Three-layer brickwork. The outer wall is three-layer stone with brick cladding. What kind of insulation is used

Facade cladding with brick is popular in the construction of private houses; it looks great and is durable. Walls lined with brick are often made of three layers to ensure the necessary heat conservation. The first layer is a load-bearing wall, the second is insulation, and the third is a self-supporting layer facing bricks, which rests on the same foundation as the main wall.

When creating a three-layer wall, a number of questions always arise, for example:

• What to make a load-bearing wall from?
• Which insulation to choose?
• Is there a need for a ventilation gap above the insulation (resulting in additional widening of the base)?
• How to connect a load-bearing wall, insulation, and facade design?

Reasonable answers to these and other questions are available in project documentation, in accordance with which construction must be carried out. To control the work or to do it yourself, you need to familiarize yourself with the design of a brick-lined wall and the nuances of its construction.

Let's take a closer look at the main aspects of the construction of three-layer brick-lined walls.

What to pay attention to

A three-layer wall compared to a single-layer wall, for example, made of porous ceramic blocks, has disadvantages, the main of which are:

• It is possible for the wall to become wet if the construction technology is violated or the layers are destroyed.
• Conventional mineral wool and expanded polystyrene insulation materials have a durability that is approximately 3 times less than that of the base and cladding. Such insulation must be changed with the destruction of the facade.

The load-bearing wall is often made of solid brick or small-format concrete blocks, then its thickness should be at least:
- For one-story buildings- 18 - 24 cm.
- for 2 - 3 storey buildings - from 29 cm.

Also, the load-bearing wall can be made of lighter materials - aerated concrete, expanded clay concrete, etc. Small-format blocks with a density of 700 kg/m3 and more are used. Thickness load-bearing wall determined by the project, based on the required strength, but usually within 25 - 50 cm. But with load-bearing wall Lightweight porous materials cause moisture accumulation problems (see below).

Typical diagram of a three-layer wall with a load-bearing wall made of masonry made of two bricks 24 cm wide (1), with insulation made of rigid mineral wool slabs (2), on a foundation (3), a ventilation gap and flexible fiberglass ties (4), with cladding made of clinker bricks(5) with ventilation holes in the seams at the bottom (6).

What kind of insulation is used

The following can be used as insulation:

• expanded polystyrene (EPS, EPS, PSB), which are characterized by high resistance to steam movement, actually act as vapor barriers.
• mineral wool, both low density 30 - 50 kg/m3, and rigid boards with a density 80 - 120 kg/m3, which are glued to the load-bearing wall in the same way as expanded polystyrene;
• foam glass, acting as an absolute vapor barrier;
• low-density aerated concrete 100 - 200 kg/m3. It's relative new insulation, which has thermal insulation qualities at the level of mineral wool (thermal conductivity coefficient 0.5 - 0.6 W/mK) and low resistance to steam movement - 0.28 mg/(m*year*Pa).

The first two insulation materials are cheap, considered traditional, and are mainly used for insulating private houses. But they give the multilayer wall the main drawback - its service life is too short - 25 - 35 years. After which, the insulation needs to be replaced, which is not cheap for a three-layer wall.

The last two without this drawback, foam glass is called “eternal”, and autoclaved aerated concrete is a porous stone, its predicted service life is comparable to brick. Moreover, unlike expensive foam glass, aerated concrete affordable price. But the popularity of this insulation is still small.

Aerated concrete slabs up to 10 cm thick are glued to the load-bearing wall and additionally fixed with 1-2 disc dowels. for one slab. From slabs with a thickness of more than 10 cm, masonry is made with glue next to the load-bearing wall with support on the foundation, while a windproof technological gap with the wall of 2 - 10 mm is possible.

The issue of ventilation gap in a load-bearing wall

A layer of mineral wool or aerated concrete will have greater vapor permeability than a load-bearing wall, but less than brick cladding. If there is no ventilation gap left between the insulation and the cladding,

then the basic principle of constructing multi-layer walls will be violated - the outer layer should be more vapor-permeable. In the wall in cold period moisture will accumulate with the consequences:
— significant reduction in the heat-saving properties of the wall;
- reduction in service life, destruction of materials.

If there is a 3 cm wide ventilation gap above the insulation layer, through which air moves from bottom to top, then moisture accumulation will not occur.

The graphs, according to theoretical calculations on a computer, clearly show the accumulation of moisture by month in a three-layer wall. Load-bearing wall - expanded clay concrete with a layer of 25 cm, insulation - mineral wool 12 cm, cladding - ceramic brick 12 cm. Region - St. Petersburg.

• The first graph is for a wall with brick cladding without a vent. gap
• second - used instead of brick mineral plaster layer 1 cm, moisture content is several times less.
• third - there is a ventilation gap between the mineral wool and the brick cladding; moisture does not accumulate.

In practice, moisture flows down the insulation, accumulates, goes through the cracks, it can be drained from the wall by drilling a hole...

If you use polystyrene foam with a density higher than 35 kg/m3 in a layer of normal thickness, then there is no need for a ventilation gap, moisture accumulation does not occur due to minimal steam movement.

But if the load-bearing wall is made of porous, vapor-transparent materials (aerated concrete and the like), then it may become moist at the dew point for any facade design (the dew point will be located mainly in the wall, due to the increased thermal insulation of its material). Therefore, from the inside, a load-bearing wall made of light porous materials must be protected with a layer of vapor barrier. But this design is more expensive and problematic, so porous structural materials are better used in single-layer walls.

It should be noted that a single-layer wall, for example, made of aerated concrete or porous ceramics, is free of such problems.

The thickness of the insulation is selected in accordance with the calculation of the required heat transfer resistance of the wall, usually in the range of 7 - 12 cm, for foam glass - up to 15 cm.

Which three-layer wall design to choose

For regions with cold winters, in the case of using vapor-transparent insulation mineral wool or aerated concrete 100 kg/m3, the presence of a ventilation gap in the wall is mandatory to ensure its normal condition.

In this case, the ventilation gap remains open under the roof, and in the lower part of the wall for air supply, the vertical joints between the bricks are left unfilled; slotted bricks are used, so that the area of ​​the holes is at least 75 cm2. for 20 square meters. masonry

Mineral wool density up to 80 kg/sq.m. must be covered with a windproof superdiffusion membrane, which prevents air from blowing through its layer. The membrane and layers of wool are secured with 10 pcs disc-shaped dowels. per sq. m. into a load-bearing wall.

EPS, aerated concrete, erected using glue, in accordance with the recommendations above. Additional fixation is usually 3 - 5 plastic dowels per square meter.

In a three-layer wall, it is recommended to use a masonry mesh that binds all layers (and brick cladding).
In this case, the vertical installation step of the mesh is 500 - 600 mm, according to the size of the insulation board (smaller possible). If fiberglass connections are used, their number should not be less than 4 pieces. per square meter, and the horizontal installation step is no more than 500 mm., near openings, at corners, the installation spacing of connections is reduced to 8 pcs. per sq. m.

The brick cladding is reinforced with masonry mesh with a vertical pitch of no more than 1.2 meters, with the mesh inserted into the load-bearing wall.

Doors and windows are located along the depth of the wall opposite the insulation-load-bearing wall boundary. In this case, better heat savings are achieved at the openings, and the risk of glass fogging is also reduced.

conclusions

Nowadays, low-density autoclaved aerated concrete is replacing mineral wool, due to the fact that it is more environmentally friendly and durable.

The use of aerated concrete insulating panels in a three-layer wall lined with brick and a load-bearing wall made of heavy materials seems optimal. But with this insulation it is advisable to create a ventilation gap, since the material itself is susceptible to moisture.

The use of heavy materials for load-bearing walls eliminates problems with moisture accumulation in the thickness of the wall. Load-bearing wall made of aerated concrete high density must be protected from the inside with a vapor barrier for any two- or three-layer wall design.

It is better to use mineral wool boards high density, from 80 kg/m3, without windproof membrane, which is also the “weak link” in the design, given its inseparability.

You can reduce construction costs and reduce wall thickness if you use expanded polystyrene for insulation without ventilation. gap They also have a lower thermal conductivity coefficient, they can be used in a thinner layer, which will ultimately result in a thickness savings of up to 5 - 8 cm. Additional savings are laying facade bricks on the edge, with a layer thickness of 6 cm. But this requires an increase in the number of connections.

The use of low-density polystyrene foam and mineral wool in a three-layer wall seems to be an unjustified saving.

How to make beautiful, strong, durable and warm exterior walls? What should be the design of the external walls of the house? A few construction tips will help you understand this issue.

What designs are used

Placing an insulating layer from the inside of the building is not considered, due to the many disadvantages inherent in this method, without any advantages.

Let's take a closer look at how the most expensive, three-layer walls are made. They are distinguished by good heat conservation, durability, and better appearance. They are often built from small blocks. Continuous casting of concrete in private construction is not so common due to the relatively high labor intensity when construction volumes are small.

How to make walls warm

The walls must have a heat transfer resistance not lower than the standard one. This value is proposed (and required) as being economically feasible. Those. building colder walls is unprofitable and not reasonable. Question: how to insulate three-layer wall? In general, there are only two options - either stone fiber in the form of rigid slabs, or foamed plastics, also in the form of rigid slabs. Due to various physical properties of these materials, and due to the special difference in resistance to the movement of steam, they are used for various design diagrams. If steam flows through plastic with difficulty (foam plastic, polyethylene) or does not flow at all (extruded polystyrene foam), then through fibrous wadding boards it flows as if there were no obstacles in the way at all. In both cases, special designs must be used that provide measures to prevent the wall from getting wet due to condensation.


If we talk about a three-layer wall structure, then two main ones will play a special role: distinctive features mineral wool slabs. High-quality and dense (more than 50 kg/m3) slabs made of basalt fiber do not change their geometry over time, they are durable. They are not eaten by rodents, which is especially important. The mineral wool boards used must be impregnated with water-repellent preparations (hydrophobic), and their water absorption by volume should not exceed 1%. Since the insulation will be covered with a non-removable expensive facade layer, it is better to use mineral slabs High Quality, as durable and resistant to external influences.

The thickness of the insulation layer is calculated in accordance with the standard, so that the total heat transfer resistance of the wall is not lower than the required values. More often than not, 10 cm of the thickness of the specified insulation is sufficient. In cold regions, 15 cm will probably be required.

Features of a three-layer wall

The design of a three-layer wall - between the load-bearing layer and the facade layer there is a layer of mineral wool slab insulation. A ventilation gap of 3–5 cm wide is left between the insulation and the façade layer, which is necessary for ventilation of the insulation. It's forming plastic limiters put on with connections, as a result of which the insulation always remains pressed to the wall and does not bridge the gap. Below and above facade cladding channels are made to supply air into the ventilation gap. The total area of ​​the supply channels must be at least 72 cm2. for 20 sq. m. walls, the same for the outlet walls (sometimes, for this purpose, individual seams in the masonry are left empty). To prevent the fibers in the insulation from weathering, it is covered with a superdiffusion (steam permeable) membrane with a vapor permeability of at least 1700 g/m2 per day.

The load-bearing layer is usually made of solid or hollow brick. The width of the layer depends on the design of the entire building, and on the purpose of a particular wall. More often the layout is carried out in 1.5 hollow bricks (36 cm), sometimes in 1 brick (24 cm), but solid. Strength characteristics of the layer, its width and type piece material determined by the project.

The facade layer can be laid with clinker bricks in half a brick or even 6 cm thick in 1/4 brick.

It is important that there is a reliable connection between the load-bearing layer and the façade layer. Flexible (non-rigid) connections made of fiberglass or basalt-plastic rods are used. The thermal conductivity coefficient of such bonds is no more than 0.5 W/m °C, while a metal rod of similar diameter is 50 W/m °C, i.e. 100 times more. The density of the connections depends on the specific conditions and on the thickness of the insulation (the greater the thickness, the more tightly it is pressed). Typically, the step of laying ties in the seams between the length of the wall is 0.5 - 1.0 m, and in height - 0.6 m. In this case, they are inserted into the seams between the bricks to a depth of 7 - 9 cm.

Construction Features

You should not use materials with low heat capacity for the internal load-bearing layer, as well as any materials that are afraid of water, for example expanded clay concrete or foam concrete. The savings compared to brick will be small, but the problems if it gets wet can be significant. Low internal heat capacity of the building means reduced comfort.


Please note, in order not to add an extra cold bridge, all ceilings and beams extend only into the load-bearing wall and are not embedded in the insulation layer. Thus, their ends are reliably protected from the cold by the same continuous layer of insulation.

It remains to pay attention to the “unobvious catch”. The wall will be wet, cold and will rapidly collapse if the outflow of steam from it is disrupted. IN this description The design of a three-layer wall with ventilation of the insulating layer using the “ventilated facade” technology is shown. It is unacceptable to reduce the ventilation gap above the insulation or close the ventilation holes. Or use a low-quality vapor diffusion membrane.

Another option for the construction of a three-layer wall - with a dense filling of the internal space with vapor-proof insulation (expanded polystyrene, polyurethane foam) without a ventilation gap - is also a popular option. In this case, the inner and outer layers are separated into pairs - each is in its own atmosphere. But due to the danger posed by a rodent, as well as due to a slight, but still present, reduction in the natural outflow of moisture from the house, and less durability of the material, it does not seem to be so preferable. However, he also has the right to life...

In some new built buildings, the insulation is placed centrally (in the middle) in the building envelope. With this option, the insulation is very well protected from mechanical damage and there are more possibilities for façade design. However, the risk of damage due to moisture is much higher than with external insulation, so the layer structure must be carefully planned and executed without defects.

This design consists of three layers: load-bearing wall, walls made of facing material and insulation, which is located between them. Carrier and facing wall rest on one foundation. Outer layer most often they are made either from facing bricks or from building bricks, followed by plastering, coating artificial stone, clinker tiles, etc.

Advantages

• handsome and respectable appearance when using expensive facing materials;
• high durability, subject to proper design and qualified installation of the structure.

Flaws

• high labor intensity of construction;
• low breathability;
• the possibility of moisture condensation between dissimilar layers of such a wall.

It is very important that all layers of the structure are compatible with each other in terms of vapor permeability. Compatibility is determined only by calculation of the system as a whole.

Underestimating this circumstance can lead to moisture accumulation in the interior of the walls. This will create a favorable environment for the development of mold and mildew. The insulation will get wet due to possible condensation, which will shorten the service life of the material and significantly reduce it heat-shielding properties. The enclosing structure will begin to freeze, which will lead to ineffective insulation and may cause its premature destruction.

Types of structures

Standard solutions Layered masonry devices can be divided into two types: with and without air gap device.

The air gap device makes it possible to more effectively remove moisture from the structure, since excess moisture from the load-bearing wall and insulation will immediately escape into the atmosphere. At the same time, the air gap increases the overall thickness of the walls, and, consequently, the foundation.

Insulation inside masonry walls

To one degree or another, the problem of vapor transfer is relevant for layered masonry with any type of insulation.

Insulating the structure with mineral wool is the most preferable. In this case, it becomes possible to create an air gap between the insulation and the outer wall for better removal of moisture from the load-bearing wall and insulation.

For layered masonry should be used semi-rigid mineral wool slab insulation. This will allow, on the one hand, to well fill all the defects in the masonry, to create a continuous layer of thermal insulation (the slabs can be “pressed in” a little, avoiding cracks). On the other hand, such slabs will maintain geometric integrity (not shrink) throughout their entire service life.

Certain difficulties in using expanded polystyrene in layered masonry are caused by the low vapor permeability of this material.

Three-layer brickwork with insulation

1. Interior brick wall
2. Mineral wool
3. External part of a brick wall
4. Connections

The traditional material for the interior of the walls is solid red ceramic brick. Masonry is usually done on cement-sand mortar 1.5-2 bricks (380-510 mm). The outer wall is usually made of face brick with a thickness of 120 mm (half a brick).

Products

In the case of a system with an air gap 2-5 cm wide, for its ventilation, vents (holes) are installed in the lower and upper parts of the wall, through which vaporous moisture is removed outside. The size of such holes is taken at the rate of 75 cm 2 per 20 m 2 of wall surface.

The upper ventilation ducts are located at the eaves, the lower ones at the plinths. In this case, the lower holes are intended not only for ventilation, but also for water drainage.

1. Air gap 2 cm
2. Bottom part building
3. Top part building

To carry out ventilation of the layer, a slotted brick is installed in the lower part of the walls, laid on its edge, or in the lower part of the walls, bricks are laid not close to each other, but not at some distance from each other, and the resulting gap is not filled with masonry mortar.

Making connections

The inner and outer parts of a three-layer brick wall are connected to each other with special embedded parts - ties. They are made of fiberglass, basalt plastic or steel reinforcement with a diameter of 4.5–6 mm. It is preferable to use connections made of fiberglass or basalt plastic due to the greater thermal conductivity of steel connections.

These connections also perform the function of fastening the insulation boards (the insulation is simply
prick them). They are installed during laying in the load-bearing wall to a depth
6-9 cm in increments of 60 cm horizontally and 50 cm vertically based on an average of 4 pins per
1 m2.

To ensure a uniform ventilated gap over the entire area of ​​the insulation, locking washers are attached to the rods.

Often, instead of special connections, bent reinforcing bars are used. In addition to ties, the outer and inner walls of the masonry can be connected with steel reinforcing mesh laid at 60 cm vertical intervals. In this case, an additional mechanical fastening slabs

The insulation boards are installed with the seams bandaged close to each other so that between separate slabs there were no cracks or gaps. At the corners of the building, gearing of the slabs is created to avoid the formation of cold bridges.

Masonry technology with insulation

• Laying the facing layer up to the tie level
• Installation of the heat-insulating layer so that its top is 5-10 cm higher than the facing layer
• Laying the load-bearing layer to the next level of connections
• Installing connections by piercing them through the insulation

if the horizontal seams of the load-bearing and facing layers of the wall in which the connections are placed do not coincide by more than 2 cm in load-bearing layer brickwork, ties are placed in a vertical seam

• Laying one row of bricks in the load-bearing part of the wall and the facing layer

Installation sequence
(Alternative option)

The material used for the external walls is ceramics or wood, last years All in great demand aerated concrete house designs are starting to be used.

Let's consider each of the wall materials in structures, giving the cost of one square meter.

Ceramic wall materials

One of the oldest representatives of this species is solid brick. Its advantages include the compressive strength of the grade M100-M150, durability, manufacturability, extensive experience in use, and as a result a large number of specialists - masons. The main disadvantage of solid brick is that it is not enough good performance thermal conductivity λ=0.6 W/(m K), as a result of which solid brick is not used in the construction of external walls without a heat-insulating layer.

Wall structures in which it is possible to use solid bricks.

Three-layer brickwork (thermal resistance structures 3.07 m 2 *S/W).

* - it is necessary to install a ventilation gap between the thermal insulation layer and the facing masonry, ensuring free air circulation in the ventilation. gap

Advantages and disadvantages.

The design meets modern heat saving standards. Application effective thermal insulation allows you to reduce the thickness of the wall, which reduces the load on the ground. Disadvantages: relatively short service life of thermal insulation and design complexity.

Calculation of costs for the construction of three-layer masonry.

Materials:

Total materials - 3,289.85 rubles/m2.

Works:

Total work - 2,650.00 rubles/m2.

Total materials and work - 5,939.85 rubles/m2.

Wet type facade (thermal resistance of the structure 3.07 m 2 *C/W).

1. monolithically reinforced belt with a stop device.
2. solid ceramic brick, it can also be sand-lime brick.
3. dowels for fastening facade thermal insulation, consumption 6-7 pieces/m2.
4. thermal insulation layer 100-120mm, which can be used as mineral wool slabs or polystyrene foam boards, both foamed polystyrene and extruded, thanks to the best parameters Due to their vapor permeability, mineral wool thermal insulation materials have become more widespread in cottage construction.
5. a layer of reinforcing putty with reinforcing mesh.
6. decorative plaster, clinker tiles, facing stone.

Advantages and disadvantages.

The design meets modern heat saving standards. The use of effective thermal insulation makes it possible to reduce the thickness of the wall, which reduces the load on the ground. Disadvantages include the limited service life of the structure, regulatory period operation of wet-type facades up to overhaul 25 years.

Calculation of costs for installing a wet façade.

Materials:

Total materials - 5,273.33 rubles/m2.

Works:

Total work - 2,850.00 rubles/m2.

Total materials and work - 8,123.33 rubles/m2.

Achieve security normal SNiP 02/23/2003 “Thermal protection of buildings” without a thermal insulation layer in the structure, possibly using ceramic large-format porous blocks.

The construction of the external wall is made of ceramic large-format porous blocks Kerakam SuperThermo30 (thermal resistance of the structure is 3.284 m 2 *S/W).

1. U-shaped ceramic porous block acting as the formwork of a monolithically reinforced belt.
2. thermal insulation layer: mineral wool insulation, extruded polystyrene foam, expanded polystyrene foam.
3. reinforced concrete slab ceilings
4. ceramic large format ceramic block Kerakam SuperThermo30, “warm” masonry mortar LM21 is used as a masonry mortar.
5. facing brickwork.

Advantages and disadvantages.

The design meets modern standards for heat conservation, without the use of effective thermal insulation. The real service life of a house before major repairs is 100 years. Due to the large format, speed increases installation work, the amount of masonry mortar is reduced, the use of “warm” masonry mortar eliminates cold bridges in the masonry. A high percentage of voids reduces the load on the soil. Thanks to the use of the most thermally efficient (Test report ST30 for thermal conductivity ) , among the Kerakam SuperThermo30 ceramic blocks produced in Russia, the overall thickness of the wall is reduced, this makes it possible to reduce the thickness of the foundation strip, as a result, construction costs are significantly reduced.

Calculation of costs for the construction of masonry using large-format porous Kerakam SuperThermo30 blocks produced in Russia.

Materials:

Total materials - 2,842.90 rubles/m2.

Works:

Total work - 1,950.00 rubles/m2.

Total materials and work - 4,792.90 rubles/m2.

External wall construction made of gas silicate blocks (thermal resistance of the structure 3.174 m 2 *S/W).

1. monolithic reinforcing belt.
2. floor slab.
3. gas silicate block; assembly adhesive is used as a masonry mortar.
4. basalt-fiber bonds, consumption 5 pieces/m 2.
5. facing brickwork.

* - it is necessary to install a ventilation gap between the load-bearing wall made of gas silicate blocks and the facing masonry, ensuring free air circulation in the ventilation. gap

** - due to the low strength grade (M25-35), according to the manufacturer’s instructions, reinforcement of the entire perimeter is required for every 4th row of masonry.

Advantages and disadvantages.

The design meets modern standards for heat conservation, without the use of effective thermal insulation. The real service life of a house before major repairs is more than 50 years (limited realistic deadlines operation of houses made of gas silicate blocks). Due to the large format, the speed of installation work increases, the amount of masonry mortar decreases, and the installation of blocks on adhesive mixtures with a masonry layer thickness of 2-4 mm, it reduces the area of ​​cold bridges in the masonry. The relatively low density of gas silicate reduces the load on the soil.
The disadvantages include low strength characteristics; as a result, extensive reinforcement of the entire perimeter of the masonry is required, as well as enhanced reinforcement of window and door openings.

Calculation of costs for the construction of masonry using gas silicate blocks.

Materials:

Total materials - 2,683.50 rubles/m2.

Total work - 2,610.00 rubles/m2.

Total materials and work - 5,293.50 rubles/m2.

Brick is the most common material for constructing load-bearing walls. It is successfully used both in multi-storey industrial construction and in private low-rise buildings. The only drawback of brick is its low thermal insulation qualities. To solve this problem, additional insulation of the walls is carried out. Brickwork with insulation inside makes it possible to build warm house at minimum costs time and finances.

Disadvantages of masonry without insulation

More recently, the issue of thermal insulation of brick buildings was resolved in a simple way- increasing the thickness of the wall. Yes, for middle zone The usual wall thickness was 3 - 3.5 bricks, and in the northern regions it could reach 1 - 1.5 m. This is due to the high thermal conductivity coefficient of the brick, which causes large heat losses.

This thickness was a necessary measure in the absence of effective and inexpensive thermal insulation materials. Another factor promoting the use of “thick wall” technology in Soviet times was the relative cheapness of bricks. This made it possible to simplify masonry technology by eliminating the use of thermal insulation materials.

However, in Lately such an approach becomes too wasteful from a financial point of view: in addition to the cost of bricks, the costs of arranging reinforced foundations increase.

Another problem that you may encounter when installing brickwork without thermal insulation is a shift in the dew point indoors.

In construction, the dew point is the point inside or outside the outdoor walls of a building where the cooled vapor contained in the air begins to condense. The transformation of steam into dew occurs when warm air comes into contact with cold surfaces.

The most preferable option is to locate the dew point outside the building, in which case the condensing moisture will simply evaporate under the influence of wind and sun. It is much worse if the dew point is shifted indoors. Dampness generated by internal surfaces walls, negatively affects the microclimate in the house, becoming a source high humidity and the cause of mold and mildew.

Uninsulated walls winter frosts cool over their entire thickness, resulting in steam condensation on their internal surfaces.

In areas where sub-zero temperatures are established in the cold season, the technology of laying bricks with insulation is the only acceptable one.

Three-layer masonry

One of the types of insulated walls is three-layer brickwork. Its design looks like this:

1. Internal wall made of brick, cinder blocks, aerated concrete, etc. Performs load-bearing function For interfloor ceilings and roofs of the building.
2. . The insulation is placed in internal cavities-wells between the outer and inner walls. Protects the inner wall from freezing during the cold season.
3. External wall with brick cladding. Performs decorative functions, giving the facade additional aesthetics.

On the image:

No. 1 - interior decoration.

No. 2 - load-bearing wall of the building.

No. 3 - insulation between brickwork.

No. 4 - ventilation gap between the internal insulation and the facing wall.

№5 - outer wall with brick lining.

No. 6 - internal reinforcement connecting the internal and external walls.

Brickwork with insulation inside, like others construction technologies, has its pros and cons. To her positive qualities should include:

• Smaller volume of masonry, which allows you to reduce the estimated cost by saving on the amount of building material.
• Less weight of the building, which makes it possible to use lighter and less expensive foundations.
• High thermal insulation performance, allowing you to retain heat in winter time.
• Improved sound insulation. The thermal insulation layer can significantly reduce the noise level, which is especially important if the building is located on a central street with heavy traffic.
• External walls, lined decorative bricks, do not require additional decorative finishing.

Among the disadvantages of multi-layer walls are:

• Greater labor intensity associated with insulation, compared to brickwork of 3 - 3.5 bricks.
• Three-layer walls do not allow periodic replacement of insulation, while its service life is always shorter than the service life of brick walls.

Choice of insulation

As heat-insulating material A wide range of insulation materials can be used that meet the recommendations of SNiP.

Firstly, the thermal conductivity of the material must be such as to ensure protection of interior spaces at the maximum minus values ​​typical for a given region.

You can familiarize yourself with the thermal insulation performance of insulation in the manufacturer’s instructions on its packaging or in the tables technical characteristics SNiP. By comparing these indicators with winter minimum temperatures, you can calculate the required thickness of the insulation layer.

Secondly, the insulation must have sufficient vapor permeability. Otherwise, moisture will accumulate inside it, which will lead to its loss of thermal insulation qualities.

And thirdly, internal insulation must be fire resistant. Due to its non-flammability, it will not only not support combustion, but will also create a fire-retardant layer inside the masonry.

Mineral wool

A large family of insulation materials based on mineral fibers have excellent heat-saving characteristics. They are made by churning molten minerals in a centrifuge: glass, basalt, slag, etc. The low level of heat transfer in this case is achieved due to the high porosity of the material - air layers do not allow cold to penetrate through the mineral wool.

Absolutely not flammable, but very afraid of dampness. When wet, it almost completely loses its heat-saving properties, so when laying it, care must be taken to ensure effective waterproofing.

Expanded polystyrene

Foamed - another one often used in three-layer masonry thermal insulation material.

It is produced by saturating liquid polystyrene with air, which after hardening takes the form of porous round granules. To fill wells in the wall, it can be used in the form of sheets or as bulk material. It is much less afraid of dampness than mineral wool, but unlike it it is flammable, so walls insulated with polystyrene foam should be protected from open fire. Even if the fire does not damage the brickwork, it will cause burnout and melting of the polystyrene foam inside it. To replace the insulation, you will have to carry out labor-intensive and expensive work to dismantle the facing part of the wall.

Bulk insulation

In private construction, sometimes three-layer masonry is made by backfilling internal wells with various mineral fillers: slag, expanded clay, etc. This technique is somewhat cheaper and simpler than laying mini-slabs or expanded polystyrene sheets, but its effectiveness is much lower. This is due to the lower thermal protection of slag and expanded clay.

Slag is very hygroscopic - it tends to absorb and retain moisture, which can cause an increase in its thermal conductivity and premature destruction of adjacent layers of brick.

Laying three-layer walls

Laying a wall with insulation is carried out in several stages.

1. Laying the interior wall. It is produced using the same technologies as laying a conventional load-bearing wall made of solid bricks or building blocks. Depending on the minimum winter temperatures, it can be 1 or 1.5 bricks thick.
2. External wall masonry with cladding. It is carried out in such a way that between it and internal wall there was a gap necessary for laying or backfilling the insulation - a well. 2 walls can be connected to each other either by connections from anchor bolts and reinforcement, or brick ligation, carried out at certain intervals.
3. needed to protect the insulation from dampness, since it is impossible to completely prevent the flow of moisture through the brick.
4. The wells are filled with backfill insulation when the walls reach a height of 0.8 - 1 m. Sheet and roll insulation it is attached to the inner wall using mushroom dowels with a wide plastic cap, after which it is covered with external facing masonry.

For the construction of a waterproofing layer, it is not recommended to use “blind” materials, such as roofing felt. This will eliminate the possibility of free gas exchange between external environment And interior spaces Houses. In external wall Ventilation ducts should be left every 0.5 - 1 m - vertical seams between the bricks that are not filled with mortar.

Three-layer brickwork allows you to solve many problems that arise when using housing in winter. The process of constructing such walls is shown in the video below..