Foam block wall 20 cm. Foam block walls - construction technology, choice of thickness and insulation rules (70 photos)

Aerated concrete belongs to the category cellular concrete and their use in the construction industry is strictly regulated. The main recommendations to determine the necessary indicators of the strength of the walls being built, the following:

it is necessary to calculate the allowable indicators of the height of the erected walls of the structure;
height restrictions bearing walls, erected from aerated concrete blocks, are four to five floors;
the strength indicators of blocks for the construction of five-story buildings are B-3.5, and for three-story buildings B-2.5;
for the construction of buildings with self-supporting walls, it is recommended to use, depending on the number of storeys, blocks B-2.0 or B-2.5.

Regulatory documents in the context of private housing construction are currently purely advisory in nature, therefore they may not be taken into account in low-rise construction, as well as in the construction of any outbuildings or garages.

This means that there is no need to rent housing to any commissions. You built it yourself, live it yourself. No one will check the strength of structures, their compliance with thermal conductivity standards and other parameters. However, if the goal is to build a house for yourself well and for a long time, then you need to focus on these recommendations.

What wall thickness is enough for a summer home

Before building any building strength calculations are required. Do it yourself such calculations are not always possible, therefore it is allowed to proceed from examples that take into account the values of strength classes, in accordance with which the wall thickness is selected. An important factor is also the purpose of the building being erected.

In low-rise construction of houses for summer living, it is advisable to adhere to the basic simple recommendations:

one storey houses in warm climatic conditions, country and garage buildings require the use of aerated concrete with a thickness of at least 200 mm;
two- or more-story houses require the use of gas silicate with a thickness of 300 mm or more;
building basements or ground floors involves the use of blocks with a thickness of 300-400 mm (here it should be remembered that gas silicate is afraid of moisture, therefore, at the risk of its presence, it is better to choose other materials);
inter-apartment and interior partitions are performed with aerated concrete with a thickness of 200-300 mm and 150 mm, respectively.

You can go to the official website of any block manufacturer and see the list of sizes of manufactured products.

Here we will see that the blocks are divided into wall (for building walls) and partition (for interior partitions).

If on suburban area it is supposed to carry out the construction of non-residential premises or a house for summer use, it is recommended to give preference to aerated concrete with a minimum thickness of 200 mm.

Thermal conductivity of walls

When building houses for permanent residence strength alone is no longer enough. Here also the thermal conductivity of the materials used must be taken into account. In accordance with the calculations, either the required thickness of the blocks for your climatic zone is determined, or the thickness remains the same as for summer buildings, but insulation is additionally used.

And in this case, you need to consider the money, which will be cheaper - an increase in the thickness of the wall due to aerated concrete or insulation.

When calculating the cost of insulation, it is worth adding the price of fasteners and the payment for the work of builders.

As I wrote at the very beginning, it was decided to do without a heater. Therefore, further calculations will be carried out for "bare" walls.

In accordance with GOST, which regulates the main technical specifications, as well as the composite characteristics and dimensions of absolutely all cellular blocks, the thermal conductivity of such a building material is 4 times lower than similar indicators solid brick, which makes it possible to build structures with narrower walls.

The thermal conductivity of a material is the ability to conduct heat. The calculated indicator of the amount of heat passing through 1 m 3 of a material sample in 1 hour at a temperature difference of 1 °C on opposite surfaces.

The higher this figure, the worse thermal insulation properties.

I will give a detailed comparison with a solid brick. The thermal conductivity of aerated concrete is approximately equal to 0.10-0.15 W / (m * ° C). For bricks, this figure is higher - 0.35-0.5 W / (m * ° C).

Thus, to ensure the normal thermal efficiency of a residential building for the Moscow region (where the air temperature rarely drops below -30 degrees in winter) brick wall must be at least 640 mm thick. And when used in construction aerated concrete blocks D400 with a thermal conductivity of 0.10 W/(m*°C) walls can have a thickness of 375 mm and conduct the same amount of heat energy. For D500 blocks with a thermal conductivity of 0.12 W / (m * ° C), this figure will be in the range from 400 to 500 mm. Detailed calculations will be below.

Thermal conductivity indicators depending on the wall thickness:

aerated concrete	Wall width (cm) and thermal conductivity
aerated concrete	12	18	20	24	30	36	40	48	60	72	84	96
D-600	1.16	0.77	0.70	0.58	0.46	0.38	0.35	0.29	0.23	0.19	0.16	0.14
D-500	1.0	0.66	0.60	0.50	0.40	0.33	0.30	0.25	0.20	0.16	0.14	0.12
D-400	0.8	0.55	0.50	0.41	0.33	0.27	0.25	0.20	0.16	0.13	0.12	0.10

Between the coefficient of thermal conductivity and the thermal insulation of the walls there is inverse proportionality, which must be taken into account when performing independent calculations.

Load-bearing walls without insulation for permanent residence

Cellular concretes have excellent thermal characteristics, therefore, subject to the calculation rules, there is no need to use heaters even when erecting buildings intended for year-round use.

To perform independent thermotechnical calculations need to know reference table values indicators such as resistance to heat transfer R req m 2 °C / W and heat conductivity of aerated concrete.

Calculation depending on the region of residence

Heat transfer data for some regions are shown in the table. Choose a locality that matches your climate zone.

Thermal conductivity

For this value, I will again go to the website of the manufacturer of the wall material that I am going to buy, and I will find the following sign there:

Now let's see the real reference data.

We see that the manufacturer indicates the characteristics for dry material. If the walls contain moisture, which is acceptable, then these characteristics will be slightly worse.

As you know, the blocks that came off the conveyor have a moisture content of up to 30%. Under normal use, this excess moisture is removed in about 3 years.

Continuous heating running in the house accelerates this process.

On the Internet, you can find reviews of developers complaining about cold walls in aerated concrete house. It turns out that the house was built during the summer-autumn. And in the winter the family settled in it. The walls of the house are damp, not yet dry properly. Water is a good conductor of heat.

Residents are starting to think about the insulation of their homes. But you just have to wait until next winter. Moisture from the walls will go away, and reside in winter period will become more comfortable.

An example of calculating the required wall thickness for the Moscow region

In the capital and the region, most often they choose between D400 blocks with a width of 375 mm and D500 with a width of 400 mm. It is on these test subjects that we will make calculations.

The minimum thickness of aerated concrete walls is determined by the standard multiplication of such parameters as the average heat transfer resistance R and the conductivity of aerated concrete blocks without the use of heaters. These parameters are shown in the tables above.

For Moscow R=3.29 m2×°C/W.

Let's make a calculation for blocks D400

For a dry state, the thermal conductivity coefficient is 0.096.

3.29 * 0.096 = 0.316 (m)

At a moisture content of 4%, the coefficient is 0.113.

3.29 * 0.113 = 0.372 (m)

Based on the calculations, it can be seen that for a perfectly dry material, a wall thickness of 316 mm is sufficient for the D400 grade.

However, manufacturers in commercials tell us that for Middle lane Russia has enough block thickness of 375 mm for the D400 brand and produces this size. From which we can indirectly conclude that the calculation includes a coefficient for humidity of 4%.

Now let's calculate block D500

For a dry state, the thermal conductivity coefficient is 0.12.

3.29*0.12=0.395 (m)

At a moisture content of 4%, the coefficient is 0.141.

3.29 * 0.141 = 0.464 (m)

So, the manufactured blocks D500 with a width of 400 mm will fit the characteristics for the ideal case. There is nothing perfect in the world. But to approach the ideal, it is necessary to avoid external wetting of the walls from precipitation by lining the house with a brick with a ventilation gap. You can also install siding or other panels.

Even housing must be constantly heated. And when severe frosts above -20 degrees, which is Lately in the Moscow region it happens extremely rarely to be prepared for short-term increased heating bills.

Obviously, in terms of thermal conductivity, the D400 block with a width of 375 mm outperforms its fellow D500 with a width of 400 mm. But if only it were that simple. You also need to look at the safety factor B. A few years ago wall material D400 was produced with a deliberately lower strength, which stopped developers from choosing such a building stone. Now leading manufacturers guarantee the strength of B-2.5 for the D400 grade.

If construction is planned alone, then an important criterion for choosing will be, which depends on the size and density.

In this way, the desired parameters directly depend on the brand (density) aerated concrete building material. For some regions, these values are calculated and collected in a table.

Useful video

In this story, there are some clever thoughts on calculating the thickness of the walls:

Internal partitions made of aerated concrete

The thickness of the aerated concrete partition must be selected in accordance with several factors, including calculation bearing capacity and height.

When choosing blocks for the construction of non-bearing partitions, you need to pay attention to the height:

the height of the structure being erected does not exceed three meters - the building material is 10 cm thick;
the height of the internal partition varies from three to five meters - the building material is 20 cm thick.

If it is necessary to obtain the most accurate data without performing independent calculations, you can use standard tabular information that takes into account the interface with the upper floor and the length of the structure being erected. It is also necessary to attach particular importance to the following recommendations for the choice of building material:

determination of operational loads on internal partitions allows you to choose the optimal material;
it is best to build non-bearing interior walls from products of the D500 or D600 brand, having a length of 625 mm and a width of 75-200 mm, which creates a strength of 150 kg;
installation of non-load-bearing structures allows the use of products with a density of D350 or D400, which helps to obtain standard sound insulation up to 52 dB;
sound insulation parameters directly depend not only on the thickness of the building blocks, but also on the density of the material, therefore, the higher the density, the better the sound insulation properties of aerated concrete.

With a partition structure length of eight meters or more, as well as a height exceeding four meters, in order to increase the strength characteristics, it is necessary to strengthen the frame with the help of load-bearing reinforced concrete structures. The required strength of the partition is also achieved due to the adhesive layer that holds the block elements together.

Affordable cost, manufacturability and excellent quality characteristics made aerated concrete blocks popular and in demand on the market of modern building materials. Properly calculated thickness of the aerated concrete wall makes it possible to provide the buildings under construction with a high level of strength, as well as maximum resistance to almost any static loads or impact factors.

Due to its low weight compared to silicate or red brick, good heat and sound insulating properties, frost and fire resistance, simplicity machining and installation, aerated concrete blocks are used in the construction of load-bearing elements and partitions of residential buildings, garages, country cottages. Many people make the wrong wall thickness from aerated concrete, which, with its low power, does not prevent the penetration of cold and requires additional installation of insulation, and with a large one, it leads to an inappropriate waste of excess material, and therefore money. In order to avoid such a situation, it is necessary to understand what affects this indicator and what it should be according to the standards and depending on external factors.

D300-D500.

Lightweight blocks with low density and excellent thermal insulation properties. They are mainly used as a heater.

D500-D900.

Unlike the previous ones, they have sufficient strength, weigh more and conduct heat a little better. Perfectly suited as the main material for the construction of walls.

D1000-D1200.

Heavy gas blocks with the highest density for the construction of buildings requiring structural strength.

How thick should a concrete wall be?

The power value is calculated depending on the following factors:

According to the requirements of such a standard as SNiP 23-02-2003, the minimum thickness (H) is calculated using the following formula: H = R req × λ, where:

R req is the resistance of the structure to heat transfer, calculated for each region;
λ – coefficient of thermal conductivity of gas blocks, (W/m∙°C) depends on the grade and humidity.

Brand of aerated concrete blocks	Thermal conductivity coefficient, W/m∙°С
Brand of aerated concrete blocks	Dry	At 4% humidity
D300	0,072	0,084
D400	0,096	0,113
D500	0,12	0,141
D600	0,14	0,16
D700	0,165	0,192
D800	0,182	0,215
D1000	0,23	0,29

The lower the value of λ, the better its thermal insulation properties - accordingly, the walls made of aerated concrete of the D300 grade have the most optimal indicator, and the worst - D1000. In wet material, due to the presence of water in the cavities, the conductivity of heat is higher than in dry material.

The value of R req characterizes the resistance of the material to the passage through it of the total amount of heat accumulated inside the room, and is equal to the product of the degree-day (D) of the heating period by the correction factor a and the addition of the constant b to the result obtained: R req = (D × a) + b.

The value of D is equal to the product of the temperature difference inside the room during the heating period and the average daily outdoor temperature by its duration in days: D=(tin.room-tout)×Pfrom.period.

So, for example, for Moscow, this figure for 214 days with average temperature air outside and inside -3.1 and + 20 ° C is equal to 4943 degree-days; the southern regions have the lowest D value, for example, in the Rostov region it is only 3523 ° C * day, and in the northern regions - Siberia, Magadan, the Urals - the highest. The values of variables a and b depend on the type of building used and for the walls of residential buildings, garages and cottages, they are 0.00035 and 1.4, respectively.

Using from the reference materials the value of the degree-days of the heating period, the above coefficients and the thermal conductivity of the block grades, it is possible to calculate what thickness, according to the standards, should be at the walls of aerated concrete in the most major cities various parts Russia and adjacent areas.

Calculation of the power of cellular concrete structures for various zones of the Russian Federation:

Cities	D,°C*day	Fencing power depending on the brand of gas blocks, cm
Cities	D,°C*day	300	400	500	600	700	800	1000
Moscow	3934	20	25	35	40	50	55	65
Saint Petersburg	4796	25	30	40	45	55	60	75
Novosibirsk	6601	30	35	45	55	65	70	90
Yekaterinburg	5980	30	30	45	50	60	65	85
Rostov-on-Don	3523	20	25	35	40	45	50	65
Ufa	5517	25	30	40	50	55	65	80
Krasnoyarsk	6341	30	35	45	55	60	70	85
Khabarovsk	6475	30	35	45	55	65	70	85
Murmansk	6380	30	35	45	55	60	70	85
Yakutsk	10394	40	45	65	75	85	95	120
Average	5994	30	30	45	50	60	65	85

thickness chart wall structures depending on the region and brand of gas silicate blocks:

The best thermal insulation properties are characterized by walls made of aerated concrete grades D300-D400. Their thickness ranges from 20 to 40-45 cm, despite this, these materials contain a lot of pores with air and little load-bearing solidified solution. The highest strength, but at the same time, the large wall thickness (up to 100 or more cm), necessary to preserve heat inside the room, is distinguished by gas blocks of the D800, D1000 brands. Most often they are used in construction. public buildings, trade pavilions and other structures with a heavy load and additional insulation.

The "golden mean" and the most optimal ratio of strength-thermal conductivity are characterized by blocks D500-D600, most often used in the construction of residential buildings and cottages, as well as other buildings.

What to consider when choosing the power of wall structures?

In addition to the calculated values, several more factors are also distinguished, on which the thickness depends.

1. Duration of stay in the building under construction during the calendar year. For country house, an outbuilding, an aerated concrete garage, heated for a short time, you can use thin walls no more than 20 cm thick that can withstand the weight of the roof and provide protection from the cold in the spring and autumn. The opposite situation is in residential buildings of permanent residence - in order for heat not to leave the premises, walls with a design capacity of 30-40 cm are needed.

2. View - bearing structures should have a thickness of 10-15 cm more than the partitions inside the room.

3. The number and location of floors - with an increase in the height of the building, gas blocks with greater strength are used. The thickness of the walls of a one-story building should be at least 25 cm, two or more - 30-40 cm.

4. Climatic conditions outside - the duration of the cold period and average temperature indicators directly affect the power of the building's fences. The walls in Siberia are made thicker than in the southern regions.

5. The presence or absence of a layer of insulation (polystyrene foam with the obligatory application of a layer on top of it facade plaster) - the use of heat-insulating materials allows the use of blocks of smaller thickness. A wall without insulation, in addition to having an unsightly aesthetic appearance, absorbs moisture faster due to the open porous structure, which increases the thermal conductivity of the structure.

Results

Cellular concrete in modern construction is one of the most acceptable both in terms of price and quality of materials for the construction of various buildings.
The walls of the house made of aerated concrete blocks have high strength, relative durability and good heat-insulating properties.
Using the formulas given in the regulations, it is possible to calculate optimal power building envelopes, taking into account the conditions of a particular region, allowing you to save material and make the thickness of the walls in the Moscow region less than in the north.
The use of insulation for lining masonry from gas blocks increases their service life and reduces consumption.

Aerated concrete compares favorably with conventional concrete by its low thermal conductivity. This property is achieved by introducing aluminum powder into the usual concrete mix. Due to hydrogen bubbles evenly distributed throughout all mixtures, aerated concrete transfers heat much worse than ordinary concrete.

But this advantage also reverse side- aerated concrete has a slightly lower strength than ordinary concrete. Therefore, when choosing the thickness of an aerated concrete wall, one must proceed not only from the required level of thermal insulation, but also take into account the strength of the wall. In this case, of course, it is necessary not to go beyond the budget.

Classification of aerated concrete blocks

Depending on the purpose of the premises, the requirements for strength and thermal insulation characteristics walls. Depending on the purpose, there are:

garage;
any ancillary space that is used only in warm time year (for example, a summer kitchen or workshop);
cottage, for living only in the summer;
House.

As for the strength of the material, it must be taken into account that with an increase in density, the strength increases and the thermal conductivity of the material increases.

Aerated concrete of several classes is available on the market:

B3.5 - can be used as a material for load-bearing walls of 5-storey buildings;
B2.5 - used as a material for a load-bearing wall if the height of the house does not exceed 3 floors;
B2.0 - this class of aerated concrete is used for the construction of load-bearing walls of buildings with a height of no more than 2 floors.

Depending on the density, aerated concrete blocks are divided into grades from D300 to D1200 (the number indicates the density of the material in kg / m 3). Blocks of high density are positioned as structural (i.e., they are able to withstand a large load), blocks of minimum density act as a self-supporting insulation.

Regulatory requirements

Construction using cellular concrete (and aerated concrete refers to this type of concrete) is regulated by STO 501-52-01-2007. The main recommendations for the use of aerated concrete blocks are as follows:

normative document requires to determine the maximum allowable height walls from cellular blocks only on the basis of calculation;
limited maximum height buildings. It is allowed to make load-bearing walls of buildings up to 5 floors (or up to 20 meters high) from autoclaved cellular concrete, the height of self-supporting walls should not exceed 30 m (or 9 floors). Foam blocks (non-autoclaved cellular concrete) are used for the construction of load-bearing walls with a height of no more than 10 m or no more than 3 floors.
the standard also indicates the strength of concrete blocks depending on the number of storeys of the building. So, for the construction of outdoor and internal walls For a 5-storey building, blocks with a strength of at least B3.5 should be used (the use of foam concrete is prohibited), the mortar grade is not lower than M100; in 3-storey buildings, the cellular concrete class should be at least B2.5, and the mortar class should be M75; in 2-storey buildings - B2 and M50, respectively.
for the construction of self-supporting walls, it is required to use blocks of class at least B2.5 - in buildings with more than 3 floors and B2.0 - in 3-story buildings.

These standards take into account only the strength side of the issue and do not cover the issue of thermal insulation of the room (SNiP II-3-79). The requirements of the regulations are mandatory in the first place for legal entities. Ordinary people, for example, during construction country house or garage, summer kitchen can use these requirements as guidelines. It is also necessary to take into account the fact that during operation the humidity of aerated concrete blocks changes, and this somewhat increases their thermal conductivity.

The best options when designing any building will, of course, be a complete calculation for strength and thermal engineering, but not everyone can cope with this task on their own. Not everyone wants to pay for the calculation either. In such cases, you can focus on the approximate values of strength classes and thicknesses of aerated concrete walls, depending on the purpose. Compared to other materials, aerated concrete wall should have a much smaller thickness with equal energy efficiency.

For construction one-story houses in warm climates, summer kitchens, garages, etc., some use aerated concrete with a thickness of 200 mm, but this thickness cannot be called recommended. Even for the construction of non-residential premises, as a rule, aerated concrete 300 mm thick is used.
For the construction of basement and basement walls, it is recommended to use aerated concrete D600, B3.5. The thickness of the blocks should be at least 300 - 400 mm.
Inter-apartment partitions - aerated concrete blocks B2.5, D500 - D600, block thickness - 200 - 300 mm.
Partitions between rooms - blocks B2.5, D500 - D600, thickness - from 100 to 150 mm.

If the partition is arranged in an existing room, then it is better to choose D300 aerated concrete. In this case, it is not the strength that is decisive, but the sound insulation of the material.

Construction of non-residential premises (garages, summer kitchens etc.) Aerated concrete D500 is used, thickness from 200 mm (depending on the load).

What you should pay attention to

Aerated concrete - effective material in terms of thermal insulation, due to its cellular structure.

But in order to take full advantage of the benefits of aerated concrete walls, you should follow a few rules:

During construction, a special adhesive mixture is used, which is laid on the surface aerated concrete block thin layer (several mm). People who are used to working with conventional cement mortar can be difficult to relearn. If the seams are made too thick, then the mortar layer will begin to play the role of a “cold bridge” and the thermal insulation properties of aerated concrete will deteriorate.

During construction in cold and temperate climate Insulation of aerated concrete walls is recommended both inside and outside.

When calculating the strength, it is necessary to take into account the additional weight created by thermal insulation, for example, plaster.

To get really warm and cozy house it is not enough just to increase the thickness of the wall to the maximum. For most climatic conditions, it is sufficient to use aerated concrete D600, B2.5 or B3.5 with a thickness of 300mm. Nevertheless, it is desirable to substantiate the choice of aerated concrete blocks by strength and heat engineering calculations.

User Questions:

Have a nice day. I want to build a house from aerated concrete (INSI block), please tell me how thick the wall should be and whether insulation is needed outside if it is lined with bricks with a ventilation gap of 6 cm. Thank you.
Good afternoon! I am designing a 5-storey house in Krasnodar. The construct is monolithic, aerated concrete acts as a filler, please tell me what the thickness should be, is insulation needed? Outside, plaster for painting!
Tell me please, is it worth it to insulate the outside wall of the house from Aerok with a thickness of 375 mm? If necessary, what thickness should be min. cotton wool Then there will be a hinged facade. House in Ropsha Len. region.
Hello! Is a house made of aerated concrete with a wall thickness of 250 mm + 100 mm front foam plastic suitable for permanent residence? The house is two-story on a strip foundation.

Foam blocks are masonry products made of cellular concrete of non-autoclave hardening, widely used in individual construction for the construction of buildings 1-3 floors high. The foam block can be used both for laying load-bearing walls and for partitions, and low-density blocks are often used as a heat-insulating material.

This article discusses the technology of laying walls from foam blocks. We will gradually study the whole process - from calculating the thickness of the walls to their reinforcement and installation monolithic belt, and also give recommendations on the choice of adhesive for laying foam concrete.

Thermotechnical calculation of the thickness of the walls of a house made of foam concrete

According to the recommendations of the manufacturers of this material, the optimal thickness of the foam block walls varies from 40 to 60 cm. This value given will differ from region to region, since it directly depends on the climatic conditions of the area in which construction is underway.

To find out what thickness of the outer walls you need to do in your case, you need to perform a heat engineering calculation of the house. The following information is required for this calculation:

thermal characteristics of foam concrete, namely the value of its thermal conductivity, depending on the density of the material;
GSOM of the region in which construction is carried out (GSOP - degree-day);
the normative resistance of the building wall to heat transfer (consists of the sum of the resistances of all materials that make up the masonry) can be taken from the SNIP No. 2-3-79 "Construction Heat Engineering" standard.

As an example, for the calculation, we use the standard GSOP 6000 for Moscow, for which the standard resistance to heat transfer will be 3.5 C * m 2 /W. The calculation will be carried out for the most common foam concrete density class - D600.

The thermotechnical calculation of the wall thickness is carried out taking into account the thermal conductivity of all materials used in its construction. Here are their characteristics:

foam concrete D600 - 0.14 W / mS;
facing brick - 0.56 W/ms;
cement-gypsum plaster - 0.57 W / mS.

Let's calculate a wall with an outer layer of facing bricks 120 mm thick and an inner layer of plaster 20 mm thick. This is done according to the following algorithm:

The resistance to heat transfer for a brick is calculated by dividing the layer thickness (in meters) by the thermal conductivity of the material: 0.12 / 0.57 \u003d 0.20;
Similar calculation for a plaster layer: 0.02/0.57 = 0.035.
The thickness of the foam concrete layer is determined based on the required thermal resistance of the wall 3.5 C * m2 / W, taken for the Moscow region. Calculation formula: T \u003d (3.5-0.2-0.035) * 0.14 \u003d 0.45 m.

Similarly, knowing the actual thermal conductivity of the building materials used in the construction of the wall, as well as the standard thermal resistance of the walls of buildings in your region, you can perform a thermal engineering calculation for any masonry option.

1.1 Features of the choice of foam blocks (video)

1.2 Which foam blocks are better to use?

If you decide to build a house from foam concrete, then when choosing blocks, attention should first of all be paid to their density, which is a key characteristic of the material. All other characteristics directly depend on the density of foam concrete - cost, weight, thermal conductivity, soundproofing abilities.

The lower the density, the less durable the block will be, and the better its thermal insulation parameters will be. This value indicated by marking D, on the market you can find foam blocks with a density of D300-D1200, while products with a density of up to 500 kg / m 3 cannot be used to build load-bearing walls, their purpose is thermal insulation of existing structures.

Depending on the density, foam blocks are classified into 3 varieties, which differ in their scope of application:

heat-insulating - D300-D500, strength class B0.5-B1;
structural and heat-insulating - D500-D900, strength class - B1-B5;
structural - D1000-D1200, strength class - B5-B13.

Blocks with a density of 500-900 kg / m 3 are suitable for the construction of load-bearing and internal walls of one-story buildings, while for the construction of houses with a height of 2-3 floors, structural products must be used.

The sizes of blocks supplied to the market vary from 100x300x600 to 400x300x600 cm. Blocks are usually selected in thickness according to the required wall thickness. The most common size is 200 x 300 x 600 mm.

Note that a high-quality factory-made foam block is distinguished by its even geometry. This allows you to use for their masonry not a cement-sand mortar, but a special adhesive composition. Laying with the use of glue is carried out with a joint thickness of 4-5 mm, while when using a mortar, the joints are made with a thickness of 10-15 mm.

The use of masonry glue makes it possible to increase the thermal efficiency of the wall, since it is deprived of cold bridges, the role of which was played by thick seams, and the cost of buying a very expensive glue is offset by low material consumption, so that the final cost of masonry remains practically unchanged.

2 Technology of laying foam blocks

Even when using glue, the first row of blocks must be laid on sand-cement mortar, while the surface of the foundation must be covered roll waterproofing. Initially, it is necessary to seat corner blocks on the solution, then the mooring cord is pulled and the laying of the entire first row continues along it.

The masonry must be constantly checked by the level and leveled with a rubber mallet in the presence of even minimal deviations. Every 4th row of masonry is subject to reinforcement, for this you can use both a mesh and ordinary metal or fiberglass reinforcement. Reinforcement bars are laid in strobes made on the surface of the masonry, which are filled with masonry glue.

It is mandatory to fill a monolithic armored belt in the places of installation of interfloor ceilings and roofs. The easiest way is to make an armored belt with your own hands using special U-blocks with an internal cavity. In this case, the process of mounting the armored belt comes down to laying the block, placing reinforcing cage and filling the cavity with concrete.

The need to form an armored belt is due to the low resistance of foam concrete to point loads. Armpoyas evenly distribute loads from ceilings and roofs over the entire wall, preventing its deformation. If construction is underway one-story house, then under a light roof on wooden rafters, you can equip an armored belt made of bricks. The thickness of the armored belts of both types must correspond to the thickness of the wall, the height is from 15 to 20 cm.,

To perform the laying of foam block walls correctly, be guided by the following recommendations:

masonry adhesive must be kneaded in small portions, which will be used within 30-60 minutes;
The 2nd and all subsequent rows of masonry must be done with dressing in the floor of the block;
optimal temperature regime for work it is 5-25 0, if the temperature is higher, then the foam concrete will need to be moistened;
for applying masonry adhesive it is convenient to use a special notched

If we speak about the thickness of the walls of the house for permanent residence, then you should try to comply with the requirements of SNiP 23-02-2003 for thermal protection of buildings. Note that the standards allow the reduction of the normalized resistance to heat transfer according to the "consumer approach". For example, for Moscow, the required value of heat transfer resistance of external walls is R req \u003d 3.13 m 2 °C / W, but can be reduced to R min \u003d 1.97 m 2 ° C / W (R min \u003d 0.63 x R req = 0.63 x 3.13 m 2 °C/W = 1.97 m 2 °C/W) provided that the requirements for specific fuel consumption for heating the building are met, in combination with compliance with the temperature difference between the indoor air and the indoor the surface of the walls, excluding dew on the inner surface of the walls [clauses 5.1 and 5.13 of SNiP 23-02-2003]. Specific fuel consumption with the above difference increases slightly.
Read about the minimum thickness of aerated concrete walls in terms of sound insulation.

Energy efficiency of buildings for permanent residence
The use of adequate wall thickness with adequate heat transfer resistance limits the temperature drop in the room at a constant specific level of energy consumption for heating the building, prevents moisture condensation on the internal surfaces of the building envelope (except for windows), and protects the building envelope from waterlogging.
Normal level energy efficiency of buildings ( class C according to SNiP 23-02-2003) allows deviation of the calculated (actual) value specific consumption thermal energy for heating the building from the normative value from + 5% to minus 9%.
building with high level energy efficiency ( class B) is characterized by a reduction in the cost of thermal energy for heating by 10-50% , and with very high level energy efficiency ( class A) - more than 51%.

Principles of choosing the method of compliance with the normalized indicators of thermal protection of the building.
The main task of designing thermal protection of buildings (selection optimal thickness walls and their insulation) is to maintain the established parameters of the microclimate interior spaces and proper sanitary and hygienic conditions for a given consumption of thermal energy for heating the building. SNiP 23-02-2003 "Thermal protection of buildings" establishes three mandatory mutually linked normalized indicators for the thermal protection of a building, based on:
"A"- normalized values of resistance to heat transfer for individual building envelopes;
"B"- a normalized temperature difference that does not allow dew to fall:
- temperature difference between the temperature of the internal air and the temperature of the inner surface of the walls (other enclosing structures), determined by the formula No. 4 SNiP 23-02. At the same time, the calculated temperature difference should not exceed the normalized values \u200b\u200bestablished in Table No. 5 of SNiP 23-02.
- the minimum temperature on all parts of the inner surface of the outer fences must be above the dew point temperature.
"V"- normalized consumption of thermal energy for heating, which makes it possible to vary the values of the heat-shielding properties of walls (enclosing structures), taking into account the choice of a method for maintaining normalized microclimate parameters.

The standards for thermal protection of the building will be met if indicators “A” and “B” are met for residential premises (that is, walls of adequate thickness will have a normalized resistance to heat transfer and dew will not fall on the internal surfaces of the walls), or indicators will be met "B" and "C" (that is, dew will not fall on the inner surfaces of the outer walls and a certain consumption of thermal energy will be normalized). In the second case, the thermal resistance of the walls may be lower than the values \u200b\u200bspecified in the group of indicators A (table 4 of SNiP 23-02-2003 ) , but not below the minimum values? referred to in clause 5.13 of SNiP 23-02-2003. The requirements of indicators of group "B" must meet all types of enclosing structures in order to ensure comfortable conditions for people inside the building and prevent dampening of the inner surfaces of walls, floors and other enclosing structures from dampening, getting wet and mold.

Table. Simplified Choice minimum thickness walls made of aerated concrete (according to the recommendations of Table I from the catalog "Low-rise houses made of cellular concrete", L., State Committee for Architecture, LENZNIIEP - 1989.)