DIY aerated concrete house.

2015-09-18

It is difficult to imagine modern low-rise construction without the use of materials made from cellular concrete, especially without a prominent representative of this family - aerated concrete.

Often, future novice developers confuse it with gas silicate and foam concrete, but despite the obvious similarities, there are also differences between them. Therefore, if a decision is made build a house from aerated concrete with your own hands You should learn more about its operational characteristics and features of working with it.

Aerated concrete is produced autoclave and non-autoclave methods from sand, cement, lime and some other components, from which aluminum powder should be isolated ( paste or suspension). It acts as a catalyst for the reaction, as a result of which oxygen is released and, accordingly, the characteristic porous structure of the material is formed.

It should be borne in mind that the production method also determines some properties of the material: autoclaved aerated concrete is stronger and has lower thermal conductivity. Made using the usual method, it is more moisture resistant, although this fact is quite arbitrary, since aerated concrete, due to its porous structure, highly hygroscopic material.

Main difference between foam concrete and aerated concrete in the method of formation of the porous structure: in the first case, it is a consequence of the action of a special substance - a foaming agent, as a result of which all the pores have a closed shape, and in the second, as already mentioned, a chemical reaction and the pores in this case are open.

But in order to easily distinguish these two materials on the market, you need to know that foam concrete has a slightly grayish tint, and aerated concrete is blinding with its whiteness.

A mistake when purchasing can have serious consequences, since these two materials, despite their similarities, differ in many performance characteristics.

About shapes and sizes

According to GOST 31360-2007, aerated concrete products must have the following linear dimensions: 625×500×500 mm. But on the construction market the material is presented in several types of products: in the form of a regular parallelepiped with a smooth surface of the edges or with a special “groove-ridge” connection, HH and U-shaped.

It is important to take into account that load-bearing walls and internal partitions can vary greatly among different manufacturers producing their products according to specifications, and vary within quite a wide range.

In some cases, you can even order the production of aerated concrete to individual sizes.

Today the most popular block sizes are:

• 625x300x250 mm – for external walls;
• 600×75(150)x250(200) mm – for internal partitions;
• 500x250(up to 400)x200(250) – for U-shaped products.

Basic operational and technical characteristics of aerated concrete blocks

When choosing aerated concrete as a material for a house, developers must be guided not only by its low cost and ease of construction work, but, above all, by its characteristics and properties.

The first thing you should pay attention to is the product labeling, according to which you can obtain information about the density of the material, indicated by an alphanumeric value, for example, D500 indicates the specific gravity of 1 m 3 of the product.

The choice of blocks for specific purposes depends on the density parameter, for example, a material with a density of D400 or more is intended for the construction of load-bearing walls; it has acceptable thermal conductivity. But in cases where the issue of heat preservation comes to the fore, and high load-bearing capacity is not of paramount importance, you should choose blocks marked from D200 to D500.

Its strength also depends on the density of the material, which, however, is not very high, for example, for common aerated concrete D500 it is only 4 MPa, but since these products are used for the construction of low-rise buildings, it is quite sufficient, but subject to mandatory horizontal masonry reinforcement.

Aerated concrete is a material with:

• low thermal conductivity coefficient, thanks to which even a small thickness of aerated concrete walls copes well with the issue of retaining heat indoors;
• satisfactory noise and sound insulation properties;
• relatively moisture resistant, subject to effective waterproofing of the masonry from the foundation and wall finishing;
• vapor permeable, but it should be borne in mind that the denser the aerated concrete, the lower this figure;
• frost-resistant, able to withstand from 25 to 50 cycles;
• fireproof and fire resistant;
• environmentally friendly and is inert to various microorganisms.

Durability of aerated concrete on average is 30-50 years guaranteed by the manufacturer, but subject to reliable external protection and preventive measures to prevent it from absorbing moisture, this period can be increased to 70-80 years.

Construction of a house from aerated concrete, video:

House made of aerated concrete: pros and cons: how not to make a mistake with the choice

Humanity, during the history of its existence, having created many new building materials, has not come up with the ideal one.

Therefore, if, for example, you “take a walk” on the Internet, then reviews from owners of aerated concrete houses They are strikingly different from each other: from complete admiration and satisfaction, to the most terrible regret. Why this happens - the answer is obvious. Having initially admired the advantages of the material, future builders of their houses completely ignored their weak or vulnerable places and properties.

So, aerated concrete material:

• durable enough;
• inexpensive;
• has large linear dimensions, which speeds up the construction process, while at the same time having low weight;
• has low thermal conductivity- this means you can save on insulation;
• optimal life cycle buildings made from it, reaching, on average, half a century;
• safe for humans, as it is made from natural raw materials.

To install it, you must first prepare trenches of calculated depth along the perimeter of the building and under all load-bearing walls and, as a result, you should get a closed loop.

For private housing construction, especially if the work is carried out on your own, this type of foundation is the most optimal both in terms of labor costs and cost. In addition, all operations can be done without the use of special equipment.

A sand and gravel cushion is laid in the prepared trenches, providing the necessary drainage of groundwater and its removal from the structure, removable formwork is installed, for which even improvised materials can be used, and poured with cement laitance, a very liquid solution, and after it dries - reinforced frame is mounted.

The next stage is pouring concrete, which can be made directly at the construction site. But given the fairly large volume of the required solution, as well as the requirement to maintain the continuity of the technological process, it is more rational to order its production at a concrete plant and delivery to the site by special transport.

After the foundation gains the necessary strength, that is, after minimum 2, maximum 4 weeks, you can start construction of masonry load-bearing walls. But before this, it is necessary to lay a layer of waterproofing, for which mastic and roofing felt are most often used.

It will serve as a protective barrier between the foundation of the house and its walls to prevent the infiltration of underground moisture into the thickness of the aerated concrete, thereby saving it from destruction and ensuring its durability.

This operation is relevant not only for strip foundations, but also for other types.

Factors influencing the choice of foundation type

It should be noted again that technology for building a house from aerated concrete blocks involves the construction of a solid foundation for it, therefore the choice of its type should be approached responsibly and be guided by the following factors, listed in order of importance:

1. soil type and condition;
2. presence of an underground level;
3. number of storeys of the building;
4. labor costs;
5. price;
6. the need to attract special equipment.

For example, the cheapest option is columnar foundation, may be more labor-intensive than tape, but is suitable for difficult soils.

Reliable monolithic slab– too expensive and cannot be installed without the use of special equipment.

There is no single universal solution, so each developer must resolve this issue independently, which foundation is better for a house made of aerated concrete, relying on objective factors and your financial capabilities.

Erection of a box house

After the foundation is ready, the construction of the load-bearing walls of the house, the so-called box, begins.

It should be noted that laying aerated concrete for this purpose has some features and one insoluble question: What to use masonry mortar or special glue.

Both options have supporters, including among professional builders. But considering that the use of glue allows you to make thin seams, no more than 2-5 mm versus 2-3 cm when using traditional cement mortar, this provides better heat-insulating characteristics for walls, as well as a more even and accurate joining of blocks, for beginners this the most correct choice.

Laying the first row

Even if the decision is made to carry out masonry of aerated concrete walls using a special adhesive mixture, The first row must be laid on a cement-sand mortar. This is necessary in order to align it horizontally as accurately as possible due to the thickness of the seam.

In the future, this greatly simplifies the work, especially in terms of adjusting the wall both horizontally, using a water level, and vertically, using a plumb line.

Laying should begin from the highest angle. If you do the opposite, then in the best case you will have to mechanically cut off part of the row, thereby leveling it, and in the worst case you will have to do everything all over again, since it will not be possible to ensure the rows are horizontal from the very beginning.

Particular attention should be paid to the implementation of corners, which must be straight, unless otherwise provided by the project. For this purpose it is used principle of diagonals: By changing the projection one by one, you can detect the error and correct it in time.

To adjust aerated blocks, a special rubber hammer is used, which does not damage the product, but allows you to easily, if necessary, slightly change its position before the solution sets.

After the first row of masonry has been completely completed, it is necessary to clean its surface from excess mortar and dust using a brush and grinding the surface. It should be noted that this operation must be performed each time after completing the next level.

Second and other rows

You can then work using glue, which will allow even a beginner to complete the job much faster. Since preparing the mixture is much easier than a solution, it is worth considering its setting time and your speed of work.

Glue is applied to the prepared surface of the gas blocks of the first row using a notched trowel and the block of the second row is installed. You should also start working from the corners, but be sure to follow the dressing rule, that is, lay the new row offset to the previous one. In those places where installing a solid block is impossible, it is necessary to make an additional element using a hacksaw or grinder.

In order to give greater strength to the building, it is necessary reinforcement of aerated concrete blocks, which is usually performed after 2-3 rows. But if a window opening is provided, then under it, in the previous row, separate reinforcement should be made, extending 30–40 cm in both directions.

The reinforcement should be placed in specially grooved parallel grooves, for which it is possible to make DIY wall chaser for aerated concrete from scrap materials or purchase a professional one.

Laying aerated concrete blocks with your own hands, video:

Window and door openings

Window openings in a house made of aerated blocks can be made in two ways:

1. arrange immediately, like door ones;
2. cut out after the box is completely laid.

The second option is simpler, but the first is more economical, since the sawn parts of the blocks are unlikely to be used and will simply have to be disposed of. And after the height of the masonry has reached the upper level of the window or doorway, it is necessary to properly design and strengthen them. For this lintels are installed above the windows in a house made of aerated concrete, which can be made in several ways:

• use special U-shaped blocks into which cement mortar should be poured;
• make them from blocks– for this purpose, products up to 100 mm thick are suitable, which are installed in two rows and reinforcement is first performed between them, and then the solution is poured;
• use traditional reinforced concrete products;
• make them from the same blocks, from which the walls are laid: cut three parallel grooves, lay reinforcement and fill with mortar. But it is important to take into account that they should be laid with the reinforcement downwards, towards the opening.

If difficulties arise when building a house on your own, you can involve specialists, especially since the cost of laying aerated concrete per cubic meter is not so high, but the work can be completed much faster.

Alternatively, professionals can be hired to perform specific jobs that are complex or require special knowledge.

Armopoyas and floor arrangement

As a rule, after installing window lintels or laying one or two more rows of gas blocks, you can begin making an armored belt, the main function of which is to impart and maintain the integrity of the entire structure.

This will require concrete or cement-sand mortar, but you must first prepare the formwork: removable or permanent. In the second case, you will need aerated concrete blocks 100 mm wide, between which reinforcement is laid and filled with mortar.

If a second floor or attic is provided, then care must be taken to install special studs that are simply embedded in the concrete. They will also be needed to complete fastening the Mauerlat to aerated concrete without an armored belt, in this case they must have a thread, which will greatly facilitate their installation both to the wall and to the base of the roof.

After this stage of work is completed, you can begin installing the first floor ceiling, which can be done using different materials. But most often used wooden floors in aerated concrete house, which, unlike reinforced concrete ones, are much lighter and do not create additional load on supporting structures.

The ceiling must be secured to wooden beams in an aerated concrete house using an armored belt; for this purpose, it must first be provided with spacing, taking into account that the minimum support should not be less than 25 cm.

You can also make a monolithic ceiling, but this is a more labor-intensive and expensive option, or you can use special metal guides designed for laying gas blocks with a thickness of 100 to 150 mm on them.

Correctly perform a roofing pie

The house is built - finishing can begin

What should it be exterior decoration of aerated concrete house not so important, the main thing is that it should be and it should be done immediately after the construction of the house and the completion of the shrinkage processes, which, given the weight of the material, take a little time.

The presence of facade decoration is not only a decoration of the house, but also reliable protection of the walls and, above all, from precipitation, which can significantly reduce its strength, as well as shorten its service life.

There are no restrictions on the choice of materials, but should be taken into account poor surface adhesion, so for example plastering aerated concrete walls indoors can be done with gypsum-based compounds, but this option is not suitable for facade work, but first the surface should be treated with special primers. But most often, in this case, plastering the facade of a house made of aerated concrete is carried out using technology.

In cases where additional insulation is required, you can use the technology of installing curtain facades or lining the house with brick, but in this case it is imperative to provide a gap of 3-5 cm and special vents for ventilation of the structure and to maintain the vapor permeability of the walls.

And here how to plaster aerated concrete inside a house depends on the interior design solution, the tastes of the owners and financial capabilities. But, as mentioned above, preference should be given to mixtures not based on cement, but on the basis of gypsum - the “native” material for aerated concrete.