Features of wall insulation with expanded clay, its advantages and disadvantages, technologies for performing thermal insulation. Expanded clay is a porous granular insulation designed for thermal insulation of building structures. The use of this material allows you to maintain a comfortable temperature in the house and reduce the cost of heating it. You will learn how to insulate walls with expanded clay from this article.
Features of thermal insulation of walls with expanded clay
Expanded clay is obtained by firing a mixture consisting of swollen clay, sawdust, diesel oil, sulfate alcohol stillage and peat. Preliminarily, low-melting raw materials are foamed, and then rolled in special drums, giving its particles a shape. The result of their subsequent heat treatment is light and strong granules, which have fractions of 2-40 mm. On this basis, expanded clay is divided into three types: sand, gravel and crushed stone. Sand has the finest fraction of 2-5 mm, gravel - 5-40 mm, and crushed stone is obtained by crushing gravel, its most used fraction is 10 mm. Slight size deviation is possible within 5%. The structure of the finished granules contains a large volume of air, which serves as an excellent barrier for the transfer of heat from the walls.
In addition to differences in fraction, granular material is divided into 10 grades, the calculation of which starts from 250 and ends with 800. The grade indicates the specific gravity of 1 m3 loose insulation and its density. For example, expanded clay M400 has a density of 400 kg / m3… With its decrease, its thermal insulation qualities increase.
The heaviest bulk insulation must be stronger in order not to collapse under its own weight. In terms of strength, expanded clay has grades P15 - P400. The minimum strength of M400 granules should be P50, for expanded clay M450 - P75, etc.
A ten-centimeter layer of expanded clay in the wall is equivalent in terms of insulating properties to brickwork 1000 mm thick or wooden cladding, having a corresponding size of 250 mm. Therefore, at a rather low air temperature outside, the material is an excellent frost-resistant insulation, and in the summer heat it keeps the house cool due to its low thermal conductivity.
Compared to other types of insulation, thermal insulation of walls with expanded clay is much cheaper and more effective. It is three times more effective than wood protection, and its cost is an order of magnitude lower than the price of brickwork. The use of this material can reduce heat losses in the house by up to 75%.
Advantages and disadvantages of wall insulation with expanded clay
There are a lot of requirements for the insulation of the walls of the house, the main of which is the environmental friendliness of the material used. This is expanded clay. It is made from natural raw materials and is absolutely safe for health.
In addition, thermal insulation of walls with expanded clay has many more advantages:
- Loose insulation due to small granules is able to easily fill a cavity of any volume.
- Expanded clay is quite affordable.
- Thermal insulation and sound absorption by this material has the best performance due to its porous structure, which makes it possible to successfully use granular backfill for insulation of walls, floors, roofs and foundations.
- Due to the low weight of expanded clay, wall insulation gives a high-quality result with little effort.
- Thermal insulation of walls with this material can be performed in any climatic zone, since it perfectly withstands temperature changes and air humidity.
- The insulation is durable and fire safe.
- Expanded clay does not rot, insects and rodents are indifferent to it, the material is resistant to chemical compounds.
- Installation of bulk thermal insulation does not require the use of construction equipment and can be done independently using simple tools.
The disadvantages of expanded clay include its prolonged drying in case of moisture. The material is rather reluctant to part with the absorbed moisture, so this must be taken into account when insulating walls. Another disadvantage is the tendency of the granules to form dust. It manifests itself especially strongly during the production of internal work. In this case, you have to wear a respirator to protect the respiratory system from dust particles.
Wall insulation technology with expanded clay
To get the most out of the use of expanded clay as insulation, you need to know how to install it. Most often, a granular ceramic heat insulator is used in a three-layer rigid wall structure or in the form of an insulating backfill made in a cavity of brickwork. To work with any of these methods of insulating the walls of a house with expanded clay, you will need the following materials and tools: cement, brick or blocks, expanded clay, concrete mixer, containers and shovels, trowel, plumb bob and tamping, jointing, tape measure and square, building level, cord.
Three-layer system of wall insulation with expanded clay
This is one of the most optimal options for thermal insulation using expanded clay. The first insulating layer of such a structure is considered to be a load-bearing wall erected from expanded clay concrete blocks, which in themselves are a good and durable insulator. In addition, such products are environmentally friendly and comply with modern concepts of building construction. The blocks used must be at least 400 mm thick.
The second layer of thermal insulation is made from a mixture of cement and expanded clay in a ratio of 1:10. The hardened mixture forms a rigid structure that transfers its load to the foundation of the house. The third layer serves as a protection for the heat-insulating material and is made of wood or decorative bricks.
Methods for installing insulating expanded clay layer
There are three technologies for insulating walls with expanded clay using interlayers:
- Well masonry… In order to perform well lightweight masonry, you need to lay out two longitudinal walls from bricks at a distance of 15-35 cm from each other, and then, along their height through a row, make a bandaging of brick longitudinal rows using transverse jumpers with a step of 70-110 cm. the way the wells-cavities need to be covered with expanded clay. Every 200-400 mm of wall height, the backfill should be tamped down and filled with cement milk for impregnation.
- Masonry with horizontal triple-row diaphragms… Applying the masonry method with horizontal diaphragms, it is also necessary to make two longitudinal walls, of which the inner one should be brick thick, and the outer one -? bricks. The distance between them should be 15-25 cm. Expanded clay is backfilled after laying every fifth row, then you need to tamp the insulation and fill it with cement "milk". After that, three three-row overlaps (diaphragms) should be laid out with bricks. The corners of the walls in the process of conducting brickwork should be performed without cavities. This will increase the strength of the surface. For the outer layer of masonry, you can use facing, sand-lime bricks or concrete blocks, which should then be plastered.
- Masonry with embedded parts… This method, when insulating a brick wall with expanded clay, provides for filling granules between two longitudinal walls, and the whole structure is connected by embedded parts - brackets made of reinforcement, or fiberglass ties.
In addition to the above-described methods of wall insulation associated with the manufacture of wells and filling them with insulation, expanded clay can be used in combination with enclosing structures made of other materials. If you need to insulate a house with them, the walls of which are lined with aerated concrete blocks, it is necessary to step back 100 mm from the main wall and erect the front part of the structure from facade material, and fill the cavities with expanded clay. After raising the masonry every 50 cm, you need to load loose insulation inside the wall, tamp it and soak it with cement "milk". To protect the surface from dampness when building a house, ventilation gaps should be left.
Some restrictions are present when insulating frame walls with expanded clay. The main problem here is that over time, bulk materials cake and can settle, leaving a section of the previously insulated surface unprotected. This circumstance reduces the quality of the insulation of the entire structure. Therefore, when laying expanded clay into a frame wall, it must be carefully tamped, which exposes the cladding to significant loads.
As for wooden walls, their warming with expanded clay causes certain difficulties. For comparison: the thickness of the outer coating using mineral wool is 10-15 cm, and for filling expanded clay, it will be necessary to prepare cavities 20-40 cm wide, since its thermal insulation properties are noticeably worse than that of mineral wool. To support the weight of the expanded clay, the load-bearing wall must be strong enough. It is problematic to hang such a mass on a log house, moreover, a backfill thickness of more than 40 cm will not allow this to be done. Therefore, to insulate a wooden wall with expanded clay, an additional foundation will have to be made outside. If we take into account its cost and the amount of insulation, which will be needed 4 times more than mineral wool, it can be understood that thermal insulation of a wooden house with expanded clay will be much more expensive. Therefore, it will be better to choose another option for insulation, which does not require strengthening the structures and broadening the foundation.
How to insulate walls with expanded clay - watch the video:
In general, expanded clay is a fairly durable, effective and inexpensive insulation. And although the work with him is somewhat laborious, but their result and cost will delight every zealous owner of the house.