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Vapor barrier for walls - how to make a wooden house warm and cozy? Vapor barrier of walls - reliable protection of the house from dampness Vapor barrier of walls indoors

Wood is a living material main feature- the ability to breathe. Natural air exchange takes place in wooden houses, and the steam from the interior freely goes outside, without lingering in the wood. Today many owners wooden houses they try to additionally insulate their home, turning its walls into a multilayer cake of thermal insulation, waterproofing and decorative finishes. In this case, an additional layer of such a cake should be a vapor barrier for walls. wooden house. From the article you will find out why it is needed, what material can be used for vapor and waterproofing of the outer walls of the log house, as well as how to attach the insulator.

Let's see if vapor barrier is needed for insulation? When the room is warm, water vapor is always formed in it, and the warmer the air, the more vapor it contains. At a certain temperature regime, which is called the "dew point", water vapor is converted to condensate. If there is a large temperature difference inside and outside the house, the “dew point” moves to the wall of the house.

When air exchange occurs naturally in the house, the steam freely leaves the room and goes outside. Now imagine that a multi-layer barrier has appeared in the way of steam. Condensate enters the heater and lingers there.

This happens every day, as a result, moisture accumulates in the heat insulator. The insulation is deformed, its heat-insulating ability decreases, moisture contributes to the formation of mold, fungi in the wood, rotting and destruction.

Avoid these unpleasant consequences allows vapor barrier, which becomes a protective barrier to steam, preventing moisture from entering the insulation.

To improve the heat-saving parameters of log and timber houses perform both external and internal thermal insulation. Insulation of a wooden house from the outside is the most effective method, which is resorted to much more often than the internal one.

Regardless of how the insulation is performed, it is necessary to choose the right vapor barrier material. If you perform thermal insulation with unsuitable material, when insulating from the inside of the house in the room, a greenhouse effect may occur, and external insulation will be ineffective. Therefore, before choosing an insulator, you need to carefully study its characteristics.

The main criteria for choosing a vapor barrier material are:

1. Water resistance, i.e. the ability of the material to withstand a certain amount of liquid, the higher this indicator, the better.
2. Vapor permeability, the maximum density of the passed water vapor.
3. Water resistance, this property is especially important for the vapor barrier of facades and wet rooms: bathrooms, baths, saunas.
4. Temperature range recommended for this material.
5. Specific gravity. This indicator is measured in g / m2, the higher it is, the stronger the material.
6. Tensile and tensile strength.

Types of materials

Materials intended for vapor barrier walls can be divided into four large groups:

• vapor barrier films.
• membranes;
• films with a foil layer;
• coating insulation.

The first group includes polyethylene and polypropylene films.

A vapor barrier made of polyethylene is usually used to save money, because, despite some of the advantages of PE ( inexpensive price and good moisture resistance) polyethylene film has a number of significant disadvantages:

1. Low strength, the film can be damaged during installation, and it can also be deformed during operation.
2. Short service life.
3. In indoor areas a greenhouse effect can be created at home, therefore, when using it, it is necessary to equip a forced ventilation system.

The film breaks down under the influence sunlight, which limits its use only to internal surfaces, it is often used for.

Polypropylene films are far superior to PE films in terms of strength and durability. The material is resistant to temperature extremes and ultraviolet. Today, films are produced from PP with a viscose and cellulose base, due to the inclusion of these materials in the composition, the absorbency of the film has increased by an order of magnitude.

Modern films used for vapor barrier walls have a multilayer structure, in which layers with vapor barrier properties alternate and a reinforced fabric that adds strength and wear resistance to the film.

Please note that when using reinforced vapor barrier films, it is necessary to leave a gap for ventilation, which contributes to the rapid evaporation of moisture.

Vapor barrier membranes

The vapor barrier breathable membrane does not interfere with air exchange and improves the ventilation of the wooden walls of the house. It is a non-woven fabric that forms a reliable protective barrier and does not allow vapors to penetrate into the insulation. There are single-sided and double-sided membranes, which respectively remove steam in one or different directions.

foil material

This group of materials has been specially developed for the vapor barrier of baths, saunas and steam rooms where conventional insulators are not suitable. On one surface of the film there is a foil, which is reflective and at the same time reduces heat loss.

Foil materials include:

• kraft paper with metallic coating;
• metallized kraft paper with lavsan coating;
• fiberglass base with foil.

Foil film can also be used for thermal insulation of the walls of residential buildings, in which, thanks to the use of this material, heat loss is reduced by 10-15%.

Coating insulation

For the walls of basements and basement floors of houses that are in close proximity to the ground, mastics based on liquid rubber or bitumen. Mastic is a water polymer solution, which is applied with a brush directly to the walls of the house. After complete drying of the composition, a strong film is formed on the surface, protecting the wall from moisture and steam.

How is the vapor barrier of the walls

In wooden houses, vapor barrier is usually placed from the inside of the room, and hydro and wind protection - from the front of the house. If it is planned to insulate the house from the outside under siding, lining or other finishing, the vapor barrier sheet is laid between the insulation and the wall of the house.

Wall cake with internal and external insulation is different. External thermal insulation is usually done in an old house to give it a more attractive look, while leaving wooden frame. Internal thermal insulation produced in new buildings after the work on the exterior finish has been completed.

Basic rules for vapor barrier

1. It is very important to monitor which side of the film faces the insulation. The smooth side of the film should be on the insulation, the rough side should be on the outside. Foil films are laid with a shiny surface towards the room.
2. The vapor barrier must overlap by at least 10 cm.
3. Sealing the joints of the canvases is carried out with a double-sided tape, the width of which is at least 10 cm.
4. Near window openings you need to leave a margin of the web for the deformation of the material.

Vapor barrier of walls inside the house

When performing internal vapor barrier, in order to establish an optimal microclimate in the room and not get the opposite effect when moisture condenses inside the house, it is necessary to strictly observe the work technology.

Before starting work, it is necessary to prepare the surface of the walls, clean them from dust and dirt and carry out antiseptic treatment.

1. Attached to interior walls wooden crate. First, vertical racks are installed on both sides of the wall, then intermediate ones. The width of the step between the slats depends on the size of the insulation and the type interior decoration. For example, under drywall, it will be 60 m, when lining with clapboard, a distance of 40 cm is sufficient.
2. A heater is laid between the slats, it must lie very tightly to each other so that there are no gaps.
3. A vapor barrier is attached to the top of the insulation. The canvases are overlapped on top of each other, gluing the joints with double-sided tape. Then the film is fixed with a construction stapler to wooden racks.
4. Next, make the installation of a counter-lattice for fastening finishing. The counter grille is necessary to create a ventilation gap between the casing and the insulation.
5. Perform the finishing touches.

Laying vapor barrier on external walls

With external insulation of a log house made of logs, it is possible to mount the vapor barrier directly on the logs without leaving ventilation gaps. Their function will be performed by natural voids between the logs.

It is impossible to fasten the vapor barrier directly to the walls of the house from the timber, since the circulation of steam will be disturbed.

Vapor barrier installation technology timber houses as follows:

1. The frame is made from wooden slats with a minimum thickness of 25 mm, which are located at a distance of one meter from each other.
2. Sheets of material are laid on the frame, fastening them together with a special tape. Additionally, the film is fixed to wooden racks with a construction stapler.
3. A counter-lattice is mounted on top of the vapor barrier.
4. Insulation boards are laid inside the frame.
5. Hydro-wind is pulled on top of the frame protective film.
6. Decorative finishing is in progress.

At frame structures there is no rigid base for fixing the material, so the vapor barrier laying technology is somewhat different.

The frame house should have the following structure:

1. External cladding (lining, siding, etc.)
2. Hydro and wind insulation, which is installed with an air gap in relation to the exterior finish.
3. Insulated frame.
4. Vapor barrier membrane.
5. Wooden crate.
6. Internal lining.

Such a wall cake is ideal solution for a frame house.

The vapor barrier of the walls of the log house can be done by yourself, but with inept performance, this will lead to numerous errors and problems. The subtleties of this work are known only to professionals.

The company "Master Srubov" is ready to provide its services to residents of Moscow and the region. We guarantee quality and fast work for insulation and vapor barrier of your home. To make your home always warm and cozy, contact the professional craftsmen of our company.

You can leave a request and contact us using the coordinates on the page.

The main task in the construction of any building is to protect the entire structure from direct exposure to moisture. It is so destructive that it can destroy any construction material. In addition to humidity, another serious enemy is also known, this is steam.

When building houses, it is important to carry out a vapor barrier of the house from the inside. This is due to the fact that moisture eventually destroys any material.

If you neglect the protection against emerging steam, mold, fungus will appear on the surface of the walls, and dampness will appear. That's why every home needs a vapor barrier on the inside of the walls.

Some Features

This is simply necessary in damp and at the same time warm rooms. A prime example maybe a sauna, maybe a heated basement. Such premises are located underground, they are most exposed to dampness attacks.

In such rooms, steam is always formed in the form warm air, with a huge number of tiny droplets of water. The resulting couple just needs to find a way out of such a room. He looks for ways and finds them in the form of the walls of the building, its ceiling.

Steam formation in this case becomes constant, there is a destruction of building structures, the building becomes emergency. To protect the walls of the building, a special vapor barrier is made, which does not allow steam to enter from the inside, as a result, the life of the walls and partitions is extended.

Installation of vapor barrier is not limited to baths and basements. Mount the vapor barrier internal walls it is also necessary in buildings that have external insulation, when the walls have a homogeneous material.

I must say that there is no special vapor barrier material suitable for all rooms in the same way. The type of vapor barrier depends on the existing structural component of the internal wall structures.

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Situations when it is necessary to install internal vapor barrier of walls?

Vapor barrier walls must be done in several cases.

Mineral wool is a breathable material, however, with this type of insulation, vapor barrier is a must.

1. If the walls have mounted internal insulation. Moreover, the material of thermal insulation was used mineral wool. Excellent thermal insulation properties are shown by mineral wool from the group of "breathing materials". But it has one negative property, mineral wool is not friendly with moisture. It quickly gets wet, gradually its properties deteriorate, it begins to quickly collapse. To prevent such cases, apply from inside the building. frame houses, having wall structures consisting of several layers, must certainly include a vapor barrier material. This also applies to buildings with internal insulation.
2. A powerful windproof function for buildings with a ventilated facade is performed by the laid vapor barrier layer. It doses and softens the air flow. As a result outer insulation is less overloaded, it acquires free "breathing". For example, a wall made of brick, which has external insulation made of mineral wool heat insulator and upholstered with siding. In this case, the vapor barrier becomes a kind of wind barrier, it reliably protects the walls of the building from powerful blowing. The existing ventilation gap removes excess moisture from the installed wind protection layer.
3. In order to ensure a good microclimate in the room, it is necessary, together with a vapor barrier, to install efficient and reliable ventilation that operates in a constant mode.

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What materials do builders use today for laying vapor barrier?

Nevertheless, the expression "wall vapor barrier" does not mean that such a protective barrier does not allow any steam to pass through. The membrane materials that builders use today are endowed with the ability to pass a certain amount of air flow. This is done for one purpose only.

There should not be a "greenhouse effect" in the room. The installed membrane retains excess moisture that has passed through it, the air that has passed through it will not be able to negatively affect the internal walls of the house and the laid insulation material. When the thermal insulation has an internal "fur coat", then the flow of the wet mass through the exhaust ventilation occurs.

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Varieties of vapor barrier materials

The classic vapor barrier material is polyethylene. This material requires careful attitude, because if the film is pulled too hard, it can tear at the moment of change climatic conditions. But there is one very important condition. Polyethylene must be perforated, otherwise it will not let in, apart from steam, also air. It will not be possible to get a comfortable microclimate in the building with such a film. If this polyethylene is used as a membrane, it will interfere with the entry of air mass, it cannot be used for vapor barrier.

It is possible to perforate a polyethylene film with a special device. Take a roller with driven nails. Such a "modernization" of the polyethylene film will not be able to provide reliable vapor barrier for internal walls. Of course, membrane materials are very similar to polyethylene film, but they differ greatly from it in their multilayer structure.

Builders often use vapor barrier materials special masks. After application, such a mastic is able to pass air, while retaining moisture. Surface treatment with such mastic begins to be done before the start of finishing.

Membrane films have become a modern material that is used today when laying a vapor barrier.

This material is able to prevent the entry of moisture, and at the same time pass the air flow. Such membranes have a certain vapor permeability, which provides normal work insulation. When such a vapor barrier is installed, the cotton wool insulation does not get wet, the walls “breathe”, there is no freezing.

Wood is an extremely breathable material that allows air and moisture to circulate well. However, this statement applies to whole wooden buildings although they are almost never made these days. Wooden houses have been equipped with artificial insulation for some time, so the wall on the cut acquires a puff appearance. Since plastics or “foil” that do not allow air and moisture to pass through are often used as heaters, buildings have become much less durable. Due to the moisture that has no way out, the wood becomes very decrepit and brittle. The solution to the problem is very simple - vapor barrier for the walls of a wooden house.

Where does moisture come from and how does it affect walls?

Where does moisture come from in a residential building - a simple question. In the kitchen, something often boils and generates steam, the bathroom of some families does not dry out at all. In addition, each person sweats and breathes. As a result, the average family can produce about 150 liters per year! If the building also has poor ventilation, you should expect quick breakdowns and a complete failure of the entire structure.

How does wood react to moisture? The porous surface absorbs it, while changing both the shape and size. We also introduce the concept of temperature into the equation. Result: wood is constantly changing under the influence of the above forces, and regular metamorphoses lead to a loss of elasticity. As a result, after a couple of years from the moment the building was built, the wood is covered with various cracks and notches. In a few years less strong tree will become rotten and, under the slightest impact, will crumble in pieces.

By the way! Treated wood building materials are usually very airtight, so these problems do not concern them.

Vapor barrier for the walls of a wooden house - why is it needed and what is it?

For a wooden house, the correct vapor barrier is a global issue. Protection of walls from moisture is needed two-sided, that is, both outside and inside. However complex systems insulation is not always convenient to use. The vapor barrier membrane is the most best material, as it does not allow moisture to pass through and at the same time allows it to breathe.

The service life of the building directly depends on the correct installation of the vapor barrier.

Types of vapor barrier. Vapor barrier for wooden and frame houses

Vapor barrier is primarily divided into external and internal. And if the external one can be started only 5 years after the construction of the building (when the tree sits down), then the internal one has to be done almost immediately. This leads to the fact that the walls are broken sealing. The scheme of work of the vapor barrier outside and inside is in many ways similar, but there are differences.

Inside

Internal vapor barrier is necessary for life, so it is done right away. The process is very simple in words: a heater is installed on the beam, and a vapor barrier is installed on it, in turn. The material must be stretched with high quality so that there is no sagging. You can fix it not only with a construction stapler, but also with ordinary nails with a wide hat. Since the vapor barrier is usually installed in strips, it is necessary to overlap it (2-3 cm is enough) so that there are no areas without protection. In wet rooms the procedure must be carried out with great care. After installing the protective film, drywall is usually installed. It is important to remember that wooden buildings are very specific and the best way out of possible problems there will be a consultation with a specialist.

There must be a minimum of 0.3 cm between the final coating and the insulation free space so that the air circulates freely, and the moisture has time to dry.

Outside

We start work only after 4-5 years and with complete shrinkage of the building. It is recommended to install the vapor barrier on a bare timber before the insulation. Installation on a timber building is carried out in the following order:

1. On the beam - vapor barrier, fixed with slats;
2. crate;
3. insulation;
4. Waterproofing;

If your building is made of chopped wood, then the protective film can also be installed on the surface finished wall. Ventilation is carried out due to gaps in the material. The frame building is vapor-insulated in the same way as a timber building.

Vapor barrier installation tips. Mounting technology - how to attach to the walls?

The materials for vapor barrier are very different, so the methods of their installation also differ. To begin with, it is worth talking about the cheapest, but short-lived, materials. Plain polyethylene film easy to install, but very unreliable. If you really want to equip your home with glory, we recommend that you take a closer look at reinforced film. It is more expensive, but much more efficient.

Polypropylene films work very simply - all the moisture remains on them and drops down in the form of drops. When choosing this material, you need to consider this nuance. Also use penofol and analogues. The peculiarity of this material is that it isolates both moisture and heat. It is installed strictly with foil inside the room.

Roofing material is also used for these purposes, but it is short-lived and does not cope well with the task. We do not recommend.

As mentioned above, the best option - diffusion membrane. Ideal to use, positioned to mount multiple layers. Lets air through but keeps moisture out. Its price is very high. But the quality exceeds all expectations. In addition, we categorically do not recommend budget analogues - they do not work, and if they do, it is bad and not for long.

When buying materials, pay special attention to their purpose. Often identical materials are responsible for different goals. For example, there are waterproofing membranes that allow steam to pass through. When installing the wrong material, the whole essence of the vapor barrier goes away.

A feature of laying vapor barrier materials is right choice sides. That is, you take a roll and you need to determine which side to glue it. Often, manufacturers indicate this nuance on the packaging, but if you did not find this information, then you need to apply the outside of the roll being rolled to the log. Fasten with rails.

When building a house, one of the main tasks is to ensure reliable protection of the building from interaction with water, which has a destructive effect on any building material. Other factors that adversely affect materials are steam and moisture. If you do not think about how to protect structural elements from them, then such frivolity can lead to the appearance of fungus and mold. To avoid this, during the construction of houses, a layer of vapor barrier is laid.

Why is vapor barrier needed?

Currently, many people who are building individual residential buildings are thinking about installing a vapor barrier. Vapor barrier is especially relevant in those houses in which warm microclimate prevails and the humidity level is quite high. This applies primarily to baths and basements located below ground level.

During their operation, steam is constantly generated in them, which must somehow leave the room. Therefore, it settles on the walls and ceiling. With prolonged exposure to steam on these surfaces, building structures are destroyed, which negatively affects the state of the structure as a whole. To prevent this from happening, install a vapor barrier. With her help Provides protection for walls and ceilings from steam penetration.

It should be noted that in addition to baths and basements, vapor barrier of surfaces in the interior should also be carried out in the case when the building has external insulation with a material with low diffusion resistance.

At the moment, there is no material that would be equally good for buildings made of various materials. When deciding which vapor barrier to choose for the walls of the house, they start mainly from the elements that make up the structure of the wall structure.

When is it necessary to install a vapor barrier on the walls?

In some cases, it is simply impossible to do without a vapor barrier device, the installation of which should be carried out correctly:

Materials used for vapor barrier

The term "vapor barrier" should not be taken as a barrier that does not allow steam to pass through. Membrane materials, which are currently used in steam protection work, provide the passage of air in a minimum amount, which completely eliminates the possibility of a greenhouse effect. Excess moisture is retained in the membrane, and the air freed from moisture is not able to harm the wall structure or reduce performance characteristics insulator. Vapor protection materials have an internal “coat” that ensures that moist air is redirected along the desired path through the ventilation system.

Types of vapor barrier materials:

• polyethylene is a material traditionally used for vapor barrier of house walls. Fulfilling installation work when using it, it should be handled with extreme care. The insulator must be fastened so that it is not too tight, otherwise the film will simply tear at the next change in climatic conditions. If polyethylene without perforation is used during vapor barrier work on the walls of the house, then it will become a reliable protection not only from steam, but also from air. And in this case about comfortable conditions living in a dwelling is out of the question. Therefore, it is best not to use such material to create a vapor barrier layer;
• the group of vapor barrier materials includes mastics that have been developed specifically for this purpose. Using them during work from inside the building, the material will retain moisture and let air through. Note that the work on applying mastic on the surfaces of walls and ceilings is performed before their finishing;
• new material for vapor barrier are membrane films. Their appearance on the market happened some time ago. In a short period, this material has become in demand and is currently actively used in vapor barrier works on the walls of wooden houses. The main advantage of these materials is that they allow air to pass through and retain moisture. The vapor permeability that is characteristic of them is relative. This allows you to ensure the normal operation of the heat insulator. The use of membrane materials to protect the walls prevents the cotton wool insulation from getting wet. It does not lose its integrity and can perform its functions for a long time.

Common brands of membrane materials

At the moment, vapor barrier materials are presented in a wide range. And each of them is designed for a specific area of ​​\u200b\u200buse.

Vapor barrier materials installed outside

This group of materials includes "Izospan A", "Izospan B". One of their features is that the materials contain flame retardant additives, which increases their fire safety. This also includes "Megaizol A", "Megaizol SD". All of these materials are used to protect structures made of timber, as well as houses built according to frame technology, and shield buildings. These insulators provide protection against precipitation, snow and wind. They are used for all types of external insulation.

When using them, it is essential to ensure tight seal of the membrane to the heater. Therefore, during work, these materials should be securely fixed. Sagging and loose areas should be absent. Otherwise, with strong winds, rare gusts will occur.

Indoor installation materials

When the task is to perform vapor barrier of walls, ceiling from inside a wooden house, then Megaizol V is used. It is a polypropylene film, which consists of two layers. On the outer side of this material there is an anti-condensation surface. The use of this material in winter time provides its protection against phenomena such as condensation and fungus. In addition, its use eliminates the destruction of elements of wall structures. Also, this material provides protection of the room from the ingress of particles of insulation. The same function is inherent in Izospan B.

Materials for hydro and vapor barrier with a reflective layer

This group includes the following materials: IzospanFD, IzospanFS, IzospanFX. They are used in cases where it is necessary to arrange a vapor barrier in rooms in which special requirements are imposed on this procedure. For example, it can be saunas or baths.

Rules for vapor barrier of frame walls

In frame-type houses, high-quality insulation is more important than in brick buildings or houses made of timber. The comfort of living depends on this in many respects. Therefore, special attention should be paid to vapor barrier. To protect the insulation from steam on the walls, the membrane must be fixed on the correct side. Should be attached to racks. with a stapler. The membranes formed after laying on the walls must be insulated with special tape. Or you can use special mastics to seal them.

If ecowool or polystyrene is used in frame buildings as a heater, and an effective ventilation system is installed in the house itself, then a vapor barrier device can be abandoned. If the owner of the building has decided to provide protection from steam, then in this case you can use one of the following schemes:

• the first scheme involves sewing the membrane onto the elements of the wall frame rack. After laying the film, surface finishing work is carried out. Drywall or lining can be used as a material. This option is optimal for wooden houses, which are used by the owners for temporary residence, and are empty in winter. It can be used in guest houses and workshops. Applying such a vapor barrier scheme for the walls of the house, it is necessary to arrange and effective system ventilation.
• the second scheme involves a device on top of the laid vapor barrier membrane crates, located in a vertical and horizontal position. Thanks to it, an air gap of 30-50 mm is provided. It is best to use this design in houses that are used for permanent residence. In this case, in the premises of a wooden house there is high humidity and structures need effective protection from steam.

Vapor barrier of the walls of a wooden house

The walls of a wooden house should have a higher vapor barrier compared to brick buildings. When choosing membrane materials for insulating surfaces in wooden structures, one should proceed from the thickness of the beam, tightness of the grooves, the presence of cracks in the material of the walls.

A popular material for the construction of wooden houses is glued beams. In the process of its manufacture, the wood is dried in special chambers. The result is a low level of humidity. finished material. It has grooves for sealing. The material is characterized by low shrinkage, so it enters the insulation in a limited amount.

When wooden house is built from a bar with a natural level of humidity, then the drying process of the material occurs during the operation of the building. During the first five years in such a house, cracks appear on the material. At the bar change geometric dimensions, the tightness of the grooves is broken. Therefore, work on finishing the house during the shrinkage period cannot be carried out. Otherwise, upon its completion, it will be impossible to restore the tightness of the grooves. In the case of such structures two options are possible:

• wait for the wood to dry;
• perform a vapor barrier of the walls of the building, using membrane films "Izospan B", "Izospan FB" or "Izospan FS" during work.

Conclusion

Now everyone understands that vapor barrier is important in every home. All work must be carried out correctly, i.e. according to technology. During work, apply modern materials High Quality. If you want to live in your home in comfortable conditions, then for you the vapor barrier should become mandatory procedure. It will provide steam protection. The house will be reliably protected from moisture and will last a long time.

The advantages of a wooden house include a unique microclimate. This is due to the ability of wood to absorb excess moisture and give it away when the air in the room is too dry. Also, through the wooden walls there is a constant air exchange - it is easy to breathe in the house.

If the house is built from dry logs or glued beams, and the thickness of the walls is sufficient to keep the heat inside the building, then it does not need additional thermal insulation. In the case when the construction was carried out from lumber natural humidity, or with insufficient wall thickness, it is necessary to install external or internal insulation.

In order not to nullify the advantages of a wooden house and not provoke wood decay, you should carefully consider the choice thermal insulation material. It must pass air, so it is recommended to opt for mineral (basalt) wool, which is not subject to biological destruction.

Due to the fibrous structure, mineral wool is able to absorb moisture. This causes:

• sharp decline thermal insulation properties material, freezing;
• deformation of the insulation (when wet, it is crushed and slides down);
• rotting of wooden walls in contact with a moistened heat insulator;
• dampness and damage to interior finishes.

To prevent moisture from entering the insulation, it is required to protect it with a special film barrier with the appropriate properties. Consider what should be the vapor barrier for the walls of a wooden house.

Vapor barrier materials

Depending on the selected insulation option, the vapor barrier is mounted outside the house or inside the building. It is important to choose a material with optimal performance, so that the house is warm and comfortable, thermal insulation cake lasted a long time, and the wooden walls were not damaged by the fungus.

A wooden house does not need absolute isolation from steam passing through the insulation and walls during natural air exchange. The use of sealed materials internal insulation will lead to the "greenhouse effect" in the room.

We will determine which vapor barrier material is better to choose. Three types of vapor barriers are used in construction:

• polyethylene film;
• mastic;
• membrane film.

The plastic film does not allow air to pass through, so its use inside the house is contraindicated - even with good ventilation in the room it will be uncomfortable. Polyethylene contributes to the settling of condensate, which can lead to damage to the wall finish.

A popular advice is to perforate plastic wrap with a spiked roller to allow air to pass through. But together with air, such a barrier will also allow water vapor to pass through, that is, it will not be able to perform its function. For external insulation, polyethylene film is also not very suitable, since the material loses its strength under the influence of high and low temperatures.

Mastic, capable of passing air, but retaining steam, is not suitable for wooden walls. This material applied directly to building construction, and we need to protect the insulation from the effects of steam.

Vapor barrier membranes are characterized by a multilayer structure and the ability to retain excess moisture, allowing air to pass through. Membrane materials are suitable for internal insulation and can be used as part of an external heat-insulating "pie".

Features of vapor barrier membranes

The membrane material is breathable and, to a certain extent, vapor permeable. This allows for normal gas exchange through the walls, taking advantage of the advantages of a wooden house. At the same time, the fibrous insulation inside the room will be protected from excess moisture, the removal of which will require high-quality ventilation. At external insulation excess moisture escapes through the ventilation gaps.

When designing an insulation system, it is required to select the appropriate vapor barrier material. Membranes differ in the degree of air and vapor permeability, in structure.

The inner side of the membrane may be rough due to the inclusion of fibrous material. This side should be turned to the insulation - in this case, the excess moisture that has penetrated the barrier will remain on the surface of the membrane, and will not enter the heat insulator. Membranes with an anti-condensation surface are intended for use as part of the internal insulation of wooden walls.

Outside, the membrane can be foil-coated - the metallized layer reflects thermal radiation, which contributes to heat saving. A vapor barrier with a foil side is recommended for use when arranging wooden baths and saunas.

The material for creating a vapor barrier is selected taking into account operational features heat-insulating "pie".

Sectional wall cake of a wooden house

On Russian market are popular:

• "Megaizol A", "Megaizol SD", "Izospan A" (including those with flame retardant additives) - for the installation of an external thermal insulation system of a wooden house;
• "Megaizol V", "Izospan V" - for internal insulation of residential and utility rooms;
• "Izospan" FD, FS, FX - for rooms with increased requirements for thermal insulation efficiency (baths, saunas, etc.).

Indoor installation

When protection is needed for the insulation inside the house, the membrane material is fixed over the crate, between the elements of which mineral wool insulation boards are inserted. Pay attention to the manufacturer's instructions to secure the membrane with the correct side facing in.

The canvases are overlapped (at least 2 cm), carefully glue the joints with aluminum tape. To securely attach the membrane to the crate, use a construction stapler with staples. The film should not sag, have gaps and gaps. Special attention is given to fixing the material around the perimeter to minimize the possibility of moisture penetration under the membrane.

Installation outside the house

When the insulation is installed outside the house, the vapor barrier separates the heat insulator and wooden wall. On flat (timbered) walls, in order for the moisture that wood will let through to leave, you need a crate of slats 25 mm thick. It is stuffed in increments of 80-100 cm and a membrane or other material is attached on top to prevent the penetration of steam into the insulation.

Insulation of the walls of a wooden house from the outside

On log wall the vapor barrier is attached without additional crate - ventilation ducts serve as depressions between the logs. The film outside the building must be mounted without sagging. To determine which side to turn the membrane to the insulation, follow the manufacturer's instructions.

A crate is attached over the vapor barrier, in the cells of which mineral wool is laid. Then you need waterproofing, on top of which external finishing is performed.

Please note: as a vapor barrier when insulating a house from the outside, it is allowed to use waterproofing materials, not passing steam - roofing material, polyethylene, foil. When choosing which material to use, cost and durability are taken into account.

When is the insulation of a wooden house required?

Installing an external or internal system insulation is needed if the house is built from undried wood. In this case, shrinkage occurs over several years and is accompanied by the appearance of gaps between the log units. Additional thermal insulation is also required for old houses or with insufficient wall thickness.

When choosing which insulation option to prefer, please note that when internal installation heat insulator to the vapor barrier are presented increased requirements- it must be breathable. It is important to mount the multilayer membrane with the correct side.

If you have any doubts about the choice of vapor barrier materials for the walls of your house, you can always contact the experienced specialists of the Marisrub company, who will provide professional advice and carry out work on exterior or interior decoration.