Easy to process, warm and inexpensive, aerated concrete is increasingly used both for construction and for the installation of internal partitions. In this article we will talk about the types of gas and foam concrete, the differences between them, the scope of application and the main technical characteristics.
Strengths and weaknesses of aerated concrete
Cellular or lightweight concrete (aerated concrete, foam concrete) is a dense, homogeneous material, the density of which is very low due to the large number of small (1-3 mm) pores formed during foaming and molding of blanks.
Initially, aerated concrete blocks are formed very large, but they can be cut at the discretion and size of the customer. No less common are ready-made products for masonry - similar to cinder blocks, but only 10 times lighter and sometimes with tongue-and-groove locks.
Lightweight concrete can withstand uniform static loads well and has high compressive strength. But under single-point dynamic influences, it easily crumbles, so critical elements and suspended structures cannot be attached to it.
The advantages of the cellular structure include low thermal conductivity and excellent noise absorption of both structural and airborne nature. You have to pay for this with fairly high water absorption. It would be a mistake to assume that lightweight concrete does not require protection and insulation. In a wall of uniform thickness, condensation forms in the thickness and destroys the structure, so walls made of aerated concrete are not a panacea at all. They are also demanding in terms of installation techniques and need protection like any other building material.
Varieties and varieties
Aerated concrete and foam concrete are often considered as completely different building materials. This is partly true, because different pore-forming substances are used in production. Foam concrete is positioned as a lower quality material due to the use of chemical foaming agents. In fact, the so-called “local” or monolithic foam concrete, which is prepared at a construction site, has deteriorated characteristics, but it is not considered within the scope of this article.
Foam concrete and factory-produced aerated concrete (despite the different technology) can be combined into one class simply because of similar characteristics; good foam concrete is rarely inferior in quality to its main competitor.
Foam concrete and aerated concrete can be autoclaved and naturally dried. The first type is preferable due to the smaller deviation of technical parameters, although in one-story buildings non-autoclaved concrete is used very often and without any special complaints.
All other indicators: density, frost resistance and others like them are specified by the construction project or standard examples of construction.
Foundation for a house
Many people are attracted to aerated concrete because of the opportunity to save on the foundation as one of the most expensive elements. Cellular concrete is indeed lighter (often an order of magnitude) than cinder block or shell rock, however, to impart the required strength, the wall pillar must be wide enough: 35-40 cm for single-story buildings and 45-60 cm for multi-story buildings. The ratio of width to depth, even for shallow foundations, is at least 1:2-1:2.5, so that the structure absorbs the load with an edge, otherwise, when heaving, the foundation will deform even under its own weight.
Among the alternative options, you can consider strengthening the foundation with screw piles or casting a crown - an expander in the upper part of the basement floor. In any case, the foundation should not be made thinner than the wall by more than 30-50 mm, despite the fact that manufacturers of cellular concrete allow an overhang of a third of the wall thickness. Also, an aerated concrete wall must be insulated from the foundation with roofing felt or other rolled waterproofing.
Load-bearing capacity of aerated concrete walls
The ability of lightweight concrete to withstand compressive loads can confidently be called sufficient, but not excessive. In practice, this translates into the fact that the floor beams cannot rest point-to-point on the wall itself; an armored belt needs to be poured. It should be reinforced, but not necessarily massive. 15-20 cm is enough for roofing or attic and 25-30 cm for interfloor slabs. Beams, if used, can be poured and protected with concrete, although due to the excessive width of the wall, they are often simply covered with blocks.
Floors made of monolithic and stacked slabs do not need to be filled with a preparatory belt. Sometimes, when pouring an interfloor ceiling, a side of thin (8-12 cm) blocks is laid out on the outside of the walls and used as formwork. This solution allows you to support the ceiling quite firmly on the walls and eliminate a very large cold bridge.
Thermal and sound insulation properties
Although foam and aerated concrete have high thermal and sound insulation, it is still necessary to make the wall structure uneven in order to somewhat optimize these properties. For example, enclosing walls are often laid out in two rows, leaving an air gap, due to which the wall will dry naturally.
Aerated concrete walls provide almost no insulation from the inside. To stop excess heat transfer, one layer of rolled insulation up to 10 mm thick is enough. In houses made of aerated concrete, the main thermal insulation is taken outside to bring the dew point into a layer of non-hygroscopic material and protect the wall from blowing. For this purpose, 30-50 mm polyurethane slabs with locks on the edges are used.
Masonry walls made of foam concrete
As for the masonry technique, even amateurs can easily master it. Due to the light weight and large size of the blocks, they can be installed alone and quickly.
The first row is laid out with grade 300 cement mortar on top of rolled waterproofing on the foundation. First, the blocks are installed at the corners, adjusted in a common horizontal plane with a water level, and aligned exactly to the design dimensions using a laser axle builder. After a few hours, the lacing is pulled over the corner stones and the first row is filled. It is carefully leveled with a slatted level and left to dry for a day.
All subsequent rows are laid with vertical joints offset by a third of the length of the block or at least 150 mm. The laying of blocks can be done with reinforcement of every second or third row. When all the walls are driven to a common level, using a special scraper, grooves are cut at the end, one for every 200 mm of wall thickness. The profile reinforcement is bent according to the shape of the grooves, then the grooves are filled with cement mortar grade 300 of liquid consistency and the reinforcing bars are embedded in it. It is optimal if the rods do not break at the corners of the building, but bend with a small radius.
When building with lightweight blocks, it is very important to lay the masonry sequentially and start a new row only if the previous one is completely finished. Before applying the adhesive, the surface of the masonry must be thoroughly cleaned with a trowel and swept away from dust, especially if the previous row is reinforced.
Aerated concrete has a cellular structure. For its production, a mixture of lime, cement, quartz sand and water is taken. As a result of the reaction between aluminum powder and lime, hydrogen is formed. This, in turn, creates bubbles that occupy 85% of the block and provide low weight and high strength to the material.
By contacting the SVOD-STROY company, you can order the construction of a house from Aerostone and Bonolit autoclave aerated concrete blocks. They are distinguished by precise geometry and maximum strength. Such cellular blocks do not require the use of tools with carbide tips during construction and finishing and are easy to process, drill, saw, etc.
Turnkey aerated block houses are easy to assemble and are identical in comfort to brick cottages. They are convenient for year-round living in the Moscow region. Their main advantages are the ability to implement complex projects, affordable cost and reliability.
Differences between aerated concrete and foam concrete
Foam concrete is made from a concrete mixture diluted with special additives. Such a mixture can be prepared directly on the construction site without any certificate.
In contrast, aerated concrete is manufactured in factories. First, as a result of a chemical reaction, a mixture is formed, which is strengthened using an autoclave and cut with special strings. At the SVOD-STROY company, the construction of aerated concrete houses is carried out strictly from materials manufactured in accordance with GOST requirements.
Advantages of cottages made of aerated concrete blocks
A house made of aerated concrete blocks needs external insulation and shrinkage within 3-6 months. After this, it can be processed in any way and can be absolutely comfortable for year-round use. Block houses belong to the middle price segment, but in terms of comfort and durability they are not much inferior to brick structures.
The undeniable advantages of this structure are:
- profitability - the affordable cost of aerated concrete and its lightness, which allows the use of simple foundations, reduce the overall price of a finished block house and the cost of builders’ services;
- reliability - strong and durable blocks, subject to construction technologies, will serve more than one generation of residents;
- moisture resistance and frost resistance - these characteristics allow you to live in such a house at any time of the year;
- speed of construction - ease of processing determines the speed of installation.
House projects
The SVOD-STROY company provides turnkey construction services for houses made of aerated concrete blocks according to standard and individual projects. Since 1997, we have been conducting professional construction of private real estate in Moscow and the Moscow region. We offer the most reasonable prices for materials, labor and architects.
Our catalog presents more than 120 original projects ranging from 65 to 520 m2. Any of them can be modified in accordance with individual wishes. Our specialists in Moscow will advise on projects and prices for houses made of aerated blocks, and will also provide guidance on the timing and work plan.
In this article I will tell you how to build a house from aerated concrete 10 by 11 meters, with an area of 150 square meters, with an attic with your own hands. We built this house in the village together, and from the foundation to moving into it, in 2 years it took us a total of 10 months and it took us 1 million rubles for all materials and other expenses.
How I built a house from aerated block with my own hands
Long before construction begins!
Four years later, having moved from the city to the village, we decided to build our own house in the village.
We purchased materials: boards, beams, approximately 50 cubic meters of gas block, 5 tons of cement, 25 tons of pgs (sand and gravel mixture), bricks for the plinth, and many other small things.
After all the materials were purchased, we marked out the house 10 by 11 meters, drilled about 30 holes 2 meters deep with a tractor, filled these holes and inserted reinforcement into them. At a depth of one and a half meters there is gravel, apparently there used to be a river here, but now it has moved lower. After the concrete had hardened, they dug a trench under the foundation, sprinkled it with sand, and compacted it.
Then we made the formwork for the foundation, tied the reinforcement together, inserted it into the formwork and began pouring concrete. Cement and gravel were transported to the concrete mixer in two wheelbarrows. All the work was done together with my father.
The markings for the foundation level were made with a level. The concrete was immediately leveled, making it smooth and beautiful.
Spring came! Birds are singing! Let's go to the house! The basement was laid out last fall, there are no photos, as there was apparently no time at all.
I dug a basement and insulated the foundation from the outside and inside with the same soil. The beams were dragged and stacked together in half an hour. Joke! In one hour! Hee hee hee! We did this in April, since it is easier to drag them through the snow. The snow melted and water formed in the basement. He scooped up water in buckets. I sanded the beams with an electric planer to make it beautiful and easier to apply paint on wood. The beams were treated with antiseptic and wood protection.
The month of May! We started laying out the walls from aerated concrete blocks.
Let's get closer! The gas block is non-autoclave, which is why it is so cheap. I fell for the price! A lot of marriage! Manufacturers hid the bad blocks inside the pallet! One block is wider, the other is narrower. Bad office! It's bad to deceive people! It's a pity! Then he built a stoker out of bad blocks.
New day! Things are going slowly! We're working!
I did the floor of the first floor in 2 days!
I mix the mortar, carry blocks, and my father lays out the walls. We are working! It's already evening!
New day, we continue construction. There is still a lot of work!
It seems to be a little small.
We already have windows and doors. We work every day!
I made scaffolding out of pallets while my father visited the bees at the apiary.
The gas block is over, only the defect remains.
We bought a foam block for the second floor and laid it upright.
We continue! We lifted the beams with a crane onto the second floor. It rains non-stop for weeks.
Lay the floor beams for the second floor
A bird has made a nest in a pallet! I can't imagine when she managed to do this?
I made the floor on the second floor of the house.
We're not sure, but we're hoping to move into our house by December.
They called a lot of relatives and set up the rafters.
There were many relatives here again, they closed the roof! Now we are not afraid of rain!
They also made a veranda. I didn’t even think that we would do it right away.
There is a lot of garbage around!
I dug a trench for the sewer. I lay down the pipe, one, two, three.
Formwork for a sewer ring, only ours is square.
Beautiful! On one side of the house!
There is still a lot of work. The stoker was laid out in two days.
We built a staircase to the second floor. Now it has become very convenient to go up there!
Second floor. I don’t remember what I did then.
I insulate the second floor attic with glass wool. Insulation thickness 200 mm.
Sawdust for insulating the second floor ceiling. Earth is also placed on top of the sawdust.
Second floor ceiling hatch.
Sawdust on the edges of the ceiling of the first floor of a house in the village.
Personal stoker.
We made a roof for the stoker. It will continue with a bathhouse.
This is the only way lumber goes away! A lot of firewood has accumulated!
Late fall! Digging a water pipeline with a tractor! Oh, we had a lot of trouble with this tractor! Either the oil is leaking or something else! We've been digging for three days! From the house to the connection with the water supply 130 meters, we dug 2 meters deep. The area here is swampy, with swamps all around. You dig half a meter and it’s already water. The pipe was laid immediately, as the ground was quickly collapsing. The house already has windows and heating. While we heat the stove with wood!
Sorry! But I don’t have any more photos of the house construction! We were in a big hurry! We plastered the walls of the first floor, screwed drywall onto wood screws, plumbing, furniture, wallpaper, electricity, gas, water supply. And yet we managed to do everything on the first floor! It was also possible to live on the second floor; there was light there, but there was no renovation. All this was done in ten months. We worked together with our father! But of course, we called our women to paint, whitewash and glue wallpaper!
In 2013, in August-September, the foundation and plinth were made. In 2014, from May to December, we did the rest! On December 26, we moved with our family to live in this, our new home. And as you understand! We invited many guests and celebrated a housewarming party on December 31st! Hurray!)))
Thanks to all! Who finished reading my story of building a house in the village! Watch my story in more detail on YouTube! Good luck! Bye!
You cannot build a building higher than 5 floors. However, for the needs of private construction this is usually quite sufficient. In this article, we will introduce you to projects for building a house made of aerated concrete, its prices, make calculations and estimates, and share useful photos and videos.
Aerated concrete is a subtype of lightweight concrete with all the ensuing advantages and disadvantages. When building a residential building, these qualities must be assessed from all points of view.
The video below will tell you more about the advantages and disadvantages of aerated concrete houses:
Advantages
- Thermal insulation– indicators depending on the type of aerated concrete vary from 0.072 to 0.14 W/(m*S). Taking into account the standards for resistance to heat loss, which are pleasant in Russia in the middle zone, for example, the wall thickness should be 37.5 cm. However, much here depends on the density of the selected material: for example, when building from structural aerated concrete, the wall thickness increases to 50 cm, since its thermal insulation qualities are lower.
- Strength– Autoclaved aerated concrete is the most durable. Due to the special features, the micropores are distributed here as evenly as possible, which also allows the load to be evenly distributed. This makes it possible to compare.
- Aerated concrete is quite different high vapor permeability, which is a definite plus for a residential building. The walls “breathe” and, to some extent, remove moisture from the room.
- Gas blocks have perfect geometric shape. This allows you to lay the “bricks” not on the mortar, but on the glue. In this way, the absence of “cold bridges” is ensured, and the surface of the walls is smooth.
- Material easy to process using any mechanical methods: it can be sawed, cut, grooves, recesses can be made in it and unusual architectural forms can be realized.
- Light weight even with large wall thicknesses, it creates a much smaller load on the foundation for a house made of aerated concrete than a brick one.
- Construction time dwellings made of aerated concrete are minimal: the foundation takes the longest to build.
- Price aerated concrete blocks are noticeably lower in cost than bricks.
Flaws
Unfortunately, the disadvantages of aerated concrete buildings are also quite significant.
- Despite the relative ease of construction, the foundation will have to be tiled or monolithic strip: aerated concrete has low resistance to tensile loads. This means that when the foundation shrinks, the walls will become covered with cracks.
- Aerated concrete absorbs moisture to an even greater extent: it is open porous. The material does not store moisture, but dries over time, but in order to get rid of dampness it must be protected.
- High vapor permeability limits the choice of exterior finishing: a ventilated facade, siding with a ventilation gap, or special porous plaster are suitable. If these requirements are not followed, moisture will actually accumulate in the wall, leading to destruction.
How to build a house from aerated concrete with your own hands?
Construction from aerated concrete has its own characteristics. The masonry technology itself is simple - ordinary brick with ligation. However, due to insufficient strength, reinforcement is mandatory for the structure. So, let's look at the main stages of building a house made of aerated concrete.
This video will tell you about building houses from aerated concrete with your own hands:
Foundation
First of all, lay the foundation - slab or strip. If the building is supposed to be higher than three floors, the foundation must be slab. This is a very material-intensive and labor-intensive foundation, but, fortunately, the foundation here is shallow.
- A trench or pit is dug under the foundation, the bottom is filled with sand to a depth of 20 cm, the sand is wetted and compacted.
- Formwork is installed - usually from boards or. The height of the foundation above ground level is 30–40 cm.
- The foundation is poured in layers - no more than 15 cm. Reinforcement is performed twice or three times: for this, the frame is tied from rods with a diameter of 12 mm. If a blind area is planned, then one of these frames also covers the blind area.
- Concrete is compacted using bayonets or vibrating attachments.
Further construction is possible only after the concrete has set and reached its design strength. Then the formwork is removed.
Laying
- Cut-off waterproofing is installed - usually 2 layers are laid on the foundation.
- The first row is laid in a ratio of 1:3. Particular attention is paid to leveling: the masonry mortar allows you to achieve precise horizontality. The first row must be reinforced: for this, two rows of rods with a diameter of at least 8 cm are placed in the masonry layer.
The thickness of the wall is 35–40 cm, the distance of the reinforcement rod from the edge of the block is 6 cm. If the thickness of the masonry is 20 cm, then reinforcement with one rod is allowed.
- It is recommended to lay the next rows with special glue. The ideal geometric dimensions of the gas blocks allow for very precise, tight joining. The adhesive layer, unlike masonry mortar, is much thinner - 0.7 cm, which subsequently prevents the formation of “cold bridges”. The glue is applied to a clean surface with a trowel and leveled with a spatula-comb.
- Every 3 or 4 rows, reinforcement is carried out. Since the glue layer is too thin, grooves are made for this - 12 mm wide. Reinforcement is placed in them and glue is applied.
- In addition, it is necessary to reinforce the row under the window opening - the width of the opening plus 90 cm, and the places where the lintels rest above the windows and doors.
- In places where the thickness or height of the walls changes, expansion joints are installed at the intersections of long walls and the like. Aerated concrete does not bend, and such gaps make it possible to partially compensate for the load. The seams are sealed with mineral wool, polyethylene, and treated with sealant.
- Lintels over openings are made from U-shaped blocks. They are laid at a width equal to the width of the opening plus 90 cm, reinforcement is placed inside - 2-3 layers and filled with concrete. The same structure can be made from ordinary boards and blocks, but in this case the blocks will have to be cut to width.
- An armored belt must be installed between floors or under the roof. In the simplest case, formwork is constructed for it, reinforcement is laid in at least two rows and poured with concrete of the same strength as the foundation.
If we are talking about a roof, then studs are embedded in the armored belt for attaching the Mauerlat.
Flooring and interior finishing
- The interfloor ceiling is constructed from concrete monolithic slabs, monolithic cellular concrete slabs or light reinforced concrete beams filled with T-shaped blocks of aerated concrete. It depends on the specifics of the project.
- or aerated concrete chips. However, this is rarely done, since in practice, insulating a floor with foam plastic turns out to be much faster and more profitable, since foam plastic is a much better heat insulator than any cellular concrete.
- Finishing a building made of aerated concrete is mandatory, and finishing must be done first from the inside and then from the outside. The material equally absorbs moisture and if you start finishing from the inside, this will not allow moisture to accumulate.
By finishing:
- Almost any material is suitable for interior decoration, since its vapor permeability should be lower than that of aerated concrete, and this is easy to do.
- For exterior finishing, special porous plaster is optimal. A good option is a ventilated facade, although it is more difficult to arrange.
Read on to find out how much it costs to build a house from aerated concrete, and what the price is for services of this type.
The following video will also help novice builders when building a house from aerated concrete:
Projects and cost estimates
If the future owner of the building is not a professional builder, the design stage must be entrusted to specialists. The cost of mistakes here is too high, but in a residential area it is necessary to provide not only the box itself and partitions, but also the installation of water supply, sewerage, electrical networks, gas pipelines, and so on.
Here you can only calculate the approximate volume of materials yourself.
Often, construction companies develop projects for free, provided that they are the ones entrusted with implementation. This does not apply to complex projects. Many of them offer a large number of turnkey projects of various configurations, sizes and prices.
- The cost of publication depends on many factors.
- A modest one-story building with an area of 50 square meters. m. costs 1,250,000–1,450,000 rubles.
- One-story building with an area of 200 sq. m. with a terrace – 3,800,000 rub.
- A two-story building will cost no less than 2 million rubles. with an area of up to 130 sq. m.
A two-storey cottage in the constructivist style with an area of 500 sq. m. will cost 5 million rubles. and higher.
Projects of houses made of aerated concrete 
Project of a house made of aerated concrete - 1 
Aerated concrete house project - 2 
Aerated concrete house project - 3 
Aerated concrete house project - 4
I receive a huge number of questions about the choice of material for the walls of a country house, so let’s look at this issue in detail again and draw the conclusion that aerated concrete has no alternatives at all. This is the best material for load-bearing and enclosing structures of buildings of any number of floors. If you want to get a “warm” permanent house, then you simply have no options. And the most important thing is that an energy-efficient house made of aerated concrete can be operated comfortably even if you do not have a connection to the gas main. And all this is possible without additional insulation!
In this article we consider only permanent stone houses. Naturally, there is also a frame construction technology, but we will consider it in a separate material.
Aerated concrete has made no less a revolution in construction technologies than, for example, geotextiles or extruded polystyrene foam. The history of aerated concrete begins in the 30s of the last century, so the material has already stood the test of time in a wide variety of climatic regions of our planet. It is important to note that not all aerated concrete can be considered energy efficient, so it is very important to pay attention to the actual characteristics from specific manufacturers.
The main negativity that is spreading online is connected to this. Homemade aerated concrete produced in violation of technology will not have sufficient strength and resistance to heat transfer. This means it will not have any advantages compared to ordinary brick. The second important point is the mandatory adherence to technology when working with aerated concrete.
It has long been known that construction in compliance with technology is not only cheaper, but also faster. Unfortunately, many people prefer to violate technology and then heroically overcome the difficulties that arise, losing not only time, but also money. After all, it is obvious that low-quality material used in violation of technology will not lead to anything good.
So, let's take my own house, which I built in 2012, as an example. This is a capital country house on a foundation slab with aerated concrete walls and a monolithic ceiling with a flat (green) roof. It was put into operation in 2014. It is important for any person that the house is inexpensive to build and economical to operate. I'm no exception here. Therefore, the most important criterion when choosing a material for walls is heat transfer resistance. After all, if the wall is “cold”, then I will simply heat the street. And this is excessive energy consumption and cold in the house (in my case, also the lack of main gas plus the limit of electrical capacity allocated in SNT).
Therefore, I chose the best of all available technologies - a single-layer wall made of YTONG aerated concrete with a density of D400 and a thickness of 375 mm. The masonry was done strictly according to technology with the obligatory sanding of each row and using a special glue for thin-seam masonry (the smaller the thickness of the joint, the less heat loss). Naturally, I additionally insulated the lintels above the windows and door, as well as the perimeter of the monolithic ceiling. I also draw attention to the presence of quarters on the window openings.
From the outside, the wall is simply plastered with 10 mm thick cement heat-insulating plaster and puttied with white cement (I still haven’t found the time to paint the walls).
The inside is a similar story: the walls are plastered with a thin (6 mm) layer of gypsum plaster, puttied and painted. Taking into account the fact that aerated concrete blocks have an almost ideal geometry, this ensured that there was no overuse of plaster due to unevenness (for example, if the walls were made of brick with cement joints 2 cm thick) and greatly simplified the work. Aerated concrete is very easy to process and for laying electrical wiring, the wall can be drilled practically with a screwdriver.
Wallpaper, simply painted walls or tiles (in the bathroom) are used as a finishing coating. Aerated concrete is also incredibly convenient because it is very easy to hang anything on it. Try, for example, driving a nail into a brick wall to hang a picture. Without an impact drill/hammer, you won’t be able to do anything, but you can hammer a nail into aerated concrete with any available tool, and it will easily support a weight of several kilograms (for a picture, this is more than enough). If you wanted to move the picture to a new place, you simply pulled out the nail, and on the wall you would be left with an invisible hole with a diameter of 1-2 mm. And in the brick wall there will be a mark from the dowel with a diameter of 5-7 mm. If we are talking about stationary fastening of heavy objects, then everything is much simpler. Especially when compared with hollow bricks, for which you will have to use chemical anchors. For aerated concrete, there are special screw dowels or universal dowels (both are sold in any hardware store) - on these dowels I hang an external air conditioner unit (80 kg), a storage water heater (90 kg), a kitchen set, a ladder to the roof and others heavy objects.
As a result, I got an ideal perimeter that reliably protects the interior of the house from the cold. Tests using the air door showed that the house is practically airtight and, therefore, there are no gaps in the building envelope. The aerated concrete wall is plastered over its entire surface both outside and inside, which completely eliminates blowing through the seams. And this is the most direct savings on energy resources.
Aerated concrete can be additionally insulated without any problems (if you suddenly decide to build a house in the Arctic Circle), or you can perform a more impressive finish using facing bricks. But the most important advantage of aerated concrete is that it combines two important characteristics: compressive strength and thermal conductivity. Aerated concrete can be safely used in load-bearing walls of five-story (!) buildings, and it will have significantly lower thermal conductivity than concrete or brick.
And here it becomes obvious that concrete or brick have no chance at all for use in low-rise construction. Because it is long, expensive and cold. Let’s take my house as an example and calculate the costs if I were to build it out of brick.
But before we start the calculations, I want to show you a picture from a thermal imaging study (see the full report on the blog), which I did in January last year, when the temperature outside was below -15 degrees Celsius. Notice the house in the background. Now we are not interested in what it is built from (in fact, it is made of cinder blocks and insulated with foam plastic). What interests us is that this house is not used and is not heated all winter. And in the foreground you see my house, which is heated. And only by the windows “glowing” in the image from the thermal imager can one understand that this is so. Pay attention to the uniformity of the aerated concrete masonry and the absence of any heat loss through the walls. For example, you can open Yandex image search and see what heated brick houses usually look like. Here my house practically does not stand out from the surrounding landscape.
Now let's move on to calculating heat transfer resistance. I won’t burden you with complex formulas, we’ll keep things simple and clear. So, to begin with, we take the initial data, and not just any data, but the official test report, certified by the seal of the research center. Let me remind you that I used blocks with a density of D400 and a thickness of 375 mm.
And here is a graph of heat loss that you need to strive for. Here you can clearly see that the heat loss of enclosing structures consists of three main things:
1. Windows and doors;
2. Walls;
3. Ceiling (floor/ceiling).
At the same time, the coldest places in any house will always be windows and there is no escape from this; today the best double-glazed windows have a reduced heat transfer resistance of 1.05. But the walls of houses built in the central region (Moscow region) should have a reduced heat transfer resistance of 2.99 (m² ˚C)/W. And please note that the ceilings should have maximum insulation.
But now we are not talking about windows and ceilings, but about walls. So, in order for our house to meet current energy efficiency standards, the reduced heat transfer resistance of the walls must be at least 3.0. Let’s use, for example, this calculator and substitute the data from the above test report into it. And we will get that
Heat transfer resistance of the building envelope [R] = 3.57
Okay, let's be realistic: let's take into account the heterogeneity of the masonry (seams), slopes and corners. Let the reduced heat transfer resistance be equal to 3.28. And this is a pure aerated concrete wall, without taking into account the additional layer of plaster on the inside and outside. That is, in reality, the heat transfer resistance will be slightly higher.
For example, let’s take a masonry of solid ceramic bricks with a density of 1800 kg/m³ on a cement-sand mortar. With a wall thickness of 375 mm, its heat transfer resistance will be only 0.62! This is almost 6 times “colder” than masonry made from aerated concrete blocks. That is, a brick wall equivalent in terms of energy efficiency should have a thickness of more than 2 meters. You understand that this is nonsense and no one will build a wall of such thickness in a low-rise building. This means you will have to build a brick wall of one or one and a half bricks, and then additionally insulate it. And after insulation, you still have to think about how to attach the finishing coating to the insulation. That is, in this case we complicate the construction process.
And the labor-intensive nature of masonry is best evidenced by the fact that one aerated concrete block (625x250x375 mm) is equal in volume to 20 bricks (250x120x65 mm), taking into account the cement joint! And in order to lay 20 bricks you will need approximately 1.5-2 buckets of mortar (if you work with aerated concrete, this amount of mortar will be enough to lay more than 20 aerated concrete blocks). That's the whole economics of brick construction. That is, just for the construction of a brick house you are greatly overpaying.
But the hardest part will begin during operation. It will simply be impossible to operate a poorly insulated brick house if you do not have an “unlimited” and cheap source of thermal energy (mains gas), because you simply do not have enough allocated electrical power (standard 15 kW).
If the walls of your house comply with current standards for heat transfer resistance, then you can economically heat a stone aerated concrete house using electricity without any problems.
The conclusion is obvious - in capital low-rise construction there are simply no alternatives to energy-efficient aerated concrete. At the same time, if we consider the final cost of enclosing structures, it turns out that such a solution is cheaper not only at the construction stage, but also during operation.
P.S. Of course, we do not forget that the energy efficiency of a building is not only the walls, but also windows/doors, foundation and ceiling (roof). And, of course, fresh ventilation. Only if all conditions are met simultaneously can a house be considered energy efficient.
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All publications about how this house was built can be found
