Methods of wall insulation with expanded clay: options for a cottage

When erecting private cottages, country houses or public buildings, zealous owners take care of how to minimize the heat loss of the facade in order to reduce the cost of using gas, liquid fuel, firewood or electric heating sources. For this, various types of insulation are used, while the most affordable option is to finish with expanded clay or expanded clay concrete.

Expanded clay is a kind of insulation, consisting of small loose fragments with a porous structure. This finishing material is obtained by foaming low-melting clay and shale. And also among the additives sawdust, diesel oil and peat bog can be declared. The raw materials are then rolled in drums and kilned at a high temperature for added strength.

The result is light and at the same time strong granules ranging in size from 2 to 40 mm. They can have the following shape: expanded clay sand up to 5 mm in size, expanded clay crushed stone, resembling cubes, as well as elongated expanded clay gravel.

Expanded clay is a very practical material. Experts have proven that only 10 cm of expanded clay in the wall is equivalent in terms of insulating properties to brickwork of 1 meter or wooden sheathing of 25 cm.That is why in cold weather such insulation does not let the cold into the room, and in the heat it does not allow the house to overheat and keeps pleasant coolness inside ... When choosing expanded clay, it is worth considering in what climatic zone the house will be built, from what materials and according to what project.

A simple rule should be followed - the characteristics of the product (density, brand, frost resistance) must correspond to the declared technical parameters.

The use of expanded clay as insulation has its own advantages and disadvantages.

Among the advantages of this finishing material, it is worth noting the following:

• affordable price;
• the possibility of using expanded clay as part of concrete mixtures for blocks that save heat better than brick or reinforced concrete;
• environmental friendliness and safety for human health;
• durability and long shelf life;
• resistance to external influences and chemical compounds - expanded clay does not rot, does not corrode and is not afraid of rodents and insects;

• ease of installation, since this does not require special equipment and tools, so even craftsmen with minimal experience in construction will be able to cope with work on thermal insulation;
• excellent heat and sound insulation due to the porosity of expanded clay;
• high fire resistance, since the material is pre-fired at high temperatures;
• light weight, so it will be easier to work with such material;
• thanks to the free-flowing texture and small granules with expanded clay, it is possible to fill a cavity of almost any volume;
• resistance to temperature extremes.

Warming of walls with expanded clay is most common in brick houses, although it is sometimes used in frame versions. The technology is the same - it is laying in bulk. Although in frame structures, in most cases, builders resort to insulation with lightweight materials. They use mineral wool, polystyrene foam, liquid polyurethane foam and foam insulation. But in favor of expanded clay, the owners make a choice primarily because of its low cost.

One of the most common ways of insulating a house with expanded clay is the organization of a three-layer frame.

• The inner part is usually about 40 cm thick and is made of expanded clay concrete - this layer plays the role of thermal insulation.

• The second layer is expanded clay, mixed with cement in a ratio of 10: 1. This mixture is called capscement. Such a solid mixture gives the frame additional strength and rigidity, and its low weight almost does not bear additional load on the building foundation.
• The third outer layer plays the role of protecting the insulation and simply decorating the building. Various finishing materials are used for it, depending on the preferences and financial capabilities of the owner, as well as the general architectural solution. This can be wood, clinker bricks, lining, granite, stone, fiber cement slabs or aluminum panels.

With three-layer wall insulation, experts, depending on the type of structure, use three finishing options.

• Masonry with diaphragms. In this version, walls are erected: one brick thick, and the other half thinner, while the distance between them should be 20 cm.After every fifth row, insulation is poured into the gap formed between the walls, rammed and poured with cement milk. Then 3 rows are laid out of bricks, and the corners are made without cavities.
• Masonry with embedded parts is done using a similar technology with expanded clay backfill between the walls as in masonry with diaphragms. In this case, the walls are fixed to each other with brackets made of reinforcement.
• Well masonry involves the construction of walls at a distance of 20-30 cm from each other. The ligation of the walls through the row occurs with the help of jumpers of 80–100 cm. The cavities are first covered with expanded clay, and then with cement milk.

The thickness of such insulation as expanded clay depends on its properties and the technical characteristics of the wall materials. Of course, it is easier to turn to the services of professional builders, who, when calculating the thickness of the insulation layer, will certainly take into account the peculiarities of the local climate.

You can calculate the required thickness of the insulation layer yourself, using the following indicators:

• coefficient of thermal conductivity of expanded clay - 0.17 W / mx K;
• minimum thickness - 200 mm;
• thermal resistance, which is equal to the temperature difference at all edges of the material and the volume of heat passing through its thickness. That is, R (resistance) = wall thickness / KTS (wall thermal conductivity).

It is worth paying attention to the fact that if we are talking about the construction of a frame house, then expanded clay will have to be tamped especially carefully. And it will be very difficult to insulate a wooden structure with expanded clay, since it is necessary to leave cavities about 30 cm thick, and this is an additional load on the structures and the foundation. Much more effective, simpler and cheaper in this case will be the use of mineral wool as a heater. And if the climatic conditions and the thickness of the log house allow, then you can do without it altogether.

Despite the positive assessment of such an insulating material as expanded clay, during installation it is worth paying attention to such a disadvantage as a high level of fragility, which should be taken into account when filling and tamping. The zealous owners advise to insulate with the help of economical expanded clay not only the walls, but also the floor, ceiling, and also the attic space. Provided proper care, such insulating material will last for many years.

Any building material, including expanded clay, if stored improperly, can lose its original properties. For example, if bags with this insulation will stand for a long time in the country, then there is a risk that the expanded clay balls will eventually turn into ordinary dust. If expanded clay is needed as a heater for walls or a filler for lightweight concrete, then it is worth choosing fractions 5-10 or 10-20.

Internet users leave a lot of positive feedback, although there are negative ones. Many users who have made repairs to the cottage using expanded clay, note that in winter, even with 20-degree frosts, the use of fuel has significantly decreased, and even without heating the premises remain warm for a long time. Not very high popularity of expanded clay, possibly due to stereotypes or insufficient information about this material. Many people believe that its use and installation technique is more difficult than that of other heat insulators.

In fact, insulating the walls of the cottage with expanded clay gives excellent results., the main thing is to choose high-quality material and ensure a good tamping without experimenting and entrusting the installation to professionals in their field. Another difficulty that can be encountered when using expanded clay is the threat of being squeezed by other material. Therefore, additional strengthening work will help to avoid such situations. But it should be borne in mind that this will result in a decrease in the usable area of ​​the room.

So, if you need to insulate a country house or cottage, then the choice of expanded clay will be an excellent solution for the construction of energy-efficient and environmentally friendly houses. In addition, it is affordable even for people with very modest financial capabilities.

How the adobe house was insulated with expanded clay, see the next video.