Foam concrete blocks from aerated concrete are different. Foam concrete and aerated concrete: is there a difference, what are the differences

There are many building materials on the market today. And aerated concrete blocks are among the most popular building materials. They are in great demand among both professionals and DIYers.

Nowadays, two types of blocks are produced from lightweight aerated concrete: aerated block and foam block. In this article we will consider which is better than foam concrete or aerated concrete.

Foam concrete or aerated concrete

Due to the large distribution of building materials on modern market, many home craftsmen are trying to figure out what is better cinder block or aerated concrete, not forgetting about such popular materiallike foam concrete.

These materials are characterized by almost identical chemical composition.

The common components here are:

• Cement.
• Water.
• Sand.

Due to the same composition, foam block and aerated concrete have the following positive properties:

• Non-flammability.
• Resistance to the effects of various biological factors (damage by rodents, decay, etc.)
• Resistance to the influence of chemically active substances.
• Ease of installation. Knowing the principles brickwork, you do not need instructions for building a wall from a foam block or aerated block with your own hands. Therefore, most home craftsmen have just such a choice: foam block, gas block or brick.

What is the difference

Consider the production technology of these materials:

1. Foam concrete is obtained by adding a foaming agent to the concrete solution. After that, the composition is poured into prepared forms, where it gains strength.
2. Aerated concrete is obtained as a result of the chemical reaction of quicklime with aluminum. This material contains the smallest particles of aluminum powder. As a result of the reaction, hydrogen gas escapes outside, which forms a porous structure. This material is manufactured in large blocks. After the block hardens, it is cut into products of the desired shapes.

It is these differences in manufacturing that influenced the properties of the materials obtained.

Compare the characteristics of materials

In order to determine which blocks better gas silicateny or foam blocks, you must first compare them specifications... Despite the rapid technological progress, today there are no ideal building materials, so you always have to choose by comparing the advantages and disadvantages of different blocks.

When determining what is better for a foam block or aerated concrete, we will make a comparison according to the following parameters:

• Strength.
• Heat and sound insulation.

• Environmental friendliness.
• Price.
• Hygroscopicity.
• The need for reinforcement.
• Readiness for finishing works and installation.
• Manufacturing quality.

Let's consider these points in more detail:

1. Moisture resistance... A good home should be dry. And foam concrete in this case is the ideal material, since it practically does not absorb moisture.

Advice!
In order to make sure of the high water resistance of the foam block, you can carry out the following experiment: place the block in a container filled with water, leaving it in it for a long time.
The material will float on the surface of the water both after a week and after a month, etc.

In view of such a high hygroscopicity, experts recommend waterproofing only the outer walls of buildings lined with foam blocks.

Aerated concrete is also waterproof, but to a somewhat lesser extent. In addition, the drying of this material takes longer.

1. Thermal conductivity... Warm housing is the dream of many of our compatriots. Given the rather harsh winters, everyone dreams of forgetting about the cold, drafts and heating appliances that are located throughout the house.

Walls erected from aerated concrete need insulation. Especially outside. Aerated concrete has a lower thermal conductivity, but thermal insulation is still a mandatory procedure.

1. Soundproofing... Separated pores in the structure of foam blocks provide more high level soundproofing than aerated concrete. However, such walls still need to be soundproofed.
2. Strength.

In our country, people are accustomed to building "for centuries." Considering the cost of modern building materials, this desire is very easy to justify. Therefore it is necessary durable material for load-bearing walls.

The strength of the foam block is lower than that of the gas block.

Advice!
Due to its lower strength, foam concrete is easier to process.
If necessary, you can easily cut such a block into the desired parts, drill a hole or grind the protrusions.

Aerated concrete blocks better withstand external loads, as a result of which they do not lose their shape and do not crumble during loading and unloading operations. Accordingly, the structure is more durable.

As you can see, in terms of strength, the answer to the question: "What is better gas silicate block or foam block?" depends entirely on the nature of the proposed work. If the material will be processed, then a foam block should be chosen, but if you need a building with smooth, strong walls, choose products from aerated concrete.

1. Wall installation... Let's figure out what is better gas silicate or foam block when laying, because ease of use is a very important parameter for any home craftsman.

Related articles:

Foam concrete blocks not afraid of cold or rain. They are ready for use immediately after manufacture. Therefore, you can get to work immediately upon arrival of the material at the venue. construction works.

Gas blocks, in turn, absorb moisture, so they should be used in masonry walls only after drying. On the other hand, the plaster is better placed on them, which greatly simplifies the finishing work.

1. Reinforcement... By determining that better foam blocks or aerated concrete, there is no way to get around the topic of material reinforcement in order to strengthen the structure.

Laying reinforcing rods prevents cracks in the foam concrete walls. Due to their reduced strength, this procedure is mandatory. Aerated concrete walls are also subject to reinforcement, however, in this case, reinforced blocks are laid only in the floors doorways and windows.

Advice!
During the construction of one-story buildings, aerated concrete may not be reinforced at all.

1. Deciding which foam blocks or gas blocks are better, many will focus on cost... Both materials fall into the category of inexpensive building blocks. However, there is still a difference in price. Since the manufacturing process of gas blocks is more complicated, they are more expensive. And the difference can be around 20%.

Ease of manufacture allows you to produce foam blocks not only semi-industrial, but also by handicraft. This significantly reduces the cost of purchasing equipment and manufacturing the material itself. Products made under artisanal conditions can be much cheaper than factory aerated concrete (up to 40%).

1. Calculation of transport costs... When determining which foam blocks or gas silicate blocks are better, you should not least pay attention to transport costs, because the delivery of material to the construction site is a mandatory step, since the construction of a house requires a large amount of building materials.

Foam concrete blocks are less resistant to transportation. Demanding high-quality styling, they can get miles damaged when transported on bad roads. Gas blocks are more durable, but they are usually transported in covered cars in order to exclude moisture ingress.

1. Fakes... Determining what is better gas blocks and foam blocks, few of the home craftsmen think about the fact that in the modern market it is quite easy to face fakes, acquiring material of dubious quality. And if the production of aerated concrete blocks excludes such cases in the bud, then easy-to-manufacture foam blocks are often faked by small cooperatives and one-day firms.

The industrial production of aerated concrete products becomes possible only with the purchase of specialized expensive equipment, therefore all building materials of this type meet all quality requirements.

But there is quite a lot of low-quality foam concrete on the modern market. And besides the low price, such building materials can have a number of other, more unpleasant characteristics, among which are increased fragility and low environmental friendliness.

Facts and misconceptions

Today there are several questions about these materials that are of interest to most home craftsmen:

1. How harmful is the aluminum contained in aerated concrete for human health?

Such experiences are completely groundless, since aluminum, being one of the most abundant materials on earth, is also present in ordinary ceramic brick... Moreover, its mass fraction in brick is much greater than in aerated concrete. This material does not have any harmful effects on the human body.

1. The gas block is laid on glue, while cement mortar is used for laying the foam block. Will work with the gas block be cheaper due to the savings in solution?

The layer of cement mortar when laying the foam block is at least 1 cm. The adhesive layer when erecting a wall from gas blocks is only 2 mm. Accordingly, the consumption of glue is 5 times less, while its cost is only 2 times higher than the cost of concrete.

Advice!
Laying on glue allows you to practically eliminate the occurrence of cold bridges, which will allow you to significantly save on wall insulation.

Conclusion

As you can see, modern building materials have certain differences, which are reflected in both advantages and disadvantages. Therefore, even experts, among whom there are different opinions, cannot decide what is better than a gas block or cinder block. Therefore, taking into account all of the above, the final decision should be made by you.

In the video presented in this article, you will find additional information on this topic.

Aerated concrete is generated by the following circumstances: firstly, for low-rise buildings, the strength, density and labor intensity of brick and even more reinforced concrete are definitely excessive, and the heat and sound insulation properties are also definitely insufficient. Secondly, any known wood processing methods guarantee durability and fire resistance. wooden building more than 30 years only in special favorable conditions exploitation. Therefore, attempts to bring the properties of concrete closer to wood by creating voids or inhomogeneities in it were undertaken back in the first half of the 19th century, and at present there are more than 10 types of cellular concrete. Foamed concretes are the most popular and promising, but things are not easy with them. ...

In Internet sources on the question: which is better, foam concrete or aerated concrete, the confusion is unimaginable, and in some cases, clearly malicious. Construction sites of some neighboring countries are especially sinful with this. It is difficult to understand what is an egg and what is a chicken, but the typical situation is as follows: there is, for example, a site on which it is fairly objectively given comparative analysis of both material. But! The properties of aerated concrete are attributed to aerated concrete, and vice versa. That is, if "foam" and "gas" are reversed, everything will correspond to reality.

Next to the text, contextual advertising and links to suppliers intrusively climb into the eyes. Go through them - they name their products correctly. Suddenly an ignorant buyer, guided by what he read, orders and pays, and completely different material will be brought to the site. And, as they say, there are no edges: suppliers and publishers do not answer for each other, and you can even push back on advertisers. Therefore, it is imperative to figure out which of these two types of cellular concrete is best for construction.

Note: from other types of cellular concrete, we will further touch on foam polystyrene concrete; not that they lie about him, but they are silent about something significant. And with expanded clay concrete, arbolite, fiber-reinforced concrete, etc., there seems to be no serious misunderstanding.

Where does the confusion come from?

Sources that have the force of law, authoritative or at least claiming objectivity, from SNiPs and polytechnic dictionaries (construction, explanatory, encyclopedic), to Wikipedia, give a clearly visible criterion for distinguishing foam concrete from aerated concrete. In the first, the pores are through, sinuous, irregular in shape; in the second - rounded closed, see fig. But within the limits of each structure, the difference in the properties and quality of the material is possible more than for different structures. Simply: good foam concrete can be better than aerated concrete. And one more important point: the initial characteristics of both of these materials change in different ways and manifest themselves during operation, see below.

Why so, we'll see. In the meantime, it is simply necessary to clarify the scale of discrepancies in question. Otherwise, it is impossible to objectively assess the pros and cons of foam and aerated concrete: behind the dry numbers in the tables there is a lot, which, in fact, this article is about.

For example: you may have heard about the real estate situation in Spain. There, according to the state program of rescuing unlucky developers from bankruptcy, about 800 thousand new (!) Individual residential housing buildings are put up for auction. The prices are amazing. Here, for example, is the wonderful resort area of \u200b\u200bCosta Calida. Granada with its Alhambra and the skiing delights of the Sierra Nevada is just a stone's throw away. And - for sale a villa of 100 residential squares on the 2nd beach line (3-10 minutes walk to the sea). The architecture is New Andalusian, there is a swimming pool. The price of this paradise is 200,000 euros, 2,000 euros per square. By the local standards, this is not at cost, but for how much they will take.

Why? We look at the specification: the construction material is a gas block of some kind of Euro standard. What is this Eurotatoito? We are looking, with difficulty, but we are finding. Ah, understandably! Eurotakoito is a surrogate aerated concrete (see below for more details). We compare the dates: the Eurotakomuto in this building has 20 years left until the end of its design life. Who will give even a Russian nickel for a house that is guaranteed to decay in less than 15 years? Is it possible to rent for a porn studio or a brothel, but for a million establishments of this kind, this is a bit too much for Spain.

Here's an example of a different kind. In the noughties-tens, a thorough revision of the foam concrete buildings of the USSR in the 30s-50s was carried out. It turned out that 95% of buildings have gained strength twice or three times (!); their other characteristics did not deteriorate. These buildings were deemed fit for use after cosmetic repair; based on the current state, a second revision is scheduled in 80 years. 5% are dilapidated due to violations of the rules for the production of work during the construction. Considering that under Stalin, forced labor was widely used in construction by unskilled work force (convicts), it must be admitted that the then foam concrete withstood the gross violations of construction technology, except for the completely unacceptable ones.

We are looking again why this is so. The answer is simpler: the bulk of the material is Portland cement with quartz sand; foaming agent - natural protein (more on this below). Here is such a costa calida comes out.

Stamps

Foam and aerated concrete is produced / manufactured in the following brands; the numbers indicate the mass density of the ready-to-use material:

1. Thermal insulation, not capable of bearing the load - D200-D400 for aerated concrete and D200-D300 for aerated concrete;
2. Thermal insulation and structural, from which partitions and enclosing structures can be installed - D400-D800;
3. Structural, for the erection of load-bearing building structures - D900-D1200.

Note: from this it is clear that the first 2 groups of brands and partially the third are lighter than water.

Production

To understand the clearly incongruous situation described above, you first need to figure out how the production of foam concrete differs from aerated concrete. Key points here:

• A way to create voids in a material; simply foaming.
• For aerated concrete - the conditions for holding the batch until solidification.
• Composition and properties of the main (carrier) material.
• Method of forming building modules.

Foaming

It is the method of forming voids that is the main difference between foam concrete and aerated concrete. Foam concrete is obtained by introducing organic foaming agents into water for mixing. They are, firstly, from animal protein: the first samples of foam concrete were obtained by adding cement-sand mortar bovine blood. Secondly, on the basis of saponins - substances that foam stronger than soap, but with a neutral chemical reaction. Saponins were first obtained from plants of the sapote family (soap root, etc.), but now they are almost completely replaced by synthetics, which are much cheaper than natural extracts.

Protein foaming agents provide practically unlimited durability of the building - remember the old buildings, for which eggs were added to the masonry mortar. But with the current situation with animal protein in the world, protein foaming agents are very expensive and there is almost no foam on protein on sale. Saponins guarantee the relative stability of the characteristics of the masonry for 40-70 years, and then its strength, moisture resistance and vapor permeability also stably and quickly fall off. The introduction of those and other foaming agents into the solution is possible directly on the site, i.e. foam concrete can be monolithic. Saponin foam is low or medium expansion, so the spread of the initial parameters of foam concrete is quite large.

Aerated concrete is kneaded in a highly alkaline solution (quicklime is usually used) with the addition of aluminum powder. At the same time, hydrogen is released, which, together with the main mass, creates a high-expansion foam, due to which the initial characteristics of the material are maintained with high precision... The technological process is organized in such a way that the volume concentration of hydrogen in the air never exceeds the explosive value of 4% anywhere. Due to the high diffusion capacity of hydrogen, it almost completely volatilizes before the mass solidifies, and its residues subsequently flowing out are harmless and safe. But powdered aluminum and caustic alkalis are carcinogens and, the latter, toxins of high hazard groups. Security production processes it is possible to provide with them only by laying it constructively in technological equipment; PPE can only be a supplement.

Excerpt

Comparison of different trade marks aerated concrete must also be produced taking into account the batch aging method before technological hardening. Maturation of the foamed mass of aerated concrete is carried out either with heating without excessive external pressure (autoclaved aerated concrete) or in an autoclave under pressure (autoclaved aerated concrete). According to their initial characteristics, they may not differ much, but a more expensive autoclaved aerated concrete gives a service life of buildings made of it over 70 years, and autoclaved aerated concrete - up to 40-50 years. Frost resistance (the number of cycles of complete freezing / thawing prior to cracking) of autoclaved aerated concrete ranges from 80-100; autoclave-free - up to 30.

The bulk

The main thing that you should pay attention to if you intend is the composition of its bulk. The best operating results are shown by mixtures of Portland cement and quartz sand; further, unless otherwise stated, we will consider cement-sand foamed concrete. However, the sale goes great amount foam and aerated concrete with a binder of slaked lime and a filler of ash from thermal power plants, ground industrial slag, etc. industrial waste, this is the so-called. surrogate concrete. Their durability and frost resistance are 1.5-2 times less than that of cement-sand foamed concretes of the same brand, but other initial qualities may be no worse.

Surrogate foamed concrete can be white, dazzlingly sparkling, like refined sugar, even in coffee luggage. But the foamed mixture of Portland cement and quartz sand can also be white, like writing paper. Here the selection criterion is a material specification or just a label on the package. Manufacturers of cement-sand foam and aerated concrete do not miss the opportunity to point out the dignity of their products, especially in conditions of tough competition, and suppliers of surrogates prudently keep silent about the origin of their goods.

Blocks and monoliths

Individual developers use foam blocks or gas blocks for work. Aerated concrete is made only in production conditions and is produced in standard modules. To knead foam concrete on the site, expensive purchased equipment is required, but all the same, the spread of material characteristics is more than acceptable. Therefore, monolithic foam concrete is made on site only of low grades; mainly for insulation and, rarely, enclosing structures. Videos about the methods of production of foam and aerated blocks give an idea:

Video: production of foam concrete blocks

Video: production of aerated concrete blocks

Note: introductory video materials. Depending on the production equipment used, those and other technological processes can differ significantly.

The dimensions of foam and gas blocks are maintained in a module of 300 mm; standard - 300x300x600 mm. Aerated concrete of low grades for thermal insulation is also produced in slabs in modules of 150 and 125 mm, for example. 1200x600x150 mm or 1250x500x125 mm.

Aerated concrete and foam concrete lend themselves to mechanical processing with ordinary steel tools, but the first crumbles weakly and only from shock loads, and the second - strongly and, apart from shock, from uneven loads. Therefore, foam blocks are formed exclusively by pouring into molds. Saponin foam creates significant pressure, expands the forms, so that the accuracy of manufacturing foam blocks is low: about 1% of the corresponding value. size. That is, the transverse dimensions of a standard structural foam block can "walk" by 3 mm, and the length - as much as 6.

Gas blocks are supplied for sale cast and cut. High-expansion hydrogen foam almost does not put pressure on the mold: the diffusion rate of hydrogen grows very rapidly with an increase in its partial pressure, and the excess gas simply evaporates. The dimensions of the cast gas blocks can be maintained with an accuracy of +/– 1 mm. Cutted gas blocks are generally fantastic for building materials accuracy of +/– 0.5 mm, but they cost 5-15% more than cast ones, because cutting tool wear and material waste cost money.

Jumpers, locks and weights

Due to better ability gas blocks to bear shock and uneven loads, together with a higher manufacturing accuracy, it is possible, firstly, to lay the lintels of window and door openings in gas block walls from 150 mm (item 1 in the figure), while for foam blocks, the same structural elements are required from 300 mm. Secondly, gas blocks are also available with shaped locks, pos. 2, providing greater strength and less heat loss to the building.

Then, to the walls made of foam concrete, you can only fasten the battens for the sheathing with steel fasteners, with the laying of dowels for hardware from 150 mm; under the concentrated loads, you need to put through anchors. A hook in a dowel with a depth of 120 mm aerated concrete wall holds weight up to 15-25 kg, depending on the grade of the material. That is, in order to hang, say, a TV on a foam concrete wall, you will need to twist the finish in the adjacent room. With aerated concrete, there are no problems, on the contrary: you do not need a perforator and a drill for concrete, it is enough hand drill without vibrator and conventional twist drill. Correspondingly, and there will be less debris.

Characteristics of foam concrete and aerated concrete

The most important performance characteristics of structural cellular concrete, red brick and construction timber are summarized in table. The required wall thickness may cause some bewilderment, but it is calculated, firstly, for a bare wall, without inner and exterior decoration, cladding and insulation for -25 outside. Secondly, it is taken into account that the homeowner does not pay for energy overruns at an increased rate. And, in order to summarize, let us go through other essential lines of it.

Cost and shrinkage

Actual prices of the cost of 1 sq. m walls change, but their ratio remains approximately the same. However, here the question may arise: how is it that foam concrete is almost a quarter cheaper than aerated concrete, and a wall made of it is more expensive? In addition to the thickness of the wall, the masonry seam plays a role here. Gas blocks are placed only on special glue. High-quality glue for aerated concrete is 2-3 times more expensive than ordinary masonry mortar, but the latter needs 3-5 times more in volume (see joint thickness).

Foam blocks can seem to be placed on glue, but foam concrete greedily absorbs moisture, see below, and the fresh seam dries up before the next block is laid. In addition, the accuracy of manufacturing foam blocks is almost equal to the thickness of the adhesive seam, which is unacceptable for reasons of strength.

Note: no need to estimate the estimated cost of construction at the price of a square of the wall. The total cost of construction depends on many factors, and, depending on local conditions, may be comparable in price or even cheaper than a stone one.

Further, a small dry (own) shrinkage of aerated concrete occurs quickly, within a month, and you can start finishing. Foam concrete settles in a year, and technical breaks also cost money. An individual developer - at least for the rental of temporary housing. Finally, due to the spalling of foam concrete under uneven load, load bearing capacity the foundation of a foam concrete house should be higher, and its shrinkage is less than under aerated concrete, i.e. and the foundation for foam concrete will cost more.

Humidity

Operating humidity means how much by weight of water vapor the material is able to "pump" from the air. 5% or 15%, there is not much difference; ex. for air-dry industrial wood, the moisture content is 20%. But the rate at which moisture is absorbed is another matter entirely. It depends on the physical mechanism of moisture absorption: capillary or diffusion. The first is typical for aerated concrete and wood, the second - for autoclaved aerated concrete, and non-autoclaved aerated concrete absorbs moisture this way and that. In turn, the rate of capillary moisture absorption is highly dependent on the cross-sectional size of the pores in the material.

Let's do the next. experience: take pieces of foam, autoclaved and non-autoclaved aerated concrete and wood of the same size, shape and density, i.e. weight. Let's let them swim in a container of water. Foam concrete will soak in water before our eyes and sink. Let's continue the experiment by adding water as it evaporates. Non-autoclaved aerated concrete will float for 2 weeks - 3 months, but autoclaved aerated concrete will remain afloat even when the piece of wood has already gone to the bottom. Let us remember: aerated concrete dampens slowly and is unimportant.

Vapor permeability

Let's compare foamed concrete with wood here. Taking into account the fact that there are no wooden structures without ends in the air, it turns out that foam and aerated concrete "breathe" almost like wood. And if we remember how autoclaved aerated concrete slowly gains moisture, we come to the conclusion that it is almost better for a bath than a traditional tree. Moreover, its thermal conductivity is lower: the bath will warm up faster.

What is not in the table

We will complete the review of the properties of aerated concrete with some additional parameters:

• Cold resistance - F35, i.e. mechanical characteristics are maintained down to -35 Celsius.
• Refractoriness - class A1, withstands heating for 20 minutes up to 300 degrees without loss of strength.
• Permissible axial load of structural grades - class B2.5; erection of walls up to 20 m high is permissible.
• Absolutely unattractive, unlike expanded polystyrene concrete (see below) for rodents and insects.

About expanded polystyrene concrete

Expanded polystyrene concrete, or foam concrete, does not belong to the number of foamed concrete, but you need to stay on it. Foam concrete has recently been heavily advertised, and there seem to be formal grounds for this: it is cheaper than aerated concrete and is not inferior to it in most parameters. But, what the foam concrete enthusiasts don't talk about: its zero fire resistance, heating is not allowed. In a flame, expanded polystyrene concrete collapses catastrophically, scatters to pieces with a crash, and emits, like foam plastic, a large volume of extremely toxic gases.

The bottom line (and what not needed)

What you don't need is to knead the foamed concrete yourself. Fussing with the components of aerated concrete at home is simply dangerous to health, see above. And as for foam concrete, there are plenty of stories about it on YouTube on the topic “do it yourself”. But you will be shown either the work of an expensive and requiring qualified maintenance purchased installation, or kneading in something like a basin or bucket. Is it possible to get cubes and tens of cubes in this way? quality material for construction - a rhetorical question. Knead a component for insulating floors from a retail one? Thermal insulation "spotty" in terms of thermal conductivity is worse than poor homogeneous insulation. causes biting and mold. And at a price comparable will be ecowool insulation, which has a lot of its own advantages in this capacity, but devoid of the disadvantages of foam concrete.

When planning and carrying out construction work, it is important to select economically advantageous building materials that provide the building with a comfortable microclimate, with excellent operational and technical data, and the installation of which does not cause difficulties. This applies equally to foam and gas blocks. Let's consider each of the blocks, talk about the features, advantages and weaknesses of each of them.

Which is best for building

The gas block and foam blocks are similar in structure, the differences between which, according to multiple reviews, are not significant. This is a stone on an artificial basis, for the production of which aerated concrete is used. The basis of the material is environmentally friendly and safe, both for humans and environment.

For foam concrete, a mixture of cement and sand is used, adding a special reagent-foaming agent to it. Curing takes place in a natural way, which allows the manufacture of foam blocks even in the conditions of a house under construction or other object - on a construction site. The material has a variable composition of raw materials, and it itself is characterized by a short storage period. The finished product offers changeable technical parameters, which in no way hinders the construction of walls or when arranging partitions.

Gas blocks in the manufacture require special conditions: high humidity and high temperature conditions. Water, sand, lime is released from the components, cement base... The role of the blowing agent is played by aluminum powder or paste. According to experts, the reagent does not emit harmful substances, is environmentally friendly and safe.

The latest technologies give the material a uniform structure, the properties of which are unchanged. It turns out a material with a long service life and excellent characteristics, not prone to burning, easy to process, which is used in the construction of houses, baths, garages of other facilities.

Difference between materials

Despite the similarities, there are some differences. Used for manufacturing different technologies... For foam concrete, mechanical mixing of a liquid concrete mixture with the foam obtained by mixing water and a foaming agent is used.

The resulting composition is to be poured into forms, which are group or individual. The holding period is 4-8 hours, which makes the product stronger and allows you to dial the required parameters. Blocks are removed from individual molds, they gain tempering strength, the value of which is up to 70%. Blocks from group shapes are cut to give nominal dimensions - this option is better than the previous one and is characterized by high dimensional accuracy.

Aerated concrete is produced by mixing a concrete composition with powder or paste on an aluminum basis. For 1 cbm. solution requires 400 g of powder. As the mixing proceeds, a chemical reaction is activated, as a result of which a special substance is formed that "carbonates" the solution. For the manufacture of 2 cbm of aerated concrete, 1 cbm of solution is required. The composition acquires strength in a few hours - in this aspect it is no different from foam concrete. After that, the blocks are cut to the required dimensions and sent to the autoclave for final hardening.

Comparing materials, it is worth noting the difference in hygroscopicity parameters. The gas block has a great value in this parameter, which makes building a house on its basis a little more problematic, and the material itself requires additional external finishing.

You can distinguish blocks by appearance - the gas block is characterized by white color, and the foam block is gray, and its surface is rough.

The method of joining is different, and for each of the blocks - the edges are straight or tongue-and-groove for a reliable connection.

Prices and costs

Let's compare prices. In some situations, this is almost a defining parameter when choosing in favor of a particular block. The cost of aerated concrete is on average 20% more expensive than foam concrete, and the monolithic format is even cheaper.

From the standpoint of cost, foam blocks are more profitable, but the full construction of an object only from them is impossible. Better to choose combined option with supporting structures from aerated concrete and non-bearing elements based on foam blocks. The thermal conductivity of such a building will be at a high level, it will be warmer, stronger than one made of one material.

Application area

It remains to figure out how each of the materials under consideration is used. The structure of gas blocks is characterized by uniformity, they are lighter than other similar materials, frost-resistant and not afraid of fire. This allows them to be used in the construction of load-bearing walls and partitions in the private construction sector. When filling the frameworks in monolithic structures this is the most profitable and justified solution - from a technical and economic standpoint.

The foam block has a slightly higher weight, it has a longer service life. Strength indicators differ, determined by the ratio of ingredients during mixing. The foam block is relevant when arranging fences, partitions and load-bearing walls, provided that the height does not exceed 3 floors.

The advantages and disadvantages of each of the materials

Among the advantages of the foam block:

• Hassle-free production;
• The production cost is cheaper than that of aerated concrete;
• Laying using inexpensive cement;
• Installation takes a minimum of time.

As for the disadvantages, they are as follows:

• The faces of the blocks have no clear geometry;
• Variability of composition and concentration;
• Significant consumption of cement during installation;
• The structure being erected requires mandatory reinforcement.

The gas block offers the following advantages:

• Workmanship of the highest level;
• High strength;
• Resistance to influences and influences;
• Involvement on construction sites without restrictions;
• Only partial reinforcement is required.

Cons of gas blocks:

• Slightly more expensive;
• Large indicators of hygroscopicity;
• Harder to manufacture;
• Laying is carried out using construction glue.

The choice in favor of a specific type of blocks is determined by the construction conditions and the characteristics of the structure being built, as well as the preferences of a particular consumer and financial capabilities.

A fairly common question on the network - aerated concrete or foam concrete, which is better? Why does he care so much land owners who develop a project for a future house and decide on the choice of materials for its construction? How important is the difference between these very similar materials?

It should be noted right away that both aerated concrete and aerated concrete belong to the group of aerated concrete, that is, building materials that have in their structural structure many tiny air cavities that reduce the density and increase the thermal insulation qualities of blocks. They are united by the common concept of "gas silicates". Nevertheless, these materials still differ significantly from each other in their characteristics, which should be studied before deciding on any one.

To understand the differences between aerated concrete and foam concrete, first it is worth considering the technology of their production. The fact is that it is during the manufacture of the material that its specific qualities are formed.

Aerated concrete production

Aerated concrete is an artificially created mineral with a homogeneous cellular structure.

Due to their structure, aerated concrete blocks are exposed to a low weight, therefore, the construction of walls of a house or other structures may well be carried out without the involvement of lifting equipment. Blocks lend themselves well to processing, and, if necessary, reduce their size - the material is easily sawn hand hacksaw... In some cases, to speed up this process, a "grinder" or an electric jigsaw can be used.

The process of manufacturing aerated concrete blocks is as follows:

• Materials prepared in certain proportions (sand, cement, lime) are poured and mixed dry in a special mixer for 4 ÷ 5 minutes. Then a suspension of water-based aluminum powder is added there.
• In the process of mixing, lime enters into an active reaction with aluminum, as a result of which hydrogen is formed in a free state. Due to the abundant gas formation throughout the volume of the mixture, bubbles appear in the raw mass with a size of 0.5 to 2 mm, which are evenly distributed in the solution.
• The finished solution is poured into special forms preheated to 40 degrees. Pouring is carried out approximately ½ the volume of the mold container.
• After the solution is poured into the mold, it is sent to the ripening chamber, where the final pore formation occurs, as a result of which the mass in volume almost doubles and gains transport strength. To activate the reaction in solution and to better distribute the composition, the molds are subjected to vibration loads.
• After the solution has reached preliminary hardening, the resulting irregularities are cut from the surface of the hardened mass with the help of stretched wire strings.
• After pouring, the finished solid is sent from the ripening chamber to the cutting line.
• At the next stage of work, the hardened products are sent to the autoclave.

Aerated concrete is often denoted by the abbreviation AGB, that is, autoclaved aerated concrete, since its production is carried out using this equipment And the autoclave itself, figuratively speaking, is a kind of "pressure cooker" of large dimensions, in which a pressure of 12 atmospheres and a temperature of 185 ÷ 190 degrees. In such an atmosphere, aerated concrete blanks are kept for 12 hours.

• After ripening in an autoclave, the blocks are additionally separated, since during their processing they can join in some places.
• Further, finished products are packed in heat-shrinkable material or polyethylene - this is necessary to maintain a certain moisture content in the structure of aerated concrete before construction begins.

• The finished material can be stored until it arrives at construction sites for two - three years old.

Here it is necessary to clarify that aerated concrete is also produced not by autoclaving. In this embodiment, the solution is hardened in natural conditions, therefore, high-tech modern equipment is not required for the manufacture of blocks.

However, such material will not have the characteristics that autoclaved aerated concrete manufacturers claim. The shrinkage of the material during the operation of the built house will be 3 ÷ 5 mm / m, while the blocks that have been processed with the required temperature and pressure have indicators of only 0.3 ÷ 0.5 mm / m. If we compare the strength, then this parameter for autoclave blocks is 28 ÷ 40 kgf / m² against products made by the non-autoclave method, which have a value of 10 ÷ 12 kgf / m².

So when choosing aerated concrete blocks, it will never be superfluous to clarify by what technology it was produced.

Production of foam concrete

The production of foam concrete blocks is carried out using a simpler technology. However, to obtain a product with high performance, it is necessary to use quality materials.

Foam concrete, just like aerated concrete, has a homogeneous porous structural structure, which is formed by artificial creation in a mixture of air bubbles. This effect is achieved through the use of special substances that are part of the foaming agent.

There are two methods of making foam blocks - cassette and sawing. The cassette method involves pouring the finished solution into separate forms. And sawing technology, therefore, consists in the processes of filling with a mixture of one large capacity , and after it has hardened - cutting this resulting array into separate blocks of the desired size.

So, for the manufacture of foam concrete, cement of grades M 400 ÷ M500 is used, sand cleared of clay impurities, a certified foaming agent, calcium chloride and water. The foam concentrate mainly determines the quality of the foam, therefore, a carefully metered tested composition is used for the manufacture of blocks. Poor-quality foaming can not only slow down, but even completely stop the process of hardening of the finished solution. In addition, the composition of the foaming agent must meet the requirements of sanitary and hygienic standards, that is, it cannot contain toxic components.

The production process of manufacturing blocks by the cassette method includes the following stages.

• The first step is to mix the cement-sand mortar. Its preparation is not particularly different from mixing ordinary concrete.
• Further, a foaming agent is added to the concrete solution, after which the entire composition is well mixed until a homogeneous state. It is important to achieve the required air entrainment for good foam formation.

• In the next step, the foamed concrete solution is poured into molds under pressure.
• The hardening of foam concrete occurs in natural conditions, but the duration of this process, in contrast to ordinary concrete, is twice as long. It will take even several months for foam concrete to gain final strength. If curing takes place at temperatures below +10 degrees, then the process will take much longer. On the production line, blocks can only be removed from the mold after two to three days. To speed up the hardening process, calcium chloride is added to the solution in the amount of 1 ÷ 2% of the amount of cement used in the mixture.

The second version of foam concrete blocks, as well as aerated concrete, is produced by cutting or sawing. Cutting of finished foam concrete to linear dimensions is carried out using special equipment.

This version of the technology for manufacturing foam blocks has a number of advantages, which include the following:

• The edges and corners of the blocks have a clear geometry, without chips or flaws, thereby reducing labor costs for their "commodity" processing.
• Perfect geometry makes masonry work easier when building walls.
• There is no lubricant on the surfaces of the blocks, which is used to lubricate each of the forms when concrete is poured into them. This approach significantly improves the adhesion of the material with the masonry mortar, as well as with the finishing material.
• It is possible to cut blocks different parameters, since the equipment can be adjusted to the required step.

It is these factors that contribute to the fact that many manufacturers are switching to this technology for the production of foam blocks.

So let's emphasize a fundamental difference in manufacturing aerated concrete and foam concrete:

- Aerated concrete - the porous structure is ensured by the active release of gas caused by a started chemical reaction. The formed gas tends to get out to the surface, "punching its way", which determines the open, non-isolated nature of the cells. The increase to the specified volume occurs after filling out the forms.

- Foam concrete - the porous structure is provided by the light formation of foam with the entrainment of air (something similar happens when using soap or detergents). The bubble turns out to be isolated from the "neighbors", that is, it is created closed-cell air-filled structure. The solution immediately reaches the required volume, and after pouring into the molds, it may sag somewhat rather than rise.

Characteristic features of materials

In this section, we will try in comparison to consider the features of materials due to the specifics of their production, and talking about some of their advantages and disadvantages.

• To begin with, about the quality of the products themselves. Of course, you cannot sign for all x manufacturers, and for all consignments of material, but nevertheless ...

The production of aerated concrete blocks in most cases is carried out at the factory, since this process requires special equipment. Therefore, the production technology is being monitored.

Foam concrete products can be produced both on high-tech equipment and in almost artisanal conditions. Naturally, very often there is no proper control over how the solution is made, what material is used to mix the mixture, they are not kept established by technology maturation time of foam concrete.

• Density of materials... The structural density of aerated concrete and aerated concrete is classified by the material grade. For both materials, this parameter ranges from 300 to 1200 kg / m³.

It must be remembered that the higher the density of the material, the lower its thermal insulation qualities, respectively, the higher the thermal conductivity. The density of thermal insulating gas silicates does not exceed 600 grade. Next come thermal insulating and structural and structural block products. High density structural blocks are manufactured for special purpose facilities.

• Strength for compression... The strength of foam blocks can vary and amount to 0.75 ÷ 12.5 kg / cm², while for aerated concrete this indicator is in the range of 1.5–3.5 kg / cm². the specific value depends on the density grade.

Aerated concrete has the same strength throughout the block. And foam blocks can also have an inhomogeneous internal structure - due to the uneven distribution of the foaming agent when mixing the solution. Both materials have low flexural strength. Therefore, if they are chosen for building a house, special requirements are imposed on the reliability and stability of the foundation base - it is necessary to prevent uneven shrinkage of the structure.

• Maturation (strength gain)... Aerated concrete. due to the peculiarities of the chemical composition and autoclave treatment, it reaches maximum strength already at the first stages of manufacture. But with the storage, as well as the operation of the erected walls, it becomes lower.

Foam concrete gains the required strength after 28 days from the date of manufacture - this factor is very important for the start of construction work. To be sure that the material has good strength, it is recommended to purchase blocks in advance, a month before the start of construction, and store them on site. Walls built from fresh aerated concrete not gaining strength, after construction, they will give significant shrinkage and may crack. If the house is built of foam blocks that have already gained the necessary strength, then it will increase during its operation - the older the walls of this material, the stronger.

• Block sizes

It is impossible to say unequivocally about the sizes of both one and the other blocks, since each manufacturer can produce them in different linear parameters. Although there are certain standards. For masonry external walls most often blocks of 200 × 300 × 600 mm are used, and for internal partitions - products with dimensions of 100 × 300 × 600 mm.

By the way, the assortment is not limited to thicknesses of 200 and 100 mm. Other sizes of standard blocks are shown in the table below.

Linear parameters of blocks, mm	Number of blocks in 1 m³, pcs	Number of products on a pallet, pcs
100 × 300 × 600	55	80
120 × 300 × 600	46	64
150 × 300 × 600	37	48
200 × 300 × 600	27	40
250 × 300 × 600	22	32

The mass of products made of foam concrete and aerated concrete is practically the same, and the weight differences of the blocks depend on the grade of the material. The table below shows the weights of standard wall and partition units for reference:

Block sizes, mm	D300	D400	D500	D600	D700	D800	D900	D1000	D1100	D1200
200 × 300 × 600	11.7	15.6	19.4	23.3	27.2	31.7	35.6	39.6	43.6	47.5
100 × 300 × 600	5.8	7.8	9.7	11.7	13.6	15.8	17.8	19.8	21.8	23.8

To know the exact dimensions of the material, they must be inquired from a manufacturer who it is planned to purchase building materials. In addition to the sizes indicated in the table, other options can be manufactured. Accordingly, the weight of block products will also depend on the linear dimensions.

• Quality and precision of linear shapes... Materials made by cutting or sawing have more accurate dimensions - this applies to both foam blocks and aerated blocks. This quality makes it possible to reduce the thickness of the masonry joint to a minimum, literally down to 2-3 mm. A very useful quality, since the masonry joints become cold bridges, since the mortar has much more high coefficient thermal conductivity.

• Moisture absorption ... Due to the fact that aerated concrete has a structural structure with open pores, it is a hygroscopic material, that is, it absorbs moisture well. Unlike aerated concrete, foam concrete absorbs moisture 8 ÷ 9 times less.

So if two materials are immersed in water for a while, then aerated concrete will absorb moisture by 45 ÷ 47% of the total volume of the block, while foam concrete will be moistened by no more than 5%. This method can be used to determine exactly what material the seller is offering, since at first sight sometimes it is impossible to determine what it is - aerated concrete or foam concrete.

Aerated concrete will become much heavier, foam concrete will practically not change its mass. Naturally, it will be difficult to check the material in a retail outlet, therefore, in order to check the seller's honesty, it is worth buying one block, placing it in water at home, leaving it for a day, and then chopping it. If it is aerated concrete, then it will be soaked in water half the depth of the block. Foam concrete will get wet no more than 15 ÷ 20 mm.

With a sharp change in the weather, for example, if after long autumn rains, which saturate the aerated concrete with moisture, the temperature drops sharply, the moisture in the structure of the material will turn into ice. As a result, the unprotected structure can become covered with small cracks. And such damage is quite capable of becoming "the beginning of the end", that is, erosion and destruction of the wall.

Therefore, a house built of aerated concrete must be covered with a plaster layer immediately after the masonry mortar has set. This finish should protect the wall surfaces from moisture penetration.

• Porosity of materials... Active moisture absorption aerated concrete is explained by the fact that the pores of the material remain open. Often its surface resembles a sponge when cut. Closed pores form in foam concrete, which makes the material hydrophobic, and if it is immersed in a container with water, it will stay on the surface for a long time like a float.

• Thermal conductivity.With the same brand of block products, they have different thermal conductivity. So, aerated concrete is more effective thermal insulation than foam concrete. For example, for a house that is planned to be erected in central Russia, the thickness of the walls (if you do not use other thermal insulation layers), built from D 500 blocks of aerated concrete - 450 mm will be sufficient, but from foam concrete it should have a thickness of at least 600 mm.
• Water vapor permeability.A high level is typical for both types of gas silicate, but still it is not the same. Water vapor permeability contributes good air exchange in the premises of the house, as a result of which a favorable environment is not created on the inner surfaces of the walls for the appearance of fungal or mold colonies.

Aerated concrete has a higher permeability. When building a house from foam concrete blocks, it is necessary to provide effective system ventilation, since the vapor permeability index of this material is slightly lower.

This comparison table shows the absolute various parameters aerated concrete and foam concrete. Guided by them, you can determine which of these materials is more suitable for building a house:

Parameter name	Aerated concrete	Foam concrete
Foaming components	Finely dispersed aluminum and lime.	Wood-saponified resin classified as moderately hazardous.
Manufacturing methods	Slicing blocks	Cassette and rifled
Place of manufacture	Factory production only	Factory or handicraft production
Structural structure	Uniformly porous with open, uniform pores.	Inhomogeneously porous with closed pores, with a range of their sizes.
Density of material, kg / m³	200 ÷ 1200	200 ÷ 1200
Compressive strength, for grade D400, MPa	2	1.2
Strength gain time from the moment of manufacture	Immediately, when solidified	Not less than 28 days after production, followed by a permanent set of strength.
Frost resistance, cycles	25	35
Thermal conductivity coefficient W / (m K)	0.1 ÷ 0.19	0.2 ÷ 0.36
Moisture absorption,% per day of constant contact with water.	Up to 47%	0.05
Accuracy of linear dimensions	Minimum errors	When sawing a whole one-piece cast block, there are minimal errors; when manufacturing by a cassette method, significant flaws in the "geometry" are possible.
Shrinkage of masonry, mm / m2	0.5	2 ÷ 3
Water vapor permeability, mg / m × h × Pa	0.16 ÷ 0.23	0.9 ÷ 0.11

Requirements for masonry materials and surface finishing

In addition to the characteristics of each of the materials, it is necessary to have information about the features of the construction of walls and partitions from blocks of foam and aerated concrete.

• Requirements for the foundation of the structurebeing built as from foam concrete and aerated concrete, are the same, since both materials are lightweight. However, the base under the walls must be strong enough, especially what hygroscopic aerated concrete, even covered with a plaster layer, becomes almost twice as heavy at high air humidity, which increases the load on the foundation. Although foam concrete does not significantly change its weight when wet, it, like aerated concrete, rather fragile material, so a reliable basis for it will not be superfluous either.

The horizontal surface of the foundation must be covered with a waterproofing layer. So you can protect the masonry material from the capillary ingress of moisture into it from the side of the concrete base, which is in direct contact with the moist soil. As a waterproofing, the well-known roofing material is most often used, laid on inflicted bituminous mastic on the concrete surface.

• Cutting, drilling holes, slittingcellular materials are produced in the same way - cutting can be carried out using a conventional hand saw, and drilling holes using a drill and a drill-crown of the required diameter. Due to the fact that the material is porous, the cutting process is quite easy.
• Building construction speed.Both materials are lightweight and linear parameters - significantly exceeding the size of a brick. In addition, the surfaces of the blocks have a sufficiently high adhesion so that the walls can be raised quickly. Especially in cases where the work will be carried out with the assistance of assistants.

• Mortar for masonry blocks. For aerated concrete masonry, ordinary concrete mortar or special masonry glue can be used. Aerated concrete is put on an adhesive mixture specially designed for this material - this will help to significantly reduce the consumption of the solution, since a seam of 3 ÷ 4 mm will be enough to fasten the blocks.
• Construction site conservation. If necessary, stop work on building a house on winter period, the object is preserved. Moreover, the walls of foam concrete will stand this period without compromising their strength, while aerated concrete must be covered with a waterproof film so that the material does not even absorb atmospheric moisture from the environment. It is also necessary to clarify here that aerated concrete during the conservation of a construction site requires protection from moisture at any time of the year. But the greatest damage can be caused to the material by autumn rains, a sharp drop in temperature, as well as spring melting of snow.

• Holding fasteners. Both materials require a special approach in this matter. However, dfor porous building materials today in specialized stores you can find a wide range of special screws, hardware, " chemical anchors »And other fastening options.
• Finishing materials for porous surfaces. Plaster solutions, lining, siding, etc. are used to decorate facades built of gas and foam blocks. In this issue, with the correct layout of the "facade pie", there are no restrictions.

• Insulation materials.Due to the porous structure of these materials, they themselves are very good heat insulators. Therefore, in many cases, additional insulation of the walls of the house is not even required. However, if such a need nevertheless arises, for example, a house is being built in a region with cold winters, then a heater is used for thermal insulation. And for external insulation it is best to use basalt mineral wool, which has excellent vapor permeability.

• Plaster mixes.Not all materials will work here. For finishing porous materials, special plaster mixthat maintain their high level of breathability. With aerated concrete surfaces, such mixtures have good adhesion, but before applying them on foam concrete on the wall surface is fixed with a reinforcing mesh, which ensures a higher adhesion of the mortar to the smooth surface of the blocks.

What and how are the walls made of gas silicate blocks plastered?

This work requires special care. as plan preparation of surfaces, and in the choice of plaster and adherence to the technology of its application. More details can be found by following the link to the article of our portal.

The cost of gas silicate building materials

An important issue is the price of building materials. It is quite understandable - any future owner of a house, when building it, is trying to find the most acceptable option, that is optimal ratio "price quality ".

Therefore, you need to know that aerated concrete will cost on average 20% more expensive than foam concrete. The latter is a more affordable material, since its production is not so complicated and energy-consuming, and does not require high-tech equipment. However, due to the possibility of producing foam concrete even in "garage" conditions, with all the necessary components, very a large number of handicraft materials. Accordingly, such products do not have all the qualities of blocks manufactured in compliance with the technology in the factory.

When calculating the cost of materials for building a house, it is necessary to immediately take into account not only the price of the blocks themselves, but also the cost of the components of the solution or the finished mixture, the consumption of which will directly depend on the quality of the block products. In addition, when using foam blocks, you may need a steel mesh to reinforce the wall surfaces, and for aerated concrete - waterproofing materialsso that you can create a weather protection at any time. Only by calculating everything necessary for the construction, it is possible to determine exactly which of the materials will cost less.

Now, knowing the quality of both materials and taking into account the peculiarities of the local climate, you can choose the option that is more suitable for specific operating conditions.

And to determine the required number of gas silicate blocks, the calculator below may help many.

When there is talk about aerated concrete and foam concrete blocks, it is often possible to face 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 aerated 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, 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 the 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 the usual cement mortar. The 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 hardening, they make it much easier, adding heat-insulating and sound-insulating properties.

Such a process can be carried out directly at the construction site, since special and high-tech equipment is unnecessary. Due to the shapes that are 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 needed, as well as a special component - aluminum powder, due to which bubbles are formed that fill aerated concrete. The process of solidification of the mixture occurs in autoclaves with sufficient 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 volume. The same cannot be said about foam concrete, which, when frozen on the street, can 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 shapes are often used that are not able to ensure accuracy and evenness.

Such processing allows aerated concrete blocks to have a number of other advantages over foam concrete, which will be discussed below.

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 that it will be easier and more convenient in construction. By the way, it is believed that foam concrete can shrink and microcracks 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 finishing.
2. Aerated concrete blocks have the best vapor permeability... The whole point, again, in 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 allows moisture and air to pass through better, and the microclimate in such a house will be much better than if you use foam concrete, which allows air to pass through much worse. That is why, if you decide to insulate a wall of aerated concrete blocks, it is better to use breathable materials so as not to negate all the advantages of aerated concrete. And foam concrete blocks can be insulated with foam plastic in order to reduce the cost of work.
3. Now about thermal conductivity... It is believed that aerated concrete and aerated concrete are capable of providing approximately equal thermal insulation performance. But if you look into some of the details, you can understand that the thermal insulation of foam concrete does not always meet the values \u200b\u200bdeclared by manufacturers. The fact is that the pores in foam concrete, as a rule, are of different sizes: they can be 1 mm, and maybe 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 in conditions of high air 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. And you will also have to spend money on more powerful wall insulation. Although there are many experts who can argue with this fact.
4. Aerated concrete blocks are often called environmentally friendly material - this is really so, because nothing is used in production except natural materialswhich have already been mentioned above. In the production of foam concrete blocks, synthetic foaming agents can be used, which cannot be called environmentally friendly. Here we cannot fail 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 aluminum goes to react with lime, as a result oxygen is released and aluminum oxide is formed: oxygen is needed to form pores, and aluminum oxide is harmless and is found in most building materials, even in clay. And the aluminum oxide itself in aerated concrete is less than in foam concrete and in brick. And here not everything is unambiguous: there are opinions that aluminum still remains in the material, not being completely consumed in the reaction, but still we remain with 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 fix such irregularities, much more mortar will be needed.
6. Mounting aerated concrete blocks will cost you relatively less than aerated concrete. This is due to the fact that glue is used for laying aerated concrete, and its thickness is much less than the thickness cement mortar for foam concrete (2 mm versus 1 cm). Even taking into account that the glue is 2-3 times more expensive than cement, and its consumption will be about 6 times lower, we get savings, not to mention 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 processingThis is largely due to the fact that they have excellent geometry.

Advantages of foam concrete over aerated concrete

findings

From everything written above, it follows that in some characteristics, foam concrete and aerated concrete blocks are similar, while foam concrete is cheaper. Thus, foam concrete can 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 than foam concrete: largely due to the production technology. And besides, if you count all the waste on installation, then building from aerated concrete blocks may not be more expensive than building from foam concrete blocks. Everyone should make the final choice before starting construction, but in most cases the use of aerated concrete blocks remains justified.