Hidden problems and reviews from owners about houses made of aerated concrete blocks. Pros and cons of houses made of gas silicate blocks Gas silicate blocks pros and cons installation of partitions

IN last years private developers, to reduce the cost and speed up the process, use a relatively new material for Russia - gas silicate. Is it suitable for capital construction? To make a choice, you should ask the opinion of those who built from gas silicate blocks own house or is a specialist. Reliable information from practitioners - best source information.

Developer reviews

Victoria, Yaroslavl.

“I bought gas silicate blocks from a reliable manufacturer and laid everything according to technology, so I can’t complain about the material. My two-story cottage It’s been standing for 5 years now – there are no cracks or subsidence. The walls were erected from D400 gas blocks, placed on glue mixture. The façade was puttied over a mesh, and a belt of concrete was made after the first floor.”

Ivan Dorofeev, Ufa.

“I will object to those who say that lime in gas silicate corrodes steel reinforcement. After autoclave treatment, only neutral calcium silicates remain in the material - they do not cause corrosion, and there is no need for polymer reinforcement. And the fact that blocks without cladding are destroyed is true.”

Grigory Stepanov, Kursk.

“I read reviews about gas silicate and decided to make an extension out of it. I spent a long time choosing a manufacturer and settled on Yutong: their blocks match the declared density, have good geometry, and have a certificate. Just in case, I checked for radiation with a dosimeter. During laying, I measured the gas blocks with a square so that the wall would not turn out skewed. With an extension height of 2.5 m, the difference was only 0.5 cm.”

Dmitry, Moscow.

Main block types and costs

The starting material for gas silicate blocks is an aqueous solution of lime and sand, foamed by adding active additives - aluminum powder or dusted magnesium. It is poured into molds, where it gains plastic strength up to 1 kg/cm2. Further possible natural drying or autoclave treatment under pressure of 12 atm at a temperature of 175-185 °C.

The length of gas silicate elements is 600-625 mm, width – 250-300, thickness – 100-400. Strength class varies from B 1.5 ( permissible load 15 kg/cm2) to B 3.5 (35 kg/cm2). According to their intended purpose, gas silicate blocks are divided into 3 groups (the marking indicates density, kg/m3):

• structural – D1000 – D1200;
• structural and thermal insulation – D500 – D900;
• thermal insulation – D300 – D500.

Autoclave blocks made of high-density gas silicate are more expensive, but, as reviews from developers confirm, their strength is much higher. From them you can build not only a bathhouse or a garage, but also a house for all-season living. The cost also depends on the brand and the perfection of the technology. Average prices for D500 gas silicate blocks in Moscow are shown in the table.

Advantages and disadvantages

Products made from foamed sand-lime mortar have both pros and cons. Compared to brick, masonry is produced at a faster pace due to the large dimensions of the elements. With the help of gas silicate blocks it is convenient to construct not only the building frame, but also carry out redevelopment. For internal walls, they are simply irreplaceable - they are affordable and do not put too much strain on the foundation.

The porous structure makes gas silicate a good sound and heat insulator. Here's an example: when building a house from aerated block D500 in the Moscow region, it is necessary minimum thickness 380 mm (according to regulatory documents in the field of building heating engineering). Brick construction under the same conditions it should be no thinner than 640 mm.

Gas silicate is fire resistant: it does not support combustion for several hours. Walls made of aerated blocks are vapor-permeable, which ensures stable moisture exchange in the room. The relatively affordable price also makes a significant contribution to the popularity of the building material.

Experts also draw the attention of developers to the numerous disadvantages of gas silicate. Main disadvantage blocks - their instability to moisture, which can penetrate into the pores both from the outside and from the inside. In addition, gas blocks are characterized by low bending strength - this is the downside of not high density material. Due to hygroscopicity and fragility, other negative properties gas silicate.

• High degree of shrinkage. To avoid cracking of the blocks, it is necessary to lay a powerful monolithic base - strip or slab. Reviews from builders claim that throughout the year interior plaster You can’t do this: it will crack due to shrinkage. To speed up the finishing process, it is better to choose drywall and wallpaper.

If a two-story house is being built, an intermediate reinforcing belt of reinforced concrete is made to distribute the load so that the lower tiers of gas silicate blocks do not collapse. In addition, reinforcement must be installed every 3 rows of masonry.

• Deformations. When saturated with moisture, the blocks lose strength and crack even more. According to reviews from builders, it is not advisable to plaster gas silicate on the outside: this increases humidity. To extend the life of the walls, the cladding is made of siding or lining, maintaining a ventilation gap. To attach such a finish, you need special dowels that are not subject to corrosion.
• Low frost resistance. It is only 15-20 cycles - this is how many cold seasons gas silicate is designed for. Window slopes 0.4 m thick, saturated with moisture, completely freeze. According to reviews, the temperature on them is lower than specified in the standards. The use of gas blocks without insulation increases heating costs, and the installation of thermal insulation leads to a significant increase in construction costs.

According to reviews, houses made of gas silicate are comfortable, warm and reliable if the disadvantages of gas blocks are taken into account and neutralized:

• do not build a building more than 2 floors;
• insulate the walls and create conditions for their ventilation;
• strengthen the base and masonry;
• use special glue, not a solution, so as not to create cold bridges;
• choose suitable look interior and exterior decoration.

We can conclude: the construction of a gas-block residential building requires additional costs and does not lead to the expected savings. Do not forget that gas blocks are very fragile: you need to buy them with a margin of 5-10%.

The construction estimate, required for the construction of private housing, shows that 50% of the cost of building materials is load-bearing walls and partitions. Therefore, developers try to choose a material that is cheaper, but with high performance characteristics. And gas silicate blocks with their low thermal conductivity coefficient and low production costs make building a house attractive and in demand. Having an idea of ​​the advantages and disadvantages of this building material, you can largely avoid negative aspects, affecting the durability of operation and the quality of housing.

The main reason why gas silicate is a leader in individual construction– its low cost. Also important role The speed and ease of laying products into a specific design plays a role. Practice has shown that 1 m2 of surface made from blocks costs half as much as the same area made from ordinary brick, even taking into account the fact that gas blocks can be produced in complex geometric shapes.

Gas silicate belongs to a subtype of cellular concrete, which is produced using an autoclave ( industrial production) or manually (at home) from the following components:

1. Portland cement and quicklime;
2. Siliceous aggregate;
3. Aluminum powder;
4. Water.

Lime serves as a catalyst in the reaction with aluminum to foam the mixture, during which the released hydrogen forms many tiny bubbles in the mass. In industrial autoclave production, this reaction is followed by steaming the mold into which the working mixture is poured, and then the solution is left to harden. This produces highly porous gas silicate concrete. Finished dimensional and molded products are obtained by cutting the plate into blocks of given dimensions: length ≤ 600 mm, thickness ≤ 250 mm, height ≤ 500 mm. Based on density, the material is divided into the following subtypes:

1. Structural products having a compressive strength ≥ D700. They are used in construction load-bearing walls and internal partitions;
2. Structural and thermal insulation products with strength grade D500-D700. Used for the construction of partitions and any walls in low-rise buildings;
3. Thermal insulation blocks with strength grade D400. For the construction of new walls and insulation of the constructed facility;

Aerated blocks are most often in demand in individual housing construction, since it is recommended to use them to construct low-rise buildings. But as insulated objects, premises made of gas silicate bricks are built into multi-story buildings or combined industrial construction projects.

Calculation of the number of gas silicate blocks

The sizes of the blocks are adjusted to existing standards of building materials and, taking into account the thickness of the mortar layer, correspond to a multiple of the brick sizes. Therefore, calculating the required number of products for building a house is not difficult, quick and simple. To do this, you do not need to use special programs or order the services of an architect. Standard size – 60 x 300 x 200 mm. Based on these figures, we obtain the volume of one product - 0.036 m 3. There will be 29 gas silicate products in 1 m3.

The dimensions of load-bearing walls and partitions are indicated in the project, and how many units will be needed is easy to calculate. From the result you need to subtract the area of ​​windows and doors, and therefore multiply this figure by the width of one product. This is how the volume of gas blocks for any walls is calculated in m3. It remains to divide the total volume by the number of products in 1 m 3, and you will get the required result. Don't forget to add 15-20% for chips, surface defects and damage during transportation and installation. Also, in order to make dressings when laying gas silicate products, you will need to saw them, and this can be done with an ordinary hacksaw or grinder. You can hammer the blocks with a chisel or a hammer drill.

It takes about 20 minutes to lay 1 m³ of a wall made of aerated silicate bricks, and up to 5 hours to lay 1 m³ of brick. This speed of operation is ensured by the larger sizes of the blocks compared to bricks, exact dimensions(deviation when sawing is 0.3-0.8 mm), and laying with special glue, and not with cement-sand mortar. Also, adhesive for gas silicate has thermal insulating properties, and its use eliminates the appearance of “cold bridges”. Even taking into account the high cost of this composition, its consumption is much less than the consumption of the solution, so masonry is cheaper.

The outer surfaces of the walls of a house made of gas silicate blocks must be insulated and isolated from moisture penetration. At the same time, the wall must “breathe” so that in the house and between the layers of thermal insulation and waterproofing materials no condensation formed. Polystyrene foam, polystyrene foam or sand- cement mortar They do not allow air to pass through well, and their use for insulation is not recommended. Most suitable material for finishing and insulation is gypsum or alabaster plaster, as well as decorative Decoration Materials– siding, plastic (lining), facing brick (clinker). Mineral wool is used as insulation, and membrane materials are used for waterproofing.

The most popular siding: it can be mounted on metal carcass immediately after the construction of the walls, without waiting for the house to shrink. Usage facing bricks makes building a house a little more expensive, but increases the thermal insulation of the walls. If the walls are not covered with plaster, using the dry method, then between the wall and decorative material must remain air gap 5-10 cm.

To avoid purchasing and installing insulation, the walls must have a thickness of at least 0.5 m. That is, the developer will have to separately calculate whether it is more profitable to purchase more gas blocks or to make thermal insulation.

Continuing the topic of building materials based on concrete and various additives, we will analyze such a popular material as gas silicate blocks. Many advantages, as well as versatility of use, have brought this material highly popular in many regions of the world, including in our country.

The blocks are based on high-quality cement, gypsum, lime and water. All these materials are mixed together, after which aluminum powder is added to the solution. The latter reacts with lime, causing the release of gas and the composition is filled with small pores. Modern technologies allow you to adjust the size of the pores.

After mixing the material, pouring it into molds and cutting the latter, the blocks are sent to autoclaves, where they undergo the final strengthening and impart those performance characteristics for which gas silicate is valued. However, there is also a non-autoclave production method, but in this case gas silicate blocks are less durable and less environmentally friendly.

Advantages of gas silicate blocks

• The gas silicate block has high compressive strength. This is a reliable building material that will allow you to obtain strong load-bearing or interior walls. Naturally, we are talking about load-bearing structures in low-rise construction;
• Ease. Aerated concrete is five times lighter than conventional concrete and has high strength. Light weight not only facilitates construction, but also makes it possible to save time and money on the construction of a massive foundation;
• The material is 8 times superior ordinary concrete on thermal insulation properties. IN winter time you will spend less resources on heating even if you save on wall insulation during construction;
• The porous structure makes the gas silicate block an order of magnitude more effective sound insulator than brick;
• Such blocks are mainly manufactured by highly qualified professionals. So the quality of the product is usually very high. The deviations are minimal, so when correct masonry, the walls will be as smooth as possible;
• For rodents, gas silicate blocks are of no interest;
• Large sizes allow you to build walls much faster than with brick. At the same time, you can work independently. By following a number of simple rules, you can build a structure from these blocks without much knowledge in construction;
• The material is completely environmentally friendly and is not subject to fire;
• High vapor permeability allows for complete gas exchange, creating a pleasant microclimate in the premises.

Disadvantages of the material

• Hygroscopicity, as is the case with other options for cellular concrete, is very high for gas silicate blocks. Having absorbed a lot of water, such a block becomes susceptible to destruction, loses its performance characteristics, and also provides the fungus with an excellent environment for reproduction. As a result, additional waterproofing measures are required;
• Low strength. When attaching heavy structures to walls, it is necessary to use special dowels;
• Mediocre frost resistance, which also increases the cost of protective measures;
• Shrinkage of these materials can be quite significant. For this reason, every three to four rows it is better to use reinforcing mesh or reinforcement. Otherwise, the walls may crack over time;
• As with all porous concretes, thermal insulation properties fall with increasing strength characteristics.

Glue or cement?

Laying of gas silicate blocks is done either with a standard cement-sand mortar or with specialized glue. What to choose? First of all, it is worth noting that both fastening substances have a higher thermal conductivity than the gas silicate blocks themselves.

On the cement side the cost is several times lower. The disadvantage is the large thickness of the layer, which increases the width of the cold bridges. The glue allows the blocks to be almost end-to-end, which is very good. However, to lay the first layer of blocks directly on concrete base Cement mortar will still be needed, as it will allow for the necessary leveling in this case.

Technology for laying gas silicate blocks

We will describe the construction of a foundation, which can be strip, in more detail in another article, since this topic is very large. As for the actual laying of blocks, the first row is placed on concrete mixture from the highest corner of the foundation. If necessary, we make additional adjustments using a solution. Use levels.

• Important! High ability The ability of the gas silicate block to absorb water must be taken into account when installing the first row of blocks on the solution. To prevent moisture from the latter from being absorbed into the block, the lower part of the block is wetted with water before installation on the concrete support.

All other rows can be laid with special glue. In this case, every three or four rows the walls should be reinforced in order to reduce shrinkage.

• Precast concrete slabs cannot be laid directly on this type concrete blocks due to their insufficient strength. In this case, it is necessary to build a reinforced concrete belt around the perimeter of the wall, made using the technology monolithic construction. When constructing two-story or more tall buildings reinforced concrete supporting structures are required. In addition, reinforced concrete belts require thermal insulation;
• The strength of the block is one of the determining factors. If you are building a one-story structure, you will need a block with a density of at least half a ton per cubic meter. If we are talking about the construction two-story houses, then you need to choose options of 600 kilograms per cubic meter. We have already said that as strength increases, the insulating qualities are lost, so walls made from such a block must have a minimum of 40 centimeters in thickness. Otherwise you will need additional insulation. It is impossible to build a base from such blocks;
• Chips and other damage to the blocks are not allowed. Since the material is fragile, it must be transported, stored and handled carefully. Try to buy more blocks than necessary, as some may get damaged. Blocks need to be cut special tool and as carefully as possible.

Gas silicate was invented as an alternative to concrete and brick. The main goal of the developers of the new building material there was a reduction in the cost of construction of buildings without loss of strength characteristics of load-bearing and not load-bearing structures. Manufacturers of gas silicate blocks position them as one of the best building materials for low-rise buildings. However, the practice of its use shows that the gas silicate block also has its pros and cons.

What is a gas silicate block

Gas silicate block is a building stone intended for laying walls, supports and partitions. It is made from cellular gas silicate concrete, the peculiarity of which is the absence of cement in its composition. The binder function is performed by a mixture of lime and quartz sand in a ratio of 0.62:0.24.

The production technology is simple:

1. Measure out the required amount of lime and sand.
2. Sift on a vibrating sieve.
3. The listed ingredients are finely ground together in a ball mill.
4. Add water.
5. Aluminum powder is added, which acts as a gas former.
6. The resulting mixture is poured into molds, filling each of them by ½ volume.
7. Maintain for two hours at a temperature of +40°C, waiting for completion chemical reaction, during which hydrogen is formed.
8. Place the blocks in an autoclave, where they remain for 12 hours at a pressure of 0.8–1.3 MPa and a temperature of up to +200°C.
9. The blocks are removed using a dividing crane and laid for further hardening and gaining brand strength.

The resulting material is a porous stone with the following technical characteristics:

• dimensions of voids (cells) – 1–3 mm;
• density - 200–1200 kg/m 3 (corresponding to brand: D200-D1200);
• thermal conductivity - 0.11–0.16 W/°C*m2.

Frost resistance deserves special attention. For blocks of brands D200-D400 this indicator is not standardized. Building stones with a density of 500–600 kg/m3 can withstand up to 35 freeze-thaw cycles without loss of strength and other characteristics. The frost resistance of blocks of higher grades (D700-D1200) corresponds to F50-F75.

Outstanding technical performance is due to the porous structure of the material

Application area

Residential and non-residential buildings are erected from gas silicate blocks. Construction technology involves the use of stones of different densities for specific purposes:

• D200-D350 - structural insulation.
• D400-D600 - masonry material for the construction of load-bearing and curtain walls in low-rise construction.
• D700-D1200 - masonry material for the construction of high-rise buildings, subject to reinforcement in every fourth row.

Gas silicate allows you to significantly save on space heating

Difference from aerated concrete

Gas silicate and aerated concrete blocks are materials of the cellular concrete class. They have a lot in common in properties and technical specifications, are used for the same purposes. All this creates confusion in the classification of these materials, and due to the external similarity, even experts cannot accurately determine which block is in front of them: gas silicate or aerated concrete.

For internal partitions, a structural and thermal insulating type of material is suitable

But there are significant differences between them. First of all, this is the composition and method of production. There are other differences that can be found in the table.

Differences between gas silicate and aerated concrete

The dimensions of gas silicate blocks are standardized by GOST 31360–2007. All enterprises specializing in the production of cellular concrete adhere to accepted recommendations. But this does not exclude the possibility of producing building stones according to custom sizes customer.

Standard block parameters

The selection of objects for construction is carried out based on the pros and cons of gas silicate blocks.

pros

The undeniable advantage of gas silicate is its low thermal conductivity. This property is due to the porosity of the material. It consists of large number hollow cells filled with air and having an irregular spherical shape. They are the best heat accumulator. The principle of insulation of buildings and communications is based on this property of air. fibrous materials (mineral wool in rolls and slabs).

Gas silicate has other advantages:

• High accuracy geometric parameters products. According to GOST 21520 89, there are three categories of accuracy, each of which allows small deviations: in height - 1–5 mm, in thickness and length - 2–6 mm. Using even, equal-sized stones in masonry allows you to save on binders: cement-sand mortar or glue.
• High rates of vapor and air permeability, corresponding to similar parameters of most types of wood. In this regard, gas silicate can be called a “breathing” material.
• Environmental safety due to the absence of components harmful to human and animal health.
• Fire resistance, allowing the use of gas silicate blocks for the construction of fire barriers. In a building made from this material, the fire spread limit is 0.
• A light weight. The mass of the block depends on its density and geometric dimensions. The weight of a standard stone 625x300x250 with a density of 400 kg/m 3 is 17 kg; density 1200 kg/m 3 – 28 kg. A low-rise building made of gas silicate blocks does not require a powerful foundation. In most cases, private developers choose between shallow-depth tape (MZLF) or slab. But with the construction of the foundation, not everything is so simple, as will be discussed below.
• Flexibility in processing. Blocks of cellular concrete can be sawed with a regular hacksaw. Nails and screws are screwed into them easily. All this greatly facilitates construction and finishing work.
• They do not attract rodents and insects and are not damaged by them.

Has the least weight thermal insulation type gas silicate blocks

Minuses

Private developers often express negative opinions about gas silicate and aerated concrete and report on their experience in building and operating houses from these materials. Based on the reviews, we can draw conclusions about the inherent shortcomings of these blocks.

Hygroscopicity

Gas silicate has one significant disadvantage that can minimize and negate all the advantages of this material: a high degree of hygroscopicity. It identifies many problems that arise during the construction and operation of houses.

The moisture permeability of porous stones is due to the presence of air in them. It is able to penetrate into the smallest cracks and fill them. The moisture contained in it is absorbed by a mixture of sand and lime (components of the gas silicate composition). Aerated concrete is also exposed to the same danger, since the presence of cement in it is not a barrier to the penetration of water into the structure of the block.

We draw conclusions: a wet block is a cold block. Consequently, the thermal characteristics of the material declared by the manufacturer correspond to the conditions of its operation: at low or normal humidity air.

In reality, this cannot be achieved, since a natural phenomenon - precipitation in the form of rain and snow - will always increase the level of humidity in the atmosphere surrounding the house. In addition, this indicator is inevitably affected by the proximity of bodies of water: rivers, ponds, pools.

To confirm the information presented, one of the recommendations regarding cellular concrete can be cited.

According to clause 1.7 of the “Reference Guide to SN and P for engineering and technical workers of scientific research and design organizations» cellular concrete, including gas silicate blocks, are classified as non-moisture-resistant and non-bioresistant materials that are not recommended for the construction of walls in rooms with damp and wet conditions.

Beams can be used to protect external walls

Fragility

For all its advantages, gas silicate has low bending strength. This causes the fragility of the blocks and the appearance of cracks in walls and partitions. The lack of elasticity makes gas silicate structures responsive to the slightest deformation.

Practice shows that houses higher than three floors are not built from this material. For construction high-rise buildings high-density blocks are required: from D700, which have lower thermal insulation characteristics. The cost of construction increases significantly, as the cost of purchasing more expensive blocks, heat and waterproofing materials increases.

But even a three-story building requires a high-quality foundation made of heavy concrete. Moreover, it is important that the foundation of the house has a high bearing capacity and had a perfectly flat, horizontal surface. In this case, the risk of shrinkage deformation of the walls and the formation of cracks in them is minimal.

The experience of builders suggests that without a reliable foundation, it makes no sense to get involved with cellular concrete. When choosing MZL or a shallow slab as the base, experts recommend building the basement floor from brick. And only after that start laying gas blocks.

A poorly laid foundation leads to cracking of gas silicate

Low mechanical strength

To secure massive structures, heat and waterproofing materials to gas silicate walls, you will need special fasteners. Ordinary ones, in the form of disc-shaped dowels, will not work. Blocks made of cellular concrete have a fairly loose structure, so they require special screw-in dowels or chemical anchors. The price for these fasteners is 5–6 times higher than for disc fasteners.

On average, the cost of insulation, waterproofing or finishing 1 m2 only due to the use of specialized fasteners increases by 250–300 rubles. total area The façade of a private house is at least 300 m2, so this feature of gas silicate blocks leads to a significant increase in the cost of construction estimates.

The structural type of gas silicate has low thermal insulation

Use of material for bath construction

An aerated block bathhouse has an optimal price-quality ratio. Adherents of log houses will find many negative aspects in construction from cellular concrete, but not every owner has the funds to purchase expensive wood. In this situation, affordable materials come to the rescue: gas silicate and aerated concrete. They have a number of characteristics that can be regarded as positive for the construction of a bathhouse:

• Pre-fabricated. Thanks to its light weight and correct geometric shape blocks, masonry can be done independently, without involving specialists. Large sizes of building stones ensure high speed of wall construction.
• Low thermal conductivity. With the same wall thickness, a bathhouse made of aerated blocks will be warmer than one made of brick.
• Light load on the foundation. A small one-story building can be erected on a strip or column base. IN Lately The Semykin foundation, patented by the author, is gaining popularity. Such a foundation is built from sand-filled car tires. It is perfect for building a bathhouse from aerated blocks.
• Walls made of cellular concrete hold heat well and give off heat for a long time.

Negative aspects of building a bathhouse from gas silicate blocks:

• high-quality hydro- and thermal insulation of walls is required;
• It is desirable to install a heated floor, which will ensure quick drying of the building;
• It is important to comply with increased requirements for storage, transportation and laying of aerated concrete blocks, preventing the occurrence of chips and cracks.

A bathhouse made of this material is an advantageous structure in all respects. You just need to properly protect it from moisture and cover it.

Gas silicate can be easily cut into pieces of the desired size

Construction of house walls from blocks

For the construction of a private house, a gas block is not the best material. If there is no other way out, it can be used, but you need to be prepared for additional expenses for insulation and waterproofing of walls and ceilings. Special attention will be required to the quality of foundation construction: it must be reliable and level.

An important point in building a house from gas silicate blocks is the thickness of the walls. Manufacturers claim that 380 mm is sufficient for Moscow and the Moscow region, but this does not meet accepted standards.

When calculating in accordance with SNiP 23–01–99 “Building Climatology” and SNiP II-3–79 “Building Heat Engineering”, it turns out that the minimum wall thickness for Moscow and the Moscow region (when using gas silicate and not taking into account seams) is 535 mm, the maximum - 662 mm. Taking into account seams - 588–827 mm, respectively. It is irrational to build such walls, so you will have to make high-quality, expensive insulation.

Lining gas silicate blocks will protect them from destruction and extend the service life of the material.

Video: house made of gas silicate

How to choose the right one

When choosing aerated blocks, first of all, they are determined by their type: wall or partition. The former are necessary for the construction of load-bearing structures, the latter - for non-load-bearing ones. The market offers a wide range of blocks different brands. For building a house optimal choice will be the following:

• D400 B2.5 - suitable for the construction of buildings up to three floors;
• D500 B3.5 - used for the same purposes, more dense and durable, but the thermal conductivity coefficient is higher than that of D400 B2.5;
• D600 B3.5–5 - high-strength stones recommended for construction ground floors, houses with ventilated facades and hanging structures.

Equally important visual inspection blocks, which will give an idea of ​​the condition of the building material of the entire purchase batch. High-quality stones are smooth, with clear edges and without cavities. An autoclave-produced gas block is much lighter than the one that gained brand strength through natural drying.

The high density of the material reduces its thermal insulation qualities

Gas silicate is not a new material, and it is well known to professionals. But recently, interest in it has only been growing. Boom on suburban construction, coupled with the desire to save as much as possible on heating, has made cellular concrete a market leader. The price of autoclave blocks is significantly higher than that of analogues manufactured using simpler technology.

The porous structure largely determined the high technical specifications. On the one side ready-made blocks they turn out to be really light and warm, on the other hand, the cellular matrix of aerated concrete is much less durable than a monolith. About the difference between gas silicon and aerated concrete blocks read in.

The density of the produced gas silicate varies from 300 to 800 kg/m3, it is divided into three groups:

1. Thermal insulation - the most lightweight material weighing up to 400 kg/m3, not particularly strong, but possessing best performance energy saving. They can withstand compression only 2.5-3.5 MPa, but their thermal conductivity barely reaches 0.1 W/m °C.

2. Structural and thermal insulation (500-600 kg/m3) - can be used for the construction of self-supporting and lightly loaded walls. This internal partitions from blocks and boxes of houses 1-2 floors high. Their strength ranges from 2.5-5 MPa, and their thermal conductivity is 0.118-0.15 W/m °C.

3. Structural - a full-fledged building material with a density of 700 to 800 kg/m3 and resistance to compressive loads of 5-7 MPa and above. Thermal insulation characteristics leave much to be desired (0.165-0.215 W/m °C), but they also exceed the corresponding indicators by more traditional options like brick or poured concrete.

All blocks are non-flammable (NG group) and at the same time have good vapor permeability, which also depends on specific gravity. The lighter the autoclaved concrete, the better it “breathes”, passing through its pores from 0.14 to 0.23 mg/m·h·Pa.

Feedback on using blocks

“I liked working with gas silicate. Moreover, I decided to buy options with tongue-and-groove edges and handles on the butt side - the price is the same. I had to build the walls myself, so the light weight and ease of installation turned out to be serious advantages for me. The glue consumption turned out to be one and a half times more than the manufacturer promised. But my seams (by no means an expert in construction) still came out neat and straight. The only negative is that these blocks absorb water very quickly. I had to hastily soak them with Aquasol so that they would last until finishing began.”

Sergey, Voronezh.

“For me, all the advantages of a gas silicate block are obvious, but the products are very demanding in terms of construction technology. At one time I had to quarrel with a foreman who did not want to make an armored belt around the perimeter under attic floor, - well, the guys at work enlightened me on time. As a result, I brought in a couple more stacks of bricks and the crew finally laid out the hard edging for me. So now I have a warm one, and most importantly - strong house In the countryside. No cracks have appeared in three years.”

Roman, Nizhny Novgorod.

“The fact that aerated concrete can be sawed, drilled and nailed well is definitely a plus. But it is very fragile and at first I was even a little scared that my house would collapse. When stacks of supposedly Hebel gas silicate from a local spill were brought to the site, I was horrified. Despite the pallets, corner strapping and several layers of film, some of the blocks arrived with chips on the sides. In general, I would advise everyone to purchase this material with a reserve of not 10%, like other piece goods, but all 20%, because in the process of work they will still be damaged a lot.”

Nikolay, Moscow.

“And I liked the result. The masonry made from autoclaved blocks is smooth and neat and requires minimal plaster. But you can’t leave the walls completely without it - expert reviews about gas silicate are right. Three years earlier, I had a garage made of it: with cement mortar and without any cladding. So after a couple of winters, the lower rows became covered with small cracks, began to crumble, and a musty smell appeared inside.”

Valery, St. Petersburg.

“I saw a house made of gas silicate at my brother’s in another city. Everything is as it should be: plastered and painted. But when you tap the walls, you can hear that there is serious peeling of the finish. In one place they knocked it down themselves, and under the plaster there were crumbling blocks and white sand. It turns out that the builders did not bother to create a vapor barrier from the inside of the premises or attach at least some kind of insulation to the façade. They shifted the dew point exactly into the thickness of the wall, where the moisture safely accumulated, and in winter it froze there, unable to find a way out through the plaster.”

Let's summarize the pros and cons

The main advantages of autoclaved aerated concrete:

• Light weight with large dimensions of stones, which allows you to quickly build a box at home, even alone.
• Excellent geometry - the blocks are cut to size, which allows you to get the correct shape and perfectly flat edges. And these are minimal seams in thickness and low consumption of adhesive mixture.
• Low thermal conductivity, comparable only to solid wood, makes it possible to build walls of small thickness and spend minimal money on additional insulation.

The main advantage of gas silicate is that with it, building a house has become more affordable for people who do not have enough money for the services of contractors, but want to acquire truly comfortable housing. In terms of energy efficiency and environmental friendliness, such material can be compared with wooden beam. The only difference is that it is easier to install and there is a 30-40% savings on the price of the blocks.

On the one hand, cutting additional elements and laying grooves for reinforcement does not cause any difficulties. On the other hand, attaching heavy hanging structures to such walls will be problematic.

They do a good job of insulating the house, they allow air to pass through well, regulating the microclimate in the room, but they also easily absorb moisture, which gradually destroys the blocks from the inside. It is undesirable to leave them without high-quality impregnations and protective finishing for a long time. This also explains the low frost resistance, which even for very dense options does not exceed 35-50 cycles.

When should you choose gas silicate?

Construction with autoclaved concrete makes sense in the southern and central regions of Russia, provided the climate is not too humid. In this case, it will be possible to get by with a relatively small wall thickness and a minimal amount of insulation. And when the construction of a house has already been completed, but there is a need to reduce energy losses, you can use light gas silicates with a density of up to 400 kg/m3 to create a warm circuit.

Porous concrete does not have great strength, so it is used only in the construction of low buildings of 2-3 floors. Fragile blocks are completely unable to resist bending loads and need a rigid foundation that does not allow the walls to warp during movements or seasonal heaving of the soil. If, due to the characteristics of the soil, you still have to use a pile-grillage, strip or monolithic foundation, it makes sense to turn specifically to the lungs wall blocks. They will reduce the load on the base, and it can be made less powerful.

It will also be possible to save a lot of money when constructing small auxiliary buildings on the site (garage, utility block, summer cuisine). Here it is quite possible to get by with a shallow strip foundation.

Price

Manufacturer	Dimensions, mm	Density grade
		D 400	D 500	D 600
Ytong	600x300x250	4750	4900	5510
Bonolit	600x200x250	3340	3300	2950
EuroBlock	600x300x400	2300	2610	3020
KZSM	600x200x375	2820	2890	3200
Poritep	600x300x200	2750	3090	3210
El-Block	600x300x200	3150	3150	3250
Bikton	600x400x250	3010	3280	3570

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