Aerated concrete (gas block), belonging to the type of lightweight concrete - porous, quite durable material, used for the construction of low-rise buildings.

Material gained popularity from developers due to practicality, ease of installation and low price.

For maximum efficiency thermal insulation work, in addition to the wall material, the characteristics of the foundation, roof and floor are taken into account. Optimal choice Insulation of aerated concrete walls must also take into account the vapor permeability of the insulation - it should be higher than that of aerated concrete blocks.

For the right choice insulation is assessed by the following indicators:

thermal conductivity - the higher it is, the thicker the insulation layer is required;
moisture resistance - the higher, the longer the insulating qualities are maintained;
vapor permeability - performs the functions of removing vapors, especially important when insulating roofs;
fire resistance - there are materials that are non-flammable, low-flammable, and flammable with the addition of fire retardants.

By type of raw material The following types of insulation are distinguished:

organic - penoplex, polystyrene foam, polyurethane foam;
inorganic are made from molten glass, quartz glass, rocks - glass wool, stone wool;
mixed - ecowool, foam glass.

For external insulation aerated concrete surfaces are most often used:

expanded polystyrene;
polyurethane foam;
mineral wool.

Solid insulation

gained popularity due to the light weight of the slabs, ease of processing, low price, and good moisture resistance.

Slab sizes can be standard and custom. The sizes 100x100 cm and 100x50 cm are used most often, since they are most convenient for installation and have minimum quantity joints

They are distinguished by density several types of foam:

the lowest density - 15 kg/m 3 is used only for temporary structures: change houses, kiosks, construction cars;
grade PSB-S 25 has a density of 25 kg/m 3 and is used for exterior finishing various structures, as well as roofs, facades, floors;
density 35 kg/m 3 and 50 kg/m 3 is used for warehouses, when arranging the floors of refrigeration rooms, etc.

When choosing foam important indicator- thickness. It can be from 20 mm to 100 mm, depending on the purpose of the building and climatic conditions.

Poor vapor permeability polystyrene foam can be a problem for aerated concrete surface- the dew point inside the wall may shift, which leads to its destruction. To avoid negative consequences, foam is used in combination with vapor barrier film. It can be combined with mineral wool, using only in places of minimal steam emission.

Foam is not used for insulation of aerated concrete houses with a height of more than 25 m, as well as for public buildings.

If steam and water can penetrate between the foam granules, penoplex almost does not allow water to pass through. The liquid absorbed by penoplex in 28 days does not exceed 0.5% of the total volume of the slab, while polystyrene foam gains up to 4% per day.

Penoplex is distinguished low thermal conductivity, low water absorption, wide operating temperature range, durability:

material with a density of 25-35 kg/m 3 is used for insulation of external and interior walls, you can use it on top decorative finishing and facing materials;
density 29-33 kg/m 3 is used for basements, plinths, foundations, septic tanks. The “Roof” view is used for roofing structures of various configurations;
density 37-45 kg/m 3 is used for road surfaces, also for roofs on which other structures are placed: platforms, pedestrian areas.

Possessing good moisture resistance, non-flammability, strength; optimal for external insulation gas concrete walls, ground floors, balconies, loggias, basements, floors in aerated concrete houses. When insulating the floor, it is laid on the base, then filled with screed.

Soft insulation

Minvata- the most popular material for insulating aerated concrete structures. It has low weight, high vapor permeability, and is not flammable.

Not attractive to rodents, which is a big plus for aerated concrete.

Mineral wool is produced in sizes convenient for installation:

for slabs 5-20 cm thickness, 60x100 cm area, density - 20-220 kg/m 3;
in rolls it is used as widely as in slabs, 50-150 mm thickness, 60x120 cm width, 9 m length.

Minvata, thanks light weight and ease of installation, optimal for roof insulation in aerated concrete houses.

Ecowool- blown-in type of insulation, mounted using special equipment. Consists of cellulose, fire retardants and antiseptics. It is very light in weight, the characteristics are determined by the thickness and density of the layer. Has no varieties.

Ecowool layers can have different densities, depending on the application method. On various surfaces are used different densities:

for floors of lower floors - it should be 35-42 kg/m 3 ;
For inclined surfaces- 45-55 kg/m3;
for vertical - 55-65 kg/m 3 ;
wet application - 65-75 kg/m3.

Soft insulation popular for thermal insulation of aerated concrete walls, as well as for floors and ceilings.

Sprayed insulation

Polyurethane foam has good heat-insulating and adhesive properties. The mixture is applied to the wall under pressure using a spray gun. After application to aerated concrete, it bonds to the surface, foams and forms an insulating protective layer.

The material forms layers without seams or joints, durable, resistant to mold, fire, and rodents. The thickness of the layer depends on surface defects.

After application a reinforcing layer of metal or fiberglass mesh is installed. Due to its good thermal insulation properties and light weight, polyurethane foam is used for roof insulation, as well as for internal insulation. aerated concrete walls.

How to properly insulate a house made of aerated concrete with penoplex from the outside

Stages of work on penoplex insulation:

Surface preparation - cleaning and leveling with plaster mixture in case of unevenness and defects.
Treatment with fungicidal agents.
The insulation boards are attached to the wall with a special glue, which is applied directly to the insulation.
Mechanical fastening. Dowels are used for it per 1 sq. m 4 pcs. Along the perimeter of the openings, 6-8 pieces are used. per sq. m.
Plastering or surface covering.
For better adhesion to the surface when plastering, it is recommended to create roughness with a brush on the foam boards. The plaster is applied in two layers: reinforcing material is embedded in the first layer, then the second is applied. After drying, the walls are painted.
When finishing an insulated surface with wood, siding, hanging systems, a frame is installed on top of the insulation.
For internal wall insulation, it is necessary to install a vapor barrier on top of the penoplex foam, for which foil-coated polyethylene film is used.

External insulation of aerated concrete structures gives tangible savings space, optimization of the heat-insulating properties of walls and displacement of "" into their outer layers.

Find out how best to attach the insulation when insulating a house made of aerated concrete from the outside from the video:

How is heat loss calculated?

The calculation of heat loss is determined based on the temperature of the internal air, the temperature of the internal surface of the enclosing structure and the temperature of the outdoor air.

The temperature inside the walls changes linearly. The angle of inclination of the graph depends on the value of the thermal resistance of the material in its different layers.

The average value of heat transfer resistance inside the building is assumed to be Ri = 0.13 m2 K / W. GOST 8.524-85 and DIN 4108

The thermal resistance of the remaining layers Re corresponds to the temperature difference between inner surface walls and street air. (T wall surface - T outside the building) dTe.

Then according to the following formula:

Ri / dTi = Re / dTe

we find Re:

Re = Ri * dTe / dTi

Total thermal resistance R = Re + Ri

R = Ri (1 + dTe / dTi)

And finally, the value of heat loss

Example

Room temperature: 20°C
to wall surface: 18°C
temperature environment: -10°C

dT = 2 °C
DTE = 28°C
Ri = 0.13 m2 K/W

dTi = 2 °C
dTe = 28 °C
Ri = 0.13 m2 K/W
R = R (1 + dTe / dTi) = 1.95 m2 K / W

TP = 0.5 W/m2 K

In addition to heat loss, areas of possible condensation are displayed.

The black graph shows the drop/increase in temperature inside the building envelope in degrees.

Blue graph - temperature dew point . If this graph is adjacent to the temperature graph, then these zones are called zones of possible condensation (marked in blue). If at all points on the graph the dew point temperature is lower than the material temperature, then there will be no condensation/dew.

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Self-insulation houses made of aerated concrete - simply and without special costs

The popularity of aerated concrete is growing steadily from year to year. If you believe independent statistics, at least a third of all private houses are currently being built from this relatively new material. But not all owners know that such houses require mandatory insulation. In this material I will tell you why it is necessary to insulate a house made of aerated concrete, I will dwell in detail on how it is better to insulate a house made of aerated concrete from the outside, and most importantly, how to do it yourself.

Why is it necessary to insulate such houses?

Novice builders love aerated concrete, or as it is also called gas silicate, for several reasons. First of all, building a house does not require exorbitant qualifications from a mason. Lightweight large blocks with clear, geometric correct forms sit on a special glue, and not on a solution as usual. Such structures do not require a strong foundation and, most importantly, by insulating the wall from the outside, the cost of the project is significantly reduced.

A few words about the nature of the material

Gas silicate itself belongs to the category of light cellular concrete. Unlike, for example, slag concrete blocks, the production technology of this material is much more complicated.

To explain briefly, a foaming agent is added to the cement-lime mixture, in this case Aluminum powder is used, as a result of which a huge amount of hydrogen is released and many hollow cells are formed in the body of the block.

But initially the porous material has too low mechanical strength and to increase it, at the final stage of production, the blocks are steamed in autoclaves under high pressure and at high temperature. As a result, at the finish we get a fairly strong block with very low thermal conductivity.

Why insulate such structures?

From a school physics course we know that perhaps the best heat insulator is air, and the more pores a material has, the lower its thermal conductivity, and therefore, the warmer the house will be.

But the problem with gas silicate is that the pores in these blocks are open, that is, the material is vapor-permeable and capable of being saturated with moisture. This means that the answer to the traditional question - is it necessary to protect such walls - is unequivocal: it is necessary, and it is mandatory.

Another question is what this protection should be and, for example, is it necessary to have 375 mm of walls under small sauna protect with insulation or you can get by with just plaster.

As you know, the thickness of the walls, no matter what they are made of, directly depends on the average annual temperature in a particular region. Advertising promises us that for the average private house made of aerated concrete, the minimum is about 300 - 500 mm. But few people clarify that in this case they mean the load-bearing characteristics of the material. That is, the house will stand.

About, for example, whether a 500 mm wall needs to be insulated, as well as what thickness of insulation is needed, is often kept silent. As for thermal conductivity, for example, for the Moscow region and the center of Russia, the thickness of an exclusively gas silicate wall without insulation starts from 70 cm.

Therefore, for those who have decided to build a house somewhere in the middle zone and are wondering whether 300 mm is needed outer wall to insulate or simply plaster, it should be taken into account that if you decorate the outside of the house with mineral wool or polystyrene foam, then a 100 mm thick slab replaces a 300 mm aerated concrete mass.

From this we conclude that for a half-meter wall in this region, ten-centimeter thermal insulation is required, if the wall is thinner than 300 - 400 mm, then the thermal insulation is made more massive.

In numbers it will look something like this. The level of heat transfer by a 300 mm aerated concrete wall, according to documents, is about 1.25 mºC/W. For temperate climate in the center of our country this value should be at least 3.2 mºС/W.

The missing 1.95 mºC/W is fully compensated by cotton or foam insulation with a thickness of 100 mm or more. This is the minimum acceptable value; naturally, the higher it is, the less money you will spend on heating.

The average price for constructing 1 m² of gas silicate wall 300 mm thick now fluctuates around 1,000 rubles. But to install a 100 mm insulating cotton coating, you will need half as much money, that is, up to 500 rubles. So draw your conclusions.

In addition to the level of thermal conductivity of the material, there is another important nuance. In building heating engineering there is such a thing as “dew point”. This term characterizes a place inside an external wall with zero temperature. It is at this point that minus and plus meet, which means that the most accumulates there.

As I already said, gas silicate material is hygroscopic and if the dew point is inside the block, then when temperatures fluctuate, the moisture in this sector will alternately freeze and thaw, thereby gradually destroying the block.

There is only one way out here, try to move this dew point into the insulation. Firstly, the insulation is less susceptible to destruction when moisture freezes, and secondly, even if it deteriorates over time, it is much easier and cheaper to replace it than to completely repair a crumbling wall. By the way, this explains the need to install insulation specifically outside the house.

Material selection

First, a few words about the choice of aerated concrete itself. This material has several levels of density, gradation goes from 350 units and higher in increments of 50 - 100 units. That is, 400, 500, 600 and so on.

The higher the value, the denser and stronger the material. But there is also a downside: the lower the density of the material, the higher its thermal insulation characteristics, which means the wall can be made thinner.

Many people are interested in whether it is necessary to insulate a house made of aerated concrete 400 units if the walls are planned to be thick and theoretically the level of heat transfer completely covers the maximum possible meaning by region.

I believe that it is necessary to do this, just instead of a layer of 100 mm, it is enough to mount slabs of 50 mm. This is explained by the need to move the dew point outside the blocks. In addition, gas silicate brand D400 is, figuratively speaking, the “softest”, and if it is simply plastered, such a coating will begin to crumble within a couple of years.

Now let's move on to the question of how to insulate the outside of a house made of aerated concrete, so that it is decent and relatively inexpensive. In this case, there are only two main contenders. These are high-density mineral wool slabs and good old polystyrene foam.

But before I talk about them, I want to dwell separately on one of the most frequently asked questions: is it possible to insulate houses made of gas silicate with penoplex? In order to answer this, you must first understand what penoplex is.

Extruded polystyrene foam, or by association with the manufacturer penoplex, is the closest relative of polystyrene foam. They are both made from the same material, but different different technologies. I will not go into the intricacies of the technology, I will only say that extruded polystyrene foam, unlike polystyrene foam, has a dense cellular structure with closed pores. As a result, it absolutely does not allow moisture to pass through and has high strength.

This is good for insulating concrete foundations, ground floor or roofs, but the walls of an aerated concrete house cannot be insulated from the outside with polystyrene foam. The fact is that aerated concrete is a vapor-permeable material. And, as you know, the movement of steam through the walls goes from the inside to the street.

If you pack the house in a strong, completely impenetrable shell on top, moisture will accumulate in the walls under this shell, thereby increasing their thermal conductivity and promoting destruction.

But that's not the worst part. Figuratively speaking, living in an expensive plastic bag is a very dubious pleasure, and to ensure a normal microclimate in such a house you will have to seriously invest in quality forced ventilation. So, no matter how much you praise penoplex, I do not recommend it for insulating aerated concrete walls.

Now let's return to the age-old question of all developers, mineral wool slabs or foam sheets. I do not take the liberty of saying that any of these materials are definitely better or worse. Both of them have approximately equal numbers of supporters and opponents, so let's compare together:

If you take it clean technical indicators, then the thermal conductivity of both materials is approximately the same; for polystyrene foam it is even slightly lower. So it's all equal here;
Level mechanical strength is also approximately on the same level. Although in this case it should be noted that dense wool, although not by much, is still superior to foam in elasticity;
Mice, birds and other small gnawing and pecking animals absolutely cannot tolerate mineral wool.. While in the foam sheathing they happily make their nests. But this is if there is free access to polystyrene foam, according to the insulation technology, at least it is covered with a layer reinforced plaster, which is a reliable barrier for rodents and birds;

Often one of the decisive arguments in favor of polystyrene foam is accessible instructions . Whatever you say, I can say with full responsibility that installing foam plastic insulation at home is much easier. Such slabs can be easily cut with a regular knife, and gaps that arise during installation can be quickly blown out with foam. Cutting cotton wool is also not difficult, but when working with it you will have to get thick overalls, safety glasses and gloves;
Mineral wool does not burn, that is, it is absolutely fireproof. Polystyrene foam is a self-extinguishing material. In other words, if a fire occurs, it will burn or at least melt, and during the combustion process it releases quite toxic gases. Although, in order to set fire to the facade of a building where there is concrete on one side and plaster on the other, you only need to pour gasoline on it or light fires around the house;
I have already mentioned such an important characteristic for gas silicate as the vapor permeability of exterior finishing. So for mineral wool it is of course higher, for foam plastic with a density of up to 25 kg/m³ this figure is on the limit of what is acceptable. Although, as much as I had to work with polystyrene foam, I never saw moisture accumulating under the sheets, which means that according to this parameter everything is in order;
Mineral wool is afraid of moisture; if the external plaster or wind barrier is damaged, it will quickly become saturated with water and become unusable. Rot and mold won’t grow in such mats, but there’s no point in wet insulation there won't be any anymore. While foam is not afraid of moisture, being vapor-permeable, it does not accumulate moisture;
And finally, the deciding factor for many is the price.. The cost of high-quality mineral wool significantly exceeds the price of polystyrene foam.

The table below shows the average parameters of the materials that are most often used for insulating houses made of cellular types of concrete.

In theory, such houses can also be insulated with polyurethane foam and so-called ecowool; these materials belong to the types of foam. But I see no point in dwelling on them in detail in this article, because the cost of such arrangement is several times higher than the price of installing mineral wool and polystyrene foam combined. Plus, it’s not possible to do it yourself; you need professionals with special equipment.

Simple home insulation technologies

We have figured out the question of whether it is necessary to insulate a house made of aerated concrete and how to insulate it; now it’s time to find out how to do it correctly. To be fair, there are several different effective technologies insulation. For you, I have chosen only those that you can bring to life with your own hands.

For example, laying insulation between an aerated concrete wall and a layer of facing brick is a very effective method. But, firstly, laying facing bricks requires highly qualified professional masons, and secondly, such a system will cost a tidy sum.

Simple and cheap

This method is called “Wet facade” among professionals. In general, its essence is extremely simple. The slab insulation is simply glued to the walls, after which it is finished with one of the many varieties of decorative plaster. Moreover, in this case it is not so important whether you use polystyrene foam or dense slabs of mineral wool; their installation principle is the same.

Naturally, any surface must be prepared in a certain way before finishing. The preparation of aerated concrete is not much different from similar work on other types of concrete. You will need to remove dust from the walls with an ordinary broom or brush and cover them with several layers of soil under cellular concrete with deep penetration;

There is one subtlety here. As you remember, gas silicate is divided according to the density of the blocks. So, the higher this density, the less soil you will need. So, about 4 layers of reinforcing compound are supposed to be applied to D400 blocks. For D500 and D600 gas blocks, three layers are already enough. On the walls with more high level density, you can get by with one, maximum two layers.
You can begin the main stage of work only after the walls covered with soil are completely dry. It is very convenient when the house was built on a wide strip or block foundation and the base protrudes at least 50 mm. This platform will be enough to support a light cotton or foam “coat”.

But, unfortunately, this does not always work out; many owners fill a narrow foundation strip and the walls go flush, and sometimes even overhang the foundation. To build a house, such a support is enough, but under our finishing we will have to install a separate border.

I usually use an L-shaped support profile for these purposes. There are such profiles different widths and, as a rule, are produced according to the size range of cotton slabs. Since the dimensions of the foam plastic are almost the same, and the weight of the material is less, these same profiles can be successfully used for any slab insulation. Attached this design along the horizontal mark with anchors in increments of 250 - 300 mm.

For applying glue to the slab, a notched trowel with a tooth depth of about 5 mm is best suited. Please note that when working on lightweight cellular concrete, the adhesive must be applied to the slabs in a continuous layer. In photos online you can sometimes see how the master applies glue at several points. This approach is justified for durable brick or concrete walls; aerated concrete and other cellular materials require continuous application of the composition.

The installation technique itself does not cause difficulties even for beginners. The boards are glued tightly, if possible without gaps. Each subsequent row is shifted by half or at least part of the slab.

To achieve a better result, I prefer to do two-layer insulation. That is, instead of one layer of thick slabs, I glue two layers of thin ones. The thickness is the same, and there are no gaps at all due to overlap and shift between the layers.

The external arrangement of cotton wool or polystyrene foam consists of 4 layers. I’m used to doing things my own way, so I’ll tell you first about my proven technique. After the glue has set, I apply another layer of the same glue on top of the insulation and while it is still wet, I embed a reinforcing fiberglass mesh, the so-called serpyanka, in it. This is not difficult to do with a spatula or a needle roller.

Next, again while the glue is still wet, the slab insulation together with the serpyanka is additionally attached to the wall with “umbrellas” ( plastic dowels with wide perforated caps). Simply use a hammer drill to drill a hole to the required depth, insert the body of the dowel into it and hammer the inner rod. But before final fixation, the dowel head must be slightly pressed into the sheet so that it does not protrude too much above the surface.

After all the “umbrellas” are filled, we leave the wall alone and let the layer of glue dry. Dry mesh reinforced A layer of glue will need to be applied with another similar layer. And only after the second adhesive layer has dried, you can begin to apply decorative plaster. To do this, I usually use a ready-made plaster composition for the “Bark Beetle” finish, although some people prefer to put on “Fur Fur”, it comes out cheaper.

Traditional instructions for finishing a wet facade sound a little different. In it slab insulation after gluing, it is immediately fixed with umbrellas, and after that the first layer of glue is applied, the serpyanka is applied to it, the second layer of glue is applied to the serpyanka and after drying, the wall is finished with decorative plaster.

Capital ventilated insulation

In the so-called ventilated façade, we will also use foam plastic or mineral wool slabs as the main insulation, but the structure itself is made more thoroughly. This approach allows you to cover the walls of houses not only with simple decorative plaster, but also to use any types, although in the case of aerated concrete, it is desirable that the finishing is not very heavy.

At the beginning of this article, we talked about whether it is necessary to insulate a house made of aerated concrete 400 units. So, soft gas silicate grade D400, with a fairly low thermal conductivity, also has a low density. In other words, it is not advisable to hang massive structures on such a wall; if you overdo it, the anchors will simply be torn out of the wall. Therefore, a ventilated facade is better suited for denser types of aerated concrete.

Now one more is enough important question— selection of installation anchors. The porous mass requires reinforced fastenings of a special configuration. A regular self-tapping screw with a plastic dowel will not hold well.

The configuration and dimensions of such fastenings may be different, but the principle is always the same. The rod plunges freely into the hole, and when screwed in, it expands or releases hooks.

This article is intended for people who are fluent in traditional household tools, such as a drill, grinder, screwdriver, etc., but are not professional builders. Therefore, I will talk about the simplest technique for installing a ventilated facade, which is accessible even to amateurs.

We will start from the fact that we need to mount a structure with an insulation thickness of 100 mm. For example, under standard, lightweight and relatively inexpensive plastic siding. The preparation here is the same as in the previous type of finishing. Only in this case there is no point in sparing the strengthening soil, because here we are directly interested in increasing the strength of the outer layer.

The horizontal strip at the bottom, if of course it is needed there, is mounted in the same way as in the case of a wet facade. Next we will need two types of wooden blocks. One set with a section of 100x50 or 100x40 mm, and the other with a section of 30x30 or 30x40 mm, and there should be equal numbers of them;
Naturally, all wood is pre-impregnated with an antiseptic. For fastening, installation anchors for aerated concrete and galvanized wood screws will be used;

First, load-bearing bars 100x50 mm are attached vertically to the primed, dry wall, with their narrow side to the surface. The step of fixing them with anchors to aerated concrete should not exceed half a meter;
The distance between the load-bearing bars should be discussed separately. If you are insulating with foam plastic and the sheet width is about half a meter, then the pitch of the guides is measured clearly according to the foam plastic; sheets that are too wide will have to be cut in half. With mineral mats it’s a little different. The slab should fit tightly between the beams, as tightly as possible, which means that the beams should be mounted 2 - 3 cm narrower than the width of the mineral mat;
When the beams are standing, apply a layer of glue to the insulation boards with a notched trowel and glue them to the walls between the beams. In theory, you don’t have to use glue, because the slabs have nowhere to go, they are clamped on both sides by guides, and a wind protection fabric is stretched on top.

With polystyrene foam this can still somehow pass, but cotton wool without gluing will give up to 5% shrinkage. So it’s better not to save money, put the slabs on glue and additionally fix them with umbrellas, especially since the instructions require this;
As we remember, the width of the supporting beam and the thickness of the slabs are the same, which means the surface should be smooth. A windproof fabric is stretched on top, this is especially important for cotton mats. Moreover, you need to buy wind protection; if you save money and buy polyethylene, the film will sweat, and naturally the insulation will get wet;

On initial stage To keep the canvas somehow, drive in a few nails or use a stapler. Now, on top of the windproof fabric, directly on the 100x50 mm load-bearing bars, 30x40 mm strips are fastened with self-tapping screws or simply nailed;
They will serve as the basis for the front finish and at the same time provide clearance for ventilation. Now all that remains is to select the cladding and screw it to wooden planks on top of insulation. That's basically all the technology is.

Interior finishing of aerated concrete

We remember that aerated concrete is a vapor-permeable material, therefore, it is undesirable to clog it both from the outside and from the inside. The most best view For interior decoration, plaster is recognized here, but unlike dense surfaces, cellular concrete requires a plaster layer 2 times thicker, which is approximately 15 mm or more.

To some extent, the exception is premises with high humidity tiled areas, such as the kitchen and bathrooms. There, a layer is first set up cement plaster about 5 - 7 mm thick, and tiles are already laid on it.

Conclusion

Aerated concrete is a unique, reliable and very practical material. It makes quite warm and quality houses. But in order for them to please their owners for a long time, they must be insulated.

Did you build or buy own house. Or you are just about to do it, planning your actions in advance. We weighed all the pros and cons and came to the conclusion that the building should be made of stone, and the walls should be built from warm and effective material: aerated concrete. It is also cellular concrete, gas silicate, foam concrete. Is there a need to insulate walls made of aerated concrete (“thermal fur coat”), and if so, how to do it correctly?

Video report on the thermal insulation of a house made of aerated concrete with ecowool

Reasons for insulation

It seems obvious: to keep the house warmer and lower heating costs. But you can just increase the thickness of the walls? Tough mineral wool, most suitable for insulating facades, with a slab thickness of 100 mm will cost (in the central regions of the country) an average of 450 rubles per m 2. In terms of thermal characteristics, this is an analogue of cellular concrete with a thickness of 300 mm. And it will cost 900 rubles. In fact, if you count the entire structure of external insulation: mineral wool boards, two layers of glue, fasteners, plaster, mesh, the price will rise to 800 rubles per meter and will practically be equal to the cost of increasing the heat-insulating properties of the wall by increasing the thickness of the masonry. However, under a thicker wall you will have to build a more powerful and expensive foundation. “Thermal fur coat” still turns out to be more profitable. The most rational option in terms of price/energy saving ratio for middle zone Russia - a foundation 300 mm thick (preferably also insulated); walls made of aerated concrete 400 mm; insulation 100 mm.

The optimal insulation option: “thermal fur coat” using hard mineral wool slabs 100 mm thick

There is another important point: durability and the notorious dew point. Our continental climate is unfriendly to stone building materials. Moisture, getting into the internal pores of aerated concrete, freezes in cold weather, expands and gradually tears apart the walls. This applies not only to cellular concrete, but also to brick and concrete. In our area stone house will never last as long as, for example, in Southern Europe. If the Parthenon had been built in Moscow, it would have long ago fallen apart into separate pebbles. External insulation will again help to extend the life of a building so that it can be passed on intact to great-grandchildren.

In heating engineering there is such a concept: “dew point”. This place is deep wall material with zero temperature. It is in this zone that condenses maximum quantity moisture and the material either freezes or thaws again. Dry blocks look and feel like they have an average moisture content of 5-8%. During the thawing-freezing process, this water little by little but inexorably wears away the stone of our walls. What's the solution?

Aerated concrete is hydrophobic (absorbs moisture) and it is not worth leaving a residential building unplastered for the winter, it will be damp

Remove the dew point from the wall, move it outward. That is, make sure that aerated concrete is constantly in the positive temperature zone, then it will last significantly longer. In addition, with the correct design, the wall will always be dry, which will create a healthy microclimate in the house. The fact that the dew point will completely shift into the insulation is not a problem. Firstly, it is an order of magnitude less susceptible destructive forces freezing water. Secondly, unlike a main wall, insulation is easy to reconstruct.

Choose a method: outside or inside

We have already mentioned that the house should be insulated from the outside. But doing it from the inside is cheaper, easier and faster? Yes, but not so. Yes, there is no need to install scaffolding. Yes, you can use cheap soft glass wool and cover the walls with plasterboard, immediately completing the interior finishing. Yes, you can work under a roof in winter and in bad weather.

Alas, by doing insulation from the inside, we lose a lot. Firstly, we shift the “dew point” not outward, but, on the contrary, inside the wall. Thus, we only worsen the operating conditions of aerated concrete and reduce the durability of the building. Secondly, almost every building has so-called “cold bridges”. “Warm” walls made of cellular blocks also have “cold” elements: floor slabs, reinforced belts, lintels. They are more thermally conductive and through them cold penetrates into the house, and money evaporates from the house. Insulating aerated concrete walls from the outside solves this problem. The house, like a fur coat, is completely enclosed in a heat-insulated shell. The internal insulation is like a gill caftan with holes: the belly is warm, but the back is cold.

Let's summarize: internal insulation only partially solves the problem, the only correct option is external. It makes sense to insulate it from the inside if there is simply no other way out. For example, for some reason it is not possible to change appearance facade.

Rigid mineral wool slabs are used for external insulation.

What material is better to use

The eternal question of all developers: mineral wool or polystyrene foam? Mineral wool is more expensive, but better. Polystyrene foam is cheaper, but worse. It’s like crayfish on Privoz: large ones cost five rubles, small ones cost three rubles. Let’s try to figure out why mineral wool is better and whether it’s worth overpaying for it:

Mineral wool and expanded polystyrene are extremely similar in thermal characteristics. The latter is even a little more effective. Mechanical properties and durability are also not much different.
Mice hate mineral wool and love polystyrene foam. If there is no finishing anywhere on the surface of the polystyrene foam boards, the Mickey Mouse family will immediately make a cozy hole there and settle in. But, if the facade is completely covered with plaster, this will not happen.
It is much easier to work with polystyrene foam, it is easier to cut, and random cracks are easy to eliminate construction foam. Mineral wool boards are a little more difficult to process and you will have to work with protective gloves, goggles and preferably a respirator.

Polystyrene foam is cheaper than mineral wool

Mineral wool is an absolutely fireproof material. Expanded polystyrene does not support a flame; it cannot be set on fire. However, when exposed to fire, it releases poisonous gases, similar to those that the Germans used during the First Imperialist War. In fact, if you don’t light fires along the facade and don’t pour gasoline on the walls, there won’t be any problems.
But in terms of vapor permeability, the materials differ radically. And this is important. Aerated concrete has optimal vapor permeability. A fairly large amount of moisture is constantly released inside a residential building. Cooking in the kitchen, washing machine, home flowers, wet cleaning. And people themselves give off moisture through their skin and breath. Aerated concrete is able to absorb this moisture and remove it through the pores of the material to the outside. The vector of vapor movement is always directed from the inside to the street. This phenomenon is called the “breathing” of the wall and it has a beneficial effect on the microclimate. By the way, cellular concrete is second only to wood in terms of vapor permeability and is considered one of the most human-friendly building materials.

Mineral wool fully supports the beneficial properties of aerated concrete. Being even more vapor-permeable, it does not prevent the walls from “breathing”. Polystyrene foam practically does not allow vapor to pass through. The house, insulated with polystyrene foam, is tightly packed, like a “stuff” in a plastic bag. Of course, you can ventilate the rooms by simply opening the window. Of course, on average, only 8% of moisture escapes through the walls in a “normal” house; the rest is removed by ventilation. However, the humidity of walls insulated with foam plastic still increases by 4-8%. Albeit insignificantly, but because of this they are decreasing thermal characteristics aerated concrete and the housing microclimate worsens.

Mineral wool is preferable for insulating aerated concrete walls

Undoubtedly, mineral wool has a significant advantage and is the best material for external wall insulation. Undoubtedly, polystyrene foam is radically cheaper and also serves good insulation. Conclusion: if your budget allows, it is better to use mineral wool. If “finance sings romances,” you can insulate the house with polystyrene foam.

What should be the thickness of the insulation?

We often see how people insulate their houses with thin slabs of 4, 3 and even 2 centimeters. This is a big mistake. Even the use of the most common 5-centimeter slabs is not very justified.

The thicker the insulation layer, the warmer the house will be and the lower the cost of gas or firewood. Everyone understands this. But it is not clear to everyone that by reducing the thickness of the insulation by as much as 40% (from 5 to 3 cm), the total savings on the structure will be only a ridiculous 10%. After all, the cost of glue, plaster, mesh, fasteners and labor almost does not depend on the thickness of the insulation and cannot be significantly reduced. That is why there is nothing stupider than investing in related materials and save on the main thing - the thickness of the insulation. Optimal, economically feasible insulation of aerated concrete walls for central regions Russia - 10 cm slab. It makes no sense to use material less than 5 cm thick.

“Wet” and “dry” insulation

We won’t go into detail existing methods insulation. Manufacturers develop complex technologies and create clear, very detailed and well-illustrated manuals to help performers. They can be obtained from material sellers or downloaded online from original sites. Let us only mention that the instructions are written for a reason, and the technology must be followed strictly. Also, do not attempt to replace any materials from complex systems to cheaper ones. For example, it happens that instead of special adhesive and plaster compositions, the cheapest tile adhesive is used for insulation. Yes, it will stick the slabs, but the service life and vapor permeability will be significantly lower than that of the “correct” composition.

"Wet" system is lightweight

In fact, with the so-called “wet” technology, the facade remains completely dry. The insulation is fixed to the wall with glue and dowels with a large head. Then two thin leveling layers of plaster are applied, and a reinforcing layer is placed between them. plastic mesh. Aerated concrete walls are smooth, there is no need to prepare them, just remove dust. Finish - decorative plaster or lungs facing tiles from porous ceramics or concrete.

One of the options for the “wet” system. You cannot skimp on dowels, corners and mesh.

"Wet" system is heavy

If you really want to clad the facade with stone or heavy ceramic slabs, you will have to use “heavy” technology. In this case, the insulation is not glued, but attached to the wall with powerful hooks, a strong metal mesh is placed on top and the structure is fixed with metal plates. A thick (20-40 mm) layer of cement-sand plaster is applied over the mesh. Now you can place the stone. Such a system is significantly more expensive than a “light” one.

"Dry" system

It is also called a ventilated or curtained façade. It involves installing a frame outside the facade, metal or wood. Insulation is placed between its elements - inexpensive soft mineral wool or even cheaper glass wool, polystyrene foam. Sheathing the frame various materials: more often it is plastic or metal siding, wooden cladding board. Curtain facades from porcelain stoneware or stone slabs, colored glass roads and for residential buildings used infrequently. A “dry” facade, if you do not use expensive types of cladding, is cheaper, but less attractive from an aesthetic point of view.

You must remember to leave an air gap of at least 2 cm between the insulation and the siding so that the walls have the opportunity to “breathe”

Brick cladding

The last option is to cover the facade with brick. In this case, a frame is not needed; the insulation can be attached directly to the wall. An air gap should be left for ventilation of the insulation. Brick and the inevitable thickening of the foundation will cost a pretty penny.

To brick cladding has not collapsed, it is attached to the main wall with anchors

To summarize, we get the following: the optimal solution in terms of price/efficiency/aesthetics ratio for temperate climatic zones of Russia is external insulation of aerated concrete walls with 10 cm thick mineral wool slabs using “wet” technology. Acceptable budget options- “wet” foam facade or polystyrene foam + plastic siding. Properly executed insulation of external walls will reduce heating costs by approximately half.

Aerated concrete blocks are very popular for the construction of residential buildings, cottages and households. buildings During construction, there is a clear saving on the price of the wall itself, on insulation and finishing, and perhaps even on the foundation... Many consider porous concrete the most suitable materials for a home. But not everything is so simple and unambiguous. Let’s consider what negatives users found in aerated concrete based on operating experience, and what experts point out.

Aerated concrete is universal and inexpensive

Factory-made aerated concrete made in an autoclave has very precise dimensions, known characteristics, and is also environmentally friendly - it does not emit anything. For the construction of walls of residential buildings, grades D400 (400 kg/m3) and D500 are usually used.

Precision manufacturing allows you to apply a thin layer of glue when laying and make the wall surface almost flat. It is enough to apply fairly thin and cheap layers of plaster on the wall. But if the vertical joints in the masonry were not filled (usually), then to prevent increased air permeability, it is necessary to have plaster on both sides, usually 10 mm thick.

Aerated concrete is very light. Therefore, a foundation can be designed with less bearing capacity, which should also be cheaper, it seems...

The walls may not be insulated

D400 is less durable, but more heat-saving. So, for the climate of the Moscow region, if the humidity of the block is not increased, and the masonry is made at thin layer glue or on a heat-saving solution, then the thickness of the wall made of it, which meets the heat-saving requirements, will be only 46 cm. That is. actually the length of one block.
For the D500, this value is actually already about 63 cm.

But, as you know, heat loss at home should not generally exceed certain standard values. Even standards allow increased heat leakage through some structures, provided that they are compensated by increased thermal insulation in other places.

Therefore, if everything is in order with the thermal insulation measures on windows and doors, floors, foundations and roofs, and the ventilation of the building is according to the standards, then insulating aerated concrete walls of large thickness is not an economically profitable measure.

The absence of an insulating layer is very significant savings compared to cold materials for wall construction.

In addition, a single-layer wall is simpler and cheaper, more trouble-free not only in construction, but also in maintenance; during operation, you do not need to expect surprises from it, in the form of shedding or wetting of the insulation...

The foundation you need is not cheap

The foundation may have a lower load-bearing capacity, but is much more rigid than for brick. Does not allow bending. In fact, it is even more expensive than usual. Aerated concrete is very fragile, and a crack in the wall due to improper laying with the formation of local stress, especially when installing lintels and reinforced belts, is a common occurrence.

Moreover, movement of the foundation is unacceptable. An expensive strip reinforced concrete foundation of increased rigidity is needed - only it can save the situation and prevent the appearance of cracks. Its design and dimensions are specified in the project, but it is by no means cheap...

The need for proper masonry and use of armored belts

The fact that the creation of point stresses, for example, from a beam above a window, can lead to the destruction of a wall made of aerated concrete has already been said. It is necessary to involve only competent specialists for construction in order to avoid too costly mistakes.

Also, to avoid point loads, it is necessary to create reinforced belts, for example, create a concrete belt for beams attic floor. And also competent thermal insulation of this concrete. All this is quite complicated and not cheap.

In addition, the strength of aerated concrete, as a rule, even with an armored belt, is not enough to support heavy rigid concrete floors. Only wooden beams are possible.

Difficult to use

Question of external plaster or additional insulation not so simple. If the plaster crumbles or cracks, then blow-out may occur in masonry with empty vertical joints. Residents will not understand why it is cold.

The second question is not correct selection by vapor permeability. Aerated concrete itself is very vapor-transparent, so the outer layer on such a wall should have less vapor permeability than the masonry itself, otherwise the blocks will get wet.

If external plaster(insulation) and paint, for some reason, or due to its own poor quality, will have great resistance to the movement of steam, then a very serious problem will arise. And the residents again won’t know about it. So there's a risk artificial creation There is moisture accumulation in the material...

Risk of destruction by water

The material is quickly destroyed by water. A wet wall made of aerated concrete cannot exist for long. This is aggravated by freezing. Violation of horizontal waterproofing on the foundation (basement), capillary suction of water into the masonry from the ground - and how to save the house is not yet known...

If the roof is damaged, there may be a water leak and a wet wall that is not noticed in time...
Violation of vapor exchange, due to an incorrect outer layer, as indicated, can lead to detrimental consequences...
Humidification by precipitation in the appropriate seasons, with unreliable façade finishing...

In general, the thoroughness of waterproofing measures during construction and during operation should be the highest. You need to monitor the condition of the walls... Will it be possible to keep all the walls dry?

Difficulty hanging anything

Everyone is accustomed to the fact that the heating boiler is “hanging”, half kitchen set- hung on the wall, boiler - “well, it’s not worth it.” But how to do this when the walls and partitions are made of porous lightweight material, such as pumice?

There are special dowels for fixing to aerated concrete. But they are more expensive. And the fastening cannot be called reliable.

As a result, under heavy objects, or placed on the wall metal frame and everything is hung on it, or a couple more sheets of cement particle board are glued to this wall...

A nail that doesn't stay in the wall is a problem and not a convenience.

Something needs to create heat capacity

Aerated concrete is too light and practically does not accumulate heat. But the house must have temperature stability. It's extremely uncomfortable without her. Comfort is achieved in a brick house large array heavy materials. And no matter how the temperature outside changes overnight, no matter how much the door is opened, everything in the house is stable.

In houses made of SIP panels, this function is performed by heated ventilation.

But what to do in aerated concrete? Don't resort to expensive but untrustworthy fans made from frame houses. It remains to place tens of tons of concrete in a heated floor, for example, or in massive interior partitions. In general, there is one more “but” that needs to be solved...

What is the durability of aerated concrete?

WITH brick house everything is clear - he is, relatively speaking, “eternal.” And they don’t give any guarantee for aerated concrete... There are no known facts that the manufacturer guarantees anything and promises to fix it if problems arise.

There are already more and more reviews that aerated concrete is starting to crumble. The service life of a wall under load is a maximum of 40 years for high-quality factory-made aerated concrete in a frosty climate... There are many such reviews, and entire aerated concrete walls older than 50 years are found only where the temperature does not pass through 0. Probably various shortcomings mentioned above in combined, plus the state of stress under load with changes in humidity and freezing, leads to the fact that the blocks are covered with a web of cracks. Which only diverge over time.

However, this material is still considered new, and extensive experience of its long-term operation has not been accumulated with clear conclusions. But there is no refutation of the above data yet...