Installation of floor slabs is a technologically complex stage of construction, which has several important features. Without their knowledge, builders can make many mistakes, fraught with serious consequences.
Types of products and features of their choice
Today, two types of similar products are produced - hollow and monolithic. Each of them has its own disadvantages and advantages, taking into account which it is necessary to choose designs for a particular structure. So, if the building is small, a monolithic product is not suitable for it because of its too much weight, which will greatly complicate the installation of floor slabs. In addition, monolithic structures have low soundproofing and heat-saving properties, so they are rarely used in the construction of residential buildings, but in the construction of industrial and public facilities, these structures are indispensable.
Hollow core products are valued for their important advantages: lower cost and lighter weight. But although the structures have a lower mass in comparison with full-bodied products, the transportation and installation of platesoverlapping can only be done using special equipment.
Features of hollow webs
The benefits of using hollow core slabs include reducing the load on the foundations and walls of buildings. Moreover, this is possible regardless of the configuration of voids, which are round, polygonal or oval.
Tip: Hollows can be used for corrugated pipes, plastic boxes or cable ducts.
Thus, the installation of precast floor slabs is a guarantee:
- Good sound and heat insulation qualities.
- Durability.
- High mechanical density.
- Fire resistance - internal cavities prevent heat from igniting wood and plastic elements from penetrating further.
Influence of slab size on their installation
Currently, canvases are produced with a thickness of 22 cm, a length of 1.8 to 6.3 m and a width of 0.99 to 1.49 m. The weight of the structure depends on the size and type (monolithic or hollow). Accordingly, the complexity of mounting a monolithic floor slab is higher than that of a hollow structure of similar dimensions.
There are a few more important points that you need to pay attention to before purchasing concrete products. You need to follow that:
- The designs were as close to face value as possible.
- The surface of the products should be free of depressions, bulges, cracks, as well as greasy traces or rust.
- Designs had an appropriatequality certificate.
Before you get started
There are several important rules for the installation of floor slabs that professional builders are well aware of. Private developers may not even be aware of this, respectively, an additional mention will not be superfluous:
- Lay products so that their smooth side is facing down, and the rough side is up.
- Fit the canvases along their underside.
- Slabs are laid close to each other, without gaps.
- The main rule for the installation of floor slabs is that the products must be laid so that they rest with their short sides on the bearing walls. Long sides are not recommended for wall mounting.
- Special equipment services are expensive, so it is necessary to prepare everything necessary for work in advance, including inviting 2-3 assistants so that the installation is quick and smooth.
Note: before starting rough work, it is necessary to fill, as far as possible, the voids in the canvases with expanded clay.
Preparation for installation work
First of all, it is necessary to level the load-bearing walls so that they are as even as possible in height. The discrepancy in their surface can be no more than 1 cm.
To find out how flat the surface is, you can use a regular beam. The accuracy of the result depends on the length of the beam - the shorter it is, the less accurate the result will be. Using the beam as a building level, it is necessary to check all the walls that will be used as supports for the slabs. If any irregularities are revealed, a designation is applied on the wall in this place.
After that, determine the highest and lowest points. Based on the data obtained, leveling is carried out using a concrete mix and a metal mesh.
An important detail: when preparing the mortar, you need to be very careful and carefully sift the sand and cement so that not a single pebble gets in - otherwise the slab will lie incorrectly and the ceiling will be uneven.
If the walls of the building were built from gas silicate, slag or foam concrete blocks, they need to be strengthened. For this purpose, you can use a reinforcing belt with a height of at least 0.15 m. Thanks to this, it will be possible to avoid possible deformation of the walls and protect the floor slab from breaking.
Preparing the site for the crane
This issue is one of the important stages in preparing for the installation of floor slabs and coatings: the quality of the installation of the canvases and even the integrity of both the building under construction and the nearby buildings, as well as safety, depend on how correctly the work is done. of people. In order for the crane to be securely fixed, it is allowed to install it only on compacted soil. Nearby there should be no houses under construction with basements - the support of special equipment during work creates a huge load on the soil, which the walls of the basements may not withstand.
If the soil on the sitebulk or loose, it is necessary to rent a crane with the longest boom - then it will be possible to install the equipment further, where the strength of the soil is not a concern. If construction has to be carried out in autumn or spring, when the ground is saturated with moisture, so that special equipment does not get bogged down in slush, they prepare the site for its installation in advance by laying out the soil surface with road slabs.
Performing slab lining
Laying one slab for two spans is not recommended - it can crack, but if you had to do it that way, then in order to avoid destruction during shrinkage of the building against the central part of the middle wall, you need to make an incision on the slab using a grinder with a diamond disk. The depth of the cut is to the depth of the disc. Then, if a crack occurs, it will go along the notch - and this is quite acceptable.
Sometimes, in order to fit the plates to the desired size, they have to be lined in length or width. To perform the work, use the following tools:
- Scrap.
- sledgehammer.
- Bulgarian. A diamond disc is installed on the tool for work.
- A board or timber that will be laid under the canvas under the line of the future cut.
Fitting the plates to the right size
First of all, on the upper surface of the canvas, markings are made and a cut is made with a grinder. Then they strike with a sledgehammer so that the plates are as close as possible to one another. Where the cut goes through the voidhole, the blade will break very quickly.
Cutting the canvas across the width will be much longer and more difficult, since you will have to cut off the fittings that come across. To do this, you can use a grinder, but so that the disk does not “bite”, you need to cut the rod not completely, but leave a couple of millimeters, and then finally break it with a sledgehammer.
No matter how well the work is done, the integrity of the slab is still violated. You can avoid this in the following ways:
- Follow the sequence of installation of floor slabs - start laying slabs on one side and finish work on the other. In no case should you start laying from two sides - even if everything converges according to the calculation, it will not be possible to lay tightly on the connecting plate so that there is no gap between it and the adjacent reinforced concrete structures. This violates both the tightness of the connection and the strength of the web.
- If the canvas is a little lacking, you can leave a void near the walls, which is then laid in blocks, and then make a cement screed. If the empty opening exceeds a distance of 30 cm, it will be necessary to make a screed from reinforcement.
- Leave the distance between the plates themselves. Then the voids are closed from below with moisture-resistant plywood, the reinforcement is laid so that it goes beyond the upper edges of the slabs, and the resulting formwork is poured with concrete. When the mortar dries, the plywood can be removed and a general screed can be made on top of the boards.
After installation is complete
In order for the future premises to be strong and durable, they carry out a bunch of reinforcing bars of allinstalled elements. To do this, one end of each rod is welded to the loop on one canvas, and the other to the loop of the adjacent canvas.
Attention: it is unacceptable to connect several reinforced concrete products with one rod - only two adjacent structures.
