Such a favorable forecast is explained by the specifics of the Russian climate, the fuel and energy complex and the understanding of the importance of energy efficiency at construction sites for various purposes, which is under development.
Thermal insulation of buildings is a rather attractive market segment, where large manufacturers and suppliers of thermal insulation materials are increasingly striving to establish their presence. This largely explains the acuteness of the controversy that has unfolded today in relation to the most common TIM in Russia - foamed and extruded polystyrene foam, mineral wool and cellular concrete. Unfortunately, the participants in the discussion often resort to incorrect argumentation of their own position, which gives rise to a lot of speculation and obvious insinuations that openly discredit one or another insulation. The purpose of this article is to guide the reader in relation to the scope of application of various TIMs based on a comparison of their main technical characteristics.
At the beginning of the conversation, you should pay attention to the fact that in conditions of an underdeveloped culture of construction work, even the advantages of any material that are obvious from the standpoint of a specialist can be nullified. In addition, we must not forget that an objective assessment of the effectiveness of the insulation can be given only on the basis of data on how it behaves as part of the structure, whether it is a "wet" facade, an illegal armed structure system, a structure with embedded thermal insulation (front brick - thermal insulation - brick or aerated concrete block). By the way, developers have accumulated a lot of complaints about the last structure due to corrosion of the connecting reinforcement, poor control over the quality of thermal insulation, etc.
Today, the scope of application of TIM is quite wide - facade and roof structures, floors, foundations, etc. In addition, it is necessary to take into account the individual style and taste preferences of architects and their customers, as well as specific climatic conditions, economic and logistical considerations, the degree of technological security of construction. That is why the table given in the article contains indicators that are largely universalized, obtained on the basis of an analysis of both experimental results and practical experience. The greatest informative value is represented by data expressed in numbers.
Starting to consider the table, we will proceed from the fact that all consumers are interested in such basic characteristics of TIM as price, environmental friendliness, vapor permeability and moisture resistance, thermal conductivity, compressive strength and durability, flammability, biological and chemical resistance.
Let's start with thermal conductivity, which, by definition, is the main function for TIM. For this indicator, foamed and extruded polystyrene foam is the most effective material. At the same time, extruded polystyrene foam, in comparison with its granular relative, shows a very low vapor permeability and a rather high cost.
As for mineral wool, there is no alternative to it in the composition of illegal armed groups, and, first of all, in systems with natural and artificial stone cladding or veneered composite panels "imitation wood", on planes of complex geometry and in other cases. At the same time, builders and designers demonstrate a far from unambiguous attitude towards illegal armed groups: aluminum fasteners with which blocks of mineral wool are fixed to the wall of the house (up to 10 - 12 pieces per m22 facade), are cold bridges and reduce the effectiveness of insulation.
Fire safety is an equally important property of any insulation. Everyone knows that mineral wool is characterized by less flammability than polymer insulation. At the same time, as already mentioned, the fire resistance of slab TIM should be assessed only as part of structures, where they are "under the cover" of other materials. It is not surprising that an IAF with a windproof polypropylene membrane and lined, most often with cheap composite panels with a combustible polyethylene core, burns no worse and no better than expanded polystyrene, which in the "wet" facade system as a whole has much better fire protection. Therefore, in terms of fire safety, these systems can be attributed to the same class.
The moisture resistance of the material is an equally significant indicator that significantly affects the thermal insulation properties of the system. Mineral wool and aerated concrete are characterized by a lower moisture resistance than expanded polystyrene and a very high vapor permeability, which, as part of a building structure, greatly reduces their heat-insulating performance. Since these materials work in an insulation system, the overall vapor permeability of a multi-layer structure is limited to the layer in which the material with the lowest vapor permeability is present. Therefore, in terms of overall vapor permeability, the systems will differ, but not as noticeably as the materials included in their composition.
From the standpoint of vapor permeability, a combination of facing brick and aerated concrete can be considered a completely acceptable option * … At the same time, the need for a ventilation gap, the thickness of the structure and its significant weight in comparison with other combined systems do not always suit the customer.
Another important aspect is durability, which for all thermal insulation materials is defined as resistance to external factors - atmospheric moisture, UV radiation, the life of rodents, aggressive environments, and their own properties. Therefore, any insulation needs protection.
Quite often we hear that the service life of mineral wool exceeds 50 years. At the same time, it is not taken into account that during the installation of illegal armed groups, as a result of the mistakes made, the plates of the mineral wool insulation prematurely lose their structural integrity and collapse. As for expanded polystyrene, here the opinions of experts differ: some believe that in terms of durability it is inferior to mineral wool and aerated concrete. But there are also those who disagree with this. In particular - a professor at the Russian University of Chemical Technology. DI Mendeleeva LM Kerber, who refers to the data obtained by specialists from the Research Institute of Building Physics. In 2001, in the laboratory of the institute, tests were carried out, during which samples of expanded polystyrene were subjected to 80 cycles of exposure to alternating temperatures, including a two-fold decrease in temperature to - 40 ° С, subsequent heating to + 40 ° С and holding in water corresponding in time to one conditional year. The samples passed the tests without any noticeable deterioration in properties. The results obtained indicate that, provided that it is used correctly, high-quality polystyrene foam will serve in structures under temperature influences with an amplitude of +/– 40 ° C for at least 80 years.
It is important that laboratory tests are confirmed by practice. So, in Germany, during the reconstruction of buildings that had stood for 40 years or more, it turned out that the expanded polystyrene in the facade structures did not change its properties.
The experience gained by the domestic construction complex cannot be ignored either. Monitoring the condition of the used hinged and "wet" facades, which have appeared over the past 15 - 20 years in regions with a sharply continental climate, shows the high thermal efficiency and structural resistance of both systems. This applies primarily to Omsk, Novosibirsk and other cities of Western Siberia, where the daily difference in winter temperatures ranges from 00 to - 270 C and vice versa.
Summing up, it should be noted that today, when installing a plaster facade with insulation, a combination of mineral wool and expanded polystyrene foam has become noticeable. Minvata is used as a fire cutoff on the external frames of window and door openings, while expanded polystyrene, being lighter, structurally strong and inexpensive, is used to insulate the main walls. This "distribution of responsibilities" is explained by the fact that a large mass of vapor-permeable mineral wool, "locked" with polymer layers, will begin to get wet, lose heat-insulating properties and deform, which will lead to a sharp decrease in the basic functional properties of the building structure.
* In this case, "aerated concrete" means a whole group of materials similar in their thermal insulation properties, capable in certain cases of carrying a structural load, or combined in plaster or curtain facades with a lightweight type TIM.
