Walls made of aerated concrete blocks cons. Pros and cons of aerated concrete construction. The composition of the aerated concrete mixture

Today, aerated concrete is the most popular stone material. It is widely advertised and therefore let's take a look at all its advantages and disadvantages.

Autoclave and non-autoclave

In the manufacture of aerated concrete, 2 technologies are used: autoclave and non-autoclave hardening of blocks. Their differences appear only at the final stage of material production. Before processing semi-baked workpieces in an autoclave or an electrically heated chamber, both technological processes are identical and include the following steps:

mixing of components;
pouring the solution into large forms;
waiting for the mixture to swell as a result of a chemical reaction;
cutting the increased volume of the monolith into separate blocks.

Aerated concrete production technology has its pros and cons. So the impact on the workpiece with water vapor in an autoclave requires a lot of energy, which increases the cost of production, but improves the technical characteristics of the finished product. Autoclaved aerated concrete is stronger, has higher frost resistance and precise geometry. This is due to the fact that the technological processing of aerated concrete under pressure is available only in industrial conditions, while a non-autoclave gas block can be manufactured at any construction site.

The main advantages and disadvantages of aerated concrete

Advantages of aerated concrete blocks:

Perfect geometry.
Low thermal conductivity.
Low specific gravity.
Flame retardant.
Resistant to mold and mildew.
Wide range of side sizes.
Relatively low cost.
Easy to handle.
Economical in finishing.
Good vapor permeability.
Ecologically pure.
Pest resistant.
High construction speed.
High thermal insulation.
Frost resistant.

Cons of aerated concrete blocks:

Fragile.
Poorly holding fasteners.
High water absorption.

Pros and cons in construction

Aerated concrete block is easy to process. Sawing, drilling, giving to an element of any required shape is done without any extra effort. A porous gas block is no less malleable than a tree. The indisputable advantage of aerated concrete is its environmental friendliness. The artificial block does not contain harmful impurities and does not emit toxic substances both during standard operation and in extreme conditions.

Has a large assortment of blocks of all sizes and shapes. For window and door openings, as well as for reinforcing the floor base, special U-shaped blocks are used. Which is very convenient, you don't need to invent anything.

In addition to the thermal insulation properties of the building material itself, which are manifested while maintaining a sufficient thickness of the masonry, thin seams serve as additional thermal protection for the house. The price of special glue for cellular gas blocks significantly exceeds the cost of sand-cement mortar. But the cost of an adhesive composition for aerated concrete elements is not more than the cost of a conventional masonry mixture in other types of construction due to the economical consumption of the connecting material.

Aerated concrete is positioned as a material that provides a favorable microclimate in the house. The honeycomb block really provides good air circulation and vapor absorption inside the house, provided that this is not impeded by the low permeability of the finishing materials. In addition, the aerated concrete block is highly hygroscopic. To protect the material from waterlogging, the consequences of which may be deformation of the finish, during the construction of a house it is necessary to use a number of special engineering and technical measures. Aerated concrete block contains residual lime in its chemical composition. The presence of this element contributes to increased corrosion of metal inclusions that are parts of various communications at home.

The high refractoriness characteristic of the aerated concrete block serves as a weighty argument for the use of this material in the construction of fire-resistant walls, ventilation and elevator shafts.

The aerated concrete block is characterized by geometric dimensional accuracy, which ensures the minimum thickness of the connecting seams and a perfectly flat wall from the outside and inside. In this case, it becomes much cheaper to decorate the walls. There is no need to apply a thick layer of plaster and spend a lot of time and effort on leveling. Therefore, the construction of a house from aerated concrete is carried out in a short time. Cellular brickwork is done 2.5 times faster than traditional brick and can be done by hand. Technologically, this is a simple process, the main thing is to be attentive and accurate in work.

The choice of the foundation depends on the feasibility study, but most often in the construction of aerated concrete, strip and shallow laying is used, since the walls of aerated concrete blocks in low-rise construction weigh significantly less compared to classical brickwork. But it should be borne in mind that the slightest mistake in the choice or construction of the foundation will lead to deformation of the base and destroy or crack the wall.

The porous structure of the blocks has a good effect on their frost resistance. But it depends on the density of the block, so the higher the density of the block, the worse it keeps heat. In some cases, low-density aerated concrete is used as insulation for a brick house. With such a combination, the already meager disadvantages described above are killed. The brick is strong and holds the heavy bookshelves well. This is a very good combination for your own home.

In general, as in the case of any other building material, aerated concrete block has its own set of disadvantages and advantages. The pros greatly outweigh the cons, which during construction can be taken into account and used to your advantage. And of decisive importance in the choice of materials are the specific conditions in which the construction of the house will be carried out.

Aerated concrete is one of the types of aerated concrete, an artificial stone, which is 85% air. Due to its good ability to retain heat, light weight, ease of cutting and processing, relatively affordable price, it is often used in the individual and professional construction of houses and other buildings. Large blocks are made of it, with which it is convenient to lay out the walls due to the small mass.

The density index is determined by marking:

D350 - 350 kg / m3, used only as insulation;
D400 - 400 kg / m3, for laying openings;
D500 - 500 kg / m3, for one-story houses;
D600 - 600 kg / m3, for masonry of two-three-storey buildings, as an additional material in multi-storey construction.

The higher the grade, the better the strength, but the lower the thermal insulation properties. By size, there are wall elements, partitions, for lintels. For supporting structures, use options not lower than D400.

They are made in two ways: autoclave and natural drying in the open air. If there is a choice, then preference should be given to the first option - the autoclave is stronger (about such blocks of the INSI brand).

The advantages of aerated concrete houses

Advantages of gas blocks:

1. relatively low price;

2. saving heating costs, gas-block houses need less energy for heating in winter;

3. low load on the foundation, but high strength is required, excluding shrinkage;

4. optimal for the individual construction of houses, outbuildings, baths, the ratio "strength-lightness";

5. One person can lay out the walls of aerated concrete;

6. Convenient transportation due to the low weight of the blocks;

7. minimal background radiation;

8. the ability to perform various bends, arched openings, stairs and other structures of any, including complex configuration;

9. good level of sound insulation;

10. simplicity of processing without the use of special equipment, aerated concrete blocks are easily cut, sawn, polished with hand tools;

11. biological resistance, fungi, mold, etc. do not appear on the surface;

12. vapor permeability, walls "breathe";

13. fire resistance, aerated concrete does not support combustion, tolerates exposure to temperatures up to + 1200C, during a fire within 3 hours it hardly collapses;

14. Homes are easy to renovate and rebuild.

Disadvantages of buildings from gas blocks

1. unsuitable for multi-storey construction as the main material of load-bearing walls due to low compressive strength;

2. a house made of aerated concrete quickly warms up (in 2 hours from 0 to 20C), but just as quickly gives off heat in the absence of heating (by 1C per hour);

3. even with minor violations of technology when pouring the foundation, causing shrinkage, up to 20% of the blocks are covered with cracks, this does not lead to the destruction of the house, but has a bad effect on the appearance;

4. the foundation must be resistant to any ground movements, otherwise the problem of cracks arises again;

5. aerated concrete masonry with glue must be made very high quality, otherwise the house will be "blown out";

6. the material is hygroscopic, quickly absorbs moisture from the air, including during fog, which forces the walls to be finished immediately after the completion of the masonry, be sure to waterproof and insulate;

7. the gas block has low frost resistance - up to 35 defrost-freeze cycles;

8. restrictions on finishing materials for facades;

9. Before plastering, careful preparation of the walls is required, since their surface is too smooth, due to which there is a very low level of adhesion to any coatings, it is necessary to use a special primer;

10. the lime contained in aerated concrete and adhesive mixtures for it quickly makes any metal objects unusable, including communication pipes in contact with the blocks;

11. gas blocks do not hold well any types of fasteners (for shelves, hanging cabinets, etc.), special fasteners are required (for example, plastic butterfly dowels, anchors);

12. Low burglary resistance, thieves can simply cut a passage with a chainsaw, and the bars on the windows hold up worse than those of houses made of other material.

Comparing the advantages and disadvantages of aerated concrete houses, you need to pay attention to the fact that most of the disadvantages are eliminated during the installation process. To do this, you just need to carefully observe the technology, take into account all the nuances.

Owner reviews

“A year ago I finished building my house from aerated concrete blocks. The walls "breathe", perfectly keep the warmth in the room. Masonry is quick and easy to perform. Several people can build a one-story house in half a month. The elements are impressive in size, but weigh a little at the same time. To carry them by forces and one. During the use of the house, I did not find any serious problems. In frosty weather it is warm and cozy. It took a little finance, dignity - to build cheaply and quickly. The disadvantage is fragility, it is necessary to pay utmost attention to the foundation, exclude the possibility of any ground movements, and reduce the consequences of shrinkage. Otherwise, the appearance of cracks cannot be avoided. "

Alexey, Irkutsk.

“Due to the low price between the gas block and the brick for the construction of the house, we chose the first option. In the process, it turned out that high costs were inevitable for a good vapor barrier and finishing. As a result, the house came out relatively expensive, but still much cheaper than brick. We haven't noticed any significant shortcomings yet, but we have been using the cottage for only three years. "

Peter, Moscow.

“I built a house from aerated concrete myself. It is fragile, so I had to spend more time and money on the foundation than I expected. I posted it quickly and without any problems. Only at the stage of final finishing did I have difficulties. Special fasteners were expensive, plus insulation. Advantages: the walls are dry, the blocks are lightweight. Cons: the material is fragile, a lot of work on steam and heat insulation and the associated financial costs. "

Ilya, St. Petersburg.

“I have a cottage made of gas blocks. For the construction of the first floor I used the D500, the second I laid out from the D400. To increase the strength under the overlap, I mounted an armopoyas. Outside, I applied vapor-permeable plaster. The result is a warm, comfortable home, but there is also a drawback. Heat only while it is heated, after turning off the heating devices it cools down quickly. "

Vasily, Krasnoyarsk.

“I chose gas blocks as a material for a country house primarily because of the low price. In one summer I built a two-story house myself. Be sure to additionally insulate. Lack of aerated concrete - due to porosity, it strongly absorbs moisture. With the onset of winter, the water freezes and it begins to crack. I solved this problem by insulating the walls with Styrofoam. The cost of heating a house is much less than that of neighbors for a brick one, and at the same time it is much warmer here. Advantage: quick and easy to build. I recommend purchasing in reliable stores from trusted manufacturers. I bought two cubes very cheaply, but they started to crumble, I had to buy more. "

Dmitry, Moscow region.

Individual developers are mostly guided by modern varieties of artificial stone, preferring them to traditional wood or brick. All the nuances of the construction and operation of houses made of aerated concrete, their pros and cons should be dealt with in detail. The main reason is the lack of awareness of the potential buyer and often diametrically opposed opinions about the advisability of such a construction.

So is it worth it or not to use aerated concrete blocks for a residential building? Where is the truth and where is the lie about this material? What hidden problems of aerated concrete are "shyly" silent about manufacturers and sellers? Let us draw our conclusions by analyzing the numerous reviews of the owners already living in these houses.

The main reason for the ambiguity in the assessment of aerated concrete is ignorance of the specifics of its production and application. Before figuring out what this building material has more - pluses or minuses - you should clarify not only with its characteristics, but also with terminology.

Aerated concrete is a generalized name for two types of aerated concrete, and both are used in the construction of houses. In most cases, due to a misunderstanding of the peculiarities of their production technology, the shortcomings of one are often attributed to the other. The basis of aerated concrete is cement; such a stone for a house can be distinguished by its grayish color. In the composition of the initial mixture of gas silicate, lime plays the role of a binder. Gas blocks of this type are white.

The fundamental difference is in the manufacturing technology. Aerated concrete products can be produced independently, at home, that is, at the place of work. But its "brother" - only by processing in autoclaves (pressure and temperature) with further transportation to the consumer. Since the price of the last version of the material is slightly higher, aerated concrete is more often used in the construction of residential buildings and other buildings in the private sector. Here on it further emphasis will be placed, especially since the difference in the pros and cons of stones for most parameters is not so significant.

Peculiarities

1. Benefits.

Sufficient strength of the artificial stone.

This property of the material greatly simplifies the construction of a house.

Firstly, the gas block does not crumble during cutting, while for a foam concrete analogue this is one of the main disadvantages.

Secondly, the installation (fastening) of attachments in the house is not difficult. In this regard, gas blocks are not much inferior to bricks. With regard to foam concrete, fixing something on the wall of the house is much more complicated - only on the anchor. And this is not always convenient, since reinforcement of the base is often required, otherwise the weight of the suspended structure is sharply limited.

Thirdly, the construction of a house from aerated concrete can be carried out in several floors, but from foam blocks - in no more than two.

The evenness of the edges.

The strict geometry of the gas blocks makes it easy to fit them in place. The seams are so insignificant that the influence of "cold bridges", judging by the reviews of the owners, practically does not affect the microclimate in the house.

Low thermal conductivity.

Simply put - such a house retains heat well. If we take into account the constant growth of tariffs for energy carriers, this is another plus, and not a small one. According to the owners' reviews of houses, the cost of heating them is much less compared to brick buildings and even more concrete goods.

Low weight of gas blocks.

Considering that the cost of building the foundation is about ⅓ of the estimate, you can save a lot at this stage. More than a significant plus of such a house.

Shortened terms.

Gas blocks have significant dimensions. Even if you buy the smallest ones, then it will turn out to build the walls of the house from them much faster than from brick or wood.

Affordable product price.

A house made of aerated concrete blocks is rightfully considered one of the best options for solving a housing problem. Regardless of whether it is being built on its own, or purchased, such construction belongs to the category of "budgetary".

2. Disadvantages of aerated concrete.

Judging by the reviews of house owners on thematic forums, increased moisture absorption is practically the only drawback of this stone. But here, too, not everything is clear, since this disadvantage of aerated concrete blocks is somewhat relative.

Firstly, residential buildings are made out in one way or another from the outside. For example, if it is necessary to insulate a building, which is done almost everywhere for our climate. Plus - waterproofing the house. Therefore, the cladding is required.

Secondly, such a minus of a gas block house is canceled if overhangs, window drains, and a drainage system are thought out and correctly mounted.

Thirdly, a lot depends on the technology used to make the stone. A house made of autoclaved aerated concrete has the best performance characteristics. It has a higher density, which means that it absorbs moisture less intensively.

Owner reviews

“I was building the house on my own, without the help of specialists. I think that all the disadvantages of aerated concrete products are attributed to those who, in practice, have not dealt with this material, and judge it only by the reviews of the same "experts". My opinion is unambiguous - subject to the technology in such a house, high performance characteristics and an acceptable cost are optimally combined. I have been living in it for the 5th year already, and so far no complaints. Moreover, heating costs are noticeably less than when my family and I were huddled in an old brick building. "

Vladimir Olshansky, Moscow region.

“I know firsthand about houses made of aerated concrete. I work as a foreman, so I built a lot of this stone and I can give my assessment. Gas blocks have much more pluses than minuses. When ordering houses (without interior decoration) on a turnkey basis, in a couple of months the box is completely ready. Another advantage is that there is no need to wait for shrinkage. Therefore, you can partially begin to settle down in parallel with construction. A variety of ready-made projects of aerated concrete houses makes them accessible to all segments of the population. For families with very modest incomes - a good option. I don't think there are any significant shortcomings in gas blocks ”.

Ilya Zotov, Moscow.

“I am quite skeptical about various reviews, reviews posted in the media. It's no secret that most of them are made to order. When I bought a building plot, I just took it and walked around the neighborhood, asking for the opinion of the neighbors about their houses. Personal communication with people allowed me to conclude that for me, taking into account material opportunities and limited time, the best solution is to build a dwelling from aerated concrete blocks. The house turned out to be of good quality, and now, having lived in it for 3 years, I can say that I was not mistaken. I believe that those who want to build both inexpensively and with high quality should pay attention to aerated concrete ”.

Sergey, Samara.

“When I started to build the house, I decided that if I could save money, it would be just not on the project. No matter how attractive aerated concrete is, it is still "foam". Experts helped to select the optimal thickness of the blocks and materials for finishing. If everything is done correctly, then a house made of such a stone will stand for a long time. Nevertheless, without taking into account all the features to build, I would not recommend it to anyone. First of all, you need a timing. If you leave the box at home for the winter, then there will be so many problems that the final cost will simply "go off scale". Therefore, "amateur performance" has its limits. "

Oleg, Omsk.

“I believe that the approach to the use of gas blocks should be professional. We must not forget about the cellular structure of the stone, therefore, the disadvantages - moisture absorption and fragility. When building a house, you need to reasonably combine aerated concrete masonry with brick, reinforcement, high-quality finishes. Those who believe that this material is a "gift of fate" are mistaken. There are certain difficulties, so it is better not to start building a house without consulting a specialist. The costs of gas blocks will justify themselves only with strict adherence to the technology of working with them. "

Ivan Pershin, Krasnoyarsk.

conclusions

The fact that aerated concrete has much more pluses than minuses is obvious. But if there is a choice, alternative options for the home, then when is it more expedient to make it in favor of this material?

1. With limited free space on the site. Gas blocks are set on glue, so there is no need to prepare a solution.

2. If a house with 2-3 floors is being built, foam concrete is clearly not suitable.

3. If you want to partially save on the house insulation. In some cases, it is enough to correctly determine the thickness of the gas blocks.

4. If it is impossible to equip a massive foundation. For example, if the soil on the site is problematic.

It is unrealistic to take into account all the nuances. But the information provided in the article is enough for the dear reader to decide for himself whether to build a house for him (or not) from aerated concrete. In any case, success!

Foam concrete blocks, which are now widespread in construction, are gradually beginning to yield part of the market to a relatively new building material - aerated concrete. This is due to its best performance, which makes it possible to use this type of aerated concrete in the construction of a wide variety of objects, among which it occupies one of the first places. With a relatively small number of disadvantages, aerated concrete blocks have significant advantages.

The advantages of aerated concrete

The advantages of this material make it possible to build a building, the positive operational characteristics of which will be maintained for a long time (up to 100 years). One of the main advantages is lightness; the density of the blocks is in the range of 400-1200 kg / m3. This makes it possible to drastically reduce the load on the foundation, which significantly reduces the cost of the foundation. there is no need to erect a solid, monolithic foundation for the building. In addition, lightweight material is easier to use in construction, and the relatively large dimensions of the block allow you to quickly erect walls.

Two other important advantages are moisture and frost resistance. In the first case, high resistance to moisture penetration is provided by a porous structure; even with an ambient humidity of 90%, aerated concrete absorbs only 8%. In the second case, tests show that gas silicate products do not react in any way to temperature changes; sharp thawing and freezing does not lead to material destruction. In addition to these qualities, aerated concrete has other advantages:

Fire resistance: the products do not contain substances that support combustion, and when exposed to high temperatures, toxic substances are not released into the atmosphere;
- biological resistance: inside aerated concrete there is no environment that would favor the development of mold, mildew;
- low thermal conductivity and a high level of noise insulation: these qualities are provided by the cellular structure;
- environmental Safety.

Disadvantages of gas silicate

First of all, it is hygroscopicity. The material does not allow moisture to pass into the building, but accumulates it inside the pores, which over time can lead to a decrease in the strength of the material. This disadvantage can be corrected if, during construction, reinforced waterproofing is carried out using, for example, a waterproofing tape.

Another disadvantage is the possibility of cracks. Most often, their education is associated with incorrect calculations, which must be carried out by professionals. And the last drawback is the high price when compared with the same foam blocks. However, aerated concrete is a relatively new material, so there is every reason that it will improve over time, and negative qualities will be minimized.