In most regions of the country, it can be ensured by using only soft insulation with insufficiently studied durability in the climatic conditions of Russia. The cost of repairing such walls significantly outweighs the savings from reducing energy costs for heating buildings.
The SNiP 23-02-2003 "Thermal protection of buildings" put into effect instead of SNiP P-3-79 * did not solve the problems that had arisen, since it retains the same overestimated requirements for the heat-shielding qualities of the outer walls of buildings. A situation has emerged in which the new system of standardizing the heat-shielding qualities of external enclosing structures does not satisfy modern construction practice and restricts the use of new domestic heat-efficient, durable, fire-resistant ceramic, aerated concrete, polystyrene concrete, polyurethane foam (with fillers), lightweight claydite concrete mineral materials, alternative soft polystyrene foam. This and the requirements of the Federal Law "On Technical Regulation" necessitated the development of a new regulatory document on thermal insulation of buildings.
Standard STO 00044807-001-2006 was developed on the basis of the requirements of the Federal Law "On Technical Regulation" in order to ensure safe living, recreation and work of citizens in the premises and to increase the durability of the walls with a rational level of heat-shielding qualities.
The standard uses a two-level principle of rationing the heat-shielding qualities of external walls:
1 - according to sanitary and hygienic conditions, which prevent the formation of condensation and mold on the inner surface of external walls, coatings, ceilings, as well as their waterlogging and frost destruction. Below this level, the heat-shielding qualities of the walls are prohibited.
The main ideology of technical regulation is the product safety system. The safety of the residence or work of citizens in the premises is characterized by the provision of the required sanitary and hygienic conditions under which there is no condensation, mold and waterlogging of the walls, as well as an increase in the relative humidity of the indoor air above the standard values. Sanitary and hygienic safety in the premises is ensured when designing by fulfilling the regulatory requirements for heat-shielding qualities, air and vapor permeability and other physical properties of fences, taking into account the climatic conditions of the construction area.
2 - from the conditions of energy saving and durability. The second level is set in order to save energy costs for heating buildings and reduce the cost of capital repairs of walls.
For the first time after 11 years of oblivion, the section "Durability of external walls of buildings" was introduced. In this section, the data presented allow a differentiated approach to the choice of building materials to ensure the required level of thermal insulation of the outer walls, taking into account the number of major repairs within the predicted durability.
The durability of the outer walls is ensured by the use of materials with adequate strength, frost resistance, moisture resistance, heat-shielding properties, as well as by appropriate design solutions that provide for special protection of structural elements made of insufficiently resistant materials. When developing external wall structures for a specific design solution of a building, it is necessary to be guided by the predicted durability and pre-repair service life. For example, predicted durability of external walls of buildings (monolithic and precast-monolithic up to 30 floors) with monolithic, reinforced concrete inter-window walls in the outer walls and large-sized hollow stones made of porous ceramics (at< 1000 кг/м3) полистиролбетонными, ячеистобетонными автоклавными блоками, огнестойкими пенополиуретановыми плитами повышенной плотности с наполнителями, минераловатными плитами из базальтового волокна повышенной жесткости, облицованных керамическим кирпичом или крупноразмерными плитами из природного и искусственного камня составляет 150 лет.
Predicted durability panel buildings up to 30 floors with external walls made of reinforced concrete load-bearing, self-supporting and hinged three-layer panels with insulation made of concrete floor and styrene, autoclaved aerated concrete, expanded polystyrene, polyurethane foam, mineral wool slabs made of basalt fiber of increased rigidity is 125 years.
The same is the predicted durability of brick buildings with self-supporting or bearing external walls made of solid masonry with a front brick layer of 1.5 - 2.0 bricks, insulated from the inside by spraying a certain brand of polyurethane foam with a layer thickness of 30 - 35 mm.
The predicted durability of the external walls of load-bearing and self-supporting solid masonry made of hollow ceramic and silicate bricks, insulated from the inside by spraying a certain brand of polyurethane foam with a layer thickness of 30 - 35 mm with floors made of reinforced concrete panels is also 125 years.
For the first time, the standard introduces a section on the duration of effective operation of various structures of external walls of buildings before the first major overhaul. So the duration of operation until the first overhaul of brick walls with a thickness of 1.5-2.0 bricks with a frost resistance of at least F35, a front layer of ceramic bricks with a frost resistance of at least F35, insulated with sprayed polyurethane foam in several layers with a thickness of not more than 30 - 35 mm is 65 years. With monolithic reinforced concrete, brick (F35) walls, insulated with polyurethane foam plates or spraying, faced with ceramic bricks with frost resistance of at least F35, the service life until the first overhaul is 50 years.
The standard allows for the same building in height to accept external wall structures with different pre-repair periods. When choosing the design of external walls, the standard requires differentiated combination of the predicted durability, pre-repair periods laid down in the project, with the required level of thermal insulation, a decrease in material consumption and load on the foundation.
The normative reduced resistance to heat transfer R 0 pr standards is established from the conditions of energy savings for heating buildings as a result of an increase in the level of heat-shielding qualities of external walls minus the cost of additional thermal insulation and major repairs within the predicted durability. The standard requires that the first major overhaul of external walls from the conditions of inadmissibility of violation of the sanitary and hygienic safety of citizens' residence and energy saving is carried out with a decrease in RonpHOpM by no more than 35% in relation to the economically feasible at the moment or no more than 15% in relation to the required resistance to heat transfer for sanitary and hygienic conditions. Before the date of the first major overhaul, a decrease in the level of heat-shielding qualities of the outer walls must be established according to the method of GOST 26254 and tests for thermal conductivity of selected insulation samples in accordance with GOST 7076. At the same time, the uniformity of the temperature fields of the walls along the facade must be recorded with a thermal imager in accordance with GOST 26629.
One of the sections of the standard is devoted to the resistance to air permeation of enclosing structures, which is not sufficiently reflected in the regulatory and technical literature. The normative values of air permeability of external walls, ceilings and coatings of residential, public, administrative and service buildings and premises, as well as industrial buildings and premises are given.
Considering that there are a lot of methods for insulating building facades, it is difficult for a non-professional to understand this issue. Therefore, we will try to summarize the information and tell you what a facade insulation system is, what systems exist and what is their difference.
Insulation systems are a complex finish applied to the walls of a building, the main function of which is to store heat energy inside the premises.
The thermal insulation system is a "pie" that includes the following layers:
- Heat insulating material;
- Adhesive composition;
- Reinforcing layer;
- Decorative finishing.
This design is not only an excellent heat insulator, but also has a protective function, protecting the load-bearing walls of the house, significantly extending its service life.
As a heater, various heat-insulating materials with different properties can be used: a heat-insulator made of porous concrete, foam plastic, mineral wool, extruded polystyrene foam, etc. The material can be in the form of plates or rolls. To fix the heat insulator to the wall, special facade glue and dowel-nails are used. A reinforcing mesh and a decorative layer are applied on top.
What systems of facade insulation exist
In modern construction, three main insulation systems are used to insulate external walls: a light plaster system, a heavy plaster structure and a ventilated facade. Let's consider what each design is, and what advantages and disadvantages it has.
Light plaster construction or "wet facade"
The easiest and cheapest way to warm your home. The technology of work using this method is as follows: sheets of heat insulator are attached to a previously prepared base (wall) using an adhesive mixture. It is impossible to confuse a wet facade insulation system with another system. Below is a photo of the finished house, insulated using the wet facade technique.
The fastening is reinforced with dowels. After that, a layer of reinforcing mesh is applied. Further, decorative finishing is carried out by applying plaster and / or facade paint. Aerated concrete slabs, expanded polystyrene or mineral wool are used as heat-insulating material.
The advantages of this insulation system include: simplicity of the device, economy, high efficiency. The insulation system using porous Velit concrete is durable, environmentally friendly and non-combustible.
The disadvantages are associated with the characteristics of other materials used, for example, expanded polystyrene is damaged by rodents, is combustible, and is not environmentally friendly. This insulation design is most often used for thermal insulation of low-rise buildings in private construction.
Heavy plaster construction for external wall insulation
According to the production technology, this option completely repeats the previous one, but the layer of plaster is applied thicker. This method of insulation makes the facade very resistant to various mechanical and climatic influences. There are still differences in the methods of installing heat-insulating plates: anchors are installed on the outer wall before fixing the insulation plates, and the reinforcing mesh used has a denser structure.
The advantages of such an insulation system: very high heat-retaining properties, the possibility of final finishing with any material. The main disadvantage of such a thermal insulation system is the creation of an additional load on the walls and foundation. And also such a structure is much more expensive than light plaster and requires the involvement of highly qualified specialists.
Ventilated facade
This design is practically not used for thermal insulation of low-rise buildings, however, it is very effective and reliable. The main feature of this system is the presence of an air gap between the thermal insulation material and the enclosing structure. The ventilated facade performs a protective function against the load-bearing walls and extends their service life.
Installation of the ventilated facade insulation system is carried out as follows: along the outer walls, vertical and horizontal guide structures are mounted, which form a lattice frame. After that, a layer of heat insulator is attached or filled up, which is covered from above with a special protective membrane. At the end of the installation, a protective screen is attached, which can be used as: porcelain stoneware, artificial and natural stone, aluminum plates, siding, etc.
Advantages of a ventilated facade: high efficiency, variability of the final finish. Disadvantages: heavy load on the facade and foundation, high cost. For the installation of a ventilated facade, it is necessary to order a project for insulation.
Here, something like this, I briefly talked about these designs. Of course, it will not be possible to describe everything in detail in this article, but now you have a general concept. Of course, I will write in more detail, perhaps even for an article on each system, but this is not now.
The problem of home insulation arose, perhaps, simultaneously with the inception of the very art of construction. It is known that already in the Stone Age, primitive people built dugouts, because they knew that by covering a house on top with a layer of loose earth, you can make it warmer. Modern building science offers us a lot of materials that can make a home cozy and warm, without spending extra work and money.
One of the most important tasks of energy saving in buildings is keeping heat in cold weather, which in Russia can be most of the year. Competent thermal insulation of walls, roofs and communications is important in terms of energy conservation, which leads to large savings in financial resources spent on housing maintenance.
Thermal insulation of private residential buildings should begin at the construction stage and be comprehensive - from the foundation and walls to the roof.
The greatest effect of energy saving is achieved through the use of modern mineral and organic insulation. These include: mineral wool, basalt slabs, polyurethane foam, polystyrene foam, fiberglass and many others that have different thermal conductivity coefficients that affect the thickness of the insulation.
Energy-saving structures must, firstly, be durable, rigid and take the load, that is, be a supporting structure, and secondly, must protect the interior from rain, heat, cold and other atmospheric influences, that is, have a low thermal conductivity, be waterproof and frost-resistant.
There is no material in nature that would satisfy all these requirements. For rigid structures, metal, concrete or brick are ideal materials. For thermal insulation, only an effective insulation is suitable, for example, mineral (stone) wool. Therefore, in order for the enclosing structure to be strong and warm, use a composition or combination of at least two materials - structural and heat-insulating.
A composite enclosing structure can be represented in the form of several systems that are different from each other:
1. Rigid frame with filling of the interframe space with effective insulation;
2. A rigid enclosing structure (for example, a brick or concrete wall), insulated from the side of the interior - the so-called internal insulation;
3. Two rigid plates and an effective insulation between them, for example, "well" brickwork, reinforced concrete panel "sandwich", etc .;
4. Thin enclosing structure (wall) with insulation on the outside - the so-called external insulation.
The use of one or another system of the enclosing structure is determined by the structural features of the building being modernized and technical and economic calculations based on the reduced costs.
The cost of insulating 1 m 2 of the outer wall ranges from $ 15 to $ 50, excluding the cost of filled window blocks, modernization of ventilation and heating systems. Nevertheless, the potential for energy savings in the operation of the existing housing stock is quite large and amounts to about 50%.
Each of these designs has its own advantages and disadvantages, and its choice depends on many factors, including local conditions.
The fourth type of building insulation (external insulation) seems to be the most effective, which, along with, naturally, with disadvantages, has a number of significant advantages, namely:
Reliable protection against adverse external influences, daily and seasonal temperature fluctuations, which lead to uneven deformation of the walls, causing the formation of cracks, opening of seams, peeling of plaster;
The impossibility of the formation of any surface flora on the surface of the wall due to excess moisture and ice formed in the thickness of the wall, as a result of condensation moisture coming from the interior, and moisture that has penetrated into the array of enclosing structures due to damage to the surface protective layer ;
Preventing the cooling of the enclosing structure to the dew point temperature and, accordingly, the formation of condensation on the inner surfaces;
Reducing the noise level in insulated rooms;
The lack of dependence of the air temperature in the internal premises on the orientation of the building, that is, on heating by the sun's rays or cooling by the wind.
To eliminate heat loss in old buildings, various projects of heat engineering reconstruction and insulation have been developed and are being implemented, for example, the so-called thermo-coat, which is a multilayer structure made of various materials.
Wall insulation.
Most of the heat is lost through the walls of the house. On average, 150-160 kW of thermal energy can be lost through each square meter of an ordinary wall per year. Therefore, the insulation of the outer walls of the building leads to the following, undoubtedly, positive aspects: saving time and money for heating the premises; additional strengthening of the structure of the house; an increase in the design options for building facades through the use of various materials.
Today, no one is building houses with thick walls - the problem of energy saving is approached differently.
First you need to figure out which part of the wall is advisable to insulate - internal or external. If you insulate the inner surface of the wall, then condensation may fall out under the layer of insulation, which will lead to the formation of fungus, and the moisture accumulated in the pores of the wall, when frozen, will gradually destroy the wall, which will subsequently lead to the need for repair. Therefore, it is advisable to insulate a residential building from the outside.
The following heaters are most often used as external thermal insulation:
- expanded clay, which is burnt clay, foamed by a special method - a fairly cheap, affordable and durable insulation used as a filler for voids and in the form of backfill;
Basalt fiber - characterized by high mechanical strength, fire resistance and biological resistance;
Foamed polyethylene is a very effective and durable insulation, which, due to its cellular structure, has high heat and waterproofing properties;
Polyurethane foam is a non-fusible thermal insulation plastic obtained by mixing two components and is distinguished by its high price and durability.
Various methods of external or facade insulation are used:
Wet method;
Dry method;
Ventilated facade system.
The wet, or plastering, method is most acceptable for owners of suburban housing. Its execution technology is as follows: first of all, to enhance the adhesion of the glue to the wall and to bind dust particles, the surface of the wall is primed. Then, using cement-glue mortars, a heater is glued to the wall, which is additionally fixed to the wall with dowels with a poppet head. On top of the insulation, a reinforced fiberglass mesh is glued onto the same adhesive solution, which is necessary to prevent the plaster from cracking. A layer of decorative plaster is applied over the mesh.
The dry method is the cladding of the walls of the house with siding or clapboard. The cladding technology is quite simple, although there are some subtleties. A crate of bars is attached to the wall of the house, the thickness of which must correspond to the thickness of the insulation, and the bars themselves must be stuffed onto the wall in increments equal to the width of the insulation sheet. Then the insulation is inserted into the lathing and fixed to the wall using glue or disc dowels. From above, the insulation is closed with a diffusion membrane, which allows steam and moisture generated under the insulation at the temperature boundary to be removed outside, but does not allow moisture from the outside to penetrate into the house. The membrane is attached to the batten with a stapler. To form a ventilation gap, bars are sewn on top, along which siding is already underway.
The ventilated facade system consists of a substructure on which a protective and decorative coating is attached - aluminum panels, steel cladding components, porcelain stoneware, etc. The system is designed in such a way that there is a gap between the protective lining and the insulation layer, in which, due to the pressure difference, an air flow is formed, which is not only an additional buffer in the path of cold, but also provides ventilation of the inner layers and removal of moisture from the structure. Thermal insulation of a residential building using such a system is the most expensive, but tangible savings on air conditioning and heating systems can be achieved.
Warming of premises from the inside has both positive and negative sides. The advantages include the fact that it is not required to change the structure of the building, you can work at any time of the year and not all areas of the premises will be insulated, but only the most vulnerable places. Cons - a decrease in the usable area of \ u200b \ u200bthe premises and an increase in the likelihood of condensation in the cold season.
One of the weak points in the thermal insulation system of a house can be called windows and entrance doors. Competent insulation of doors can reduce the heat loss of a room by 25-30%. The choice of high-quality insulation for the front door is the key to success in the struggle to save energy.
Most of the heat loss occurs from poor-quality adjoining of the door leaf to the door when closing. Cold masses of outside air enter the cracks formed, invisible to the naked eye. This is especially true for wooden doors and is due to the lack of reliable seals. Due to the fact that wood tends to change its geometric dimensions (dries up, swells), materials are needed to ensure reliable sealing of the doorway.
The most accessible and cheapest are foam seals, but this material cannot be called the best choice. Foam rubber itself is short-lived, it is very sensitive to moisture. On an intensively used door, its use is undesirable. It can be used, for example, on a balcony door, provided that it rarely opens in winter.
Currently, profile rubber seals on a self-adhesive basis, which are more durable and reliable, are widely used, which is quite suitable for entrance doors. When installing, it is worth considering the thickness of the seal, since if an excessively thick seal is used, it may be difficult to close the door.
Almost the only way to insulate a wooden door is its upholstery. In this case, cotton wool, foam rubber and isolon are usually used as insulation.
Vata has been losing ground recently. Despite its good thermal insulation properties, its use is explained mainly by traditions, since until recently, wool was practically the only thermal insulation material. At least two significant disadvantages should be noted. Firstly, cotton wool quickly rolls down the door leaf and shifts down, and secondly, it is a fertile environment for various pests that can cause irreparable damage to the wooden structure.
Foam rubber is an artificial material often used as a heat insulator. The main disadvantage is its fragility - under the influence of moisture, it decomposes within two to three years, so its use is advisable in dry interior rooms.
Izolon is a modern heat-insulating material, which, in spite of its higher cost, is most optimal for insulating doors. This flexible polyethylene foam is available in a huge range of thicknesses and densities and is distinguished by its durability and high performance of heat and sound insulation.
The use of mineral insulation is impractical, since they will not be able to maintain the volume under the influence of the outer skin.
As an upholstery material, depending on taste and financial capabilities, leather, dermantin and various types of leatherette are used.
Insulation materials for a metal entrance door are also varied. Standard metal doors are usually supplied without internal insulation. Mineral insulation and foam, both extruded and non-extruded, are usually used as internal insulation materials.
Polyfoam (expanded polystyrene) has a slight hygroscopicity and low thermal conductivity. The extruded foam is also non-combustible.
Mineral insulation - fireproof, provides reliable heat and sound insulation. It is desirable to use a material with a high density.
The existing choice of heaters can significantly reduce heat loss and help solve the problem of energy saving.
Characteristics of heaters. The main purpose of the insulation is to "help" the structural materials of the walls, roof, floors of the house to maintain a constant temperature inside the room, i.e. do not let cold (or, conversely, heat) into the house, and do not let heat (coolness) out of it. Therefore, the main characteristic of the insulation is the resistance to heat transfer (thermal resistance), which depends on the composition and structure of the material.
In addition to resistance to heat transfer, all types of insulation have other characteristics that are important for installation and subsequent operation:
Hydrophobicity - the ability of a heater to get wet or absorb water, or, conversely, repel it. Thermal conductivity also depends on the degree of hydrophobicity, since the thermal conductivity of water is much higher than that of air. For example, a mineral plate, when absorbing about 5% moisture, reduces its ability to resist heat transfer by 2 times;
Fire resistance - the ability to resist exposure to high temperatures or open flames. This is a very important indicator because determines the field of application of this or that insulation and the structural features of the house;
Other indicators: durability, resistance to mechanical stress, chemical resistance, environmental friendliness, density, sound insulation, etc.
Types of heaters.
Depending on the characteristics, all types of insulation can be divided into the following types:
Loose ones (slag, expanded clay, vermiculite, etc.) - exist in the form of small pieces or granules, which are poured into voids in walls or ceilings. The voids between the granules determine the resistance to heat transfer. They are cheap, but short-lived (over time they are compressed or destroyed), absorb water well (hydrophilic), so their use is limited - usually it is a basement or attic floor filling;
Roll materials - usually consist of wool of inorganic origin (glass wool, mineral or basalt wool) or soft organic material (penofol), which is characterized by high resistance to heat transfer. It is used universally for both vertical and horizontal surfaces. The combination of "hydrophobicity / fire resistance" varies depending on the material: mineral wool does not burn, but easily absorbs moisture, and organic matter is a water-repellent, but combustible material;
Board materials - in their manufacture, again, mineral wool, organic materials (polyethylene, polyurethane, polystyrene, polystyrene) or wood chips (fiberboard, wood-cement boards) are used. They have a high degree of rigidity, therefore, they are mainly used for structural insulation of walls and ceilings;
Materials based on aerated concrete (foam concrete, gas silicate blocks, etc.) They are distinguished by high hardness and strength, which allows them to be used also as structural materials. However, aerated concrete is highly susceptible to moisture and, when wet, quickly collapse, therefore, it can only be used in combination with other insulation materials;
Foamy - a relatively new class of insulation. Usually this is an organic substance (polyurethane foam, etc.), which is supplied to the facility under construction in the form of liquid foam and is applied directly to the surface to be insulated or into voids. Within a few minutes, the foam hardens to form a relatively rigid, porous material. They are characterized by fairly good thermal and waterproofing characteristics.
Roof insulation. Up to 10% of the heat is emitted through the roof of the building, therefore its insulation is also important for the energy saving of the whole house.
When insulating flat roofs, high requirements are imposed on thermal insulation in terms of compressive strength, rupture, thermal conductivity and low specific gravity. These requirements are largely met by boards made of extruded polystyrene foam. They are successfully used on all types of flat roofs: exploited and unexploited, lightweight and traditional. Another important property of this material is its low water absorption, which has a positive effect on the stability of its thermal insulation qualities.
On pitched roofs, all the same insulation materials can be used as for walls.
Polyurethane foam as a modern thermal insulation building material can be used for thermal insulation:
External wall joints;
Gaps between window and door blocks;
Ground floor floor;
Overlapping over unheated rooms;
Outer walls;
Roofs (especially those roofs, the load on which should be minimal).
There are two methods of polyurethane foam insulation for roofs:
Installation of rigid polyurethane foam insulation boards with stepped seam;
Spraying polyurethane foam directly onto the roof surface.
The second method is considered the most promising (Fig. 4.32.).
The main idea of this approach is that in addition to spraying thermal insulation, the roof is sealed, whereas in the case of a conventional flat roof, several layers of different materials would have to be installed, performing different functions. During roof reconstruction, thermal insulation by spraying with polyurethane foam can be applied even without first dismantling the roof.
Figure 4.32. Spraying polyurethane foam
Temperature resistance of sprayed materials for flat roofs is from -60 to +120 ºС, water absorption of the material is about 2% by volume. Practice shows that after continuous intense rain (8 hours), water does not penetrate deep into the polyurethane foam coating. Thermal conductivity of polyurethane foam spraying is in the range of 0.023-0.03 W / (m? K).
When using solid polyurethane foam, a crust forms on its outer surface, which, under the influence of ultraviolet radiation, acquires a brown color over time, while the mechanical properties of the polyurethane foam coating do not change.
To increase resistance to weather conditions, the outer surface of the polyurethane foam must be protected from ultraviolet radiation either by painting or by gravel backfill with a thickness of at least 5 cm.
Insulation of communications.
In addition to the walls and roof, for the best energy saving of the building, it is necessary to insulate the communication systems of the building. The cold water supply system and sewerage system must be protected from freezing, hot water pipes - to reduce heat losses. Modern heat-insulating materials for pipes make it possible to effectively solve this problem.
There are many solutions for performing thermal insulation, they all depend on the operating conditions of the pipeline.
The most common types of thermal insulation are:
Polyethylene foam insulation is the most democratic and cheapest material. It is produced in the form of pipes with a diameter of 8 to 28 mm. Installation does not cause any difficulties: the workpiece is simply cut along the longitudinal seam and put on the pipe. To increase the thermal insulation properties, this seam, as well as the transverse joints, are glued with a special tape. It is used in domestic conditions for thermal insulation of all types of pipelines, even in freezing equipment;
Expanded polystyrene, better known as polystyrene foam. Insulation made of this material in everyday life is called a shell (due to the design features). It is made in the form of two pipe halves, connected by means of a tenon and a groove. Billets of various diameters are produced, with a length of about 2 m. Due to its properties, it retains operating characteristics for up to 50 years. Differs in high thermal stability both in conditions of high and negative temperatures. Penoizol is a type of foam - it has the same technical characteristics, but differs in the method of installation. Penoizol is a liquid heat insulator, which is applied by spraying, which makes it possible to obtain sealed surfaces;
Mineral wool. These heat-insulating materials for pipes are characterized by increased fire resistance and fire safety. They are widely used in the insulation of chimneys, pipelines, the temperature of which reaches 600-700 ºС. Thermal insulation with large volumes of mineral wool is unprofitable due to the high cost of the material.
There are also alternative ways to reduce heat loss, for which, perhaps, the future:
Pre-isolation. It consists in the processing of pipe blanks with polyurethane foam in the factory, at the production stage. The pipe comes to the consumer already protected from possible heat loss. During installation, it remains to insulate only the pipe joints;
A paint with thermal insulation properties. A relatively recent development by scientists. It contains various fillers that provide unique properties. Even a thin layer of such paint is able to provide thermal insulation, which is achieved by a large volume of foam, mineral wool and other materials. Easy to apply to the surface, allows you to process communications even in hard-to-reach places. Among other things, it has anti-corrosion properties.
Modern thermal insulation materials are used in various pipeline lines. They are capable of operating both at high temperatures and in extremely harsh permafrost conditions.
The use of thermal insulation allows you to achieve the following results:
Reduction of thermal energy leaks on heating and hot water supply lines;
Protection of various pipelines from freezing in conditions of negative temperatures;
Increase in the service life of networks due to a decrease in the aggressive impact of the environment;
In refrigeration and air conditioning systems, a significant reduction in the cost of maintaining the required temperature;
Reduced risk of injury and burns from contact with hot or cold surfaces.
The use of high-quality thermal insulation of pipelines allows to increase the period of trouble-free operation of communications and pays off within several years of operation.
Thermal bridges. Thermal insulation measures are effective only in cases where the absence of thermal bridges and leaking joints is ensured.
By "thermal bridges" are meant those weak links in thermal insulation through which, due to geometric features or design flaws, a large amount of heat escapes through small areas.
Geometric thermal bridges appear, for example, not only in bay windows and dormers, but also in the area of the outer edges of the building.
Constructive thermal bridges appear, first of all, at the junctions of various structural elements and on the lines of intersection of their surfaces. During reconstruction, they should be eliminated whenever possible, and when new structural elements are added, they should be avoided.
The better the surface of a building's structural element is thermally insulated, the more pronounced the effect of thermal bridges. This effect not only leads to unwanted heat leaks, but also to damage to the building if thermal bridges are located on cold surfaces, since moisture condensation and mold formation occur in this place.
To avoid the appearance of thermal bridges, the following measures must be taken:
Thermal insulation should be installed tightly so as to avoid leaks, and special attention should be paid to the insulation of joints, where structural elements are connected to each other or pass through each other;
Interpenetrating and protruding structural elements (for example, balcony slabs) must in any case be covered with insulating material from all sides;
Structures subject to increased thermal stress (made of steel, concrete or timber) must be provided with additional thermal insulation.
The calculations were made for a typical two-story house with an attic with a total area of 205 m2, insulated in accordance with old and modern standards. The required power of the heating system before insulation is 30 kW. After the house has been insulated, the required power does not exceed 15 kW. So the conclusion is obvious.
The location of the insulation
There are three options for the location of the insulation.
1.From the inside of the wall.
Advantages:
The exterior decoration of the house is fully preserved.
Convenience in execution. Work is carried out in warm and dry conditions, and this can be done at any time of the year.
You can resort to the most modern technologies at the moment, using the widest selection of materials.
Disadvantages:
In any case, the loss of usable area is inevitable. Moreover, the greater the thermal conductivity of the insulation, the greater the losses.
An increase in the moisture content of the supporting structure is likely. Water vapor passes through the insulation (usually a vapor-permeable material) without hindrance, and then begins to accumulate either in the thickness of the wall, or at the “cold wall-insulation” border. At the same time, the insulation delays the flow of heat from the room into the wall and thus lowers its temperature, which further aggravates the waterlogging of the structure.
That is, if, for one reason or another, the only possible option for insulation is to place the insulation from the inside, then it will be necessary to take rather tough constructive measures to protect the wall from moisture - install a vapor barrier from the side of the room, create an effective ventilation system for air in the premises.
2. Inside the wall (sandwich structures).
In this case, the insulation is placed on the outside of the wall and covered with a brick (facing). The creation of such a multi-layer wall can be quite successfully implemented with new construction, but for already existing buildings it is difficult to do, since it causes an increase in the thickness of the structure, which, as a rule, requires reinforcement, and therefore alteration of the entire foundation.
3. From the outside of the wall.
Advantages:
External thermal insulation protects the wall from alternating freezing and thawing, makes the temperature fluctuations of its array smoother, which increases the durability of the supporting structure.
The "dew point", or the condensation zone of the escaping vapors, is carried out into the insulation - outside the load-bearing wall. The vapor-permeable heat-insulating materials used for this do not impede the evaporation of moisture from the wall into the external space. This helps to reduce the moisture content of the wall and increases the service life of the entire structure.
External thermal insulation prevents heat flow from the load-bearing wall to the outside, thus increasing the temperature of the load-bearing structure. In this case, the array of the insulated wall becomes a heat accumulator - it contributes to a longer retention of heat inside the room in winter and coolness in the summer.
Disadvantages:
The outer heat-insulating layer must be protected both from moisture by atmospheric precipitation and from mechanical impact with a durable but vapor-permeable coating. We have to arrange the so-called ventilated facade or plaster.
The so-called dew point gets inside the insulation layer, and this always leads to an increase in its moisture content. This can be avoided by using heaters with high vapor permeability, due to which moisture both got into the layer and evaporates from it.
Having weighed all the pros and cons of each of the three methods of placing insulation, we can definitely say that outdoor insulation is certainly the most rational.
WAYS OF INSULATION OF FACADES
It should be noted right away that when a building is insulated from the outside, its decoration ceases to play only an aesthetic role. Now it must not only create comfortable conditions inside the building, but also ensure the protection of the supporting structure and the insulation reinforced on it from the effects of various weather factors, but without losing its visual appeal. In this regard, it is impossible to talk only about the methods of insulating houses and about the materials used for this - whatever one may say, we will have to talk about finishing at the same time, since both operations are simply inseparable from each other.
First of all, it is worth considering wooden structures, since it is for them that the scheme of the wall "puff cake" turns out to be the most complicated and it is they who are most susceptible to destruction due to the wrong device. It will be useful to consider along the way the processes taking place in the insulated structure.
Thermal insulation of wooden structures
As you know, wood is one of the most traditional building materials from which frame and log houses are erected not only in Russia, but also in many other countries. True, no matter how wonderful properties a tree may have, it is not a sufficient heat insulator. Since we are talking about a relatively moisture-absorbing material that is highly susceptible to decay processes, the effects of mold and other diseases caused by its moisture, the most optimal scheme is considered to be external insulation with a protective and decorative screen (outer sheathing) with a ventilated gap between the insulation and this very screen ( see figure).
This scheme includes such components as interior cladding (from the side of the room), vapor insulation, wooden supporting structure, insulation, wind protection, ventilated air gap, external cladding (from the street). If we want to understand why each of these components is needed, it is worth considering in more detail the physical processes that occur in an insulated structure (see Fig.).
On average, during the year-round operation of the building, the heating season lasts 5 months, of which three are in winter. This means that 24 hours a day there is a stable temperature difference between the inner space (zone of positive temperature) and the street (zone of subzero temperature). And since there is a temperature difference, it means that in a wall structure with a certain thermal conductivity, a heat flow in the direction "from heat to cold" is inevitably formed. Simply put, the wall takes away the heat from the room and removes it outside. So, the main task of the insulation is to reduce this flow to a minimum. At present, the use of heaters is regulated by the requirements for thermal protection of enclosing structures, specified in amendment No. 3 to SNiP 11-3-79 * "Construction heat engineering", which entered into force at the beginning of 2000.
It is important to know that the thermal insulation material is effective as long as it remains dry. For example, basalt insulation with a volumetric moisture content of only 5% loses 15-20% of its thermal insulation properties. Moreover, the higher its moisture content, the more significant the losses become. In fact, the insulation ceases to be a heater, which means that the main question becomes: where does the moisture come from in it?
The air always contains water vapor in one volume or another. At 100% relative humidity and a temperature of 20 ° C, 1 m3 of air can contain up to 17.3 g of water in the form of steam. As the temperature decreases, the air's ability to retain moisture sharply decreases, and at a temperature of 16 ° C, 1 m3 of air can already contain no more than 13.6 g of water. That is, the lower the temperature, the less moisture the air is able to retain. If, with a decrease in temperature, the real content of water vapor in the air exceeds the maximum permissible value for a given temperature, then the "extra" vapor will immediately turn into drops of water. And this is the source of moisture insulation.
This whole process takes place as follows. The relative humidity in the room is about 55-65%, which greatly exceeds the humidity of the outside air, especially in winter. And since there is a difference in the values between the two volumes, then a "flow" will inevitably arise, designed to equalize these values - warm water vapor first moves from the room to the street through the insulated structure. But since it has to move "from heat to cold", along the way it will condense (turn into drops), thus moistening the heat-insulating material.
It is possible to suppress the humidification process by creating a so-called vapor barrier, arranged from the side of the room. To create it, you will need either a couple of layers of oil paint, or rolled vapor barrier materials, which are covered with decorative cladding. In this case, moisture vapors are removed from the premises by means of forced ventilation (see Fig.).
But the organization of such a vapor barrier is far from the only necessary condition. The air contained in the insulation, warmed up from the inner (bearing) wall, will begin to move towards the street. It must be said that simultaneous vapor-permeable heat-insulating materials will not interfere with such movement, and as the air cools, moisture can also begin to condense from it. To avoid this, water vapor that has reached the outer boundary of the thermal insulation material must be given an unhindered opportunity to leave it before condensation occurs. So, the second condition for ensuring the normal operation of the insulated structure is the presence of well-organized ventilation - the creation of a so-called ventilated gap between the outer skin and the layer of heat-insulating material, as well as conditions for the occurrence of "traction" (air flow) in this gap. It is precisely the "draft" that will remove the water vapor that comes out of the heat-insulating material.
But even these measures will not be enough. It is also necessary to insulate the heat-insulating layer from the street side, and if this is not done, the heat-insulating properties of the insulation may deteriorate. First, due to atmospheric moisture (penetration of rain, snow, etc.), the layer of thermal insulation can be moistened. Secondly, because of the wind, it is impossible to “blow through” low-density heaters, which is accompanied by heat carryover. Thirdly, under the influence of a constant air flow in the ventilated gap, the destruction of the heat-insulating material can begin - the process of "blowing" the insulation.
In order to preserve the heat-shielding characteristics of the structure, on the bordering surface of the thermal insulation; with a ventilated gap, a layer of windproof, moisture-insulating and, at the same time, vapor-permeable material is laid.
It is unacceptable to install the same vapor-proof (“non-breathable”) material from the street side as from the inside (the so-called vapor barrier), since in this case the insulated structure would become insulated. The fact is that in an isolated space, air also moves "from heat to cold", but at the same time it has no opportunity to go out towards the ventilated gap. With the movement of air towards the outer skin and simultaneous cooling inside the heat insulator, active condensation of moisture occurs, which eventually freezes into ice. As a result, the thermal insulation material loses most of its effectiveness. With the arrival of the warm season, the ice will melt, and the entire structure will inevitably begin to rot.
Summing up all of the above, the following basic condition for the successful operation of an insulated wall structure can be formulated: the thermal insulation must remain sufficiently dry regardless of the season and weather conditions. Due to the fulfillment of this requirement, the presence of a vapor barrier on the side of the room and a wind barrier on the side of the ventilated gap is ensured.
The design and the order of its installation of the lathing will mainly depend on the material that will be used as a protective screen. For example, the process of installing the lathing for laying insulation with the subsequent installation of siding looks like this. On the outer surface of the wall, vertical, pre-treated with an antiseptic composition, wooden beams are fixed - their thickness is 50 mm, and the width should exceed the thickness of the plates of the selected insulation. For example, with a thermal insulation thickness of 80 mm, the thickness of the frame beams should be at least 100-110 mm - this is necessary to ensure an air gap. The step of the lathing should be selected in accordance with the width of the insulation boards. The latter fit into the grooves between the beams and are additionally attached to the load-bearing wall by means of anchors. The number of anchors per 1 m2 of insulation is determined in accordance with the density (and therefore strength) of the selected insulation and can vary between 4-8 pcs. A windproof layer is mounted on top of the insulation, and only then siding (see fig.).
Of course, this is the simplest, but not the best scheme, since during its implementation there are still so-called cold bridges (zones with significantly lower thermal resistance than insulation), which in this case are the sheathing beams. The installation scheme is much more efficient from a thermal engineering point of view, in which the insulation layer is divided into two equal parts (for example, with a required thickness of 100 mm, two plates with a thickness of 50 mm are used) and for laying each of these layers, its own lathing is used. In the latter case, the beams of the sheathing of the upper layer are packed perpendicular to the beams of the lower one. Of course, the creation of such a structure is a more laborious process, but there are practically no "cold bridges" in it. In conclusion, it remains to close the insulation with a layer of wind insulation, securing it with vertical beams, and mount the same siding already on them (see Fig.).
As already noted, vapor barrier materials are used in insulated wall structures as "internal" protection for thermal insulation materials. When choosing a particular material, they are usually guided by the principle: the higher the value of the resistance to vapor permeation of the material (Rn), the better.
Vapor barrier materials are sold in rolls and can be mounted both horizontally and vertically on the inner side of the enclosing structure close to the thermal insulation. The connection to the elements of the supporting structure is carried out either with staples of a mechanical stapler, or with galvanized nails with a flat head. It should be borne in mind that water vapor has a sufficiently high diffusion (penetrating) ability, in connection with which the vapor barrier should be created in the form of a solid screen, which means that the tightness of the seams is a prerequisite. Among other things, care must be taken to ensure that the film remains intact.
For a long time, the sealing of seams has been achieved by using butyl rubber connecting tapes with adhesive layers on both sides, or by overlapping "strips" of vapor barrier material with fixation along the seam with a counterbeam.
When we deal with the ceilings of residential spaces, mansard superstructures and rooms with high humidity, it is required to provide a gap of 2-5 cm between the vapor barrier and the material of the inner lining, which should prevent it from humidification.
At the moment, the Russian building materials market offers vapor barrier materials from such manufacturers as: JUTA (Czech Republic) - Jutafol N / Al; TEGOLA (Italy) - Bar line; ELTETE (Finland) - Re-Rar 125 line, ICOPAL (Finland) - Ventitek, Ventitek Plus, Elbotek 350 White, Elbotek 350 Alu, Alupap 125, Elkatek 150, Elkatek 130; MONARFLEX (Denmark) - Polykraft and some others.
Wind-insulating materials are used in wall structures (including systems of ventilated facades), performing the function of external protection of heat-insulating materials. The main task of these materials is to keep moisture and wind out of the insulation layer, while not preventing water vapor from escaping from it.
When choosing wind-insulating materials, it is important to take into account that the resistance to vapor permeability of a multi-layer enclosing structure should decrease in the direction of movement of water vapor - “from heat to cold”. That is, the lower the value of the resistance to vapor permeation of the selected material (Rn), the less the likelihood of condensation of water vapor inside the insulated structure. True, when following this principle, there is a risk of overdoing it. As the practice of ventilated facades shows, the vapor permeability of windproof materials in the range of 150-300 g / (m2-day) is quite sufficient, and their price is adequate for the wave (about 0.5 conventional units / m2). As for the use of superdiffusion materials (their vapor permeability exceeds 1000 g / (m2-day)), in this case they will not bring anything fundamentally different to the operation of the structure, but the cost of the structure will noticeably increase, since the prices for such materials exceed 1 ... e. / m2.
Installation of windproof materials is carried out on the outer side of the enclosing structure close to the thermal insulation. The material can be laid both horizontally and vertically. The overlap between the canvases (width) must be at least 150 mm. It is extremely important to follow the manufacturer's recommendations for installation and installation and in no case to confuse the front side with the wrong side. The latter is of great importance due to the fact that many vapor barrier materials have one-sided vapor conductivity, and if the sides are confused, the insulated structure will turn into an insulated one, which is detrimental for it.
In the process of installation, the curtains of the windproof material are pre-fixed with galvanized stainless nails with a wide head, or special brackets with a pitch of 200 mm are suitable for these purposes. The final fastening is carried out using a bar with a section of 50 x 50 mm, nailed with galvanized nails 100 mm long with an interval of 300-350 mm.
Then the installation of the facing material is carried out.
At the moment, to create a wind barrier, the Russian market offers vapor barrier materials from such manufacturers as: JUTA (Czech Republic) - Jutafol D, Jutakon, Jutavek; DUPONT (Switzerland) - Tyvek series membranes; MONARFLEX (Denmark) - Monarflex BM 310, Monarperm 450, Difofol Super; ELTETE (Finland) - Elkatek SD, Elwitek 4400, Elwitek 5500, Bitupap 125, Bitukrep 125, etc.
Thermal insulation of a stone (brick) wall
Warming with further plastering
For these purposes, the so-called contact facade thermal insulation systems are used (Fig. 40). There is a great variety of options for such systems: Tex-Color, Heck, Loba, Ceresit (Germany), Termoshuba (Belarus), (USA), TsNIIEP dwelling systems (RF), Shuba-plus, etc. In such systems, constructive solutions differ in the type of insulation used and the methods of its fastening. As well as the thickness and composition of the protective and adhesive layers, the type of reinforcing mesh, etc. The insulation schemes proposed by each of them are largely similar: adhesive or mechanical fastening of the insulation using anchors, dowels and frames to the existing wall with further protective coating ( but always vapor-permeable) with a layer of plaster (for example, in the Dryvit system, acrylic plaster is most often used).
A dry, strong and clean unplastered or plastered brick, concrete or foam concrete facade wall can serve as a base. Significant irregularities should be eliminated with cement or lime-cement mortar. When the surface of a brick wall does not need to be hardened with a primer, it is worth using it for all other types of bases.
The order of work is approximately as follows. The function of the support for the first row of heat-insulating material can be performed by the protruding edge of the foundation or the edge of the concrete floor slab. If there is none, then with the help of dowels, a false support is installed - a wooden or metal support rail (the wooden one is removed immediately before plastering). The consumption of glue, for example, for brickwork will be from 3.5 to 5 kg / m2, which directly depends on how smooth the base is. The slabs are laid, as when laying bricks, - closely to each other with "bandaging the seams".
I must say that the gluing procedure for small-area facades is by and large not necessary - the glue is only needed to hold the insulation plates on the facade until they are mechanically fixed to the load-bearing wall.
- It is imperative to fix the insulation plates mechanically, for example, this can be done using plastic expansion dowels with a stainless steel rod. The number of dowels depends on the type of insulation used, for example, for expanded polystyrene, it should be at least 6 per 1 m2. The depth of fixing the dowels at the base of the wall must be at least 50 mm.
Work is carried out 2-3 days after gluing. The corners and edges of window and door slopes are reinforced with special corner profiles made of perforated aluminum or plastic. After that, you can start applying the main plaster layer. If you intend to make a small layer of plaster (within 12 mm in the case of using a dense mineral insulation), you can use a plasticized alkali-resistant fiberglass mesh, with a thicker layer (2-3 cm in the case of using expanded polystyrene), it is better to use a metal mesh (see Fig.).
Plaster is applied in two layers. A thicker layer is put first - strips of reinforcing mesh are pressed into it. This is done so that the mesh, and therefore the plaster, perceives temperature and other loads as best as possible, it should be located in the outer third of the thickness of the plaster layer, and not at the very surface of the heat-insulating coating. The second is to put a thinner layer of plaster - immediately after pressing the mesh into the bottom layer. Both the width and the length of the mesh strips overlap by 10-20 cm, and at the corners of the building they are folded over with an overlap.
It is worth paying attention to the fact that both the same solution and different ones can be used for gluing insulation boards and making the main plaster. For example, for gluing - Ispo Kleber Mortar, and for plastering - Ispos No. 1 Verbundmortel with a thin layer, or Ispo SL 540 Armierungs-Leichtputz with a thick layer. Also, compositions reinforced with microfibers are suitable for plastering, which will give them additional strength and reduce the likelihood of cracking (one of these is Jubizol Lepilna Malta, manufactured by JUB, Slovenia).
When the plaster is dry, you can proceed with the final finishing. At this stage of work, the choice will largely depend on your preferences: plaster treated with a roller, trowel, spray; plaster "with a fleece", with rubbing like "oak bark", etc.; With its further staining or simply staining the main plaster layer after filling (see fig.).
With the method described above, there is no need to use vapor barrier and windproof materials. The vapor barrier will be replaced directly by the supporting structure itself - it has a sufficiently high coefficient of resistance to vapor permeation, and the windproof ones will be replaced by a layer of vapor-permeable plaster. Small amounts of water vapor, nevertheless, trapped inside the wall, will be freely discharged outside through the plaster and a layer of insulation.
Vented Gap Design
This insulation option is, by and large, something in between the options already discussed above for a wooden and for a stone house with further plastering. Although the insulation in this case is not glued, but is attached to the facade with dowels. After that, its surface is covered with a wind-insulating material, and a ventilated gap is arranged, which from the outside will have to cover a protective and decorative screen. As in the previous case, there is no need to use vapor barrier materials (Fig. 43).
The curtain wall can be mounted both on a wooden lathing or on a metal one. Metal profiles and other elements that make it possible to quickly and fairly easily carry out such an installation are now offered in large quantities by many companies - for example, such as "METAL PROFILE".
The main advantage of this insulation scheme is that it can be fastened at low temperatures (there are no so-called wet processes). However, the system has its limitations when applied to buildings with complex architecture, as well as in cases where an accurate reproduction of the original appearance of the facade is required.
In low-rise construction, it is best to use decorative and protective screens with additional sources of air convection feed on the surface of the screen. In reality, they are made in the form of slotted air intakes, which are formed during the production of facade elements. A classic example is the now popular plastic siding with perforation at the bottom bend of the panels. The same screen can be mounted using ARDOGRES facing tiles - during installation, a technological gap of 10 x 160 mm is formed under each tile.
For many years, the motto of the Soviet construction industry was total economy. Such an erroneous economic policy made it possible to minimize capital construction costs as much as possible, which made it possible to quickly and easily build residential, public and industrial buildings. The permissible temperature and humidity conditions for living or working a person were achieved due to the high operating costs of heating, the price of which was regulated by the planned economy. Times have changed, the planned economy of the USSR is history, but the thin walls remain. Prices for all types of energy sources are steadily increasing, and the centralized heating system has ceased to justify itself. Wall insulation is one of the main solutions to ensure comfortable living conditions, while minimizing the cost of additional heating.
Insulation of external walls from the outside
It is correct to insulate the outer walls from the outside by adding to the wall a layer of effective insulation made of polystyrene or similar material, characterized by high thermal resistance, sufficient strength and low water absorption.
Why it should be insulated outside is clearly demonstrated by the following drawings:
Fig. 1 - "classic" thin wall; L1 - thickness of the main wall, 1 - lightweight concrete material with porous fillers; 3 - outer and 5-inner decorative layer, they are usually neglected in heat engineering calculations; 6 is a graph of the temperature inside the wall, where T (HV) and T (HA) are the internal and external air temperatures. 7 - graph of the "dew point" temperature. Analyzing the circuit, we can note the proximity of graphs 6 and 7, there is very little left to create the conditions for the occurrence of condensate.
Fig. 2 - the same wall, but the situation has changed: the outside temperature has dropped, the heating power is not enough. Temperature graphs 6 and 7 - "dew points" intersected, a condensation zone - L (k) was formed, the wall inside became wet, condensation could penetrate deeper, deteriorating the characteristics of the wall. Prolonged exposure to moisture on the outer wall material leads to the appearance of fungus and efflorescence. Internal putty can flake and crack just like paint.
Now the outer wall has been insulated by placing a layer of effective insulation on the outside.
Fig. 3 Legend:
- Outer wall.
- Effective insulation, such as expanded polystyrene.
- The outer decorative layer is made of a special putty, which is reinforced with glass mesh and painted with paint for facade work. Will reliably protect expanded polystyrene from weather influences, increase the fire resistance of the structure.
- The glue solution provides mechanical fastening of the insulation layer and its tight fit to the wall, if the area of the insulated surface is more than 8 m², special dowels are additionally used.
- Internal decorative layer.
- Temperature graph.
- Dew point graph.
The temperature graph - 6 and the dew point graph - 7 are far from each other, which means that the occurrence of a condensation zone does not threaten such a layered structure.
If the heating is central, then the room will become warmer, if it is individual, you can save a little by screwing the boiler thermostat.
Materials and technology of external wall insulation.
Most often, foam is used for insulation, or more precisely, expanded polystyrene made by extrusion. Such a material is characterized by a very low thermal conductivity, sufficient strength at a low weight, practically does not absorb moisture, since it has closed pores. The chemical industry produces a sufficient range of similar expanded polystyrene in the form of plates of various thicknesses (from 2 to 10 cm), density and strength.
Expanded polystyrene plates of the Technonikol firm, Carbon series. The edge of the sheet is made with a special "L - shaped" groove, which excludes the formation of "cold bridges" at the seams.
Plates made of rigid URSA expanded polystyrene, with a special groove, allow walls, floors, attic floors and basements to be insulated in one layer.
Conventional foam boards are not recommended for wall insulation, but due to their low cost (3-5 times cheaper than extruded polystyrene foam) they are still used very often, which in turn negatively affects the quality and durability of insulation.
General scheme of external wall insulation with expanded polystyrene:
The outer wall can be brick, panel made of foam - or expanded clay concrete.
The technology of conducting work when insulating walls with expanded polystyrene:
- The surface of the walls is cleaned of dirt and peeling paint or plaster fragments.
- Depressions and irregularities are filled with facade plaster solutions.
- The prepared surface is primed, depending on the condition, with primers that strengthen and increase adhesion.
- Plates are installed on the prepared surface with the help of an adhesive composition. The adhesive can be applied both to the slab and to the wall.
Adhesives from Caparol.
Dry mixes of the "Ceresit" firm, for gluing CT83 expanded polystyrene, for gluing and reinforcing CT85.
Schemes for applying adhesive solution: 1 - solid, 2 - in stripes, 3 - beacons. The glue solution is applied so that 1-2 cm remains to the edge of the plate, and the composition does not get into the seams.
Slabs are glued, similarly with brickwork with dressing:
- Mechanically, polystyrene foam plates are fixed using plastic dowels with a wide plate head, at the rate of at least four pieces per plate, the installation of which should be carried out a day after gluing to the mortar. Such dowels are suitable for fixing all types and brands of expanded polystyrene boards, regardless of the manufacturer.
Dowel-sets with a metal rod are characterized by high strength, and those with a plastic (reinforced polycarbonate) rod have thermal performance indicators that exclude the appearance of a "cold bridge".
When installing an insulating layer made of ordinary foam or from expanded polystyrene plates that do not have a groove, very often the dowels are installed in the seams or at the joints, but this may not be entirely true.
Large firms, manufacturers of construction chemicals and mixtures, for example, the German "Ceresit" have developed their own technologies for wall insulation. They produce a range of construction chemicals and mixtures designed to fully satisfy the need for materials at all stages of insulation.
It should be noted that insulation with extruded polystyrene foam reduces the overall vapor permeability - the walls "do not breathe" and therefore, measures and engineering solutions are needed to ensure sufficient ventilation of the premises.
Insulation of external walls from the inside.
Consider the case of external wall insulation when the insulation is located on the inside.
Fig. 4 Legend is similar to Fig. 3. The temperature graphs-6 and "dew point" -7 intersected, forming a vast zone of condensation - L (k), both in the wall itself and in the insulation.
Despite the fact that theory and practice have proven the fallacy of insulating external walls from the inside, such attempts continue. Why is insulation from the inside so attractive to itself:
- Work can be carried out at any time of the year, even in winter or in the rain.
- Ease of work: no need for stairs, scaffoldings, cars with lifts or climber equipment, which means you do not need to hire specialists.
It is rational to insulate the first and second floors from inventory scaffolds.
For builders who have mastered climbing equipment, the floor does not matter.
A false wall made of plasterboard with mineral wool insulation is cheaper than external insulation both in terms of material and cost of work.
Negative aspects of external wall insulation from the inside:
- Condensation may appear on the wall and, as a result, fungus, efflorescence and rust stains.
- The condensation zone moves into the volume of the insulation, and mineral wool in such humid conditions loses its properties and can collapse.
- The device of an impenetrable vapor barrier will greatly complicate the "breathing" of the walls, which is not permissible in the absence of ventilation (ventilation duct systems and vents).
- Insulation inside reduces the useful area of the premises.
In theory, it is possible to insulate the outer walls from the inside. As a heater, you should use extruded foam or ordinary foam with a density of at least 50 kg per cubic meter, which is not only durable, but also moisture-proof, since it has closed pores. It should be glued to the wall with a special cement-based foam polystyrene glue. The cement stone of such glue, like extruded polystyrene foam, is not affected by moisture. A layer of foam-2 (see Fig. 4) will act as a vapor barrier. Thus, there will be no condensation problem. Moreover, in winter, thanks to heating, the air humidity is less than normal (to ensure normal humidity, stores of household and climatic equipment sell special humidifiers and dehumidifiers that reduce humidity). In practice, it will be very difficult to perform a sufficiently high-quality installation of foam sheets with the organization of the same ideal joints. In addition, polystyrene is a combustible material, therefore, in the event of a fire, it will emit poisonous combustion products, which can cause death.
It should be added that in connection with the massive use of plastic windows and entrance doors with rubber seals, ventilation must be made a rule, otherwise it will be very difficult to achieve normal room humidity.
Variants with a vapor barrier between the insulation and a drywall sheet with decorative trim, as well as with the ventilation of the internal mineral wool insulation using air gaps and ventilation holes, are quite costly. When insulating the outer wall from the inside, it is logical to insulate a part of the adjacent floor and ceiling by introducing a vapor barrier to these areas. Craftsmen can add insulation and foam forms to such a "layer cake", where a 1-3 cm layer of foamed polymer material is reinforced with aluminum foil. If such calculations turned out to be erroneous, then black mold and traces of efflorescence, red spots will appear on the walls (see Figures 5 and 6).
Insulation of walls from the inside is considered incorrect, but it cannot be completely ruled out. Regardless of the opinion and evidence of the majority, each landlord makes a decision himself.
The only case when the installation of insulation from the inside is fully justified is the insulation of basements, because there is soil outside.
Insulation of outer walls will reduce operating costs with individual heating or with central heating to make the premises warmer. It should be insulated only from the outside, and it is recommended to use extruded or high density expanded polystyrene as insulation. Rigid mineral wool slabs are used in ventilated façade systems, which are rarely suitable for thermal insulation of residential buildings, and this is more suitable for public buildings.