Indoor vapor barrier. Vapor barrier for walls - how to make a wooden house warm and cozy? Vapor barrier materials

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In SP 31-105 (design, construction of energy-efficient frame housing), SP 64.13330 (wooden structures) internal vapor barrier for walls wooden house indicated in mandatory. This protective layer prevents the penetration of moist air into wooden structures. External vapor barrier becomes necessary for external insulation or operation of cottages in hot regions.

Purpose, types, characteristics

There are several types of insulation materials that individual developers usually confuse:

• waterproofing - cuts off only water, but allows moist air to pass through;
• vapor barrier – retains moist air, preventing it from penetrating the building’s load-bearing frame, and it does not matter what materials the building is built from;

• hydro-wind protection - used only in systems of ventilated facades, roofing pies, covers external thermal insulation, prevents the destruction of expanded polystyrene, mineral, glass wool from weathering.

When installing a vapor barrier layer, the following should be taken into account:

• some interior finishes have their own vapor barrier, so the layers in the building wall pie should be positioned in such a way that the vapor barrier properties increase from the inside out, otherwise the dew point will shift inside the wall, condensation will form on the surfaces of the lumber;

• any vapor barrier material automatically makes the walls non-breathable, so installation may be required ( supply valves on the windows, fans in the walls, vents).

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The main installation errors are incorrect placement of the vapor barrier inside the wall pie, inverted sides of the membrane, or lack of continuity of contours. Films on the walls must be combined with materials on the ceilings and floors.

Films

The industry produces smooth polymer films without perforation, which have maximum vapor barrier. For baths that have specific operating conditions (rapid heating to extreme temperatures), aluminum foil is glued to one or both sides. It reflects heat back, allowing you to save energy.

The most in demand are polyethylene and PVC films, which are mounted either under wall cladding or on top of external insulation. If, in violation of SP standards, there is no internal vapor barrier of the home, the film is installed outside under basalt wool.

Membranes

Diffusion membranes, unlike classical films, have a different design. The molecules inside them are arranged in a labyrinthine order, which allows moisture from the air to condense on their surface and prevent it from reaching the lumber from which the frame is assembled.

At the same time, it is necessary to install a vapor barrier for the walls of a wooden house using the following technology:

• under internal lining walls;
• with a mandatory ventilation gap between the decor and the film.

When moisture increases outside, vapor penetrates inside the walls, but can freely pass through the pores of the film, condensing on its inner surface. Thus, if you change sides during installation, the effect of the vapor barrier layer will be exactly the opposite:

• all moist air will pass inside the wall;
• Condensation forms on wooden structures.

Manufacturers mark each side of the membrane, supply products detailed instructions that must be observed during installation.

Roll materials

Individual developers should not be confused roll materials with film. The last category is listed above; the following products belong to rolled vapor barrier:

• roofing felt - based on fiberglass or fiberglass with one layer of bitumen material;
• roofing felt - cardboard impregnated with tar;
• glassine - cardboard impregnated with bitumen.

Attention! The vapor permeability of these materials is 50 times higher than that of polymer films and membranes, so their use in wooden house construction is not recommended.

Polymer varnishes

Most often, varnishes with the VD-AAK-001D index are used to protect the decorative layer of log houses. The material is ready for use, applied in several layers, preserves the texture of wood, forms protective film. Typically, semi-matte, glossy, colorless varnishes are used, drying in 4 to 7 hours. The average consumption is 1 liter per 8 – 14 square meters of surface.

If finishing is planned in the log house interior walls decorative materials, instead of varnish, cheaper polymer films are used.

Selection criteria, installation technology

When designing a vapor barrier, the main selection criterion remains the construction budget. Therefore, in 90% of cases, polymer films with a thickness of 0.15 mm or more are used. As they take cover decorative layer, resistance to solar ultraviolet radiation can be ignored. However, there are nuances of choice:

• vapor barrier of walls from the inside of a wooden house is usually done with budget polyethylene film;
• vapor barrier of the walls of a wooden house from the outside is provided by polypropylene or PVC canvas, since these materials are weather-resistant.

Membranes are used less frequently because they weigh more and are more difficult to fix on vertical surfaces. Only those with sufficient attractive design log walls, since this material is at least three times more expensive than others.

Films are stapled using a stapler, varnishes are applied with a brush, roller or sprayed with a special tool.

Pros and cons of vapor barrier materials

When choosing a vapor barrier, it is necessary to take into account the structural and operational characteristics of existing materials:

• diffusion membrane - only three-layer materials, which are expensive, have the required properties, the membrane can be installed inside/outside without restrictions;
• polypropylene film - in 50% of cases they cover unfinished objects for winter conservation; there are modifications with an absorbent layer to collect condensate;
• polyethylene film - the only drawback is destruction from ultraviolet radiation, so it is necessary to cover the material from sunlight.

Due to the above reasons, polymer varnishes are used for a limited number of construction and finishing technologies.

conclusions

Thus, home handyman you can independently choose a vapor barrier material and install it to protect the wooden walls of your home. The most commonly used are polymer films and membranes.

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One of the main tasks at each stage of construction is to protect all structural elements structures from direct exposure to water. Its destructive power can negatively affect any construction material. But there is another one, less obvious, but no less dangerous enemy– steam or moisture. Fungus, dampness and mold are the consequences of neglecting measures that can prevent the impact of these factors on the walls of the building.

Why is vapor barrier needed?

Vapor barrier is especially necessary in damp and at the same time warm rooms. For example, this applies to baths and heated basements, which are located below ground level and are therefore susceptible to dampness. Steam formation occurs inside such buildings - warm air with droplets of water, which requires a way out of the room. These paths become the walls and ceiling. Since in this case steam formation is a constant process, gradually the steam begins to destroy the surface building structures, which causes detrimental consequences for the home. Vapor barrier is the barrier that is designed to protect walls from steam penetration into them, and, consequently, their subsequent destruction.

Installing a vapor barrier is an event carried out not only for premises such as a bathhouse or basement. The need to carry out such work does not disappear even in cases where the building is insulated from the outside with a material with low diffusion resistance or the walls are constructed from a homogeneous material.

There is no universal vapor barrier material that works equally effectively for all building structures from the roof to the basement. Which vapor barrier to choose is determined by the structural components of the wall structure.

When is laying vapor barrier on walls necessary?

There are a number of cases when vapor barrier is mandatory:

• When insulating walls from the inside, especially if the thermal insulation is made of cotton-type materials. Mineral and glass wool have excellent heat-insulating properties; moreover, they belong to the category of “breathable materials”. However, cotton wool has a very important drawback - the fear of moisture, under the influence of which they get wet and lose their valuable qualities and are gradually destroyed. A vapor barrier installed indoors makes it possible to avoid these negative consequences.
• Multilayer wall structures in frame houses must necessarily contain a vapor barrier material. This case similar to the previous one - structures with internal insulation.
• For ventilated facades and external walls, the vapor barrier layer plays a windproof role. Vapor barrier measures and softens the flow of outside air, protects external insulation from overloads and provides him with free “breathing”. An example of such a case would be Brick wall, insulated on the outside with cotton wool insulation and covered with siding. The vapor barrier, which plays the role of a wind barrier in this situation, prevents increased ventilation of wall structures. The ventilation gap serves to remove excess moisture from the surface of the windproof layer.

An important factor in ensuring a normal indoor microclimate, along with heat and vapor insulation, is the presence of effective, constant ventilation.

What building material is the best? Read what to choose to protect your apartment from noise!

Before installing soundproofing walls, carefully study how it is done. We have collected tips from professionals.

Materials used for vapor barrier

The term “vapor barrier” does not mean that the barrier should not allow steam to pass through at all. Modern membrane materials are able to ensure the passage of a minimum amount of “controlled” air flow, which guarantees the absence of a “greenhouse effect” in the room. Excess moisture is retained by the membrane, and the air released from it is not capable of damaging the wall structure and insulation material. Insulation materials, equipped with an internal “coat”, transport the main flows of moist air along the desired path - through the exhaust ventilation system.

Kinds vapor barrier materials:

• Polyethylene is considered a traditional vapor barrier material. During installation, it must be handled carefully, without pulling too much, so that the film does not break through seasonal changes in climatic conditions. However, if the polyethylene is not perforated, then it will not allow the passage of not only steam, but also air. It is simply impossible to create a comfortable microclimate in such conditions. And since polyethylene will not allow air to pass through, like a membrane material, it is not suitable as a vapor barrier.

Some forums advise perforating plastic film with a roller with nails or other devices driven into it. However, such a “modernization” of polyethylene is completely incapable of providing vapor barrier for insulation and building structures. Membrane materials are similar to polyethylene film appearance, but are radically different in their multilayer structure.

• One of the vapor barrier materials are mastics specially developed for this purpose. The mastic applied to the surface of the walls and ceiling will allow air to pass through and retain only moisture. Surfaces are treated before finishing.
• A new generation of vapor barrier materials are membrane films. They have the ability to stop moisture while allowing air to pass through. Membranes have a specific, correct to ensure normal operation insulation vapor permeability. Cotton insulation with such a vapor barrier does not get wet or freeze, the walls “breathe”, maintaining their integrity and ability to perform their functions for a long period.

When using membrane materials, an air gap is often not required.

Common brands of membrane vapor barrier materials

Membrane materials are produced in a wide range. Moreover, each model is intended for a specific area of ​​use, where it can maximize the properties inherent in it:

• Vapor-tight materials installed on the outer side of the insulation, external to the heated space - “Izospan A”, “Izospan A” with OZD (fire retardant additives), “Megaizol A”, “Megaizol SD”. These materials are used to protect the external walls of structures made of timber, panel, frame, combined buildings from snow, wind, atmospheric moisture for all types of exterior finishing - siding, lining, with external wall insulation.

It is important that the vapor barrier membrane fits tightly to the insulation, is securely fixed to the elements of the installation system, and does not have loose areas or sagging, which can cause “popping” noises when exposed to sudden gusts of wind.

• For installation indoors, use “Megaizol V” - a two-layer polypropylene film with an anti-condensation surface. IN winter time this material protects walls from the formation of condensation, fungus, and corrosive destruction of structural elements. "Megaizol B" also protects inner space premises from insulation particles getting into it. Izospan V performs a similar function.
• Materials for hydro- and vapor barrier with a reflective layer - “IzospanFD”, “IzospanFS”, “IzospanFX” - are intended for installing vapor barriers in rooms with special requirements for their thermal insulation characteristics, for example, in baths and saunas.

Rules for vapor barrier of frame walls

It is especially important to do vapor barrier in frame houses correctly: install the membrane on the desired side, carefully fasten it to the studs with a stapler, glue the joints with special tape or coat them with mastic.

In cases where ecowool, polyurethane foam, polystyrene foam is used as insulation, and effective ventilation is installed in the room, in frame structures you can do without a vapor barrier layer. If a decision is made about the need to install a vapor barrier, then it is possible to use one of two existing design schemes:

• According to the first scheme, the vapor barrier is sewn onto the frame posts. On top of the vapor barrier membrane, the room is lined with plasterboard, clapboard or other wall materials intended for interior decoration. This option is most suitable for buildings that are intended for seasonal living and are not used in winter. These are dachas guest houses or workshops combined with a parking lot. With this option, effective ventilation of the room must be ensured.
• Second design diagram provides for the installation of a vertical or horizontal sheathing on top of the vapor barrier membrane, providing an air gap of 30-50 mm from the wall. This design is suitable for houses permanent residence or long-term use in winter period, since in this case increased humidity forms inside the house.

Features of the vapor barrier device for the walls of a wooden house

The vapor permeability of wooden walls significantly exceeds that of walls made of brick or stone materials and depends on the thickness of the logs or timber, the tightness of the grooves, and the presence of cracks.

Glued laminated timber used for the construction of walls is dried in production conditions until low level humidity, has grooves for sealing, low shrinkage and therefore steam enters the insulation in limited quantities.

The walls of buildings made of logs or beams with a natural moisture level are dried already during their operation. Over the course of 4-5 years, as a result of shrinkage, cracks appear, deformations appear, beams and logs change in size, and the tightness of the grooves is constantly compromised. During this entire time, you cannot spend time in the house. interior decoration, since access to the grooves to restore their tightness will become impossible. In this case, there are two options. The first is to wait until the wood is completely dry. The second is to install a vapor barrier on the walls using, for example, membrane films “Izospan B”, “Izospan FB” or “Izospan FS”.

The vapor barrier of the walls must form a single vapor barrier circuit with the basement and attic floors.

If the work on installing a vapor barrier on the walls was carried out competently and professionally, then such a house will always be warm and cozy, and the walls will receive reliable protection from moisture. Detailed diagrams and photos of wall vapor barrier:

And if after reading the article you still have questions, we invite you to watch this video, in which experts will talk about why vapor barrier is needed and how to make it yourself:

Vapor barrier installation for walls in buildings for various purposes , 2.9 out of 5 based on 30 ratings

In all residential buildings, a vapor barrier is always installed on the walls. This also applies to wooden houses. In them, measures to protect against accumulating moisture can be carried out both inside and outside.

Do you need a vapor barrier for a wooden house?

Nowadays, private houses made of wood are very rarely built with single-layer walls. Every person wants his home to be as warm as possible. Therefore, now houses made of wood are built with multi-layer walls. In addition to the interior decoration and the wall itself, they also have an additional insulating layer. This led to the fact that the residential building began to “react” completely differently to the evaporation of moisture formed in the rooms.

In buildings with single-layer walls, steam from inside the room escaped from the wooden house without any problems, thanks to the special ability of wood to “breathe.” There was a uniform circulation of excess moisture between the building and the street. In dwellings with walls in several layers, this phenomenon does not exist. Various resistance indicators of the materials used disrupt the natural “breathing” of the paving stones, resulting in moisture remaining inside the premises.

It causes rapid destruction of wood structures and, in addition, does not allow the insulating layer to perform its function in full. Vapor barrier of walls allows you to prevent these negative phenomena. Its installation ensures protection of the insulating layer from steam, prevents the possibility of mold and mildew appearing on the walls of a wooden house, and prevents the walls from freezing and becoming damp.

Vapor barrier is considered a strictly mandatory procedure for buildings made from carriages, chopped logs and semi-carriages. The point is that such material is characterized by a natural level of humidity. Residential buildings made from it “dry” very actively throughout the year. And then they need another 3-4 years to “reach” the optimal humidity level. If you do not install a vapor barrier, the house will experience:

• active shrinkage of walls;
• formation of cracks;
• the appearance of serious deformations.

Moreover, all these defects will not stop even after five years, but will only progress. If another wood material(for example, glued or rounded timber), a vapor barrier may not be required. This is due to the fact that such products are dried to the required degree of humidity at the enterprises where they are manufactured, due to which they become less prone to deformation and shrinkage.

What material can be used?

Reinforced polyethylene has long been a well-known “protector” of living space from moisture. Now it is used extremely rarely. It does not provide a truly comfortable microclimate in houses made of wood, since neither air nor moisture passes through the polyethylene layer. Some " craftsmen“It is recommended to make small holes in the polyethylene film and then use it to perform a vapor barrier.

Specialists construction industry they say that such “perforation” will not give any result. There is no point in wasting your time and money on such an undertaking. But you can buy laminated plastic film with a special layer of aluminum on the surface. This material has a real effect. It will not only protect the walls from excess moisture, but will also be able to reflect heat from the walls into the rooms, making the house warmer.

Many people choose modern products for vapor barrier:

• On foamed polypropylenes and other foil-type polymers. According to the principle of operation, they are similar to films on which there is a layer of laminated and aluminum coating. Such polymer material characterized by fairly high vapor barrier characteristics, and also serves as a high-quality heat insulator.
• On polypropylene films. They catch steam coming from inside the room to the street and accumulate it on their surface.
• On diffusion membranes. This innovative material considered ideal for protecting the walls of a wooden house from moisture. It retains steam and at the same time easily allows air to pass through, providing an excellent microclimate in the home. The only drawback of diffusion membranes is their high price. If you plan to vapor barrier your walls with their help, get ready for serious financial expenses.

Note that diffusion films are now produced in a wide range by different companies. There are many models of such membranes. Moreover, they differ from each other in the recommended area of ​​application, having certain properties. Conventionally, diffusion films are divided into the following groups:

• For installation inside a living space.
• For installation with outside insulation. This material is ideal for protection frame house, timber buildings.
• To perform simultaneous vapor and waterproofing. Films of this type Usually used to protect baths from moisture in private homes. There is no particular point in using them for residential premises, due to the high cost of membranes.

Outside, residential buildings are often insulated with roofing felt. And indoors in Lately A special mastic is often used. It is used to treat walls before applying them. finishing coating. This mastic retains moisture, but allows air to pass through without problems.

Vapor barrier device from inside and outside - possible options

The easiest way to protect a residential wooden structure is to use a method that is carried out after the wood has dried to optimal humidity levels. This method assumes that all the joints of the house from the outside will be processed, the existing grooves will be caulked, and the gaps will be filled with a special sealant. After such preparation, you can lay a vapor barrier (it is advisable to take a material with maximum density, for example, roofing felt).

The described technique allows the walls to “breathe”, which means the microclimate in the home will be good. But it is worth understanding that in this case, steam from the premises goes to the insulating layer, which in most cases leads to depressurization of the house. After some time, you will have to caulk the grooves again, seal the cracks in the walls with sealing compounds, and so on.

If this option does not suit you, it is better to protect the walls from steam from the inside. This can be done using the materials we described above. It is recommended to use diffusion films. Please note that their thickness should not be more than 0.1 millimeters. Another important point. Always remember that the vapor barrier of the walls must be carried out in such a way that the result of the work is a general vapor barrier circuit. It must include insulation of the attic, basement, basement room and the walls themselves.

The described method of protecting houses from moisture by laying insulating materials from the inside is more durable. But, as you yourself understand, when it is sold in a home, the result is a shell that “does not breathe.” It spoils the microclimate. And not every person likes this. It is better for such people to use the third method of vapor barrier, which involves the device diffusion membrane between the insulation layer and the wall.

This technique is suitable for situations where walls are insulated with polystyrene foam made using extrusion technology or with ordinary foam plastic. Vapor barrier material should be placed between the insulation and the wall. Moreover, it is necessary to provide a 4–5 mm gap (ventilated) on the wall side. It is connected to the rooms of the home through vents installed above and below. Their presence allows you to balance the temperatures inside the house and in the area of ​​the ventilated gap.

Protecting the walls of a wooden house from moisture and steam

Now let's look at how to perform vapor barrier work on residential buildings made of wood. If you intend to do interior decoration on the walls, you are allowed to place an insulating and moisture-proof layer from the inside. This is done like this:

• apply a layer of waterproofing, which will protect the wall from moisture coming from outside, over the log, fixing it to the sheathing;
• leave (required!) a gap for ventilation of about 5 mm;
• use a stapler to fasten the waterproofing onto which the metal profiles are mounted (on top);
• Place the selected material for the profiles between the profiles, and lay a vapor barrier on top of it.

After this you can do finishing walls Vapor barrier of a frame dwelling, as well as buildings made of timber, can be done by installing a vapor barrier membrane on the outside. In this case, it is necessary to make a slatted frame for the film (the distance between the individual slats is about 100 cm). Then attach a vapor barrier to it, fill the lath on top of the slats for the insulating layer and stretch the layer of waterproofing material. Now you can start finishing the walls.

It is prohibited to install vapor barriers on frame and paving structures without slats.

One more thing. Whatever vapor barrier material you choose for the walls, its individual pieces should be overlapped. They should be 2-4 centimeters apart from each other. If you use foil polymers, the joints between the insulation strips are sealed with metallized tape. Other types of films are usually joined with self-adhesive tape.

If you have no experience in performing work to protect the walls of a frame or other wooden house from moisture, we advise you to ask for help from professionals. They will tell you which vapor barrier method will be optimal for your home. And it will absolutely become warm and very cozy for your family.

IN modern construction Wooden houses with single-layer walls are rare. The owners' desire to make the building warmer led to the emergence multilayer walls, in which, in addition to the wall itself and the interior decoration, there is also a layer of insulation. As a result, the design of the house began to react differently to couples, which are full of interior spaces and who are looking for a way out. If in single-layer walls steam circulated evenly between the street and the house due to the “breathing” properties of wood, then in the wall pie it began to “get stuck” due to the different resistance of the materials. And the moisture inside prevents the insulation from properly performing its heat-saving function and leads to destruction wooden structures. To avoid such sad consequences, a vapor barrier is created - another layer in the wall pie, the task of which is to prevent steam from entering the insulation.

• log thickness;
• type of material processing;
• number of cracks;
• quality of sealing of rims, grooves, etc.

If a house is made of chopped logs, a carriage or a half-carriage, then the wood in it has natural humidity. The walls will dry out gradually, already standing in the log house. As a rule, the box will reach the optimal humidity level in about 5 years. But the most active period is the first year. The moisture level of logs varies greatly and can lead to deformations, cracks, and shrinkage of the walls. It’s not for nothing that the house is allowed to “stand” for the first year, by bringing the log house under the roof and stopping all work. If you do not insulate the tree from steam in the future, it will “play” long years.

Other types of timber (rounded, glued) are already dried in production to the level of the required minimum humidity, so such houses are less susceptible to shrinkage and deformation. Due to the factory grooves and precisely calibrated dimensions, the walls are sealed and themselves become a barrier to steam, which penetrates them much more slowly. As a rule, such a house does not need a vapor barrier device.

Due to factory drying, rounded timber becomes sufficiently airtight and does not require vapor barrier

When to start laying the vapor barrier layer

Option 1. We wait 5 years until the logs are completely dry, and only then we begin the installation of the wall pie and interior decoration. If you properly caulk all the cracks that appeared as a result of shrinkage, then you can not lay a vapor barrier at all, but make three-layer wall, consisting of an external wooden layer, insulation and internal plasterboard finishing. In this case, you will preserve the unique microclimate that only a wooden structure can create. But steam will enter the insulation, because both wood and drywall are permeable. With this design, you will have to periodically (every 5-6 years) open the finish and change the insulation, which will lose its thermal insulation characteristics as it becomes saturated with moisture. To extend the service life of the heat-insulating layer, purchase materials that indicate “with hydrophobized treatment” and “increased density.”

Option 2. If you don’t have time to wait so many years, there is only one way out - vapor barrier. By doing this, you will save the insulation and reduce the degree of vapor passage, but the climate of the wooden house will “suffer” because all the properties of the wood will be “hidden” under the vapor barrier. But the heat saving and durability of structures will increase noticeably. It is possible to create a vapor barrier layer, like the entire wall pie, already a year after the construction of the log house.

Vapor barrier material protects the insulation from vapors penetrating into it from inside the premises

How to lay a vapor barrier for external insulation of a house

Wall pie with external and internal insulation different at home. External insulation of houses is carried out when an old wooden house has been inherited and it needs to be given more modern look, while maintaining wooden base. Internal insulation is done, as a rule, in new houses in order to leave the beauty of the logs open to the eye, or in cases where external finishing has already been produced.

Let's look at how to properly install a vapor barrier if the insulation is done from the outside.

Since the log remains inside, then on it outside, facing the street, and a vapor barrier material will be laid. For these purposes, you can choose a vapor barrier or regular film, roofing felt, or aluminum foil. Of the proposed options, the most short-lived ones are ordinary polyethylene and roofing felt, because they have a short service life.

Roofing material should be chosen as bituminous, having a double-sided coating, film - more than 0.1 mm thick, foil - more than 0.02 mm thick. Foil, in addition to vapor barrier, has the ability to repel internal heat, returning it back to the rooms, so heat saving in such houses is higher than in buildings with another vapor barrier.

There must be a ventilation gap between the wood and the vapor barrier layer, which is created using wooden slats

Features of installation of vapor barrier films

If you create protection with a vapor barrier film, then when purchasing, carefully read what the coating is intended for. Vapor barrier is often confused with waterproofing. In our case, the film should not allow steam to pass through. Waterproofing films are permeable to steam. They create a barrier only for water. This option is not suitable for us, since if steam penetrates into the insulation, then there is no point in creating a vapor barrier at all.

You also need to pay attention to which side to lay the vapor barrier. The manufacturer indicates this in the instructions, but if you did not find instructions, then the principle of laying out the roll is as follows: lay it on the log with the side that is adjacent to the roll as it rolls out, i.e. external.

Among waterproofing films There is one type that can also be installed as a vapor barrier. They are called anti-condensation films. One side of such films is smooth, and the other is fleecy due to the cellulose layer. Look carefully at which side to attach the vapor barrier: the smooth side is fixed to the log, and the fleecy side will face the insulation. Why is this so? The smooth side creates protection for steam. But no film can give a 100% guarantee that steam will not leak inside, because even the manufacturer does not provide this guarantee. Moisture that gets onto the inside of the anti-condensation coating does not flow down, but gets “entangled” in the cellulose fibers, and then comes out with the air flow through the ventilation gap. This property is very beneficial for insulation, which will not absorb moisture flowing from below and will remain dry.

Vapor barrier device outside the house

How vapor barrier materials are installed

Regardless of the type of the above materials, the canvases overlap. In this case, the layers should overlap each other by 2 cm or more. To seal the joints, self-adhesive tape is used, and for foil, metallized tape is used.

If the house is made of round log, then the vapor barrier layer is fixed directly on the tree, because the ventilation gap will be provided by the voids formed at the junction of the logs. If the beam has a rectangular or square cross-section, then the surface will be smooth and there will be insufficient air circulation. In this case, narrow slats 2.5 cm thick are placed on the logs in increments of about a meter, and a vapor barrier material is fixed onto them with a stapler.

After the vapor barrier layer, a timber frame is laid into which insulation is laid, then waterproofing and external finishing.

If funds allow, you can buy a material that will be both a vapor barrier and insulation. These are foil polymers, i.e. foamed polyprofen, penophone, etc., or fiberglass, which is sprayed with foil on one side. Such materials are especially popular when insulating baths. Remember which side to lay the vapor barrier with such coatings: foil to the sheathing or logs, insulation to the outside.

When insulating with foil polymers, the foil should “look” into the building

Vapor barrier device for internal insulation of a house

If the owner plans to hide the walls of a wooden house under interior decoration, then he can lay insulation from the inside. Although this option causes a lot of controversy and is considered less successful for wooden buildings, rather than external insulation.

Let's consider why a vapor barrier is needed for internal insulation, and where in the wall pie it is created:

1. A waterproofing layer is applied over the log, which is needed to protect the walls from moisture from the outside. It must be secured to the sheathing to create a ventilation gap of 3-5 cm.
2. The waterproofing is fixed with a stapler, and a metal profile frame is laid on top if finishing with plasterboard is planned.
3. Insulation is laid in the gaps of the frame.
4. A vapor barrier film is laid over the insulation.
5. Plasterboard slabs are laid.

Options for vapor barrier and insulation of wooden walls of a house

As you can see, the vapor barrier separates the insulation and interior decoration. Even if you decorate a house with clapboards rather than plasterboard, a vapor barrier is needed, because wood allows steam molecules to pass through well, which means it harms the insulation.

Wooden house construction has its own specifics, so before insulating a house it is better to consult with professionals. If installed incorrectly, the wall pie will quickly destroy even the most resistant wood.

When building a house, a special place is occupied by the stage of protecting walls from moisture and steam. It is absolutely necessary to do this, because dampness can cause harmful fungus and mold to appear. To prevent this from happening, it is necessary to perform high-quality vapor barrier. We will consider below what materials are used for this.

The main task performed by the vapor barrier of walls is to prevent the accumulation of moisture in the insulation. Materials that allow air to pass through well are used to construct the thermal insulation layer. If moisture gets into the insulation and accumulates there, the insulation layer ceases to perform its functions. In places where moisture accumulates, wallpaper peels off the walls over time, the plaster coating deteriorates, and fungus and mold appear. In the future, mold and mildew can spread throughout all the walls. It is very difficult to get them out later. In addition, fungal spores are harmful to human health.

Vapor barrier prevents moisture accumulation in the insulation

The installation of a vapor barrier layer is carried out in several cases:

1. 1. When insulating indoors. This is especially important if the thermal insulation is made of materials based on cotton wool. Glass wool and mineral wool are excellent thermal insulators; in addition, they allow the walls to “breathe” by allowing air to pass through. Their main drawback is that they absorb moisture. The more it accumulates, the worse these materials retain heat and the faster they become unusable. This can be avoided if the walls are vapor-proofed.
2. 2. For buildings with wall structures made of several layers. Multi-layering requires mandatory protection from evaporation and moisture. This is true for houses from frame structures.
3. 3. For external walls and ventilated facades. In this case, the vapor barrier serves additional protection from the wind. Its presence prevents air flows from actively circulating. Thereby exterior decoration experiences less stress and performs its functions better.

Vapor barrier materials must allow air to pass through well

For vapor barriers, materials are used that prevent the penetration of moisture, but at the same time allow air to enter the premises through micropores. So that there is a vapor barrier maximum effect, it is necessary to arrange a ventilation system, since natural circulation there won't be enough air. Together with high-quality ventilation, a layer of vapor barrier materials will protect the room from dampness. However, there are no universal vapor barriers that can protect any structure from the roof to the basement. Their choice depends on the material and design of the walls. If the humidity level in the room is normal, then there is no need for a vapor barrier layer.

Several types of materials are used to protect walls from damp vapors. Firstly, these are mastics. Such materials are applied directly to the surface of the wall, creating a layer that not only effectively protects against moisture penetration, but also allows the walls to “breathe”. Mastic is applied to the walls before construction finishing layer finishing with decorative materials.

Mastic is applied to the surface before finishing

Polyethylene film with a thickness of less than 0.1 mm is also used. This is one of the frequently used vapor barrier options. When installing a layer, do not stretch the film too much so that it does not tear. The disadvantage of conventional film is that it does not have perforations and therefore does not allow air to pass through at all. But now the industry has begun to produce perforated polyethylene, which is breathable, which allows you to create a comfortable microclimate in your place of residence.

The most profitable option is membrane film. It is similar to its polyethylene counterpart, but has several layers that effectively retain moisture while allowing sufficient air to pass through. Due to their performance properties, membrane-type films provide maximum functionality of the heat insulator. When using them, the walls will not freeze or collapse, which extends the life of the entire building.

The most profitable vapor barrier option is membrane film

Membrane films are produced various types.In each specific case, you can select a vapor barrier that will demonstrate its properties most effectively during operation:

• When insulating the walls outside the building, Izospan with additives that increase fire safety, Megaizol A, Megaizol SD, is laid on top of the heat insulator.
• For internal use"Megaizol B" is used - this is a polypropylene film made of two layers with an anti-condensation surface.
• For buildings with wet rooms, for example, baths and saunas, the vapor barrier of which is subject to special requirements high requirements, steam and waterproofing materials type "Izospan". Distinctive feature these materials – the presence of a reflective layer.

All polypropylene films should be reinforced with fiberglass.

Construction of a vapor barrier layer - learning the procedure

To properly perform a vapor barrier, you need to know that it is performed differently outside and inside the building. is carried out from the inside, so the vapor barrier is also laid with inside. On the ground floors and in the basement, the vapor barrier layer is installed from the outside. In swimming pools, vapor barrier is required on both sides; the installation technology is the same as for the basement floor.

Before thermal insulation works the ground floor should be prepared work surface. It should be cleaned first, then applied protective covering. More complex in terms of application technology is liquid rubber, as it requires the use of special equipment. The material consists of two mixtures, which, after mixing, instantly polymerize. Therefore, the solution is prepared immediately before use and applied using a two-torch gun that sprays liquids under pressure.

When installing a protective layer against water vapor with bitumen, the following steps are performed:

• The first layer is applied with mastic, which acts as a primer;
• Then bituminous materials in the form of rolls or mastic are applied in two layers.

For structures located above the basement and ground floor, vapor barrier of walls is carried out indoors. When installing internal vapor barrier, a number of rules should be followed:

• first you need to install the sheathing;
• a heat insulator is placed in the sheathing;
• then the film is laid, and if it has a reflective surface, then the reflector should be turned inward;
• for tightness, the joints are glued;
• for polypropylene, a counter-lattice is installed;
• on final stage finishing is being done.

When installing a protective layer from moisture and steam, it is advisable to leave free space for air movement and removal of excess moisture.

Features of the technology for vapor barrier installation of frame and wooden buildings

In a house made of frame structures, insulation occupies a third of all walls, with a thickness of at least 150 mm, so it is absolutely necessary to install a vapor barrier layer. If the vapor barrier is weak, the insulation will begin to accumulate moisture, lose its thermal insulation qualities and begin to deteriorate. The vapor barrier is mounted on the frame and trim. It is attached with construction stapler. The joints are sealed with tape or lubricated with mastic.

The vapor barrier of the walls is mounted on the inside of the insulation, thus creating a gap between the layers that provides the necessary ventilation, creating an optimal microclimate in the room.

For wooden buildings, vapor barrier is also necessary. But it doesn’t happen right away. The fact is that when constructing houses from timber and logs, the fact is taken into account that the wood is dried to a certain extent even before construction, and it finally dries out during further use finished house. It is not recommended to perform a vapor barrier until wooden structures are completely dry.

In a wooden house, vapor barrier for walls can be internal or external. At external thermal insulation the vapor barrier is overlapped. The joints are sealed with tape. Next, a thermal insulation layer is installed, which must be protected with a waterproofing material. At the final stage, external finishing is performed.

If thermal insulation is carried out indoors, then the sheathing is first installed. It serves as the basis for the installation of a waterproofing layer. Next it is mounted on the wall metallic profile, on which the heat insulator is laid. The next layer is made from vapor barrier film. The joints should be carefully sealed with tape. Finally, the interior finishing is done.

Thus, we found out why vapor barrier is needed for walls. Its main task is to create an obstacle to the penetration of moisture and protect the insulation and internal structures. If you follow the technology and use the appropriate vapor barrier, the structures will be reliably protected from dampness and the life of the structure will be extended.

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