Last time we defined . Today we will compare heaters. table with general characteristics you can find in the article summary. We have chosen the most popular materials, including mineral wool, polyurethane foam, penoizol, foam plastic and ecowool. As you can see, this universal heaters with a wide range of applications.
Comparison of thermal conductivity of heaters
The higher the thermal conductivity, the worse the material works as a heater.
We start comparing heaters in terms of thermal conductivity for a reason, since this is undoubtedly the most important characteristic. It shows how much heat a material transmits not in a certain period of time, but constantly. Thermal conductivity is expressed by a coefficient and is calculated in watts per square meter. For example, a coefficient of 0.05 W/m*K indicates that square meter constant heat loss is 0.05 watts. The higher the ratio, the better material conducts heat, respectively, as a heater it works worse.
Below is a comparison table popular heaters by thermal conductivity:
Having studied the above types of heaters and their characteristics, we can conclude that with an equal thickness, the most effective thermal insulation among all is liquid two-component polyurethane foam (PPU).
The thickness of the thermal insulation has archi importance, it must be calculated for each case individually. The result is influenced by the region, the material and thickness of the walls, the presence of air buffer zones.
Comparative characteristics of heaters show that the thermal conductivity is affected by the density of the material, especially for mineral wool. The higher the density, the less air in the structure of the insulation. As you know, air has a low thermal conductivity, which is less than 0.022 W/m*K. Based on this, with an increase in density, the coefficient of thermal conductivity also increases, which negatively affects the ability of the material to retain heat.
Comparison of the vapor permeability of insulation
High vapor permeability = no condensation.
Vapor permeability is the ability of a material to pass air, and with it steam. That is, the insulation can breathe. On this characteristic of heaters for the house recent times manufacturers focus a lot of attention. In fact, high vapor permeability is needed only when . In all other cases, this criterion is not categorically important.
Characteristics of insulation in terms of vapor permeability, table:
A comparison of wall insulation showed that the highest degree of vapor permeability is natural materials, while at polymer insulation ratio is extremely low. This indicates that materials such as polyurethane foam and polystyrene have the ability to retain steam, that is, they perform . Penoizol is also a kind of polymer that is made from resins. Its difference from PPU and polystyrene lies in the structure of the cells that open. In other words, it is a material with an open cell structure. The ability of thermal insulation to pass steam is closely related to the following characteristic - moisture absorption.
Overview of the hygroscopicity of thermal insulation
High hygroscopicity is a disadvantage that needs to be addressed.
Hygroscopicity - the ability of a material to absorb moisture, measured as a percentage of the insulation's own weight. Hygroscopicity can be called weak side thermal insulation and the higher this value, the more serious measures will be required to neutralize it. The fact is that water, getting into the structure of the material, reduces the effectiveness of the insulation. Comparison of the hygroscopicity of the most common thermal insulation materials in civil engineering:
Comparison of the hygroscopicity of insulation for the house showed a high moisture absorption of penoizol, while this thermal insulation has the ability to distribute and remove moisture. Due to this, even when wet by 30%, the coefficient of thermal conductivity does not decrease. Despite the fact that mineral wool has a low percentage of moisture absorption, it especially needs protection. After drinking water, she holds it, not allowing it to go outside. At the same time, the ability to prevent heat loss is catastrophically reduced.
To prevent moisture from entering the mineral wool, use vapor barrier films and diffusion membranes. In general, polymers are resistant to prolonged exposure to moisture, with the exception of ordinary polystyrene foam, it quickly collapses. In any case, water to none thermal insulation material did not benefit, so it is extremely important to exclude or minimize their contact.
Installation and operational efficiency
Installation of PPU - quickly and easily.
Comparison of the characteristics of heaters should be carried out taking into account the installation, because this is also important. Easiest to work with liquid thermal insulation, such as PPU and penoizol, but this requires special equipment. It is also easy to lay ecowool (cellulose) on horizontal surfaces, for example, when or attic floor. For spraying ecowool on walls using the wet method, special devices are also needed.
Styrofoam is laid both on the crate and immediately on the work surface. In principle, this also applies to slabs of stone wool. And lay plate heaters it is possible both on vertical, and on horizontal surfaces (under a coupler including). Soft glass wool in rolls is laid only on the crate.
During operation, the heat-insulating layer may undergo some undesirable changes:
- absorb moisture;
- shrink;
- become a home for mice;
- be destroyed by exposure to IR rays, water, solvents, etc.
In addition to all of the above, the fire safety of thermal insulation is important. Comparison of heaters, combustibility group table:
Results
Today we reviewed the heaters for the home, which are used most often. According to the results of the comparison different characteristics we received data regarding thermal conductivity, vapor permeability, hygroscopicity and the degree of flammability of each of the heaters. All this data can be combined into one common table:
| Material name | Thermal conductivity, W/m*K | Vapor permeability, mg/m*h*Pa | Moisture absorption, % | Flammability group |
| mineral wool | 0,037-0,048 | 0,49-0,6 | 1,5 | NG |
| Styrofoam | 0,036-0,041 | 0,03 | 3 | G1-G4 |
| PPU | 0,023-0,035 | 0,02 | 2 | G2 |
| Penoizol | 0,028-0,034 | 0,21-0,24 | 18 | G1 |
| Ecowool | 0,032-0,041 | 0,3 | 1 | G2 |
In addition to these characteristics, we have determined that it is easiest to work with liquid heaters and ecowool. PPU, penoizol and ecowool (wet installation) are simply sprayed onto the work surface. Dry ecowool is poured manually.
Vapor permeability table building materials
I collected information on vapor permeability by linking several sources. The same sign with the same materials walks around the sites, but I expanded it, added modern meanings vapor permeability from the websites of manufacturers of building materials. I also checked the values with the data from the document "Code of Rules SP 50.13330.2012" (Appendix T), added those that were not there. So on this moment this is the most complete table.
| Material | Vapor permeability coefficient, mg/(m*h*Pa) |
| Reinforced concrete | 0,03 |
| Concrete | 0,03 |
| Cement-sand mortar (or plaster) | 0,09 |
| Cement-sand-lime mortar (or plaster) | 0,098 |
| Lime-sand mortar with lime (or plaster) | 0,12 |
| Expanded clay concrete, density 1800 kg/m3 | 0,09 |
| Expanded clay concrete, density 1000 kg/m3 | 0,14 |
| Expanded clay concrete, density 800 kg/m3 | 0,19 |
| Expanded clay concrete, density 500 kg/m3 | 0,30 |
| Clay brick, masonry | 0,11 |
| Brick, silicate, masonry | 0,11 |
| Hollow ceramic brick (1400 kg/m3 gross) | 0,14 |
| Hollow ceramic brick (1000 kg/m3 gross) | 0,17 |
| large format ceramic block(warm ceramics) | 0,14 |
| Foam concrete and aerated concrete, density 1000 kg/m3 | 0,11 |
| Foam concrete and aerated concrete, density 800 kg/m3 | 0,14 |
| Foam concrete and aerated concrete, density 600 kg/m3 | 0,17 |
| Foam concrete and aerated concrete, density 400 kg/m3 | 0,23 |
| Fiberboard and wood concrete slabs, 500-450 kg/m3 | 0.11 (SP) |
| Fiberboard and wood concrete slabs, 400 kg/m3 | 0.26 (SP) |
| Arbolit, 800 kg/m3 | 0,11 |
| Arbolit, 600 kg/m3 | 0,18 |
| Arbolit, 300 kg/m3 | 0,30 |
| Granite, gneiss, basalt | 0,008 |
| Marble | 0,008 |
| Limestone, 2000 kg/m3 | 0,06 |
| Limestone, 1800 kg/m3 | 0,075 |
| Limestone, 1600 kg/m3 | 0,09 |
| Limestone, 1400 kg/m3 | 0,11 |
| Pine, spruce across the grain | 0,06 |
| Pine, spruce along the grain | 0,32 |
| Oak across the grain | 0,05 |
| Oak along the grain | 0,30 |
| Plywood | 0,02 |
| Chipboard and fiberboard, 1000-800 kg/m3 | 0,12 |
| Chipboard and fiberboard, 600 kg/m3 | 0,13 |
| Chipboard and fiberboard, 400 kg/m3 | 0,19 |
| Chipboard and fiberboard, 200 kg/m3 | 0,24 |
| Tow | 0,49 |
| Drywall | 0,075 |
| Gypsum slabs (gypsum boards), 1350 kg/m3 | 0,098 |
| Gypsum slabs (gypsum boards), 1100 kg/m3 | 0,11 |
| Mineral wool, stone, 180 kg/m3 | 0,3 |
| Mineral wool, stone, 140-175 kg/m3 | 0,32 |
| Mineral wool, stone, 40-60 kg/m3 | 0,35 |
| Mineral wool, stone, 25-50 kg/m3 | 0,37 |
| Mineral wool, glass, 85-75 kg/m3 | 0,5 |
| Mineral wool, glass, 60-45 kg/m3 | 0,51 |
| Mineral wool, glass, 35-30 kg/m3 | 0,52 |
| Mineral wool, glass, 20 kg/m3 | 0,53 |
| Mineral wool, glass, 17-15 kg/m3 | 0,54 |
| Expanded polystyrene extruded (EPPS, XPS) | 0.005 (SP); 0.013; 0.004 (???) |
| Expanded polystyrene (foam plastic), plate, density from 10 to 38 kg/m3 | 0.05 (SP) |
| Styrofoam, plate | 0,023 (???) |
| Ecowool cellulose | 0,30; 0,67 |
| Polyurethane foam, density 80 kg/m3 | 0,05 |
| Polyurethane foam, density 60 kg/m3 | 0,05 |
| Polyurethane foam, density 40 kg/m3 | 0,05 |
| Polyurethane foam, density 32 kg/m3 | 0,05 |
| Expanded clay (bulk, i.e. gravel), 800 kg/m3 | 0,21 |
| Expanded clay (bulk, i.e. gravel), 600 kg/m3 | 0,23 |
| Expanded clay (bulk, i.e. gravel), 500 kg/m3 | 0,23 |
| Expanded clay (bulk, i.e. gravel), 450 kg/m3 | 0,235 |
| Expanded clay (bulk, i.e. gravel), 400 kg/m3 | 0,24 |
| Expanded clay (bulk, i.e. gravel), 350 kg/m3 | 0,245 |
| Expanded clay (bulk, i.e. gravel), 300 kg/m3 | 0,25 |
| Expanded clay (bulk, i.e. gravel), 250 kg/m3 | 0,26 |
| Expanded clay (bulk, i.e. gravel), 200 kg/m3 | 0.26; 0.27 (SP) |
| Sand | 0,17 |
| Bitumen | 0,008 |
| Polyurethane mastic | 0,00023 |
| Polyurea | 0,00023 |
| Foamed synthetic rubber | 0,003 |
| Ruberoid, glassine | 0 - 0,001 |
| Polyethylene | 0,00002 |
| asphalt concrete | 0,008 |
| Linoleum (PVC, i.e. not natural) | 0,002 |
| Steel | 0 |
| Aluminum | 0 |
| Copper | 0 |
| Glass | 0 |
| Block foam glass | 0 (rarely 0.02) |
| Bulk foam glass, density 400 kg/m3 | 0,02 |
| Bulk foam glass, density 200 kg/m3 | 0,03 |
| Glazed ceramic tile (tile) | ≈ 0 (???) |
| Clinker tiles | low (???); 0.018 (???) |
| Porcelain stoneware | low (???) |
| OSB (OSB-3, OSB-4) | 0,0033-0,0040 (???) |
It is difficult to find out and indicate in this table the vapor permeability of all types of materials, manufacturers have created a huge variety of plasters, finishing materials. And, unfortunately, many manufacturers do not indicate this on their products. important characteristic as vapor permeability.
For example, when determining the value for warm ceramics (position “Large-format ceramic block”), I studied almost all the websites of manufacturers of this type of brick, and only some of them had vapor permeability indicated in the characteristics of the stone.
Also at different manufacturers different meanings vapor permeability. For example, for most foam glass blocks it is zero, but for some manufacturers the value is "0 - 0.02".
The 25 most recent comments are shown. Show all comments (63).
When conducting construction works it is often necessary to compare properties different materials. This is necessary in order to choose the most suitable one.
After all, where one of them is good, the other will not work at all. Therefore, when carrying out thermal insulation, it is necessary not only to insulate the object. It is important to choose a heater that is suitable for this particular case.
And for this you need to know the characteristics and features different types thermal insulation. That's what we'll talk about.
What is thermal conductivity
To ensure good thermal insulation, the most important criterion is the thermal conductivity of heaters. This is the transfer of heat within one object.
That is, if one object has one part of it warmer than the other, then the heat will move from the warm part to the cold one. The same process takes place in the building.
Thus, walls, roofs and even floors can give off heat in the world. To keep the heat in the house, this process must be minimized. For this purpose, products with a small value of this parameter are used.
Thermal conductivity table
The processed information about this property of different materials can be presented in the form of a table. For example, like this:
There are only two options here. The first is the coefficient of thermal conductivity of heaters. The second is the thickness of the wall, which will be required to ensure optimum temperature inside the building.
Looking at this table, the following fact becomes apparent. Construct a comfortable building from homogeneous products, for example, from solid bricks, impossible. After all, this will require a wall thickness of at least 2.38 m.
Therefore, to ensure right level heat in the rooms requires thermal insulation. And the first and most important criterion for its selection is the above first parameter. For modern products, it should not be more than 0.04 W/m°C.
Advice!
When buying, pay attention to the following feature.
Manufacturers, indicating the thermal conductivity of the insulation on their products, often use not one, but as many as three values: the first - for cases when the material is operated in a dry room with a temperature of 10 ° C; the second value - for cases of operation, again, in a dry room, but with temperature at 25 ºС; the third value is for the operation of the product in different conditions humidity.
It can be a room with humidity category A or B.
For estimated calculation the first value should be used.
Everything else is needed for accurate calculations. How they are carried out can be found in SNiP II-3-79 "Construction Heat Engineering".
Other selection criteria
When choosing a suitable product, not only the thermal conductivity and the price of the product should be taken into account.
You need to pay attention to other criteria:
- volumetric weight of the insulation;
- form stability of this material;
- vapor permeability;
- combustibility of thermal insulation;
- soundproof properties of the product.
Let's consider these characteristics in more detail. Let's start in order.
Bulk weight of insulation
Volumetric weight is the mass of 1 m² of the product. Moreover, depending on the density of the material, this value can be different - from 11 kg to 350 kg.
The weight of thermal insulation must certainly be taken into account, especially when insulating the loggia. After all, the structure on which the insulation is attached must be designed for a given weight. Depending on the mass, the method of installing heat-insulating products will also differ.
Having decided on this criterion, it is necessary to take into account other parameters. These are volumetric weight, dimensional stability, vapor permeability, flammability and soundproofing properties.
In the presented video in this article you will find Additional information on this topic.
There is a legend about the "breathing wall", and legends about the "healthy breathing of the cinder block, which creates a unique atmosphere in the house." In fact, the vapor permeability of the wall is not large, the amount of steam passing through it is insignificant, and much less than the amount of steam carried by air when it is exchanged in the room.
Permeability is one of the most important parameters used in the calculation of insulation. We can say that the vapor permeability of materials determines the entire design of insulation.
What is vapor permeability
The movement of steam through the wall occurs with a difference in partial pressure on the sides of the wall (different humidity). In this case, there may not be a difference in atmospheric pressure.
Vapor permeability - the ability of a material to pass steam through itself. According to the domestic classification, it is determined by the vapor permeability coefficient m, mg / (m * h * Pa).
The resistance of a layer of material will depend on its thickness.
It is determined by dividing the thickness by the vapor permeability coefficient. It is measured in (m sq. * hour * Pa) / mg.
For example, the vapor permeability coefficient brickwork taken as 0.11 mg/(m*h*Pa). With a brick wall thickness of 0.36 m, its resistance to steam movement will be 0.36 / 0.11 = 3.3 (m sq. * h * Pa) / mg.
What is the vapor permeability of building materials
Below are the values of the coefficient of vapor permeability for several building materials (according to normative document), which are most widely used, mg/(m*h*Pa).
Bitumen 0.008
Heavy concrete 0.03
Autoclaved aerated concrete 0.12
Expanded clay concrete 0.075 - 0.09
Slag concrete 0.075 - 0.14
Burnt clay (brick) 0.11 - 0.15 (in the form of masonry on cement mortar)
Lime mortar 0.12
Drywall, gypsum 0.075
Cement-sand plaster 0.09
Limestone (depending on density) 0.06 - 0.11
Metals 0
Chipboard 0.12 0.24
Linoleum 0.002
Polyfoam 0.05-0.23
Polyurethane, hard polyurethane foam
0,05
Mineral wool 0.3-0.6
Foam glass 0.02 -0.03
Vermiculite 0.23 - 0.3
Expanded clay 0.21-0.26
Wood across the fibers 0.06
Wood along the fibers 0.32
brickwork from silicate brick on cement mortar 0.11
Data on the vapor permeability of the layers must be taken into account when designing any insulation.
How to design insulation - according to vapor barrier qualities
The basic rule of insulation is that the vapor transparency of the layers should increase outward. Then in the cold season, with a greater probability, there will be no accumulation of water in the layers, when condensation occurs at the dew point.
The basic principle helps to decide in any cases. Even when everything is "turned upside down" - they insulate from the inside, despite the insistent recommendations to make insulation only from the outside.
In order to avoid a catastrophe with wetting the walls, it is enough to remember that the inner layer should most stubbornly resist steam, and based on this, for internal insulation apply extruded polystyrene foam in a thick layer - a material with very low vapor permeability.
Or do not forget to use even more “airy” mineral wool for a very “breathing” aerated concrete from the outside.
Separation of layers with a vapor barrier
Another option for applying the principle of vapor transparency of materials in a multilayer structure is the separation of the most significant layers by a vapor barrier. Or the use of a significant layer, which is an absolute vapor barrier.
For example, - insulation of a brick wall with foam glass. It would seem that this contradicts the above principle, because it is possible to accumulate moisture in a brick?
But this does not happen, due to the fact that the directional movement of steam is completely interrupted (at sub-zero temperatures from the room to the outside). After all, foam glass is a complete vapor barrier or close to it.
Therefore, in this case the brick will enter into an equilibrium state with the internal atmosphere of the house, and will serve as an accumulator of humidity during its sharp jumps inside the room, making the internal climate more pleasant.
The principle of separation of layers is also used when using mineral wool - a heater that is especially dangerous for moisture accumulation. For example, in a three-layer construction, when mineral wool is inside a wall without ventilation, it is recommended to put a vapor barrier under the wool, and thus leave it in the outside atmosphere.
International classification of vapor barrier qualities of materials
The international classification of materials for vapor barrier properties differs from the domestic one.
According to the international standard ISO/FDIS 10456:2007(E), materials are characterized by a coefficient of resistance to steam movement. This coefficient indicates how many times more the material resists the movement of steam compared to air. Those. for air, the coefficient of resistance to steam movement is 1, and for extruded polystyrene foam it is already 150, i.e. Styrofoam is 150 times less vapor permeable than air.
Also in international standards it is customary to determine the vapor permeability for dry and moist materials. The boundary between the concepts of “dry” and “moistened” is the internal moisture content of the material of 70%.
Below are the values of the coefficient of resistance to steam movement for various materials according to international standards.
Steam resistance factor
First, data are given for dry material, and separated by commas for moist (more than 70% moisture).
Air 1, 1
Bitumen 50,000, 50,000
Plastics, rubber, silicone — >5,000, >5,000
Heavy concrete 130, 80
Medium density concrete 100, 60
Polystyrene concrete 120, 60
Autoclaved aerated concrete 10, 6
Lightweight concrete 15, 10
Fake diamond 150, 120
Expanded clay concrete 6-8, 4
Slag concrete 30, 20
Burnt clay (brick) 16, 10
Lime mortar 20, 10
Drywall, plaster 10, 4
Gypsum plaster 10, 6
Cement-sand plaster 10, 6
Clay, sand, gravel 50, 50
Sandstone 40, 30
Limestone (depending on density) 30-250, 20-200
Ceramic tile?, ?
Metals?
OSB-2 (DIN 52612) 50, 30
OSB-3 (DIN 52612) 107, 64
OSB-4 (DIN 52612) 300, 135
Chipboard 50, 10-20
Linoleum 1000, 800
Substrate for plastic laminate 10 000, 10 000
Substrate for laminate cork 20, 10
Polyfoam 60, 60
EPPS 150, 150
Polyurethane hard, polyurethane foam 50, 50
Mineral wool 1, 1
Foam glass?, ?
Perlite panels 5, 5
Perlite 2, 2
Vermiculite 3, 2
Ecowool 2, 2
Expanded clay 2, 2
Wood across grain 50-200, 20-50
It should be noted that the data on the resistance to the movement of steam here and "there" are very different. For example, foam glass is standardized in our country, and the international standard says that it is an absolute vapor barrier.
Where did the legend of the breathing wall come from?
A lot of companies produce mineral wool. This is the most vapor-permeable insulation. According to international standards, its vapor permeability resistance coefficient (not to be confused with the domestic vapor permeability coefficient) is 1.0. Those. in fact, mineral wool does not differ in this respect from air.
Indeed, it is a "breathing" insulation. To sell mineral wool as much as possible, you need a beautiful fairy tale. For example, that if you insulate a brick wall from the outside mineral wool, then she will not lose anything in terms of vapor permeability. And this is absolutely true!
An insidious lie is hidden in the fact that through brick walls 36 centimeters thick, with a humidity difference of 20% (outside 50%, in the house - 70%), about a liter of water will leave the house per day. While with air exchange, about 10 times more should come out so that the humidity in the house does not increase.
And if the wall is insulated from the outside or from the inside, for example with a layer of paint, vinyl wallpaper, dense cement plaster, (which, in general, is “the most common thing”), then the vapor permeability of the wall will decrease several times, and with complete insulation - tens and hundreds of times.
Therefore, always brick wall and households will be absolutely the same whether the house is covered with mineral wool with “raging breath”, or “dull-sniffling” foam plastic.
When making decisions on the insulation of houses and apartments, it is worth proceeding from the basic principle - the outer layer should be more vapor-permeable, preferably at times.
If for some reason it is not possible to withstand this, then it is possible to separate the layers with a continuous vapor barrier (use a completely vapor-tight layer) and stop the movement of steam in the structure, which will lead to a state of dynamic equilibrium of the layers with the environment in which they will be located.
In domestic standards, the vapor permeability resistance ( vapor permeability Rp, m2. h Pa/mg) is standardized in chapter 6 "Resistance to vapor permeability of enclosing structures" SNiP II-3-79 (1998) "Construction heat engineering".
International standards for the vapor permeability of building materials are given in ISO TC 163/SC 2 and ISO/FDIS 10456:2007(E) - 2007.
The vapor permeability resistance coefficient indicators are determined on the basis of the international standard ISO 12572 "Thermal properties of building materials and products - Determination of vapor permeability". Vapor permeability indicators for international ISO standards were determined in a laboratory method on time-tested (not just released) samples of building materials. Vapor permeability was determined for building materials in a dry and wet state.
In the domestic SNiP, only calculated data on vapor permeability are given at a mass ratio of moisture in the material w,%, equal to zero.
Therefore, to select building materials for vapor permeability at cottage construction it is better to focus on international ISO standards, which determine the vapor permeability of "dry" building materials at a moisture content of less than 70% and "wet" building materials at a moisture content of more than 70%. Remember that when leaving the "pies" of vapor-permeable walls, the vapor permeability of materials from the inside to the outside should not decrease, otherwise the inner layers of building materials will gradually "freeze" and their thermal conductivity will increase significantly.
The vapor permeability of materials from the inside to the outside of the heated house should decrease: SP 23-101-2004 Design of thermal protection of buildings, clause 8.8: To provide the best performance characteristics in multilayer structures of buildings on the warm side, layers of greater thermal conductivity and greater resistance to vapor permeation should be placed than the outer layers. According to T. Rogers (Rogers T.S. Designing thermal protection of buildings. / Lane from English - m.: si, 1966) Separate layers in multilayer fences should be arranged in such a sequence that the vapor permeability of each layer increases from the inner surface to outdoor. With such an arrangement of layers, water vapor that has entered the enclosure through the inner surface with increasing ease will pass through all the openings of the enclosure and be removed from the enclosure with increasing ease. outer surface. The enclosing structure will function normally if, subject to the formulated principle, the vapor permeability of the outer layer is at least 5 times higher than the vapor permeability of the inner layer.
Mechanism of vapor permeability of building materials:
At low relative humidity moisture from the atmosphere in the form of individual water vapor molecules. With an increase in relative humidity, the pores of building materials begin to fill with liquid and the mechanisms of wetting and capillary suction begin to work. With an increase in the humidity of the building material, its vapor permeability increases (the vapor permeability resistance coefficient decreases).
ISO/FDIS 10456:2007(E) vapor permeability ratings for "dry" building materials apply to internal structures of heated buildings. The vapor permeability values of "wet" building materials are applicable to all external structures and internal structures of unheated buildings or country houses with variable (temporary) heating mode.
Loading...