Vapor barrier of walls - reliable protection of the house from dampness. Features of vapor barrier of a wooden building Vapor barrier film for the walls of a wooden house

One of the main tasks at each stage of construction is to protect all structural elements of the structure from direct exposure to water. Its destructive power can negatively affect any building material. But there is another, 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 thermal insulation 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 become wet, 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 is similar to the previous one – structures with internal insulation.
For ventilated facades and external walls, the vapor barrier layer plays a windproof role. The vapor barrier measures and softens the flow of outside air, protects the outer insulation from overload and provides it 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.

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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 insulating 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. When installing, it must be handled carefully, without pulling too much, so that the film does not break during seasonal changes. 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 have a similar appearance to polyethylene film, but are fundamentally 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 only retain 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. The membranes have a certain vapor permeability that is correct to ensure normal operation of the insulation. 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 for protection purposes external walls structures made of timber, panel, frame, combined structures 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, 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 residence and is 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 permanent residences 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

Vapor permeability wooden walls significantly exceeds the similar characteristic of walls made of brick or stone materials and depends on the thickness of the logs or beams, the tightness of the grooves, and the presence of cracks.

Glued laminated timber used for the construction of walls is dried in production conditions to a low level of humidity, has grooves for compaction, 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, interior decoration cannot be carried out in the house, 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:

Installation of vapor barrier for walls in structures for various purposes, 2.9 out of 5 based on 30 ratings

High-quality vapor barrier for walls wooden house absolutely necessary. Global and domestic manufacturers building material offer a huge number of types of materials with extremely high quality for vapor barriers. How not to get confused in such a wide range and choose exactly what you need - recommendations from construction technology experts.

Why is vapor barrier needed?

Why is a vapor barrier needed? wooden house? The answer is simple and clear: only thanks to the vapor barrier in frame house you can create the ideal atmosphere in the room, i.e. optimal combination of humidity and heat.

The vapor barrier device is a flat installation building elements houses an additional layer of special vapor barrier material. Depending on the purpose of the room (i.e., a residential building or an unheated outbuilding), a vapor barrier layer can be laid from the inside of the building or from the outside of the walls.

Is a vapor barrier necessary to ensure longer operation of the building? Absolutely yes! Natural processes of human life, as well as external natural phenomena, lead to an increase in air humidity in the house.

This moisture penetrates either through the interior decoration of the walls of the room (wallpaper, plaster, etc.), or from the street into the house (for example, during periods of precipitation, drop in temperature, etc.) and is retained by the wooden sheet from which the house is built. Excess condensation accumulates on the surface of the wood, which leads to irreversible consequences: rotting of the wood, the development of fungal microorganisms there, etc.
The use of vapor barrier neutralizes all of the above factors. Operation without vapor barrier wooden log house will be no more than 50 years, and if the vapor barrier from inside and outside the house is done efficiently and in accordance with all construction and repair rules, the house will last for centuries!
Another purpose of thermal vapor barrier is to preserve the insulation of the house. A special material that is highly porous and perfectly absorbs moisture, which leads to its weight and gradual deterioration. Vapor barrier utafol, rockwool or other analogues do not allow air masses with a high vapor content to reach the insulation, which ensures its safety and normal temperature and climate conditions in the room.

Pros and cons of vapor barrier

The properties of vapor barrier materials are different: there are advantages, but there are also disadvantages.

The undeniable benefits of vapor barrier of premises include:

A layer of vapor barrier in a frame house will become an additional insulation for the walls, and will also protect the insulation itself (mineral, basalt wool, etc.) from moisture accumulation and destruction;
Covering the attic, roof or walls of a house with a hydro vapor barrier is an excellent fire-fighting agent;
Internal and external installation vapor barrier not only significantly extends the service life of the building, but also carefully takes care of the health of the residents of the house. Installing a vapor barrier on the walls of a wooden house utilizes excess moisture, which means it prevents the development of mold and fungus on wood, which are considered the most dangerous provocateurs of allergies, upper respiratory tract diseases, etc.

The only disadvantage of vapor barrier in a frame house can be considered that this gasket material has many types, the characteristics of which are very different. For example, Izospan vapor barrier, which has a warranty of more than 50 years, can completely correct the fragility of operation and the low technical strength of a water vapor barrier made from a conventional film.

Which side to lay the vapor barrier on?

To understand how to properly install a vapor barrier, you need to know some of the features of this material. Almost always (with the exception of polyethylene film) vapor barrier material is produced in the form of a multilayer one.

Each layer is responsible for implementing certain tasks: either retaining moisture and evaporating, or blocking the access of moisture to the main building materials of the house (frame, insulation, etc.). This is why it is important to consider which side to lay the material when installing a vapor barrier.

Good vapor barrier materials are vapor condensate film (a combination of viscose and cellulose) and a membrane (double-sided diffusion). The sides of such a vapor barrier: one is perfectly smooth, the other is rough. It is clear that the installation is carried out with the rough side towards the direction of moisture entry (i.e. when finishing the attic interior: the rough side into the house, and the smooth side towards the street; or for working on the facade of the house - vice versa).
If a foil vapor barrier is used, the purpose of which is to reflect heat flows, then such a reflective vapor barrier has a metallized layer, which must be placed in the direction of the flow of heat rays.

Which side should the vapor barrier be laid?

Types and types of vapor barrier

When choosing a specific material to implement vapor barrier tasks, you should answer the following questions::

Where do you plan to lay it? this material? This can be the roof, walls, floor and ceiling of the attic, exterior decoration of the house, as well as for a barn, bathhouse, summer kitchen, garage, etc.
Special purpose? The purpose of use can be either simply for moisture insulation (from the inside or outside?), or for additional wind and heat insulation.
Price? The price indicator of vapor barrier materials is designed for any budget, and choose accessible view everyone can do it.

Film

This vapor barrier product is the most inexpensive, but also the most short-lived. Easily damaged by mechanical stress and low temperatures. Absolutely does not allow moisture to pass through, i.e. isolates building materials from damage by moisture, but, at the same time, prevents the slightest air exchange.

The modern manufacturer produces different kinds films: single-layer, double-layer, and also different in thickness and density. There is a view waterproofing films, which cannot be used at all instead of vapor barrier: they allow steam to pass through perfectly, but retain water.
A vapor barrier for a bathhouse can be equipped with a steam-condensate film, which will evaporate (return) the steam back into the room. Good choice for a bath - this is a foil film type that will allow you to hold high temperature in the bathhouse, reflecting heat rays back into the room.

Membrane

Diffusion (or vapor barrier), vapor diffusion, and superdiffusion membranes are created from polymer film and non-woven polypropylene. The last two types are only waterproofing agents, and only the diffusion membrane has the ability to provide vapor and moisture insulation.

Vapor barrier for windows in the form synthetic fabric diffusion membrane is characterized:

Excellent ability to pass air but retain steam;
The product is environmentally friendly;
It has high practicality due to long-term wear of the material.

The membrane can be single-sided or double-sided. Depending on this feature, installation will differ:

A vapor barrier for a flat roof or other part of the house with a one-sided membrane must necessarily take into account how to properly attach such material (i.e. which side to turn it towards the insulation). Simple advice: smooth side must be pressed against the insulation, because There is absolutely no steam passing through it.
When vapor barrier work for the attic is performed with a double-sided membrane, then choosing the correct side of installation is not important: this material will work in any case.

The only disadvantages of the membrane include the rather high cost of this material, although the long service life and ease of installation can confidently compensate for such issues.

Polymer varnishes

Many masters include special positive indicators of using this type:

Speed and ease of work execution. Here the question will not arise: how to install vapor insulation from polymer paints and varnishes. The substance is applied to the surface in several layers and dries.
Polymer varnishes belong to the category of low-flammability and extremely resistant to acids and alkalis, as well as to UV irradiation;
100% inert to the penetration of steam and moisture.

Coating vapor barrier is ideal for protecting windows, doors, walls, roofing and other wooden structures from steam and moisture. The thickness of the paint layer determines the duration of the repair-free condition.

Roll materials

Some types of roll materials with vapor insulation function have already been described above - these are films and membranes based on polyethylene or polypropylene. It’s easy to understand how vapor barrier with roll materials differs from other types. Installation technology: in order to properly attach the vapor barrier in a roll, a sheathing design for the vapor barrier is required.

Materials in rolls are much easier to install on the surface and guarantee a more thorough seal. They are especially convenient to use for steam and thermal insulation of the roof (especially in the absence of insulation).

For example, a special type of combined material made of polypropylene or lavsan spunbond, laminated with a melt of polyethylene or polypropylene, is perfect solution for arranging cold roofs.

Installation technology

The selected type of vapor barrier material also determines the features of its installation technology.

If it is polyethylene or polypropylene in in roll form, then you can fix this material on the surface of the wooden (metal) frame with which the insulation on the ceiling/walls is sheathed using small nails with wide heads, staples or a construction stapler. Thin ones can be used wooden slats(or cardboard strips) that should be used to press the film against the frame slats.
The edges of the material overlap each other by 10-15 cm.
Foil or regular adhesive tape for vapor barrier runs across the joints of the vapor barrier material. Vapor barriers from rockwool, tyvek or another brand are accompanied by special recommendations to use only vapor barrier tape from these companies to secure joints.
For better sealing vapor barrier material, edges adjacent to door or window openings, to corners, ceilings, floors or places with complex terrain should also be taped.

Step-by-step DIY instructions

The installation diagram is simple and clear:

Decide on the choice of vapor barrier material and calculate the required quantity;

Mount a frame from wooden beams or metal profiles;

Determine exactly which side the material should be mounted to the surface;

Slowly and carefully attach the vapor barrier material to the prepared frame.

The final stage of vapor barrier repair will be the arrangement appearance surfaces.

Laying vapor barrier inside

From the middle of the room, the material is laid with the smooth side facing the insulation, and the rough side on the side of the room. Why should a vapor barrier in the form of a rolled polypropylene film or membrane be laid exactly this way: so that steam from the house does not penetrate the wooden walls and destroy them. And also to prevent heat from leaving the house along with the steam. In this way, the roof, walls, and ceilings are insulated/vapor-insulated.

On top of the steam insulator in the room they make finishing surfaces:

Primer;
Whitewash;
Wallpapering, painting or other interior decoration options.

Laying vapor barrier outside

A popular option for vapor barrier work on the outside of the house is vapor barrier materials under the siding. There are quite a lot of varieties of siding - for every taste. These are plastic, wooden, polymer panels, etc.

You can combine façade insulation with wind, steam and moisture insulation using penoplex vapor barrier, i.e. using extruded polystyrene foam.
If the choice fell on a vapor barrier film type, then it is worth considering that this material should be mounted with a rough (porous) surface to the insulation, and a smooth surface to the street. Film materials are also overlapped by more than 10 cm.
All holes formed during installation, as well as the joints and edges of the canvas, are taped with tape. The top layer of the house facade is a vapor barrier layer made on top exterior decoration walls

Manufacturers

In construction and repair companies specializing in work with vapor barrier materials, positive reviews characterized by vapor barrier rockwool, TechnoNIKOL, Izospan and Tyvek, Delta. These are materials from leading companies in the global building materials market, which have proven themselves to be of high quality, wide variety and affordable cost of their products.

A special word should be said about the axton vapor barrier: it is a diffusion membrane with excellent vapor permeability, wind and heat insulation. An analogue of such recognized types as vapor barrier Izospan or rockwool. Ideal for isolating steam and moisture from the attic, roof, etc.

Almost every manufacturer, in addition to a chic variety of products, also produces vapor barrier tape.

Insulation and vapor barrier of walls outside a wooden house, finishing with siding

The most important stage in the insulation of any structure is the vapor barrier of the walls. Why is it needed, what functions does it perform, and why is it impossible to do without it in most cases? Amazing fact: in the course of normal life activities, a family of three allocates environment about 150 liters of water in the form of steam. This volume is enough for a large, nice bay of neighbors! Meanwhile, all this moisture does not go down, but rises up and to the sides and tries to naturally leave the room through the walls and ceiling.

Wood is a very porous material that allows air to pass through and absorbs moisture. Imagine that it is now about -15° “overboard”. The house is warm. You breathe, cook borscht for lunch, do laundry, and take a hot bath in the evening. All this leads to the formation of water vapor. Moisture is absorbed into the walls and tries to come out. Somewhere in the thickness of the wall - closer to the outer or inner surface(this depends on the thickness of the walls and the quality of the insulation) - there is a “dew point”: the boundary at which water vapor turns into water.

This water freezes (it’s cold outside!), as a result of which several very undesirable processes occur at once:

Dampness of the wall and/or insulation.
Freezing of walls due to moisture trapped inside turning into ice.
Gradual destruction of the wall structure.
The appearance of fungus and mold.

Vapor barrier of the walls of a wooden house helps to avoid all this.

In extreme weather conditions, some water may get under the cover. Therefore, when building a house, ventilation gaps are made and a vapor barrier film is installed.

Installation of external and internal vapor barrier

In our climatic conditions, insulating the walls of houses is a necessity: to ensure comfortable temperature indoors in winter, without spending astronomical sums on heating, you have to use the benefits of civilization in the form of insulating materials. In order for them to work efficiently, it is necessary to vapor barrier the walls of a wooden house from the outside or from the inside - it depends on where the insulation is located. If moisture gets into the heat-insulating layer, it will significantly increase its thermal conductivity, which means heat loss and reduce the service life of the insulation - vapor barrier allows you to avoid this.

Vapor barrier films are made using the weaving method. Consists of a polypropylene base coated with laminite on one or both sides

How to insulate wooden walls from the outside

Insulated walls are a multi-layer structure. Its base is the walls of the house. A sheathing of wooden blocks is attached to them, between which insulation slabs are laid - stone, basalt wool. Then a vapor barrier film is attached over them, which is pressed against the sheathing with slats. Mounted on them facing material– lining, siding, etc. As a result, an air gap is formed between the vapor barrier and the cladding. It is necessary so that moisture, condensing on the vapor barrier, gradually evaporates without getting inside the structure and without moistening the lining.

Another version of the same design provides an additional layer of wind-waterproofing, which is located immediately on the wall of the house, between it and the insulation. This prevents the insulation from getting wet vapors into the insulation from inside the house.

Scheme of vapor barrier device and insulation of the house from the outside

Vapor barrier of walls from the inside

In this case, the work is carried out in a similar way. The layers of materials are arranged in the following order:

House wall.
Frame bars, between which insulation boards are laid.
Vapor barrier membrane pressed to the frame with slats.
Wall cladding - plasterboard, lining, which are attached to slats.

The sheets are attached to each other using a stapler, then the vapor barrier is secured with pre-antiseptic 4x5 cm slats

Vapor barrier of frame house walls

Frame houses They differ in that they do not have a rigid base for insulation - a wall. It is located between the racks of the timber frame. In such houses, the cross-section of the walls looks like this:

External cladding (OSB boards, siding, lining, block house).
Hydro-wind protection is a membrane that protects the insulation from moisture from the outside. A ventilation gap is required between it and the outer cladding, thanks to which moisture that gets on the membrane gradually evaporates from the surface due to natural ventilation.
The frame of a house with insulation embedded in it.
Vapor barrier membrane. It is necessary to install vapor barriers on walls using the rough side of the insulation film.
Lathing.
Interior decoration walls

Since 70% of the volume of frame walls is insulation, its protection from moisture is very important. Otherwise, it loses its properties, crumples and moves away from the frame, cracks appear, and the house freezes.

During construction frame houses It is mandatory to use wind protection and vapor barriers

Features of laying vapor barrier on walls

Manufacturers offer different types vapor barrier materials. The most modern and high-tech of them are vapor barrier membranes. They are made from polypropylene, with a fiberglass mesh base that gives the material strength. One or both sides of the film have a special coating that is rough to the touch. This is a layer of cellulose-viscose fibers that absorb moisture well. When it gets on the surface of the membrane, it lingers in the rough layer, without passing further and without getting into the insulation and the thickness of the walls. This moisture is then evaporated through natural ventilation. Vapor barrier materials with a metallized coating on one side are also produced. It serves to reflect thermal energy into the room, thereby reducing heat loss.

Important: the foil surface should be facing away from the insulation, towards the room.

Foil vapor barrier not only retains moisture, but also retains heat

Installation of the vapor barrier membrane on the wall is done in horizontal stripes, starting from the floor. At the joints of the strips, it is necessary to overlap them with each other by at least 10 cm. The joints are glued with a special connecting tape, which gives hermetic connection. The junctions of the film with wooden or stone surfaces must also be carefully glued, achieving complete tightness. The membranes are attached to the wooden frame using a construction stapler or galvanized nails.

Laying vapor barrier on walls in a wooden house

Of course, vapor barrier of walls with your own hands is quite feasible. True, it is quite difficult for a non-specialist to carry out the entire complex of work on wall insulation: mistakes when using high-tech modern materials are fraught with serious troubles. To new house did not require urgent repairs, it is much safer to turn to the services of professional builders.

When building a house, one of the main tasks is to ensure reliable protection of the structure from interaction with water, which has a destructive effect on any building material. Other factors that negatively 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, when building houses, a layer of vapor barrier is laid.

Why do you need a vapor barrier?

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

During their operation, steam is constantly generated in them, which must somehow escape from the room. Therefore, it settles on the walls and ceiling. With prolonged exposure to steam on these surfaces, the destruction of building structures occurs, which negatively affects the condition 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 bathhouses and basements, vapor barrier of surfaces in interior spaces should also be carried out in cases where 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 a house, one starts mainly from the elements that make up the structure of the wall structure.

When is it necessary to install vapor barrier on walls?

In some cases, you simply cannot 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 vapor to pass through. Membrane materials, currently used when performing work on steam protection, ensure the passage of air in a minimum amount, which completely eliminates the likelihood 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. Steam protection materials have an internal “coat” that redirects moist air 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. Carrying out installation work When using it, it should be handled with particular care. The insulator must be fastened so that it is not too stretched, otherwise the film will simply tear when the climatic conditions change again. If polyethylene without perforation is used during vapor barrier work on the walls of a house, it will become reliable protection not only from steam, but also from air. And in this case about comfortable conditions when 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, which were developed specifically for these purposes. Using them during work from inside the building, the material will retain moisture and allow air to pass through. Note that work on applying mastic to the surfaces of walls and ceilings is carried out before finishing them;
new materials for vapor barriers are membrane films. Their appearance on the market happened some time ago. In a short period of time, this material has become in demand and is currently actively used for vapor barrier work on walls. 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 normal operation of the heat insulator. The use of membrane materials to protect walls prevents the cotton insulation from getting wet. It does not lose its integrity and can perform its functions for a long time.

Common brands of membrane materials

Currently, vapor barrier materials are presented in a wide range. Moreover, each of them is intended for a specific area of use.

Vapor-proof materials installed outside

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

When using them, it is extremely important to ensure tight membrane fit to the insulation. Therefore, these materials should be securely secured during work. There should be no sagging or loose areas. Otherwise, in case of strong winds, rare gusts will occur.

Materials for installation indoors

When the task is to perform a vapor barrier on walls and ceilings from the inside of a wooden house, “Megaizol V” is used. It is a polypropylene film, which consists of two layers. On outside This material has an anti-condensation surface. The use of this material in winter ensures its protection from phenomena such as condensation and fungus. In addition, its use eliminates the destruction of wall structure elements. This material also protects the room from insulation particles. 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 install a vapor barrier in rooms where special requirements are imposed on this procedure. For example, these could be saunas or baths.

Rules for vapor barrier of frame walls

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

If ecowool or polystyrene foam is used in frame buildings as insulation, and an effective ventilation system is installed in the house itself, then you can refuse to install a vapor barrier. 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 a membrane onto the wall frame post elements. After laying the film, surface finishing work is carried out. The material can be plasterboard or lining. 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. When using such a vapor barrier scheme for the walls of a house, it is necessary to arrange and effective system ventilation.
the second scheme involves installing a sheathing on top of the laid vapor barrier membrane, 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, increased humidity occurs in the premises of a wooden house and the structures need effective protection from steam.

Vapor barrier of wooden house walls

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 buildings, you should based on the thickness of the timber, tightness of grooves, presence of cracks in the wall material.

A popular material for the construction of wooden houses is laminated veneer lumber. During its manufacturing process, the wood is dried in special chambers. The result is low humidity levels finished material. It has grooves that provide a seal. The material is characterized by low shrinkage, so it enters the insulation in limited quantities.

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

wait for the wood to dry;
Perform a vapor barrier on 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 must be used modern materials High Quality. If you want to live in your home in comfortable conditions, then vapor barrier should become a mandatory procedure for you. It will provide protection from steam. The house will be reliably protected from moisture and will last a long time.

The design of the walls of a wooden house always involves the creation of several layers, one of which serves as a vapor barrier - it prevents moisture entering the wall from the room from destroying the insulation material.

Why is a vapor barrier needed?

For the walls of a wooden house, a layer of vapor barrier (also called waterproofing) is necessary in almost all cases. The reason is in the characteristics of wood as a building material: it allows air to pass through well, but at the same time absorbs a lot of moisture, which is why it swells. If timely measures are not taken, this can lead to negative consequences:

walls will begin to curve or heave;
the structure of the house will inevitably begin to sag due to increased wood density;
finishing materials (lining, drywall and others), as well as wall coverings (wallpaper, MDF, PVC) can be damaged due to wall movement;
mold may grow in thick walls and corners, which will create bad smell in the house;
if water freezes during the winter cold, it will increase in volume, which will cause cracks and microcracks in the wood to increase, and the material will wear out faster;
an increase in cracks also has another negative effect - over the years, the walls will freeze much faster, which is why you have to spend more resources on heating the room;
finally, when moisture is absorbed into the insulation material, this quickly leads to its softening and deterioration - eventually you will have to dismantle the wall and install a new layer.

All these consequences can be easily avoided if, after completion of construction, a vapor barrier layer is laid, which follows immediately after the finishing material (for example, lining) and is tightly adjacent to the insulation, as shown in the diagram.

NOTE. Sometimes a vapor barrier layer is understood as a material that does not allow moisture to pass through, but allows air to pass through, and waterproofing is a material that does not allow either water or air to pass through. In a practical sense, the words are often used as two synonyms.

Is it possible to do without vapor barrier walls?

This option is, in principle, possible if the walls of the house are made of rounded or laminated veneer lumber, which is thoroughly dried during production. In addition, all the dimensions of the grooves where the logs will fall are calculated to the nearest millimeters, which ensures their tightest contact with each other.

But even in such cases, it is impossible to give a firm guarantee that moisture will not penetrate the tree, since the following risks remain:

Wood as a material has its own specifics - it is porous, fibrous, and serves as a breeding ground for the development of microorganisms.
Protective varnish treatment works well during the first 5-10 years, but over time it tends to disappear - accordingly, after this period, moisture can gradually begin to penetrate into the wood.
Finally, if it is assumed permanent residence in a wooden house, it is best to take care of a vapor barrier to protect its walls - the constant action of moisture coming from the kitchen, bath, aquarium and other household sources will make itself felt over several years.
To house a bathhouse, a layer of vapor barrier is, for obvious reasons, necessary in any case.

If the house is located in a humid coastal climate, then waterproofing is absolutely necessary measure: It is done both from the inside and from the outside.

Approximate calculations show that in 1 year an ordinary family consisting of 3 people (two adults and a child) releases 150 liters of moisture into the air.

Vapor barrier materials: types, selection rules and prices

Modern industry offers many types of materials for waterproofing. Almost all of them are artificial polymers, because natural fibers always absorb moisture well and allow it to pass in both directions.

The main indicator of the quality of such products is vapor permeability, which is defined as the amount of water (in grams) that a unit area of the material will let through (1 square meter) for one day: g/m2. Normal vapor permeability does not exceed 15-20 g/m2.

From the point of view of advantages and disadvantages, the material is judged on the basis of the following consumer qualities:

life time;
mechanical strength;
ability to pass air, i.e. “breathe” while retaining moisture.

Many waterproofing materials have low air permeability, which creates Greenhouse effect– you have to constantly ventilate the room, including in the cold winter.

A comparison of the pros and cons of the most common materials is presented in the table (price - in rubles for 1 roll, the total area of which is standard 70 m2). In the case of a vapor barrier membrane, the average cost is given for a roll with dimensions of 75 by 1 meter (area 75 m2).

material	pros	minuses	price
single-layer polyethylene films	affordable price, easy installation	low mechanical strength, insufficient vapor barrier	1000
reinforced (double-layer) polyethylene film	affordable price, high strength	create a greenhouse effect	1400
polypropylene film	high strength and long service life	create a greenhouse effect	1300
vapor barrier membranes	long service life, good vapor barrier, high strength and good ventilation properties	high price	6500
isospan (reinforced polypropylene film)	high strength and long service life, good protective qualities	Greenhouse effect	1200

If you make small holes in a polyethylene or propylene film, this will not provide enough air - the walls must “breathe” the entire surface. In addition, warm air currents will penetrate into these cracks along with the moisture evaporated into them. Therefore, such a vapor barrier will not give the desired effect.

Types of vapor barrier membranes

From point of view consumer properties materials for waterproofing the walls of a wooden house can be divided into membranes and all others. The reason is that membranes are a new generation material, different from traditional artificial polymers (polyethylene and polypropylene).

Their key advantages are as follows:

allow moisture to pass through in an amount of no more than 10 g/m2 per day (they are especially often used in baths, saunas, and swimming pools);
thanks to the porous structure, they retain condensation well, preventing it from penetrating into the insulation;
withstand temperature changes from –40°C to +80°C;
thanks to the reinforced structure, the fibers are able to work without wear for decades;
the porous structure of the material ensures sufficient gas exchange between the room and the environment;
Some membranes are reinforced with foil, which reflects heat coming from the house - thanks to this, it helps the insulation maintain the internal temperature in the room in winter.

Thus, from the point of view of their functions, all membranes are divided into:

They are much more expensive on the market and are mainly sold in rolls of 75 m2. Comparative prices in rubles indicating the roll dimensions are presented in the table.

The main manufacturers of high-quality membrane films are German brands. High prices pay off if major finishing of the house is planned, because if you do the calculation, then frequent replacement insulation and laying a new vapor barrier layer will become more expensive than the initial selection and installation of high-quality material.

Types of vapor barrier materials for a wooden house

Depending on the location of the material in one or another part of the house, the following are distinguished:

type A and AM - protection of insulation in walls and roofs from external influences;
type B and C – protection of insulation in walls and roofs from internal moisture;
type D – protection of the floor from dampness coming from the ground.

Type A

The materials of this group are intended for external insulation of the walls and ceiling (roof) of the house from the action of wind and air moisture. Installed:

under external finishing walls with insulation;
under the roof of the roof;
into ventilation shafts.

In order for the membrane to work correctly, allowing moisture to pass through from the inside and blocking it from the outside, you need to carefully lay the layers - the marked side (with the inscription of the brand and manufacturer) must “look” towards the street.

The material is installed on the counter-lattice so that excess moisture can drain off. It is important to create an appropriate angle on the roof (at least 30-35o).

Type AM

At the place of installation, this material is mounted in the same way as type A. It has a more complex multi-layer structure:

layers of spunbond (1-2);
diffuse film.

It is thanks to the diffuse film that steam escapes from the inside, but liquid does not pass through from the outside. Important Feature of this material - it does not need a ventilation gap, so it is mounted close to the surface of the insulation.

Spunbond refers to a special technology for the production of polymer moisture-proof film, as well as the product itself of this production. In this case, the fiber consists of artificial threads, which are stitched together under the influence chemical substances, heat or using water jets.

The result is a very durable porous fiber that allows air and moisture to pass through well, but at the same time reliably protects not only from precipitation, but also from the effects of wind. All these valuable properties are explained by the structural features of the multilayer material.

Type B

This vapor barrier is used to protect the walls of a wooden house from internal moisture. It is also used for finishing the roof from the inside, especially in cases where it is intended to create a living space in the attic with the possibility of year-round living (like an attic).

And one more use case - internal insulation floor, as well as interfloor ceilings.

Multilayer materials additionally protect from wind, and foil materials retain heat inside by reflecting it from its surface.

Type C

It is a particularly durable membrane consisting of 2 layers. It is used in the same cases as B. It is also used for insulation in unheated rooms, adjacent directly to the house:

attics;
basements;
plinths;
verandas, canopy.

Such materials are made of polypropylene and reinforced with an additional laminating layer, due to which they are used in floor and roof insulation - i.e. in cases where heavy mechanical load is expected (pressure from furniture, movement and wind exposure).

Methods for fixing vapor barrier film

Materials are fixed using two methods:

construction stapler;
special tape (adhesive tape).

Often both methods are combined together. At the same time, the adhesive tapes themselves are made from approximately the same materials as the vapor barrier. They are reinforced using spunbond technology, since it is assumed that they will be subject to constant load. There are several types adhesive tapes, which correspond to the considered types of waterproofing membranes:

Do-it-yourself vapor barrier installation: step-by-step instructions

The technology for laying a vapor barrier layer into the walls of a wooden house depends on its design:

frame house;
house made of timber.

In addition, there are features of laying the material indoors and outdoors. Since in the latter case it makes sense to protect the house from cold winds, a layer is almost always installed that protects against them. And waterproofing is installed in cases where the house is quite old and the walls need to be protected from the destructive effects of moisture.

Vapor barrier from inside

When laying a layer of waterproofing inside the walls, you must take into account that water, evaporating on the surface of the material, must drain somewhere. Thus, the layer should not be in too tight contact with the insulation - a small gap is necessary.

The sequence of actions is as follows:

If the house is built from a cylindrical beam, then due to its natural rounding it creates a sufficient gap for moisture removal - in this case, the membrane is attached directly to the logs using a stapler.
Next comes the sheathing and internal finishing material (lining, drywall, etc.).
In the case of houses made of rectangular timber, as well as when installing insulation (in cold winter conditions), the membrane is attached to a counter-lattice, which is mounted to the main beam through small wooden beams of the same size. They are located at a certain interval and hold the insulation, on top of which a vapor barrier is placed. The same technology is proposed for a frame wooden house.

A visual representation of the installation method for internal vapor barrier can be seen here.

Possible errors that are important to take into account immediately when laying the layer are presented in the video.

NOTE. The layers of material are overlapped by at least 15-20 cm and securely fastened with joints.

Vapor barrier outside

In this case, the film or membrane should lie immediately under the sheathing layer (for example, siding) and fit tightly to the insulation.

Space for the accumulation and natural removal of condensate must also be present.

The technology is as follows:

Features of the technology are shown in the video.

The external vapor barrier membrane must allow air to pass through well. The use of polyethylene, polypropylene and other films in this case is unacceptable, since the moisture leaving the house will encounter a barrier and will not be able to go outside - it will settle on the walls and insulation, which is why they will begin to rot.

Vapor barrier and insulation: what is the ratio

Since vapor barrier of walls in a wooden house is carried out mainly to protect the insulation, you should figure out in which cases this is especially necessary, and in which cases it is enough to simply cover the walls, for example, with plastic film. In this sense, there are 2 options:

If polystyrene foam, polyurethane foam and similar materials are used as insulation, then a film or membrane is not needed directly to protect them, since they do not absorb moisture.
If the house is insulated with mineral or ecowool, as well as sawdust, the membrane is extremely necessary - damp cotton wool will turn into dust in literally 1-2 years.

If the house is old and made of wooden frame or according to the design of the bulk structure, a moisture retention layer will be needed in any case to protect the wood itself.

By correctly choosing and installing a vapor barrier layer, you can not only improve the microclimate in the house, but also significantly extend the service life of the insulation and wood.