The surface of the reinforcement is thoroughly cleaned of concrete, after which it is cut with a grinder using a metal disc.

The resulting shortened slab will have a not entirely smooth cut edge, which must subsequently be sealed with backfill bricks and mortar, which will not only hide the unevenness, but also strengthen the slab.

The slab can also be cut lengthwise. The technology is almost the same, but requires less effort and more time, because the length is greater than the width. In this case, you only need to use your fist to break the wall of the void running along the slab, having first made a longitudinal cut with a grinder along the intended line. Next, the lower wall of the pipe is broken through with a crowbar. During the cutting process, smooth bars of reinforcing mesh with a diameter of 3-8 mm will be encountered in the concrete layer. They can be cut with a grinder.

When cutting reinforcement, you need to take into account that it is stressed and can jam the grinder's cutting disc. To prevent this from happening, the reinforcement bars are slightly not cut to the end, and then the resulting cut is finally separated by the blow of a crowbar or a cam. Another reliable way cutting reinforcement - using autogen.

The relative ease with which a round-hollow slab is cut suggests that it is not that strong. But that's not true. In fact, this slab can withstand a load of up to 800 kg/m2, which is mainly carried by reinforcement and ribs.

How to cut a hole in a hollow core slab?

In the same way, a hatch is cut out in the slabs. Since its edges will be visible, it is better to immediately try to make them as smooth as possible. To do this, you need to make a preliminary cut with a grinder along the intended contour.

The hatch is cut at the junction of two slabs, evenly distributing its area between them. The dimensions of the hatch depend on the width of the slabs and the degree of their load, as well as on the type of ladder used. The wider and less loaded the slabs are, the larger the hatch can be cut into them. Loads from building structures, resting on the slabs, significantly reduce the permissible hatch area. For ladders, a hatch with an area of 900x900 mm is usually made in slabs whose width is 1.2 m. In this case, a hole measuring 450x900 mm is made in each of the slabs.

Using ladders is not always convenient. They must first be installed, then taken away, and their fixation in place is quite unreliable, especially if they are old wooden stairs. It is much more convenient to use folding attic ladders. They are securely attached to the hatch cover and folded when closing it, without taking up extra space. The hatch sizes for such stairs are 600x1200 mm, 600x1300 mm, 700x1200 mm, 700x1300 mm or 700x1400 mm. The large side of the hatch must be placed along the slabs.

How to cover a room if the width of the slab is a little short?

When covering a room, it may turn out that its dimensions are not a multiple of the dimensions of the slabs, which leads to the formation of gaps between the slabs or between the slab and the wall. You can cut out the missing piece from existing slabs, but this is time-consuming and troublesome. There are easier ways to fix this problem.

Let's take for example the case when, when installing slabs, a gap of half a meter remains between the last slab and the wall. What to do in this case? There are several options. Let's look at the simplest of them first. The gap size is 500 mm and is divided into two parts – 250 mm each. The first slab is laid at a distance of 250 mm from the wall, then all slabs are mounted end-to-end. As a result, there will be a gap of 250 mm between the last slab and the wall. A cinder block is installed into the resulting voids, from which the walls are erected. In this case, the cinder block is securely fixed, resting against the slab. The cinder block should be placed so that its holes are directed to the sides, and not up or down. The erected external wall will additionally clamp the cinder block, strengthening its fixation.

This design, although it looks unreliable, is actually quite durable. If anyone doubts bearing capacity cinder blocks, when pouring the floor screed on the second floor, you can further strengthen the gaps by installing reinforcement or masonry mesh on top of them. Rods with a diameter of 6 mm are used as reinforcement.

Another way to bridge the gap is to distribute its size between the plates. For example, there is an extra half meter and ten floor slabs, between which there are nine gaps of 55 mm each. Why 55 mm? The total value of 500 mm is divided by the number of joints - 9. The result is 55 mm.

The first slab is laid flush against the wall. The second is indented from the first by 55 mm, etc. The last slab should be pressed flush against the wall.

A board is tied under each gap, acting as formwork. Reinforcement is laid into the resulting formwork and concrete solution is poured.

The floor slab burst. What to do and why does this happen?

Sometimes during the construction process it turns out that the floor slab has cracked even before installation. What is the reason? Typically cracks appear when wrong conditions storage or transportation. As for storage, the slabs must be stored in a certain way, subject to several conditions.

The slabs must be stacked so that they do not touch the ground. Under the bottom slab you need to place a reliable base that does not get wet or rot, otherwise moisture will get on the slab, which will cause cracks.

The base must be strong and high enough. Since several slabs will rest on it, it may sag, but even when sagging, the bottom slab should not touch the ground. If, during subsidence of the soil base, the middle of the lower slab touches, cracks will appear not only on it, but also on those slabs that are located above.

It is better to store the slabs in a horizontal position.

Gaskets - wooden slats - are installed between the slabs. When installing them, you need to consider:

the thickness of the slats, which should prevent touching adjacent slabs;
the position of the slats, which should be strictly one above the other;
the distance from the slats to the edge of the slab should be 0.2-0.4 m.

If all conditions are met and there is a sufficiently strong base, the stack can consist of 8-10 rows of slabs, which is up to 2.5 m in height. A higher height value is unacceptable.

What to do with a cracked slab? Is it possible to cover a house with it?

But what to do if the slab is already cracked, and can it be used in the future?

In fact, builders quite often use cracked slabs for flooring, so if the cracks are small, further use of the slabs is possible. The main thing is not to load them too much and secure them additionally.

Here are some examples of where it is better to install cracked slabs:

lower it onto the outer or load-bearing wall by 0.1-0.15 m. In this case, the slab will rest on three walls at once, not only with its short edges, but also with its long one. Additional fastening of the slab is provided by the higher walls, which press it securely. This technique is usually used for slabs with fairly large cracks;
lay the slab in place of the installation of the brick partition, which will subsequently support it;
mount the broken slab between two intact ones. During installation, rustles form between the slabs, which are then carefully sealed with mortar, creating an almost monolithic ceiling;
lay the slab in place with minimal stress. It can be used for attic floors, where there are practically no loads, the main thing is that the structural elements of the roof do not rest on it;
in case of significant damage to the surface of the slab, when the crack is large (about 4-10 mm) or there are several of them, you can use only its entire part, cutting off the damaged one.

If the installed broken slab does not inspire confidence in you, you can strengthen its strength by reinforcing the floor screed on the upper floor with reinforcement. The reinforced concrete screed will evenly distribute the loads between all slabs and strengthen the structure.

Sealing joints between slabs

The next issue under consideration is sealing rust. The rust is the junction of the long sides of adjacent slabs. To obtain a durable and solid ceiling, all rustications must be filled with mortar. Round-hollow slabs have locks on the sides in the form of round recesses. When pouring rustications, these recesses are filled with concrete, ensuring reliable adhesion of the slabs. This prefabricated floor works almost like a monolith.

Among the slabs you may find defective ones with incorrectly made sides with locks. When they are connected, the recess is at the bottom, while at the top the slabs are tightly joined together. As you can easily guess, filling such rust with concrete is problematic at first glance. But it's not all that scary. To seal defective rust, adjacent slabs are not joined end-to-end, but with a small gap of about 2-3 cm. The gap should be in the upper part of the slabs, where they can be joined. From their lower part along the entire length of the rust is tied wooden board– formwork for pouring concrete. The solution is poured into the rust through the upper gap. The consistency of the solution should not be thick, it should spread evenly over the entire length. But you shouldn’t make it too liquid either. After the solution has hardened, the sealing of the rust can be considered complete.

Floor slab laying technology

What else should you pay attention to when installing round hollow core slabs? Of course, for safety precautions. Installation is carried out at height using special equipment, which must be taken into account when working.

The slabs are lifted and laid using a truck crane. The slabs are laid on the mortar, so within 10-20 minutes they can be easily moved with a crowbar until they take the desired position. On load-bearing walls the slabs should rest on them by 0.12-0.15 m.

It is important to create as much comfortable conditions when laying slabs. For example, a dish with a solution can be lifted onto the first installed stove so that you don’t have to go downstairs to get it each time. The rusts are filled with the same solution. Such, at first glance, little things often take a lot of time and effort.

After completing the installation of the slabs, you need to seal their ends to protect them from freezing. If the slab rests on an external wall, sealing the end will also additionally retain heat in the house and prevent the cold from getting inside.

To seal the ends of the slabs, you can use one of the following methods:

fill pipe voids mineral wool approximately 0.2-0.3 m deep;
fill the voids lightweight concrete mortar 0.12-0.25 m deep or install concrete plugs;
close the voids with backing bricks on mortar, and then seal the surface with mortar; You can insert a one-and-a-half backing brick into the hole.

In some cases, the slab is too close to the facing masonry. If there is no insulation between them and the ends are not sealed, the slab will begin to freeze in the cold season, becoming covered with ice in the room. Such a stove will be a source of cold in the house, and when the heating is turned on, “dew” will form on its surface due to a sharp temperature difference. If such slabs are already available in finished house, of course, no one will dismantle the walls and seal the ends. The problem can be solved in a less radical way. To do this, use a hammer drill to drill a hole in the frozen pipes from the underside of the “problem” slab. A tube is inserted into the resulting hole with an inclination towards the outer wall, through which it is blown polyurethane foam. In this case, a foam plug should form, extending into the pipe to a depth of 0.1-0.2 m. It will play the role of a heat insulator.

The ends need to be sealed not only for those slabs that rest on external walls, but also for those that rest on internal main walls. By building regulations the ends are sealed at the slabs, starting from the third floor and below. For example, two-story house has three floors: between the basement and the first floor, between the first and second floors and between the second floor and the attic. In this case, the ends of the slabs in the attic floor are sealed to strengthen the structure, which can take a significant load from above. The ends are poured concrete mortar or they are laid with one-and-a-half bricks. It is easier and more convenient to do this before installing the slabs by placing them on a horizontal surface.