Wall insulation with mineral wool. All about the technology of wall insulation with mineral wool Means of protection when working with mineral wool
Heat loss through the walls of the house can reach 30% of the total heat loss, so one of the main stages of building thermal insulation is wall insulation. Mineral wool is often chosen as a heater for walls. Mineral wool is made from melted glass, rocks or slag, resins are used as a binding element. The material has a fibrous structure, and, depending on the purpose, the direction of the fibers may be different.
Wall insulation from the outside with mineral wool has a number of advantages:
- This is a relatively cheap insulation with low thermal conductivity;
- Mineral insulation has good sound-absorbing characteristics;
- Mineral wool does not support combustion, therefore it can be used for insulation of easily combustible structures;
- This material is vapor-permeable and does not create the effect of a thermos, the building "breathes";
- Mineral wool is easy to install - the insulation is sold in the form of mats or rolls, you can choose the most convenient option;
- Depending on local conditions, you can choose the required thickness of the insulation;
Mineral wool does not rot, is not susceptible to fungus, microorganisms and rodents.
The disadvantages of mineral wool include the deterioration of its heat-insulating characteristics when wetted, so it must be protected from atmospheric moisture and condensate. In terms of environmental friendliness, mineral insulation, operated under normal conditions, does not pose any danger, since the release of harmful components occurs only when mineral wool is heated to 300 degrees or more.
The choice of the thickness of the insulation is made using a heat engineering calculation, while taking into account the thermal conductivity of the wall material, their thickness, as well as the normative thermal resistance of the walls for a particular region. For a simplified calculation, you can use the table.
Technology of wall insulation with mineral wool
- The preparation of walls for laying insulation depends on the material from which they are built. Wooden walls must be impregnated with an antiseptic to avoid damage to the log house by microorganisms. Areas damaged by rot, fungus, mold must be thoroughly cleaned and impregnated with appropriate solutions - after laying the insulation, access to them will be impossible. It is enough to free brick and foam concrete walls from peeling plaster and paint. If the walls are damp, they must be thoroughly dried. The platbands and slopes of the windows must be dismantled, as well as fasteners and decorative elements that can damage the vapor barrier and insulation layer must be removed from the walls.
- A layer of a vapor-permeable membrane is placed under the mineral insulation. The film is positioned so that the vapor-permeable side faces the wall of the house, and the smooth side faces the insulation. The vapor-permeable membrane is necessary in order to ensure the removal of water vapor from the walls of the house through the insulation. It is allowed to lay mineral insulation on even walls without first laying the membrane film.
- On top of the vapor-permeable film, guide rails made of wood, or a profile for attaching drywall, are attached. They are attached to the wall with self-tapping screws or with the help of a dowel-nail mounting pair. The distance between the slats is chosen so that it is 1-2 centimeters less than the width of the insulation. The thickness of the rails should be equal to the thickness of the insulation. Fastening rails start from the corner of the house. When attaching the rails, use the level. If the wall is uneven, perforated drywall hangers can be used to fix the frame. If insulation in the form of mats is used, a horizontal rail can be additionally fixed along the lower border of the wall, on which the lower insulation mat will be installed.
- Heat-insulating mats or rolled material are placed in the space between the guide rails, while laying the mats starts from the bottom, and roll materials - from the top, fixing the insulation on the wall either between the rails or with the help of several dowels with a wide cap. Plate material to brick or block walls is attached to a special adhesive that ensures a snug fit of the insulation. There should be no gaps between the insulation and the guides. First, solid pieces of insulation are fixed, then the remaining areas around the window and door openings are filled.
- Another layer of film is placed on top of the mineral insulation - wind protection and waterproofing. The film must also be vapor-permeable so that moisture is freely removed from the insulation layer to the outside. The film is fastened with brackets to the rails without tension, after which the entire layer of insulation and vapor barrier is additionally fixed to the wall using dowels with a wide head, the attachment points for better waterproofing can be glued with metallized tape.
- An important step in wall insulation is the installation of a ventilated facade. The ventilation gap should be at least 5-6 cm; for this, additional counter-rails are stuffed over the guides or profiles are mounted on which the ventilated facade is mounted: siding, block house or other finishing materials.
- When the walls are insulated from the outside, their thickness increases, so you will have to install new window slopes, window sills, as well as trim and trim elements. It is better to purchase them immediately when buying a ventilated facade.
Insulation of walls outside with mineral wool is one of the most popular ways of thermal insulation of buildings. The popularity is due to the low thermal conductivity of mineral wool, due to which most of the heat remains inside the building, as well as the environmental friendliness of the material, its ability to remove moisture from the inside of the house. In addition, mineral wool is an excellent sound insulation.
Advantages and disadvantages of insulating walls from the inside with stone wool, the choice of insulator and other materials for forming an insulating layer, options for attaching products to partitions.
The content of the article:
Wall insulation from the inside with stone wool is one of the most economical ways of thermal insulation of a room, which is used if it is impossible to fix the material externally. This method allows you to reliably retain heat in the house, but only if all the requirements for the formation and installation of an insulating layer are met. We will talk about the options for fixing the material to the partitions from the side of the room in this article.
Features of work on wall insulation with stone wool from the inside
Insulation of partitions from the inside of the room is carried out in exceptional cases. The main problem of this option of thermal insulation is the unpredictable consequences of poor-quality installation of the coating. The dew point can move closer to the room and cause the wall to get wet, resulting in dampness in the house. Such problems do not arise if the heat insulator is fixed from the outside.
For interior work, stone wool is best suited - a type of mineral wool, which is made from mountain basalt rocks with the addition of hydrophobic substances. The material is filled with an inert gas that does not let heat out. It is characterized by low weight and low density (10-90 kg/m3).
Stone wool is produced in the form of rolls, mats, slabs of various sizes. It is desirable to mount the insulator in rolls on the walls. They are produced with a width of 0.6-1.2 m and a length of up to 10 m. The soft structure allows you to lay the material in the most inaccessible places. Mats insulate large areas, plates - small areas.
During installation, it must be vapor-proofed with a special film. This is due to the fact that the insulation absorbs moisture well and under its influence quickly loses its qualities.
Cotton wool has a harmful effect on the human body due to the presence of formaldehyde in its composition and the irritating effect of fibers on the skin. Therefore, when insulating partitions from the inside, it is necessary to adhere to the following safety rules:
- When insulating walls with stone wool, avoid contact with the product. Wear safety goggles, heavy gloves, long sleeves, respirator. At the end of the process, change into other clothes.
- Remove food from the room during installation.
- Do not allow children to play with the heat insulator.
- Do not allow the fibers to spread throughout the apartment. Clean up trash immediately after work.
Advantages and disadvantages of wall insulation from the inside with stone wool
The use of such an insulator for insulation from the inside has a number of advantages, as follows:
- The product does not burn, does not emit toxic fumes when heated, it can be used in any room.
- The insulation is well cut, so installation is carried out in a short time.
- Stone wool, in comparison with other products of a similar purpose, has a slight hygroscopicity and can be used in rooms with moderate humidity.
- It is useful even in summer, with internal insulation, the insulator does not let heat through.
- The product has a relatively small thickness, so the area of \u200b\u200bthe room is reduced slightly.
- Repair of wall covering is very rare, because the service life of the material reaches 70 years.
- The indisputable advantage is the price of the insulator, which is lower than the cost of any other product.
- Mounting mats from the inside increases the sound insulation of the room.
- Warming with stone wool from the inside allows you to keep the facade of the house in its original form.
- It contains harmful substances that should be neutralized.
- The insulation absorbs moisture well, which reduces its quality, so the room must be equipped with forced ventilation.
- The usable area of the room is reduced.
- During work, people will have to be evicted from their homes.
The technology of wall insulation from the inside with stone wool
Work on the formation of an insulating layer requires the execution of operations in a certain sequence. Deviation from the insulation technology will lead to the accumulation of dampness and the formation of black mold.
Preparatory work before installing stone wool
The process of insulation with stone wool from the inside does not require careful leveling of the wall surface, irregularities can reach 3 mm.
Preparation for thermal insulation is as follows:
- Free surfaces from peeling plaster and paint.
- Thoroughly clean the wall, remove dust and dirt with a vacuum cleaner.
- Pay special attention to areas with traces of mold, fungus, rot. They must be cleaned with a spatula, dried with a building hair dryer or infrared heater, and then treated with an antiseptic.
- Seal cracks and gaps in cement and concrete bases with cement mortar. This procedure is mandatory, because a large number of voids increases heat loss.
- If you plan to glue stone wool, make sure that there are no greasy or oil stains on the wall. If necessary, remove them mechanically or with a solvent.
- Remove cracks on wooden walls using caulking. Fill deep voids with tow and foam. Seal recesses up to 3 cm with mounting foam. Saturate the structure with agents that prevent fire, rot and insects. Apply each solution after the previous one has dried.
- Dry the wall thoroughly. If the base is constantly wet, find the cause and fix it.
- Remove fasteners and decorative elements that interfere with the installation of vapor barrier film and insulation.
- Treat the wall with a special liquid waterproofing material that prevents dampness.
The choice of stone wool for insulation from the inside
When buying an insulator, we recommend paying attention to the following points:
- Place and conditions of storage of goods. If stone wool is kept outdoors under a canopy, it must be packed in a protective film. If the packaging is different, the products should be stored in the most dry room possible.
- Wet insulation is not recommended to buy even at a very favorable price. After drying, it loses its qualities and becomes unusable.
- Buy samples of the same density, because manufacturers produce products with a variety of characteristics. For one-story houses, you will need a heat insulator of low density. High partitions are insulated with more dense and rigid materials, but they are more expensive.
- Do not use stone wool that has already been used.
- Buy products from well-known manufacturers, which will help to avoid fakes.
Fastening stone wool to staples
The technology of stone wool insulation implies the mandatory use of a vapor barrier film, with the help of which moisture is removed from the wall into the room. The membrane has a vapor-permeable side to the base and a smooth side to the room.
Start installing the film from the top of the surface and run horizontally with an overlap on the walls and ceiling. Lay each fragment with an overlap of 10 cm on an already fixed segment and fix it with self-tapping screws or a construction stapler. Lubricate the joints with the adjoining wall with sealant. Glue the joints of the film with mounting tape or construction tape.
- Fasten to the wall with vertical rows of brackets for fixing drywall profiles. They are screwed at a distance of 50-60 cm between them. Thus, there will be 4-5 brackets between the floor and the ceiling.
- Bend the elements in the form of the letter "P".
- Unwind the stone wool roll. Cut a piece of insulation 10 cm longer than the distance between the floor and the ceiling. The stock is necessary due to the property of the material to shrink, and a precisely cut panel will not be enough for the wall. For cutting, a drywall aluminum profile is best suited, and for cutting, a clerical knife is best.
- Screw the strip onto the mounting brackets and fix it in a vertical position. Install the sealant with an “accordion”, which will straighten itself and cover the wall without breaks. Next fix the next piece.
- During installation, gaps must not be left between the stacked elements. Moisture will form in them, which will then cause the drywall to get wet. It is also possible the appearance of fungi and mold, which are very difficult to get rid of.
- Fasten the CD profiles to the brackets, to which the drywall will be fixed.
- Lay metallized paper or foil on top to create a hydro-barrier between the cotton wool and the humid air in the room. It will also additionally protect the room from the spread of mineral fibers. Lay the film overlapping on the wall and between each other. Glue the joints with construction tape. Fix the membrane to the profiles with self-tapping screws or double-sided tape. If the crate is wooden, you can use a furniture stapler.
- If you plan to use a foil-based product, do not install a waterproofing film. In this case, the insulation is placed with foil towards the room.
- Fasten slats 15-25 mm thick to the crate from above to create a gap between the cladding and the hydro-barrier through which air will circulate.
- The last stage is the installation of a plasterboard wall.
Installation of stone wool on a wall with a frame
Fix the vapor permeable film to the wall. On top of it, mount the crate for fastening drywall sheets. It is made from wooden slats or metal profiles for sheet material. The thickness of the strips should be equal to the thickness of the insulation.
Align the profiles in a vertical plane with a level and secure with dowels and self-tapping screws. The distance between the rails should be 1-2 cm less than the width of the insulator. If the wall is uneven, the frame can be fixed with perforated drywall hangers. When using slab insulation near the floor, fix the rail set to the horizon.
The insulator is placed between the profiles and fastened at a distance between the rails or dowels with a wide head. If you have rolls, start laying from above, if in the form of mats - from below. During installation, check the absence of gaps between the product and the profiles. Filling areas near window and door openings is done last.
Dowels for fixing stone wool, choose according to the following recommendations:
- The length should allow the product to enter the wall at least 6 cm.
- Fasteners must be with a metal rod.
- For fixing to aerated concrete, use a dowel with an extended expansion base.
- To avoid the appearance of cold bridges, it is advisable to use hardware with a thermal head.
- It is not allowed to sink the head into the insulation by more than 1 cm, because. over time, the leg may break.
- For fastening, it is allowed to use anchor dowels, which are fired with a pneumatic pistol. They significantly reduce installation time. They leave no debris behind.
Fixing stone wool with glue
For gluing cotton wool, it is advisable to use a special glue intended only for this material. When buying, make sure that the product is suitable for indoor use. It must be waterproof and provide good adhesion between the insulation and the partition. It must contain microfiber. You should also consider the type of surface, for example, for a brick and concrete wall, the means will be different.
Gluing is performed in the following sequence:
- If the product is sold in dry form, prepare the components (water and powder) in the proportion indicated in the instructions for use.
- Pour the mixture into the water and stir with a low-speed drill until a homogeneous consistency is obtained. Check for clots and lumps.
- Leave for 5 minutes and stir again. The solution must be used quickly, after a short period of time it loses its properties.
- It is allowed to stick cotton wool at a temperature of +5 ... +30 degrees. Under other conditions, the insulation may change the operating parameters.
- Coat the surface of the insulator with a thin layer of mortar and rub it thoroughly into the fibers with a simple spatula. Only then apply a base layer 1 cm thick and level it with a notched trowel over the entire surface.
- Press the insulator firmly against the wall. When laying the next block, press it down until a flat surface is obtained with the adjacent sheet. You can correct the position of the product within 10 minutes.
- Insulate the entire wall in the same way. If mats or blocks are used, the vertical seams must not overlap.
How to insulate walls from the inside with stone wool - look at the video:
Opponents of wall insulation from the inside argue that this method will not lead to the desired effect. This statement is not entirely true if stone wool is used for thermal insulation, and all work is carried out in compliance with the repeatedly proven installation technology.
Wall insulation with mineral wool allows you to reduce overall heat loss, which can reach 30%. This is a popular and affordable heat-insulating material obtained by melting metallurgical slags and rocks. Due to such qualities as non-flammability, resistance to rotting and deformation from mechanical stress, the necessary density, as well as excellent heat, sound and wind insulation, mineral wool is often used to insulate the facades of wooden and brick houses.
Features of mineral wool
Being a heater, mineral wool has become widespread due to its characteristics and ease of installation. Plates for external insulation of a house differ from the material for internal work in density and hydrophobic qualities. The release of insulation in the form of plates simplifies the installation process, and knowledge of the technology allows you to carry it out correctly.
Manufacturing companies produce slabs with a thickness of 5, 10 and 15 cm. Most often, work on the insulation of external walls with mineral wool is carried out using 10 cm slabs.
Insulating a house from the outside with mineral wool is not only effective, but also cheap.
The raw materials for the manufacture of mineral wool can be very different, depending on this mineral wool is divided into basalt, fiberglass, dolomite and slag. Thin fibers of insulation are held together by resins that do not have any harmful effects on human health and the environment. The structure of the mineral wool can be:
- spatial;
- corrugated;
- horizontally layered;
- vertically layered.
Advantages of mineral wool
Houses insulated with mineral wool are perfectly sound and heat insulated.
Insulation plates hide imperfections and curvature of the walls. In addition, it is much cheaper than polystyrene foam. It perfectly withstands mechanical stress. The duration of operation of such a material is many times longer than that of polystyrene. By the way, unlike the latter, the density of mineral wool allows the walls to "breathe". This is especially true when warming a wooden house. It should also be noted the following advantages of the material:
- low thermal conductivity;
- the density of mineral wool allows the walls to "breathe";
- excellent noise and sound absorption;
- non-flammability (especially important for thermal insulation of wooden walls);
- low cost;
- ease of installation, the ability to select plates of the desired thickness and density;
- resistance to rot and mold.
Warming technology
Sometimes thermal insulation is carried out from the inside, however, it is correct to fix the mineral wool to insulate the walls of the house from the outside. This technology has the following advantages:
- fixing the insulation outside the house protects the walls from frost, wind, humidity and temperature changes;
- there is no reduction in usable living space;
- there is a transfer of the "dew point" outside the outer walls, which protects the facade from dampness and prolongs its service life;
- insulation works are combined with the outer cladding of the facade.
Wall insulation with mineral wool involves the use of a heater with a thickness of at least 10 centimeters.
External thermal insulation is traditionally carried out with plates of different densities. In general, the density of mineral wool can be 75 - 150 kg / m3. First, less dense slabs are attached to the walls, which perfectly fill all the irregularities of brick, wooden or concrete walls. And on top of them, mineral wool is mounted, the density of which is 100 - 150 kg / m3. They form a flat surface, on top of which finishing work is carried out.
Warming of a wooden house
Particular attention should be paid to the choice of insulation for a wooden house. The fact is that wood is prone to rotting and untimely destruction.
This is especially true when the density of the insulation exceeds the density of wooden walls. As a result, moisture penetrating from the interior through the wooden walls of the house settles on the inside of the insulation and leads to the appearance of mold, fungus and, as a result, to decay of the facade.
Unlike denser materials such as foam and polystyrene foam, mineral wool perfectly passes air and vapors, allowing wooden walls to "breathe". Traditionally, work on insulation with mineral wool is carried out using rolled insulation. Before its installation, wooden walls are treated with special antiseptic and flame retardant impregnations.
Insulation installation instructions
In general, regardless of the material from which the walls of the house are built, the process of insulating them with mineral wool can be represented as the following instructions:
Results
Thermal insulation of the facade with mineral wool is one of the most popular ways to insulate a house. Due to the low thermal conductivity of this material, most of the heat remains in the house, and moisture is removed outside. Mineral wool is an environmentally friendly, non-flammable material that does not let in street noise and sounds. This is an affordable and highly demanded material in the construction and repair industry.
The comfort of living in any house or apartment is directly related to both a properly planned, efficiently operating heating system and the degree of insulation of building structures. It is absolutely pointless to spend a lot of money on energy carriers, if insufficient or poor-quality thermal insulation does not minimize heat losses, and heating devices waste a significant part of their power on useless “street heating”.
One of the "main routes" of heat leakage from residential premises is external walls that do not have sufficient thermal insulation. Good for owners of private houses - they still have the opportunity to mount external insulation. But not everyone is free with such an optimal choice, and one has to look for other approaches. It would seem that nothing particularly complicated - you can organize the insulation of the walls from the inside with mineral wool plus drywall, a layer of which will become the basis for. Such a method of thermal insulation, as they say, "has the right to exist", however, not everything is as simple as it seems at first glance.
Insulation of walls from the inside with mineral wool is a rather controversial event, concealing a lot "pitfalls". And it should be resorted to only in extreme circumstances, when there is absolutely no way to perform thermal insulation from the outside. Let's try to figure out what are the disadvantages of this approach, and how you can minimize them.
A few words about insulation - mineral wool
First of all, let's consider the property of the insulating material in the title of the article.
Mineral wool as an insulating material in industrial construction has been used for quite a long time. With the advent of new technologies for the production of mineral wool, which led to an increase in product quality, a decrease in the degree of harm to humans and the environment, the scope of application has expanded significantly, and her actively used for thermal insulation work in residential buildings.
It should be well understood that the concept of mineral wool hides several of its types, which have significant differences, and not all varieties are applicable in a residential building. The main parameters are summarized in the table, but a few words about each of the varieties still need to be said.
Name of parameters | stone wool | slag wool | glass wool |
---|---|---|---|
Miniature | |||
Average fiber diameter, µm | 4 to 12 | 4 to 12 | 5 to 15 |
Hygroscopicity of the material for 24 hours (no more) % | 0,95 | 1.9 | 1.7 |
causticity | No | Yes | Yes |
Thermal conductivity coefficient, W/(m-K) | 0,035-0,042 | 0,46-0,48 | 0,038 -0,046 |
Sound absorption coefficient | from 0.75 to 0.95 | from 0.75 to 0.82 | from 0.8 to 0.92 |
The presence of a binder, % | from 2.5 to 10 | from 2.5 to 10 | from 2.5 to 10 |
Sintering temperature, °С | 600 | 250-300 | 450-500 |
Limiting application temperature, °С | up to 1000 | up to 250-300 | from -60 to +450 |
Flammability of the material | NG - non-flammable | NG - non-flammable | NG - non-flammable |
Emission of harmful substances during combustion | slightly | Yes | slightly |
Heat capacity, J/kg*K | 1050 | 1000 | 1050 |
Vibration resistance | moderate | weak | weak |
There are three main types of mineral wool.
- Known to all glass wool - it is obtained by melting quartz sand or glass cullet. Fibers with a thickness of about 5 ÷ 15 µm and a length of 15 to 50 mm are drawn from the loosened mass, which are then pressed into light and elastic mats using a binder. Usually glass wool is easy to distinguish from other types by color - it is characterized by yellow shades.
The material is chemically inert, not prone to decay, and will not become a breeding ground for any form of biological life. The disadvantage is that glass wool fibers are very brittle, prickly, and can cause serious skin irritation when laying the material. The same quality predetermines the undesirability of using glass wool in residential premises - microparticles of fibers can be carried with dust, enter the respiratory system, cause allergic reactions or asthmatic attacks in people suffering from chronic diseases.
Thus, it is still not worth using glass wool to insulate the inner surface of walls in residential premises.
- Slag wool is the second representative of this class of heaters. We will not talk much about it - it is not suitable for thermal insulation of a residential building. There are many reasons for this. In addition to the disadvantages inherent in glass wool - brittleness, causticity, dust formation, slag wool is the most hygroscopic, gives the greatest shrinkage with a loss of insulating qualities. In addition, there are many questions to it from the point of view of environmental cleanliness. The raw material for its manufacture is blast-furnace slag, sometimes they have a very ambiguous composition and even a radiation background, and increased acidity, coupled with moisture absorption, creates a very aggressive environment, which has a particularly destructive effect on metal parts.
- If you already take mineral wool for internal insulation, then exclusively basalt (stone). Compared to others, it is the most durable, resilient, its fibers are not so brittle, do not cause irritation of the skin and mucous membranes. At the same time, this is all absolutely without loss of insulating qualities - the coefficient of thermal conductivity is no worse than that of glass wool.
Stone wool is also able to absorb moisture, but its hygroscopic index is the lowest. The binder in the manufacturing process of such mineral wool is completely polymerized, and cannot pose a significant danger to the human body (of course, if we are talking about high-quality, certified products from well-known manufacturers).
Basalt wool is extremely easy to install - mats or slabs of it keep their shape well, are easy to cut, some of them can be fixed on the walls with building glue if necessary (this can be very important for high-quality thermal insulation).
What is extremely important for residential premises - basalt wool belongs to the group of non-combustible and non-combustible materials, and its heat resistance is the highest among all heaters produced in the form of panels, slabs or mats.
In a word, basalt stone wool, with certain drawbacks that it still has, becomes the only right choice.
Mineral wool prices
Mineral wool
Let's go to theory "underwater rocks" wall insulation from the inside
So, subject to certain technological rules, basalt mineral wool can be used for insulation work both outside and inside the premises. Why, then, are there so many opponents of thermal insulation from the inside?
Probably, many have seen "bright spots" on the facade walls of high-rise buildings. apartment owners, not satisfied with the degree thermal insulation of walls, go to considerable expense in order to use external insulation.
It is almost impossible to perform such insulation on your own. You have to resort to the services of companies that have specialists in the field of industrial mountaineering. Agree that such work at height, which includes preparing the wall for thermal insulation, and installing insulation, and high-quality finishing, cannot be cheap. However, many go for it.
By the way, in order to perform such external insulation of the walls of the apartment, one will also have to face administrative problems. - you need to get the appropriate permission for it. And there is no guarantee that the "good" will be received. Thus, the refusal may be motivated by a violation of the appearance of the building or the style of the street, especially if the house is classified as an architectural monument or is part of a single urban ensemble. Permission will not be obtained if the apartment is adjacent to the technological expansion joints of the building, to the elevator shafts, and other structural elements of the building. In a word, difficulties in this matter, even in the presence of the required material resources, are expected to be quite a few.
So why not carry out internal insulation, because there is a mass benefits?
- The performance of work is in no way tied to the time of year and weather conditions - carry it out when you want.
- Work on internal insulation, at first glance, requires much lower costs - both in terms of acquiring materials, and in terms of the possibility of carrying them out on our own, without the involvement of specialists.
- In addition to insulation, the walls also receive effective sound insulation.
- Work can be carried out in stages, from one room to another, as far as possible and need.
However, this whole “rainbow picture” is seriously spoiled. shortcomings a similar method of insulation:
- Carrying out work temporarily paralyzes life in a particular room and violates the convenience of living in others - you have to move furniture, construction debris inevitably spreads around the apartment.
- The total cost of insulating external walls may not be so insignificant - this entails, in addition to thermal insulation measures, also large-scale work to restore or even completely update the interior decoration of the room.
- Internal insulation will oblige the owners to radically revise the system of quality
- Wall insulation from the inside is always a loss in the usable area of rooms.
- And most importantly, by carrying out such insulation, the owners, winning in one, get a “time bomb” - a high probability of dampness, mold, fungus appearing and spreading on closed walls, which not only leads to unpleasant odors, but also poses a certain danger to the health of residents .
In addition, in damp walls, the processes of decomposition, erosion, and corrosion of the building materials from which they are built are much faster and develop.
Consider the main disadvantages in more detail.
Is it a significant reduction in floor space?
It would seem - how much space can "steal"? But this - only at first glance seems insignificant.
Take for example a room measuring 5 × 3.5 meters. Its useful area is 17.5 m².
Suppose there are two external walls (pos. 1) in a room that require insulation. A layer of mineral wool (pos. 2) 50 mm thick was used as thermal insulation. From above, it is closed with plasterboard sheathing (pos. 3) in one layer - this, with installation and putty, will take another 15 mm. The total length of the two sides of the room is reduced by an average of 65 mm (even if you do not take into account the possible curvature of the walls - in this case, the difference will be even greater).
We calculate the area: 3.435 × 4.935 = 16.95 m². In total, the total loss of usable area in the room, which is already small in size, amounted to 0.55 m²! And, as already mentioned, the theoretical straightness of the walls and the minimum thickness of the insulation were taken into account - only 50 mm.
If we add to this the forced transfer of heating radiators, the expansion of window sills, then the losses look very significant. In a spacious room, you can somehow optimize the space, minimizing the consequences of such losses. But in a cramped kitchen, where sometimes every centimeter counts, it will be more difficult to get out of the situation.
But these, as they say, are everyday problems that can be dealt with with “little blood”. The situation is much more serious with questions lying in the plane of thermal physics.
Balance between high-quality insulation and condensation
It is here that the most vulnerable point of internal wall insulation lies. And the main “enemy” is water, which passes from vapor to liquid state (condensate) at a certain meeting point of the internal heat of the premises and the cold from the street. Place condensation has its own name - "dew point".
The dew point varies non-linearly and depends on many factors - the level of humidity, temperatures from the outside to the inside, the construction of the wall and the materials used.
It should be clearly understood that the level of absolute humidity in residential premises is often higher than in the open air. This is explained simply - in addition to the general humidity background, which depends on the climatic conditions of the area, season, established weather, etc., a considerable amount of air vapor is added to it, which are formed in the course of everyday human activity. This includes exhaled vapors, cooking or boiling water, taking water procedures, wet cleaning, washing and drying clothes, and in some cases even special air humidifiers are used to increase the comfort of living.
Excess moisture always requires a certain outlet in order to maintain the overall balance. Part of the problem is solved by airing the premises or the operation of the ventilation system. But still a very large amount of water vapor finds its way through the walls. Most building materials have good vapor permeability - they say that "the wall breathes". Under optimal conditions, vapors penetrate through the barriers and freely escape into the atmosphere, unless, of course, they "stumble" on the dew point.
One of the main tasks in thermal engineering calculations of enclosing structures is to bring the dew point as close as possible to the outer edge of the wall or even beyond it, into the layer of external insulation. Then, under certain conditions, the condensed moisture will simply evaporate into the atmosphere without causing any harm to the wall structure.
It is much worse if the dew point falls on the inner surface of the wall. Moisture begins to accumulate, leading to negative consequences, which have already been described above. In addition, if the wall is closed from the inside with mineral wool insulation, then it begins to dampen, losing its thermal insulation and noise-absorbing quality.
How to achieve such a state of affairs in order to “kill two birds with one stone” with internal insulation - to provide the necessary total resistance to heat transfer and to exclude the formation of condensate on the walls? Alas, in the stated conditions, in the complete absence of high-quality external thermal insulation, this task is impossible in principle. And we can rather talk about minimizing the negative consequences of such a method of warming.
There are special calculation methods that allow you to determine the optimal design of the wall insulation system. Their main principle is based on the fact that in order to compensate for the heat losses of the building, the total value of the thermal resistance of the wall structure must correspond to the tabular parameters calculated for the climatic conditions of a given region. The table itself would take up a lot of space in the article, so it is better to provide a diagram of the RF, on which the required values \u200b\u200bof thermal resistance for walls, ceilings and roofing are marked. In this case, we are interested in the first value, for walls - it is shown in purple numbers.
Thermal resistance value R (m²×° WITH/W) of a wall structure, having, say, n layers, is calculated by the formula:
R = R1 + R2 + ... Rn
hn is the thickness of a particular layer
λn is the coefficient of thermal conductivity of the material, the layer is made from the finished one.
The value of the coefficient is a tabular value, which is easy to find on the Internet.
By calculating the resistance of each layer, it is possible to calculate the temperature difference on its outer and inner surfaces, and this will allow us to estimate the location of the dew point.
However, such accurate calculations are usually carried out by specialists, the formulas are quite complex and cumbersome, and not everyone will be able to do it. Such a task is not before us now. But in order to argue the thesis about the undesirability of insulation from the inside, let's, for example, see how a brick wall of 1.5 bricks (380 mm thick) will “behave” with various variations in the location of thermal insulation.
All diagrams show two lines. Black is a graph of temperature changes in the thickness of the wall structure. Blue is the dew current temperature graph. Accordingly, the point of their intersection or coincidence is the very place where condensation will form abundantly. All calculations are based on winter conditions - the temperature inside the apartment is + 20 ° WITH, outside - frost -20 ° С. For evaluation, we take the value R = 3.24 m²×° WITH/W, which corresponds, for example, region of the Middle Volga region, for which these temperatures are average.
When calculating, it is taken into account that the air in the room has a certain thermal resistance (on average - 0.13 m² × ° WITH/W) and outside (0.04 m²×° WITH/W).
A. "Naked" outside and inside brick wall
1 - brick wall, h = 0.38 m
Graphs do not intersect - condensation will not form. But the insulating qualities of such a wall do not meet the requirements in any way - heaters will spend a lot of energy on heating the wall, eventually- heat escapes to the outside. Let's look at the table:
Material of the layers of the wall structure | Thickness [cm] | Thermal resistance, [m² °C / W] | T inside, [°C] | T outside, [° C] |
---|---|---|---|---|
Total | 38 | 0.75 | ||
indoors | 0.13 | 20 | 13.03 | |
Brickwork | 38 | 0.58 | 13.03 | -17.85 |
Street | 0.04 | -17.85 | -20 |
The resulting total value R = 0.75 is not even close to the desired 3.24.
B. Externally plastered wall
Mineral wool is commonly called a fibrous material that is used as thermal insulation; it is made on a synthetic basis. For its manufacture, basalt minerals are used. Obviously, due to belonging to the basalt group, it is sometimes called stone wool. Wool is resistant to high temperatures, it almost does not react to the influence of chemicals, but most importantly, this material is ideal for sound and thermal insulation.
Fibrous products are currently quite popular and in demand, and in most cases they are used for thermal insulation. Until now, disputes and debates continue about how generally it is permissible to use mineral wool as thermal insulation for residential and industrial buildings.
Each of the parties has quite strong facts and arguments, both “against” and “for”, however, this does not affect the popularity of this material at all and is not displayed in any way, its sales volumes are constantly increasing every day.
If you decide to insulate your home with this material, then you should follow some safety measures. The complex of these measures is simple and cannot cause additional difficulties.
First of all, work with this material should be in a well-ventilated room. You can cut cotton wool with a simple knife, but it should be sharpened as sharply as possible, in extreme cases, you can use a fairly sharp chisel.
We should not forget about protective equipment. Everyone who will come into direct contact with this material must be dressed in protective overalls, and gloves must be worn on his hands without fail.
If you have to carry out grinding, then a mask should be added to this set, but it is better to take a respirator in order to provide protection against small elements of cotton wool in the respiratory tract, and eyes should be protected with special glasses. The mucous membrane of the eye is quite sensitive and getting the smallest particles into them is extremely dangerous.
After the actions with mineral wool are over, you should immediately change clothes, rinse your hands thoroughly with cold water, and only then move on to your face. If, despite all the protective measures, after completing work with cotton wool, you feel itching and redness begins to appear on the skin, you should not panic and worry too much.
The side effect is caused by the smallest particles of cotton wool that have fallen on the skin, it is short-lived. No consequences other than slight discomfort await you, and after a few hours these unpleasant sensations will also disappear.
Safety precautions should be observed when working with any type of material, of course, mineral wool is no exception.
Some refer to the likelihood of an allergic reaction, but there is no official information on this topic. If you feel the development of an allergy, you should immediately consult an allergist. You should not self-medicate, as more serious consequences are likely to develop.