If you set a goal and calculate through which points and surfaces the room loses the most heat, it turns out that the greatest heat loss (more than 50%) occurs through walls and windows, at least 20% of the heat goes through the roof, and half is lost through the basement. In order to reduce heat loss to minimum values, a lot of very different heat insulators are used in construction. The leading position in this area is occupied by the basalt plate. What kind of material is this?
Production technology
The raw materials for the manufacture of mineral basalt insulation are certain rocks. The most commonly used are basalt, dolomite, limestone, diabase, clay, etc. Manufacturing technology consists of two main processes:
1. Getting the melt.
2. Its conversion into thin fibers with the simultaneous introduction of binding components. Basalt fibers used in the manufacture of products usually have a length of 2 to 10 mm, and the diameter does not exceed 8 mm. Actually, the basalt insulation itself is obtained in the process of rock melting. The melting temperature tends to 1500˚. In the next step, the fibers are bonded to each other using an inorganic binder component (filtration deposition technique). Simultaneously with this process, pre-pressing is carried out, and everything is completed by thermal drying. As a result of all these actions, a basalt slab is obtained, the characteristics of which allow it to be used in various fields of industrial and civil construction.
Scope of basalt slabs
Basalt mineral slabs today occupy one of the first places in terms of consumer demand. The main field of application is insulation and thermal insulation. The construction of residential buildings and structures, industrial facilities is not complete without this material. Using basalt slabs and cotton wool, thermal insulation of pipelines, plumbing and heating equipment is carried out. The same material is used to insulate surfaces inside and outside the premises: roofing, floors, walls, attics, basements.
Insulation is used as the lower and upper layer of sound insulation in the ceilings of flat roofs.
Separately, I must say a few words about how to properly insulate the facade with a basalt slab. If the living room is sheathed from the inside, condensation will form between the insulation and the wall due to the temperature difference, which favors the development of an aggressive biological environment (mold, bending, etc.). But basalt slabs laid outside the building on the surface of the facade will retain heat in the room, will not allow mold to develop and will further improve the sound insulation of the entire structure.
Basalt insulation is also widely used in industrial construction and in the energy sector (thermal insulation of boilers and furnaces in power plants). Basalt slabs and mechanical engineering do not bypass their attention. In this industry, with the use of basalt heaters, thermal insulation of the chambers of furnaces and refrigerators, car bodies is carried out.
Excellent material quality
The good thermal insulation characteristics of basalt slabs are due to the low thermal conductivity of the air. The multidirectional fibrous structure completely excludes the free movement of warm air masses inside the material. Basalt heat-insulating plates in the dry state have a thermal conductivity coefficient in the range of 0.04-0.047 W / m².
Material density
Modern manufacturers offer customers mineral basalt slabs with a density in the range from 35 to 200 kg / m³. For various types of construction works, materials with different indicators are used. For example, for laying on an inclined roof, the density of basalt slabs should not be less than 30-40 kg / m³. Otherwise, over time, the insulation will sag. To warm the outer walls of buildings, experts recommend the use of basalt slabs with a density of 80 kg / m³. In the interior partitions to improve sound insulation, a material with a density of 50 kg / m³ is used.
Insulation layer thickness: which is the best?
The answer to this question is quite simple. The heat preservation indoors depends on two characteristics: the thickness and density of the plate. Therefore, the thicker the insulation, the better, and the denser - the warmer. For example, for a residential attic, 150 mm is the required minimum thickness. The basalt slab should have a density of at least 30-40 kg / m³. The insulation layer for exterior walls is usually at least 100 mm thick.
In general, in order to create conditions in a residential building regulated by GOST 30494-96 (air temperature in the range + 20-22˚, relative humidity - 30-45%, lack of drafts), it is important to use basalt thermal insulation materials correctly.
Is stove and cotton wool the same thing?
As mentioned above, the first stage of the production of basalt plates is called melt. In order to give the basalt fibers more fluidity, 10 to 35% of the charge or limestone can be added to the melt. Such components will reduce the resistance of the material to high temperatures and the influence of an aggressive environment. This is not to say that a product with such a component composition is a natural basalt plate. Rather, it is basalt mineral wool.
However, it will be wrong to think that mineral wool has much worse characteristics than a slab. The material can withstand temperatures up to 600 ° C (up to 1000 ° C - it changes color, higher it melts). The thermal conductivity of cotton wool is in the range of 0.042-0.048 W / m². The material is resistant to mechanical stress.
Soundproofing characteristics of plates
Basalt fibers in the structure of the material are randomly arranged in different directions, so basalt slabs have good acoustic characteristics. In a room with such a heater, the probability of excitation of sound waves vertically is significantly reduced. Improved airborne sound insulation and sound-absorbing characteristics of the walls and ceiling in the room. The reverberation time is significantly reduced (a gradual decrease in the intensity of sound during its multiple reflection).
We can say that these heaters (basalt slab, cotton wool) quite effectively soundproof the room from noise both from inside and outside the building.
Environmental friendliness of basalt heaters
Basalt and limestone, which are used to make slabs, are natural materials. Basalt - once spilled from the bowels of the Earth and frozen magma. This material is perhaps the most common on the earth's surface at present. Limestone is a sedimentary rock formed from calcite. Warming with basalt plates actually saves energy reserves a hundred times more than it takes to manufacture them: mining, processing, transportation.
Strength and hydrophobicity parameters
Basalt fibers inside the slabs are arranged randomly, which allows to achieve a sufficiently high level of stiffness of the insulation. Considering the fact that during the production process binders are also added to the composition, we can talk about excellent strength parameters and product characteristics. And the mineral basalt plate is able to maintain such strength over a long period of time.
Today, manufacturers are ready to offer potential buyers both light insulation materials for working with non-loaded structures and hard basalt slabs. The latter are able to withstand severe loads. The strength characteristics of basalt heaters are such that slabs and mineral wool can be used in any existing building sound insulation and insulation system. They will provide the most effective quality of protection and durability of structures.
Hydrophobicity (water repulsion, the ability to avoid contact with water) of basalt plates is provided at the production stage by adding hydrophobizing additives to the melt. As a result, the basalt plate acquires excellent water-repellent characteristics, has a fairly low water absorption, which ultimately has a beneficial effect on the coefficient of thermal conductivity (it decreases). That is, the less the basalt slab is saturated with water, the lower this indicator is.
How not to make a mistake when choosing a brand of material?
To choose the right insulation, before buying you need to determine the scope, think about what kind of work you need a basalt slab. The characteristics of any brand will be effective only when used for a certain type of work. For example, if you intend to use the material where there will be no increased loads on it, it is perfectly acceptable to use soft grades of a heat insulator. These places include facade ventilation systems, wall insulation in high-rise buildings (but not higher than 4 floors).
For the insulation of a multi-storey building, in which a ventilated facade is finished with an unlimited speed of air flow, it is better to use semi-rigid types of basalt slabs. Specialists recommend using hard brands of heaters in those places of construction sites where heavy loads are expected.
Danger to people
Is the harm caused by basalt plates to human health a myth or a reality? In order to give a certain shape to a basalt plate or mat, manufacturers add formaldehydes (resin) to the insulation. A priori, the latter are considered harmful and dangerous substances to the human body. And in mineral wool, these resins are freely available. If water gets into the insulation, decomposition processes begin there, and the toxic substances released in this way enter the human body. However, in certified factories, formaldehyde resins and phenol are in a bound state by the time the insulation is already made, and absolutely inert to the environment. From this we can conclude that basalt mineral wool plates are harmful to humans and the environment only if they were made from low-quality materials and artisanal methods. Such heat-insulating materials, of course, do not meet sanitary standards, have a lot of harmful impurities and are dangerous to humans.
If we are talking about the harm from getting the smallest particles of basalt plates into the respiratory tract or under the skin, then this is practically excluded. Modern basalt heaters are very durable, their fibers are soldered to each other, and the separation of small particles is not possible. In this, basalt heaters are much safer than materials of past generations, such as glass wool.
Development perspective
Already today, a basalt plate has been widely used in various fields of human activity. Currently, this insulation occupies one of the leading places in the field of construction. Even though the production process of basalt insulation is quite energy-intensive, this material is available to a wide range of consumers with completely different financial capabilities. And, as you know, the optimal combination of the price of a product and its quality is the path to success and recognition.