What is warmer aerated concrete or foam concrete. Which is better: gas blocks or foam blocks? Cost and reviews

The choice of building material is an important stage in the preliminary preparation of building a house. Comfort, coziness, warmth of the structure depend on it. Lightweight, porous materials are popular in modern construction. It remains to choose - aerated concrete or foam concrete. Gas blocks and foam blocks are cellular materials. The main difference is the way air bubbles are formed inside, their technical characteristics. It is worth comparing two materials, identifying similarities and differences between them.

aerated concrete

The name of the gas comes from the manufacturing process. You can distinguish aerated concrete block by its white color, rough surface with small pores. Gas composition:

• quartz sand;
• Portland cement;
• water;
• aluminum shavings, lime.

The result of a chemical reaction is a gas that promotes the formation of aerated concrete. When released, the gas forms pores (small cracks). Advantages:

• Lightweight, large-sized elements allow you to quickly, without the necessary heavy equipment, erect building partitions.
• Correct geometric shape.
• Good thermal insulation keeps the heat in in the winter and keeps the room cool in the summer.
• Due to the porous structure, the material has good breathability.
• Easily amenable to external processing.
• Environmentally friendly product. Natural components are not harmful to health. The aluminum included in the composition is a harmful component, but during the process it dissolves in the total mass and loses its harmful properties.

Disadvantages:

• High moisture absorption. By placing aerated concrete blocks on the street, having correctly made a system of ebbs, nothing critical happens when moisture is absorbed, the material is not inferior to foam concrete.
• Insufficient density in aerated concrete makes the elements brittle.

Despite the stated disadvantages, correctly selected parameters will allow you to build not only partitions, but also any type of building walls.

Production

At the initial stage, the components included in the composition are measured according to the required amount, mixed in a special mixer. The resulting mixture is poured into a mold, left to acquire the primary setting. According to the method of acquiring strength, blocks are divided into the following types:

• Autoclave. Hardening is facilitated by high pressure, with the addition of water vapor.
• Non-autoclave. Cures the material in natural conditions. It is possible to use steam, heating with electricity, but the pressure does not increase.

Aerated concrete blocks belong to the first type. The strength of the autoclaved material is much higher than that obtained strength in natural conditions. The autoclave method is used only in the factory. For the appearance of porosity, aluminum paste is used. The interaction of aluminum, water leads to an increase in the volume of the mass. After preliminary setting, with a special tool, the raw material is cut into equal gas blocks. The building material is placed in an autoclave, where the effect of pressure, temperature, steam, finally adds strength to aerated concrete.

Foam blocks

Signs of foam material: gray color, smooth surface, closed porous cells. The composition of foam concrete includes:

• Portland cement;
• water;
• special chemical additives.

Advantages:

• High frost-resistant, heat-shielding characteristic.
• The closed pore structure does not allow moisture to pass through.
• Has good durability. Although in comparison with aerated concrete, the strength is lower.

• Chemical blowing agents are used to form porosity.
• Imperfect geometry.
• The structure of the foam block lends itself to temporary changes.

Production

First, using an industrial mixer, an ordinary cement mortar is prepared, the ratio of components is maintained, according to future strength. Foam is added to the mixed mixture, thoroughly mixed. After that, the finished solution is distributed into molds. Foam concrete blocks gain strength, harden in natural conditions. The initial setting of the mixture occurs in the first hours after the distribution of the solution. Then the foam blanks are loaded onto a pallet and removed for subsequent drying. The drying process takes 2 to 3 weeks. This time is enough to be able to use . The final strength of the foam block is gaining in six months.

Comparative technical indicators

Foam concrete or aerated concrete is produced according to the same building standards, it is strictly forbidden to deviate from them. It would seem that the difference should be minimal, and the technical parameters are the same. Let's try to compare, distinguish indicators and find out what is more reliable - aerated concrete or foam concrete?

Strength

The density of materials ranges from 300 to 1200 kg per m³. A comparison of gas and foam concrete of similar density shows that the second option is less durable. The quality of the chemical blowing agent directly affects the strength of the product. Many manufacturers save on it, since the price of foaming additives is high. In addition, it does not differ in the same strength of the material over the entire area. Aerated blocks are homogeneous, the same strength at different points of the material.

Hygroscopicity, cold resistance

These indicators are influenced by the dissimilarity of production methods. Aerated concrete strongly absorbs water, in foam concrete water absorption is lower. In practice, the outer part of the materials can be processed - they are covered with plaster, tiles, so they do not always pay attention to the hygroscopicity index. In this indicator, gas blocks lose before foam concrete.

Security

In the autoclave method, a chemical reaction takes place between lime and aluminum paste, as a result of which hydrogen is released. In the process of hardening, it does not completely evaporate from the materials, it partially disappears during the construction process. This gas is not considered bad, it does not bring harm to health.

Used do not contain harmful substances, and the pores are hermetically closed. It follows that the two construction products are not harmful. When choosing a material, the safety criterion should not be used as a determining factor.

Gas block and foam block are related building materials. They are actively used including private construction. But people often ask the question which one is better.

Both types belong to the class of lightweight concrete. To make a choice in favor of one or another material will allow knowledge of the main characteristics of each of these concretes. I must say that this is not the same thing as it may seem to many at first glance.

What is a foam block

Foam concrete blocks are a cellular material that is obtained from a mixture of foam, sand, cement and water. The solution hardens, the foam allows it to retain air particles, which are evenly distributed throughout the mass. These air bubbles create closed cells. The block is very light in weight.

The foam block has fire resistance, it is not combustible, withstands fire on one side for up to 7 hours.

Characteristics

Foam blocks have the following attractive characteristics:

• Low heat transfer. The cellular structure provides good thermal insulation.
• Excellent sound absorption, especially for noise frequencies.
• The low weight makes this material easy to transport. It also provides ease of installation, savings in construction. To build a house from foam blocks, it is not required to create a capital expensive foundation, to use special equipment.
• Durability and long service life.
• The processing is simple. The product is easy to cut, drill. The material is very resistant to strong compression. It should be noted that over time, the quality characteristics only improve. This is due to the duration of its internal maturation.
• The material does not rot or age.
• High resistance to low temperatures, this parameter provides its finely porous structure.

What is a gas block

The gas block is made from cellular concrete. It is a lightweight cellular building material. For its production, certain conditions are required - high temperature and humidity. Composition: cement, lime, sand and water. For the formation of gases that provide a porous structure of the material, aluminum powder is used. Next, the solution is prepared, cut. The material is processed at high temperatures in an autoclave. This is done only in production conditions.

The gas block has a low thermal conductivity. Houses from gas blocks can not be insulated, which allows you to save a lot. And in the warm season, the wall does not overheat.

Characteristics

Gas blocks have the following characteristics:

• Ease of processing, it can be drilled, sawn, planed, driven into it with nails and staples.
• Environmental friendliness. It is made from natural derivatives, the material is non-toxic. Perhaps, in its naturalness, it is second only to wood. But unlike it, gas blocks do not rot, are not affected by bacteria and bugs.
• Fire safety. This material is not combustible, it belongs to the 1st and 2nd degree of fire resistance.
• Durability. Its service life exceeds 100 years. Old buildings made of this material currently show no signs of aging or decay.
• High strength. This is due to good heat treatment during production.

What's better

The main requirements for the building material from which it is planned to build walls are as follows:

• Environmental friendliness.
• Convenient form for work.
• Big size.
• Preferably light weight.

Foam blocks and gas blocks satisfy all these requirements. But there are still differences. To understand which material is preferable, you need to familiarize yourself with these differences.

Differences:

• Geometry of individual blocks. Since gas blocks are produced under production conditions, their dimensional accuracy is somewhat higher than that of foam blocks. The latter are often produced in artisanal conditions. This provides more convenient laying of the material and less consumption of fastening compounds. But at the same time, it cannot be unequivocally stated that it is better to use aerated concrete.
• Differences in manufacturing technology. Gas blocks are absolutely environmentally friendly. While in the production of foam blocks, production waste is often used instead of quartz sand. In addition, by-products of the leather industry, lye, are used for foaming. For this reason, such blocks have a limited shelf life, and the technical characteristics of this material are not constant. Since the gas blocks are produced in the factory, the quality control of the product is higher. And the technology for the production of foam blocks is much simpler, which allows them to be produced in private conditions. The finished solution is poured into molds where it hardens. This results in an uneven shape.
• Package. Again, the question is in the conditions of production. Gas blocks on this point benefit, since the material is carefully packaged after manufacture. This allows it to be easily transported without thinking about protection from external influences: dirt, precipitation, dust. The foam block does not have packaging, so it is more vulnerable to precipitation. In this regard, foam blocks are inferior to gas blocks if they need to be transported over long distances.

Price

If you compare prices, you can see that there is no particular difference in the cost of building buildings and structures. Therefore, this parameter rarely has a serious impact on the choice in favor of a particular material.

One cubic meter of a gas block costs approximately 3,000 to 4,500 rubles, depending on the region. The unit cost depends on such parameters as the density and size of the product, and is approximately 50-90 rubles. For a cubic meter of foam block, you will have to pay from 2000 to 3000 rubles. One unit costs around 60-100 rubles. Prices are, of course, averaged.

What is better to use for construction

To decide on the question of which material is better to give preference to in the construction of various buildings, it is worth considering the scope of their application.

Namely:

• Autoclaved gas blocks are most often used for the construction of load-bearing structures and internal walls and partitions in private construction. They are also actively used to fill the frames when creating a monolithic house. They can be used in the construction of multi-storey buildings and the construction of high-rise structures.
• The gas block, the drying of which was carried out in natural conditions, has more limited application possibilities. It is less dense and durable, the dimensions are not so clear. It is often used to create a heat-insulating layer, as well as a foam block.
• The scope of foam blocks is as follows: the construction of internal walls and partitions, external load-bearing walls up to the 3rd floor, the creation of fences. They are also used for the construction of industrial buildings, thermal insulation of walls, floors, ceilings in non-residential premises.

For home

For the construction of buildings of 2-3 floors, a private house, guest houses and permanent residence, gas blocks are often used.

for garage

Buildings from gas blocks are durable, long-lasting. But if you look at the cost, it is more economical to choose foam concrete. It is also actively used in the construction of non-residential buildings.

Such requirements are imposed on the walls of the garage as strength, reliability, resistance to mechanical stress. The choice of material may depend only on the personal preferences of the owners.

It is easier for beginners to work with gas blocks, which have fixed dimensions, and there is no need to adjust them.

For a bath

Unlike foam concrete, gas silicate blocks are afraid of water, easily absorb it and dry for a long time. They provide excellent heat and sound insulation, but it is not recommended to use them for building a bath.

Foam blocks can be used for building walls in places with a high level of humidity. This allows you to build baths from them. Its advantages are also frost resistance and good thermal protection.

When talking about aerated concrete and foam concrete blocks, you can often encounter the fact that not everyone understands well what kind of materials they are and what is the difference between them. Aerated concrete and foam concrete are united by the fact that they belong to cellular concrete, i.e. have a porous structure. This provides them with high performance in terms of thermal insulation properties, ease of processing and use, good strength and reliability, and, most importantly, a relatively low price - after all, a brick wall will cost much more. But aerated concrete and foam concrete also differ from each other, which is due to some differences in their manufacture, hence the difference in some technical properties. It is impossible to say exactly which material is better, but we hope that after reading this material you will form the correct conclusion for yourself.

Features of the production of foam concrete blocks

The most important differences between foam concrete and aerated concrete should be sought in the technology of their production.

So, foam concrete blocks are obtained by adding special foaming additives of organic or synthetic origin to an ordinary cement mortar. Foam is formed on the basis of water, and the water itself evaporates naturally during the drying process. Foaming additives foam the concrete, thereby filling it with air bubbles. Such bubbles are distributed throughout the entire volume of concrete, and after solidification, they make it much lighter, adding heat-insulating and sound-proofing properties.

Such a process can be carried out right at the construction site, since especially specific and high-tech equipment is unnecessary. Due to the shapes used in the manufacture of the foam block, finished products may differ in size, sometimes by 10-20 mm.

Features of the production of aerated concrete blocks

To obtain aerated concrete, quartz sand, lime, cement and water are required, as well as a special component - aluminum powder, due to the presence of which bubbles are formed that fill the aerated concrete. The process of solidification of the mixture takes place in autoclaves at a sufficiently high temperature and high pressure, and not in natural conditions, as is the case with foam concrete. And since special equipment is used for production, all the characteristics of the future aerated concrete block can be controlled, making them the same throughout the entire volume. This cannot be said about foam concrete, which, while hardening on the street, may have a slightly heterogeneous and unequal structure and properties. And the shape of the gas blocks produced in this way is ideal, has minimal deviations from each other, which cannot be said about foam concrete, for which forms are often used that are not capable of ensuring accuracy and evenness.

Such processing allows aerated concrete blocks to have a number of other advantages over foam concrete, which we will discuss later.

Advantages of aerated concrete over foam concrete

1. Strength- this is the main advantage of aerated concrete. With the same density, aerated concrete is much stronger than foam concrete. And if we compare blocks with the same strength, then, naturally, aerated concrete will have a lower density, which means it will be easier and more convenient in construction. By the way, it is believed that foam concrete can shrink and microcrack after construction is completed, so it is useful to wait at least a year after building a house from foam concrete blocks before starting expensive repairs and decoration.
2. Aerated concrete blocks have the best vapor permeability. It's all about, again, the structure of the material and the method of production. So, in aerated concrete, all the pores are interconnected, which cannot be said about foam concrete, where they are isolated. Therefore, the aerated concrete block passes moisture and air better, and the microclimate in such a house will be much better than if you use foam concrete, which passes air much worse. That is why, if you decide to insulate a wall of aerated concrete blocks, then it is better to use breathable materials so as not to negate all the advantages of aerated concrete. And foam concrete blocks can also be insulated with foam plastic to reduce the cost of work.
3. Now oh thermal conductivity. It is believed that aerated concrete and foam concrete are capable of providing approximately equal thermal insulation performance. But if you understand some of the details, you can understand that the thermal insulation of foam concrete does not always meet the values ​​declared by the manufacturers. The fact is that the pores in foam concrete, as a rule, are of different sizes: they can be 1 mm, or they can be 5 mm, while in aerated concrete the pore size is usually constant. It follows from this that the value of thermal conductivity may differ in different places of the block. But this is not as scary as the fact that under conditions of high humidity, the thermal conductivity of foam concrete can increase significantly, which will lead to the fact that the walls simply will not keep the temperature that is comfortable for residents. Yes, and more powerful wall insulation will also have to be spent. Although there are many experts who can argue with this fact.
4. Aerated concrete blocks are often called environmentally friendly material - this is true, because in the production they do not use anything other than natural materials, which have already been mentioned above. In the production of foam concrete blocks, synthetic blowing agents can be used, which can no longer be called environmentally friendly. Here it is impossible not to mention the myth that aerated concrete contains aluminum, and it is harmful to our health. It is pointless to argue about the harmfulness of aluminum - it is harmful, but is it available in ready-made aerated concrete blocks? All the aluminum reacts with the lime, eventually liberating oxygen and forming aluminum oxide: oxygen is needed to form pores, and aluminum oxide is harmless and is found in most building materials, even in clay. Yes, and the aluminum oxide itself in aerated concrete is less than in foam concrete and in brick. And here, not everything is clear: there are opinions that aluminum still remains in the material, not completely spent on the reaction, but still we remain of the opinion that aerated concrete is more environmentally friendly.
5. The form aerated concrete blocks are almost perfect, and the error is no more than 2 mm, so it is very easy to work with them, the walls are smooth, and you need a little glue. Foam concrete blocks can have such significant deviations in size that it will be noticeable to the naked eye, and it will be more difficult to correct such irregularities, much more mortar will be needed.
6. Mounting aerated concrete blocks will cost you relatively less than foam concrete. This is due to the fact that glue is used for laying aerated concrete, and its thickness is much less than the thickness of the cement mortar for foam concrete (2 mm versus 1 cm). Even taking into account that glue is 2-3 times more expensive than cement, and its consumption will be about 6 times lower, we get savings, not to mention the fact that when using glue for aerated concrete, there are practically no cold bridges, which makes the house more comfortable and warmer.
7. Aerated concrete blocks are much easier in the subsequent decorative processing, this is largely due to the fact that they have excellent geometry.

Advantages of foam concrete over aerated concrete

conclusions

From everything written above, it follows that, according to some characteristics, foam concrete and aerated concrete blocks are similar, while foam concrete is cheaper. Thus, foam concrete may be suitable for a certain type of construction, where some of its shortcomings will not fail. Aerated concrete, on the other hand, has more attractive properties compared to foam concrete: largely due to production technology. And besides, if you count all the installation costs, then building from aerated concrete blocks may not be more expensive than building from foam concrete blocks. The final choice is made by everyone before the start of construction, but in most cases the use of aerated concrete blocks remains justified.

Construction begins with the choice of which the building will be erected. It is optimal that it be strong, durable, with good insulating characteristics. Cellular concrete possesses all these properties. Let's figure it out what is the difference between a gas block and a foam block, the most sought after of its varieties.

Features of cellular concrete

Traditionally, houses are built of wood, brick,. Each of them has advantages that improve the quality of construction. Modern technologies have made it possible to create a composition in which all these advantages are successfully combined. The cellular mass is used for the construction of internal and load-bearing walls, partitions, insulation, etc.

The defining moment is the density of the product and its porosity. The more pores, the lower the density and, accordingly, the strength. Compositions with high porosity belong to the category of thermal insulation. More dense are designed for the construction of load-bearing structures. In any case, the cellular mixture is distinguished by:

• security.
• Good warm and soundproofing.
• Sufficient strength.
• Ease of processing.
• Fire safety.

Under the name cellular concrete, a whole group of materials is hidden, similar in structure, but differing in properties. The most popular of them are foam and aerated concrete, which are produced using different technologies. Specialists recommend using them for the construction of low-rise buildings.

What is a foam block

This is the name of the building module, made by foaming the mixture. The production technology is quite simple:

1. A mixture of water, Portland cement, sand and fiber is kneaded in a concrete mixer with inclined blades.
2. A foaming agent is added to the solution, after which kneading continues.
3. The finished composition is poured into molds.
4. It is left to dry completely in natural conditions. Sometimes an autoclave is used, in which case products of higher quality are obtained.

The ease of manufacture of foam allows you to do it literally on the construction site. What does it look like similar production can be seen on the net. However, it is almost impossible to achieve uniform density under such conditions.

Air bubbles move randomly inside the solution. Therefore, the porosity of foam concrete varies not only within the batch, but also within the same block, but it costs cheaper other varieties. Let's get acquainted with its characteristics:

• Light weight, which removes a significant load from and facilitates installation.
• Low thermal conductivity. A wall made of standard-sized parts retains heat in the same way as a brick partition 0.7-0.8 m thick.
• Sufficient strength. Depends on the density of the module, but in any case lower than that of a brick or. Nevertheless, a number of models can be used with additional reinforcement in the construction of buildings no higher than three floors.
• Moisture resistance. pores foam block closed, which makes it non-hygroscopic. When it enters the water, it will float without absorbing liquid for seven days.
• Fire resistance. Does not support combustion, substances released under the influence of a flame are not toxic.
• Good frost resistance. The material retains its properties at low temperatures.

Significant disadvantages include non-uniform density. The geometry often depends on the manufacturer. Handicrafts can have significant deviations, which seriously complicates installation.

All about the gas block

Production technology in comparison with foam concrete has minor differences at first glance. However, it is they who determine the difference in their characteristics. Aerated concrete is made as follows:

1. A blowing agent is added to a mixture of Portland cement, sand, fiber and water. Most often it is aluminum paste. After stirring, a chemical reaction begins, which is accompanied by the evolution of gas.
2. The solution is laid out in forms so that they are only partially filled.
3. Within two hours, the mixture increases in volume, after which the excess mass is removed.
4. Products are sent to the autoclave for drying.

The result is homogeneous in composition, almost perfect geometry. Given certain difficulties in manufacturing technology, it cannot be produced in a handicraft way.

We list the main properties of the module:

• Light weight, which is about a third of a brick of the same volume.
• Low thermal conductivity. The air trapped in the pores is a good insulator. The material accumulates heat, resulting in heating costs Houses reduced by about a third.
• . Gas blocks are completely safe. The toxic aluminum paste used in the manufacturing process dissolves without residue.
• Ease of processing. Modules easily amenable to any cutting tool. They can be sawn, drilled, etc.
• Frost resistance. It is estimated at a minimum of 25 cycles, subject to construction regulations.
• Fire safety. The product can withstand direct exposure to a flame for about 3-7 hours.

The main disadvantage of aerated concrete is hygroscopicity. Unlike from the foamed analogue, its pores are open, it quickly absorbs water. For this reason, effective waterproofing of the building is essential.

Gas block and foam block: what is the difference

It may seem that these varieties of cellular concrete have a set of almost identical properties. but difference between them is and it is essential. Let's compare the most significant characteristics.

Module geometry

The better it is, the easier it is to carry out. So, even structures can be mounted using a special one. The thickness of the seam is only 2-3 mm, which allows you to completely get rid of cold bridges. At the same time, the speed of working with geometrically correct elements is much higher. Finishing costs are also reduced, since leveling is not required. Foam blocks according to this indicator are noticeable different. The error of their sides is 3 mm and higher, for gas blocks it is no more than 1 mm.

Insulating properties

Both varieties are filled with air bubbles, but their number is not the same. Aerated concrete is more porous, therefore, it retains heat better and dampens noise. However, the differences are small. In both cases, structural and insulating models are produced. The latter are designed to insulate buildings from more "cold" materials, for example, cinder blocks.

Hygroscopicity

Foamed concrete is absolutely non-hygroscopic, it can build without special protection against moisture. The open structure of the gas modules makes them vulnerable to moisture. They are quickly soaked with water, which worsens their performance properties. Therefore, mandatory additional waterproofing of the structure is necessary.

Strength

Characteristics depend on the density of the modules and how they are produced. Stronger all products made of aerated concrete, processed in an autoclave. They are allowed to be used in the construction of houses up to 3 floors for mounting, load-bearing and external walls. When filling the frame, the products are placed without restrictions. Foam concrete has less strength, therefore project construction should provide for mandatory reinforcement of structures.

Weight

Both options are cellular concrete, on the basis of which it can be assumed that their mass is approximately the same. So it is in fact. However, a little harder foam blocks. Due to the low weight, it became possible to produce parts that are much larger than, for example, standard bricks. This noticeably speeds up the laying process, since there are fewer elements per unit area.

Durability

Estimated life time both compositions is at least a hundred years old. It has not yet been possible to verify this empirically, since they appeared only in the second half of the last century. However, you need to understand that this will be possible only if the building is properly erected and further properly maintained.

Foam block or gas block: which is more profitable for construction

There is no doubt that a building made of cellular concrete will be much more economical than a brick one. But the debate continues about which one is better suited for individual construction. Not everything is clear here opinions divided. The fact is that, other things being equal, foam concrete will be cheaper. This is due to the low cost of its manufacture. However, the overall construction costs can be more significant.

A geometrically correct gas block can be placed on a special glue. Thickness strong is only 2-3 mm, so the consumption of an expensive composition will be minimal. Whereas the foamed module most often has significant irregularities, as a result of which it can only be laid on a cement mortar. To obtain reliable seams of the latter, a lot will be required, which will increase the expense item.

Additional reinforcement of foam concrete, which is mandatory for the construction of any building, even a small one baths, will also result in some amount. The next cost item is finishing. Aerated concrete, with its almost perfect geometry, does not need alignment. Foam concrete should at least be plastered. As a result, it turns out that initially cheaper material gives a noticeably larger cost estimate. This should be taken into account when choosing.

However, it is necessary to take into account one more aspect, namely the experience of the installers. Professionals can easily cope with laying aerated concrete on. This is more difficult than laying on cement and requires certain skills. Therefore, it is better for novice builders to work with foam concrete. In this case, you need to choose only high-quality material.

We dismantled differences between foam block and gas block. There are quite a few of them and they are significant. But at the same time, both types of cellular concrete are in demand, because they allow you to quickly and cost-effectively build a strong and warm house.

• Material prepared: Inna Yasinovskaya

Basically, both one and the other belong to cellular concrete - a group of building materials characterized by the presence of many cells in their structure.

However, they differ from each other in many ways. Which is better - foam concrete or aerated concrete? A review of the possibilities and disadvantages is worth starting with how each of them is made.

Characteristics of aerated concrete

This material is not very difficult to manufacture, but its production requires special high-tech equipment. According to the type of processing, it is divided into:

• autoclave (sintering of blocks occurs at a high temperature, so it is stronger, therefore, more expensive);
• non-autoclave.

The main components that make up the material are Portland cement, lime, water, quartz sand and aluminum powder. Strength is regulated by changing the combination of substances, as well as controlling the swelling of the mass to a certain volume.

After gas formation and acquisition of initial strength, the mass is cut into "bricks" and dried either in a special device or in air. This happens with both materials, regardless of whether it is foam concrete or aerated concrete. What's better? Autoclave drying gives the chemically formed material greater strength, allowing it to outperform the competition.

In Western Europe, aerated concrete is used much more often than in our country. For example, in the UK, the frequency of its use in low-rise construction is 40% of the total number of modern buildings, in Germany - 70%.

However, if we are talking about non-autoclave, and even more so home production, then it does not really matter what exactly they do - foam concrete or aerated concrete. What is better - a material made according to a repeatedly tested and re-tested scheme using special equipment, or one that was made, even by very good and accurate specialists, “on the knee”? In fact, everything, of course, is not so bad, however, non-autoclaved aerated concrete may be inferior in properties to its “bubble” competitor.

foam concrete

When talking about cellular concrete, two names usually pop up. But which is better - aerated concrete or foam concrete? What is the difference? Comparison of the two should start with the facts - the first was created using a chemical reaction, the second - a special foam.

At the factory, this is done in a special installation, but in small firms or on a construction site, an ordinary concrete mixer can be used.

As in the case of the use of gas-forming substances, the final material needs to be dried - it can be carried out in a special installation or in a natural way - in air. It is difficult to say which is better - aerated concrete or foam block. Almost every expert has an opinion on this matter.

The subtleties of the production of foam concrete

There are several ways to make blocks from this material.

1. Filling forms, disassembling them and extracting finished "bricks" manually.
2. Pouring a large "slab" and then cutting it into identical bars.
3. Filling cassette molds and then disassembling them automatically.

Each method has its pros and cons. In addition, with such production, the question of form arises. To date, the most common are three types:

• Plywood. Differ in low cost and small weight. However, they also have a whole list of disadvantages: they quickly fail due to soaking and damage to plywood (the average service life is 1-2 months), the blocks become “humpbacked” if the walls are not additionally strengthened. Therefore, they are suitable for production "for themselves" and are categorically unsuitable for industrial use.
• metal(no reason). They are usually made using laser cutting machines. Details are cut very precisely, as a rule, sheet metal 4 mm thick is used. They are much stronger than plywood, but they have their drawbacks: it is difficult to tighten the side fasteners tightly (due to which the shape “walks”), the metal bends and, again, without additional strengthening of the walls, the blocks turn out to be “humpbacked”.
• metal(with hinged base and sides) - best suited for industrial production. The blocks are even, "correct" shape, and the form itself lasts a long time.

Using collapsible forms

The foam concrete poured into the mold hardens for about 12 hours, then it can be removed and sent to a special room to dry. Deviation in dimensions is allowed (no more than 1-2 mm).

This technology is expedient if no more than 40 m 3 are produced per day. It is very simple and does not require large financial costs. However, at the same time, it is difficult to produce blocks in large volumes in this way, and besides, you have to make them all the same.

Slab pouring

The second option looks like this: the foam concrete mass is poured into one large form without partitions. After it hardens, the slab is fed for cutting - blocks of a given size are cut out of a single array with saws in automatic mode.

This technology is productive and high-tech. Its advantage over the previous method is that you can get bars of any size. However, the equipment is expensive, in addition, this type of production generates waste - 0.5% of the board becomes a crumb when sawn.

Pouring cassette molds

With this method, foam concrete mass is filled with molds with partitions, allowed to harden in them, and then transferred to an installation in which the finished blocks are automatically squeezed onto pallets. The method is very simple and productive, but it has the same drawback as manual production - it cannot be reconfigured for the production of foam concrete of other sizes.

Advantages of aerated concrete

The main advantages of this material are its lightness, high insulating properties and manufacturability of processing:

• The material is easy to process. It is easy to cut, drill, and can be shaped to any shape right on the construction site. And all this with the help of both electric and hand tools (drills, chisels, hacksaws). In the walls of aerated concrete, strobes are well laid for sewer and water communications, not to mention electrical wiring.
• The volumetric weight of gas blocks is in the range of 300-1200 kg/m 3 . Approximately the same range for foam concrete. The question arises: foam concrete or aerated concrete - which is better for a home? Both are preferable to brick - it has this figure in the region of 1200-2000 kg / m 3.
• Good indicators of thermal insulation.
• Frost resistance - not less than F35.
• Fire resistance - class A1. This means that the material tolerates short-term exposure to temperatures up to 300 °C.
• Doesn't rot or age.
• Provides good sound insulation.
• Withstands axial pressure up to level B2.5, allows you to build walls up to 20 m high. According to this parameter, it makes no sense to compare which is more productive - foam concrete or aerated concrete. What is better for the construction of load-bearing walls and floors? Definitely aerated concrete. It is not recommended to use its "foamy" competitor in this capacity, especially in multi-storey buildings.
• Aerated concrete walls are not airtight, they "breathe", like walls made of ceramic bricks.

Advantages of foam concrete

That's right, with the observance of technology, the manufactured material surpasses traditional brick and wood in its characteristics and has a number of useful properties:

• small weight, does not require special lifting mechanisms for low-rise construction;
• identical block sizes simplify calculations and allow you to get a smooth, beautiful wall;
• foam blocks are laid on a special glue - this not only makes the masonry stronger, but also avoids "cold bridges" in the wall;
• does not require vibration compaction when filling voids;
• well distributes the load;
• has a low coefficient of thermal conductivity (0.07-0.38) and thermal insulation properties;
• low water absorption (14% by weight), in this indicator it is second only to clay bricks;
• it is possible to fill at the construction site and create monolithic walls, floors, ceilings (however, this is where the serious advantages of foam concrete over aerated concrete end);
• does not burn;
• resistant to frost;
• due to the porous structure creates good sound insulation;
• simple production technology allows you to produce blocks directly on the construction site;
• resistant to deformation;
• convenient to transport.

In addition, due to the small mass of the blocks, there is no need to build a reinforced foundation and frame. It is possible to process foam concrete with both manual and electric tools - for example, saw it with an ordinary saw, it will not be difficult to drive a nail into the wall from it.

Also, structures made of foam blocks have greater seismic resistance - they can be erected in problem areas.

Cons of foam concrete

This type of cellular concrete has certain disadvantages, which completely equalize the shortcomings of aerated concrete. In addition, a lot of foam concrete is produced at various enterprises, so that products of different quality get on sale.

Among them, there are also those that were not made in violation of technology. If we do not take into account marriage, then we can distinguish the following disadvantages:

• In the field, that is, on a construction site, it is difficult to achieve ideal fulfillment of technical requirements, density and weight can fluctuate, and as a result, the blocks will not have all the declared properties or will be only partially.
• In the case of manual sawing, the material crumbles.
• Foam concrete shrinks - the material gains strength within a month, so the finish has to be pushed back to a later date.

Cons of aerated concrete

Perhaps the main disadvantage of this material is fragility. In addition to it, you can name the following:

• It can only be manufactured at a factory where there is special equipment.
• Finished blocks are quite fragile - withstanding high compression, they are very sensitive to shock. Therefore, throwing them or hitting aerated concrete is dangerous. It is necessary to transport in the original packaging on euro pallets.
• The material is hygroscopic and absorbs moisture not only upon contact with it, but also from the air. It is impossible to store blocks in the open air, and the walls must be hidden under plaster as soon as possible (however, not only aerated concrete or foam concrete differs in this property). Which is better to choose from these two depends on the plans for finishing, on the area where the house will stand, on the quality of ventilation. When moisture is absorbed, the material increases in weight, its strength decreases, and the thermal insulation properties deteriorate. When frozen, it can collapse. For the same reason, blocks of this material are not used when laying the foundation.
• The property of aerated concrete to absorb moisture is also manifested during laying - it quickly absorbs liquid from the solution, and it becomes more difficult to work. Especially hot summer.

Everything is relative

Which is better - foam concrete or aerated concrete? How do these materials differ from each other during operation? If you bring all the above facts together and compare them with each other, you will find the following:

• In the case of foam concrete, it is possible to pour into the formwork directly at the facility, and this makes it possible to create monolithic structures. Aerated concrete is manufactured at the factory and “arrives” at the construction site in the form of “bricks”.
• Fire resistance is a property where aerated concrete or foam concrete cannot be distinguished. What is the difference is in the level of stability, however, in a real fire, the result also depends on related factors.
• Aerated concrete that has not undergone heat treatment is inferior in strength to a competitor.
• Both types of cellular blocks have almost the same moisture resistance and vapor permeability.
• Both provide good sound and heat insulation.
• A comparison of aerated concrete and foam concrete in terms of properties will also reveal the phenomenon of shrinkage - it is characteristic of the foam mass, and its main period falls on the first 28 days after manufacture. It cannot be completely eliminated. Ultimately, foam concrete loses in this indicator to autoclaved aerated concrete.
• Foam concrete is more affordable and cheaper, but there is a risk of purchasing low-quality material.
• Aerated concrete is stronger and is suitable for the construction of both one-story and multi-story buildings.