Hardware stores today provide an extensive range of materials and systems, different price ranges and destinations. One of them is aerated concrete. It does not apply to new developments, but the greatest prevalence has been noted in the last ten years. Due to the increase in popularity, more and more people are interested in the question of how to lay aerated concrete with their own hands.
Features
The basis of aerated concrete is made up of artificial components pre-mixed in water, such as cement, lime, sand and gas-forming additives. The structure is characterized by the presence of many small cellular pores, which is why the blocks are characterized by large voids. The material is made in the process of exposure to high temperatures and pressure, followed by curing in an autoclave. The cost of wall aerated concrete varies from 50 to 100 rubles per piece, depending on the size.
The blocks have a relatively small mass, due to which they do notrequires the use of special equipment. It is also possible to cut any desired shapes with a standard wood saw.
Flaws
This building material is not universal, and many people prefer to use other construction methods. This is due to the presence of a sufficient number of shortcomings, the main of which are the following:
- Fragility. If the laying of aerated concrete will be carried out in an area with seismological activity, it is worth remembering that soil movement can lead to dangerous cracks in the building. This cannot but affect the interior decoration of the premises. Given that the surface of the material is easily damaged with a screwdriver, it becomes clear that it is necessary to use special fasteners to transfer the load when fixing furniture to wall structures and creating engineering systems.
- Hygroscopicity. Reducing this property is almost impossible, due to the presence of many pores that contribute to the active absorption of moisture from the environment. This is especially noticeable in regions with cold winters and hot summers. Hygroscopicity leads to an increase in the level of humidity in the structure, there is also a possibility of cracks on the surface of the walls, since the aerated concrete masonry absorbs water, which begins to freeze at low temperatures and expand, damaging the material.
The disadvantages mentioned above, although quite serious, can be de alt with. Suitable dowels for mounting,external insulation and high-quality moisture insulation will nullify them.
Materials and tools
Before starting work, you need to prepare the following:
- cement mortar;
- special adhesive;
- level;
- trowel;
- rebar;
- rubber mallet;
- spatula;
- grinding board.
Glue consumption
On the modern market there are many compositions for working with materials with a high level of moisture absorption, such as aerated concrete, the average size of which is 30x20x60 cm, and foam concrete. It is also possible to use solutions for processing and puttying the resulting surfaces.
Application of glue does not cause any difficulties. All components are simply mixed in the specified proportions. Work can be greatly simplified using a special drill with a mixer attachment.
When applying the material in a layer of 1 cm, about 1.5 kg of dry compound is needed for 1 square meter of blocks. In the presence of irregularities, the consumption of glue increases. It is advisable to use a mixture on a fine-grained basis, which reduces the likelihood of the formation of "cold bridges".
Advantages of adhesive
Glue for a gas block has many advantages that cement mortar cannot boast of. Fractional sand and Portland cement contained in the composition provide the possibility of spreading the mixture in a thin layer, which reduces consumption without changing the quality of the connectingcharacteristics. Adhesive properties and uniform filling are achieved by adding polymer components to the composition. Moisture retention is provided by special modifying additives.
The curing of the adhesive is characterized by the absence of shrinkage, it is also water-resistant, plasticity and a sufficient level of adhesion. When using this material, the installation of the block should be carried out within 10-20 minutes, about 5 minutes are allotted for correction. After preparation, the mixture must be used up no later than three hours later. Under the condition of low temperatures, the time of use of the composition is reduced. During work in winter, special attention must be paid to the thickness of the joints and the completeness of their filling.
Progress of work
Aerated concrete masonry technology includes the construction of the foundation of the building, which acts as the basis for the first row of blocks. The base should be at a distance of 60-80 cm from the ground surface. Mandatory waterproofing is required between the aerated concrete and the base of the building.
For the installation of the first row, a solution is used, distributed on the waterproofing layer. The laying of aerated concrete walls, regardless of the type of structure, is always done from the corner. To do this, a cord is pre-tensioned in each of them, with which the correct installation of all blocks is checked, while the building level is additionally used for verification. The rubber hammer allows you to change the arrangement of the elements. It should be noted that the adhesive mixture is not necessary when using blocks withtongue-and-groove system. The cost of this type of aerated concrete is about 100 rubles apiece. All irregularities should be removed after each row is installed, after which a sanding board is used for grouting.
Additional elements must be pre-sawn. Due to their composition, work can be done with a conventional hacksaw. A band saw may be used to ensure a smoother cut. In this case, each time the accuracy must be measured using a square.
The installation of the next row is carried out after 2-3 hours from the moment the laying of the lower one is completed. Corner binding of blocks is an integral part of the work for each row. Protruding elements are periodically corrected with a rubber mallet.
Features
Laying aerated concrete requires careful adherence to the rules for pairing walls. In internal partitions, every second row should have a connection with the main wall structure, it is formed using brackets or anchors, on which a perforated galvanized strip is fixed. Also, do not forget about the hydro and sound insulation of interior partitions.
Planning floor slabs between floors should provide support for a reinforced belt. It is performed on the last row of blocks and is a concrete belt with reinforcement in the form of reinforcing elements. It has many functions, including: uniform distribution of the load from the roof truss system, protection of wall structures from cracking. To connect wallswith a roof, a Mauerlat is used, which is fixed precisely on the armored belt.
Structure reinforcement
Aerated concrete, the dimensions of which vary depending on the purpose and shape, for example, the dimensions of a straight block for creating partitions are 600x250x150 mm, is a rather fragile material and requires reinforcing work. The purpose of this process is to reduce the load exerted by the roof of the building or floors. Masonry reinforcement provides additional structural strength and increases service life.
Work must be carried out on the first row, as well as on every third. In addition, the belt located under the interfloor ceiling, window and door openings are reinforced.
Grooves are cut along the perimeter of the wall masonry for mounting reinforcement. Most often, two strips with a width of not more than 4 cm are enough. They should be at a distance of 6-8 cm from each other. For pouring, any semi-liquid mortars for laying aerated concrete are used, the strobes are pre-cleaned of dust. Reinforcing elements are completely immersed in the solution, the diameter of which should be about 10 mm. The solution that has gone beyond the surface is immediately removed. Laying the next rows can be done immediately, without having to wait for the mortar to dry.
Work during the cold season
It is desirable to lay walls at a positive temperature, otherwise there will be additional costs for heating the building material. Glue forthe gas block contains a sufficient amount of water, which is why it quickly freezes in frost and does not have time to fix the structure.
Creation of load-bearing walls at negative temperatures can be carried out provided the average daily level is not lower than -6°C, there should also be no prolonged freezing of the structure and precipitation. In this case, a solution should be used, which includes antifreeze additives. The finished mixture is consumed within 30 minutes, while heated water is used for preparation. Blocks are immediately laid on the applied layer of glue, without interruptions. Otherwise, the mass will become icy and work at this place will become impossible. Film is used to cover the last row.
Cost and material saving
Blocks must be stored under suitable conditions to prevent loss of processing properties and quality. If at least a month passes from the moment of purchase to use, the original packaging is not removed from the material, which protects it from the negative effects of the environment. It must be removed a few days before the start of work, so that excess moisture has time to evaporate.
The cost of laying aerated concrete blocks is affected by transportation costs, the properties of the material itself and the cost of construction work. It is also worth remembering the volume of purchases and seasonality, which also have a significant impact.
The price of a cubic meter of material depends on the marking of blocks, strength indicators and is within2000-4500 rubles. Additional factors, in addition to the purchased volume and time of year, also include the availability of shares and the manufacturer.
