Do you need vapor barrier on walls? Why and how to vapor barrier the walls of wooden houses?


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 without problems. wooden house, 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 “traditional craftsmen” recommend making small holes in the polyethylene film and then using it to create 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 is 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 cost. 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 recently, special mastic has often been used indoors. 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 until optimal performance humidity. 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 the steam from the premises goes to 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 that 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 and walls directly.

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. For such people, it is better to use the third method of vapor barrier, which involves installing a 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 on the walls interior decoration, it is 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 carried out by installing vapor barrier membrane 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.

Vapor barrier is one of the most important stages building a house made of wood. It protects building materials from exposure to steam, deformation, as well as the occurrence of fungus and mold.

Vapor barrier: necessary or not

A steam protection device is required if:

  1. If the base is insulated from the inside with mineral wool. This is due to the fact that moisture negatively affects the properties this insulation. To do this inside the building.
  2. Frame houses, the walls of which consist of more than one layer.
  3. If brick walls insulated from the outside with mineral wool and. In this case, the vapor barrier will perform a windproof function, which protects the walls of the house from strong blowing. The ventilation gap removes excess moisture from the windproof layer.
  4. For external walls located in close proximity to the foundation, where condensation forms most actively.
  5. Walls made of logs or timber with natural moisture. Drying of such timber is carried out directly in the clearing, and the tree reaches optimal humidity no earlier than after 5 years. The maximum degree of moisture content changes during the first year, so the beams are erected under the roof and left to dry for at least a year.

From which the walls of a house are erected, it is dried to low humidity at the stage of its production, it has sealing grooves, slight variations in size, and also slight shrinkage.

The material is impermeable and provides optimal limitation of steam penetration into the thermal insulation layer.

Therefore, walls built from timber are a good vapor barrier. Often they do not require additional protection.

Laying a vapor barrier for a wooden house can be done a year after its construction. This allows you to preserve thermal insulation and reduce the level of vapor passage.

It is not recommended to install a vapor barrier on both sides; this prevents the natural drying of the wood.

Vapor barrier of external walls

Steam insulation can be done in several ways, depending on the type of log used:

  1. When constructing the walls of a house from round log the insulation layer is attached directly to the tree using construction stapler. Ventilation gaps in in this case are not required, it will be provided by the voids formed at the junction of the beams.
  2. If the beam has a rectangular or square section, the surface is smooth and air movement is insufficient. Then planks 2.5 cm thick are stuffed onto the logs with a step between them of 1 meter. Vapor barrier material is laid on the completed sheathing and secured with a stapler.


To provide vapor barrier, the following materials can be used:

  1. Ordinary polyethylene film. It should be noted that this material is not very effective; its main drawback is the formation of a greenhouse effect; it does not allow moisture or air to pass through. Some experts advise perforating the film with your own hands, that is, making many small holes on the roller on which nails are mounted. However, this option is not advisable; the resulting pores conduct moisture in two directions, and accordingly it will not be possible to provide membrane insulation from steam. The cost of the film depends on the manufacturer and ranges from 500 to 1100 hryvnia.
  2. Membrane films. This material is capable of allowing air to pass through while retaining moisture. There are three types of membranes: diffusion, superdiffusion and three-layer. The films are made according to a two-layer principle, one of which provides protection from steam from the outside, the second helps the penetration of steam from the insulation into the interior of the house. The quality of the film depends on the vapor permeability index; the higher it is, the better. The price of membranes ranges on average from 750 to 4,500 rubles per roll.
  3. Mastic. The material is intended for application to the base before finishing work. The cost varies from 32 to 92 rubles per 1 liter.

Let's look at how to properly install a vapor barrier on the outside of the walls of a house.

It is not recommended to lay a vapor barrier directly on the outer surface of a wooden wall.

Wood base compared to brick or concrete wall, has strong thermal resistance, which can be compared with the heat transfer resistance of the thermal insulation layer.

The redistribution of temperatures and moisture content in the insulated base layer may be such that on the inside of the film the temperature will be lower than the temperature necessary to cool the air so that the steam begins to condense into dew. This promotes the formation of condensation on the inside of the insulator and moistening the wall.

As a result, a ventilation gap of up to 5 cm is required along the line of the base and the film, thanks to which the temperature in the room is set equal to the room temperature, that is, exceeding the dew point.

To remove the resulting moisture, it is necessary to install special channels near the foundation and eaves of the house.

Vapor barrier of walls from inside a wooden house


Vapor permeability wooden base largely depends on the tightness of the sealing of seams, grooves, as well as the absence of cracks in the wood.

Therefore, the walls of a wooden house often require auxiliary protection– installation of a vapor barrier layer during their insulation.

Vapor barrier can be done by inner surface tree, but such a solution would not be entirely correct. The best option - installation of sheathing, which will subsequently serve as a frame for the internal cladding.

To do this, wooden planks are placed on the base surface in a vertical direction, which are leveled (wedges are placed along the depressions, and the material is removed on the protrusions). First, the outer slats are set, along which the intermediate slats are aligned using a thread.

The insulating material is stretched onto the sheathing from the bottom up and secured using a construction stapler.

It is necessary to lay the insulation in such a way that the matte rough side is directed inward, this reduces the formation of condensation. There is no need to stretch the film very tightly, since after a while the wood will dry out, the tension may increase and the vapor barrier will simply break.

The canvases are overlapped and glued with moisture-proof adhesive tape.

A canvas with a self-adhesive strip along the edge will help speed up the process, thanks to which the joints are reliably glued without additional costs time for their subsequent sizing.

To install a vapor barrier indoors, the following materials are used:

  • polyethylene film, the thickness of which is more than 0.1 mm;
  • membrane film;
  • mastic (excellent for plasterboard bases, the material perfectly allows air to pass through while retaining moisture);
  • aluminum foil, at least 1.02 mm thick.

The foil is laid with a reflective surface towards the air space, this ensures a decrease in the degree of heat transfer.

Estimated cost of the material (depending on the manufacturer), the price is for 1 roll:

  • aluminum foil – 800–6300 rubles;
  • connecting tape – 150–500 rubles.

For effective device vapor barrier layer must adhere to certain rules:

  1. Inside the house vapor barrier materials mounted on walls that divide the living space into zones. These areas are often insulated with mineral wool, which, accumulating moisture, loses its positive properties. Therefore, it is recommended to lay a vapor barrier on top of the insulation.
  2. It is best to secure the film on the inside of the base with wooden planks pre-treated with an antiseptic. It is laid on both sides of the partition bases. At the junction, an overlap of approximately 2.5–3 cm should form between the panels, while the edges on both sides should not coincide with each other, and the distance between them should exceed half a meter.
  3. For effective ventilation of the walls and an optimal environment, the insulation is installed with inside thermal insulation layer.
  1. Materials that prevent steam penetration often confused with waterproofing materials, therefore, when purchasing, you should pay attention to what purposes they are intended for.
  2. To ensure high-quality insulation from the vapor of the walls from the inside, it is necessary to maintain a distance from the film to the finish of at least 3 cm. This promotes free air circulation and the removal of moisture formed on the membrane.
  3. Vapor barrier material reduces wall ventilation to zero, Therefore, it is necessary to install auxiliary ventilation, such as valves on windows, fans in walls and vents.
  4. Due to the fact that certain internal claddings have their own vapor barrier, layers in the thickness of the wall should be placed so that the vapor barrier properties increase from the inside to the outside.
  5. During installation, the material must adhere tightly to thermal insulation material , firmly fixed to the components of the installation system. There should also be no loose areas or sagging.
  6. The vapor insulation must form a continuous loop with the basement and attic floors.
  7. Before installing a vapor barrier layer, it is necessary to check the surface of the base for seams and cracks and seal it with a sealant.

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

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

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

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

By the way! Treated wood building materials are usually very airtight, so they are not affected by such problems.

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

For a wooden house correct vapor barrier– this is a global issue. Walls need to be protected from moisture on both sides, that is, both outside and inside. However, complex insulation systems are not always easy to use. The vapor barrier membrane is the most best material, since it does not allow moisture to pass through and at the same time allows it to breathe.

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

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

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

Inside

Internal vapor barrier is necessary for life, so it is done right away. The process is very simple in words: insulation is installed on the timber, and a vapor barrier is installed on it. The material must be properly tensioned so that there is no sagging. It can be secured not only with a construction stapler, but also with ordinary nails with a wide head. Since the vapor barrier is usually installed in strips, it is necessary to install it overlapping (2-3 cm is enough) so that there are no areas without protection. In wet areas The procedure must be carried out with special care. After installing the protective film, drywall is usually installed. It is important to remember that wooden buildings are very specific and the best way out possible problems There will be a consultation with a specialist.

There should be at least 0.3 cm of free space between the final coating and the insulation to allow air to circulate freely and moisture to dry out.

Outside

We begin work only after 4-5 years and when the building has completely settled. It is recommended to install a vapor barrier on bare timber before insulation. Installation on a timber building is carried out in the following order:

  1. On the timber there is a vapor barrier secured with slats;
  2. Lathing;
  3. Insulation;
  4. Waterproofing;

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

Tips for installing vapor barriers. Installation technology - how to attach to walls?

Vapor barrier materials vary greatly, so the methods for installing them also vary. First, it’s worth talking about the cheapest, but short-lived, materials. Regular polyethylene film easy to install, but very unreliable. If you really want to decorate your home to perfection, we recommend taking a closer look at reinforced film. It is more expensive, but much more effective.

Polypropylene films work very simply - all the moisture remains on them and falls down in the form of drops. When choosing this material, you need to think about this nuance. They also use penofol and analogues. Peculiarity of this material is that it insulates both moisture and heat. It is installed strictly with foil inside the room.

Ruberoid is also used for these purposes, but it is short-lived and does not cope well with the task. We don't recommend it.

As mentioned above, best option - diffusion membrane. Ideal for use, suitable for mounting in several layers. It allows air to pass through, but does not allow moisture to pass through. Its price is very high. But the quality exceeds all expectations. Besides, budget analogues we categorically do not recommend - they do not work, and if they work, it is bad and not for long.

When purchasing materials special attention give them their purpose. Often identical materials serve different purposes. For example, there are waterproofing membranes, which allow steam to pass through. When installing wrong material the whole essence of the vapor barrier goes away.

A feature of laying vapor barrier materials is right choice sides. That is, you take a roll and you need to determine which side to glue it on. Manufacturers often indicate this nuance on the packaging, but if you did not find this information, then you need to apply the outer side of the rolled roll to the log. Secure with slats.

Vapor barrier for the walls of a wooden house is good protection for wooden structural elements and insulating material. It protects against moisture and dampness, thereby extending the life of the structure. But buildings have different purposes, age, shape and thickness of the walls. The choice of material for vapor barrier and the method of its installation largely depend on these factors.

A significant advantage of a wooden house is the excellent heat-insulating characteristics of wood. A wooden house, due to the naturalness of the material, does not produce emissions that are dangerous to the health of others.

Along with such advantages, there is a serious danger of material damage, which can occur due to violations of the rules of equipment and operation of the building. Wood can absorb moisture well.

A residential building may have sufficient sources of steam emission. This can happen when cooking or when wet cleaning premises. A serious cause of steam formation can be the use of the bathroom. Steam vapors are formed during the breathing process of residents and with a significant accumulation of plants in the premises of the house.

A wooden house is a general designation for the following buildings:

  • Log house It is constructed from calibrated, planed or glued beams. Logs can have a round or rectangular profile.
  • Frame building or half-timbered building. For the walls of the building is being built wooden frame, which is sheathed with boards or OSB board, wood panels or shields. Interior space the frame is used to fill with insulating material.

The constant accumulation of moisture in the wood and its drying out will lead to the fact that the material will begin to warp, cracks will appear, and the tightness of the joints will be compromised. The presence of moisture in wood sharply reduces the level of heat transfer of the material. Subsequently, the appearance of mold and fungal diseases and the proliferation of wood pests may occur. Eventually, the wood will lose its characteristics and begin to biodegrade.

To avoid this, it is necessary to equip the building with vapor insulation. It will allow air to pass freely and will retain moisture. If there is a vapor barrier, wooden elements structures will be protected from moisture, and steam will leave the building through ventilation shafts or naturally.

Vapor barrier materials include a variety of films, polymers and membranes. Each of them is used for a specific method of constructing a wooden house.

Materials for protecting walls from steam

There are several types of materials for equipping a home with a vapor barrier. All of them have good vapor barrier characteristics, but differ in their composition and properties:

  • Polyethylene film. It is recommended to use reinforced film. Most budget option, affordable and widely distributed in trading network. Significant disadvantages include the complete lack of penetration of air and moisture. This leads to condensation accumulating on the surface, which reduces the vapor barrier characteristics. In addition, it has low strength, which leads to a relatively short period of operation.

  • Laminated polyethylene film with aluminum coating. It has another name - aluminum foil. Its thickness is only 0.02 cm, but it has excellent vapor barrier characteristics. Installation of such a vapor barrier is carried out with an aluminum coating inside the room. As a result of this installation, heat is reflected from the film and remains inside the building. The disadvantages include the cost of the material.
  • Diffusion membrane. This vapor insulator is made of several layers. The number of layers is determined based on the degree of humidity in the building. The membrane can be single-sided or double-sided. In addition to vapor insulation, it additionally performs the functions of waterproofing and thermal insulation. The disadvantage of this material is its high cost and the impossibility of installation from the outside of the building.

Before installing the film, you must study its markings. The film should be installed with the logo inside the room.

  • Polypropylene film. The characteristics are similar to polyethylene film. But, unlike it, it is more durable. Cellulose fillers in polypropylene film prevent condensation from forming on its surface.
  • Foil polymer. It includes such vapor barrier materials as kraft paper with a metallized layer, kraft paper with a metallized-lavsan layer, fiberglass with a foil coating.

They can be used in combined version, as they have good thermal insulation characteristics. Installation is carried out with the foil side facing the inside of the building. Just like aluminum film, heat is reflected and remains inside the building.

  • Rolled vapor barriers. This could be roofing felt - a material saturated with fiberglass with a layer of bitumen. Rolled materials include roofing felt, which is cardboard impregnated with tar. You can use glassine, which is cardboard impregnated with bitumen. Rolled materials are used to equip the exterior of buildings with vapor barriers. The main positive characteristic roll materials is excellent adhesion. It makes it possible to retain not only steam, but also moisture on the surface of the mastic.
  • Izospan. A relatively recent invention that combines films of varying strengths and vapor barrier membranes. Easy to install, but quite expensive.

You can choose any type of steam protection, depending on the age of the building, the content of the walls, and financial capabilities.

Accessories for the job

In order to perform a high-quality vapor barrier on wooden walls, you will need a small set of tools. This list will include:

  • construction stapler;
  • hammer;
  • screwdriver or drill;
  • building level or cord;
  • chisel;
  • wood hacksaw;
  • construction knife.

The set of materials for the work will consist of: vapor barrier material, thin slats for sheathing, wide tape, self-tapping screws and nails.

Steam insulation methods

Both wooden houses made of beams and logs, as well as different types frame wooden buildings. The obstacle is often not completely dry wood, which remains saturated with moisture for five years after it was cut down. During the drying process, it becomes deformed and cracks may appear.

You can wait until the wood is dry and finishing work. If you don’t want to wait, then equipping the building with a vapor barrier can be done taking into account this drawback. Installation of steam protection can be carried out in the following ways: from the outside and inside of the building.

Insulation from the outside of the building

On the outside of the building, a vapor barrier is installed, after the insulation and before protective coating. This is very important, since the insulation must be protected from external influences of moisture.

Insulation from the inside of the premises

Installation of a vapor barrier on the inside or outside of a building often depends on temperature regime in the region. If the climatic conditions are cold, then it is recommended to install vapor barriers indoors. If the climate is warm or hot, then vice versa.

General questions about installing steam protection

Before you begin installing a vapor barrier, you must follow a number of general recommendations. They are carried out regardless of whether the installation is carried out outside or indoors. They consist of the following:

  • installation of the material must be carried out with markings on itself;
  • the canvases should overlap each other;
  • construction tape for gluing strips must be at least 10 cm;
  • exit strips at window and doorways must be carried out with reserve. The reserve is added up, necessary in case of wood deformation.

Do not confuse waterproofing and vapor protection. Waterproofing serves to protect against moisture that may result from rain, fog, melting snow or ice. Vapor barrier protects against formed condensation and creates conditions for normal air movement.

  • The vapor barrier material must be protected from direct exposure to sunlight.
  • Before installation work surface must be cleaned of dust and dirt. The presence of dust can subsequently lead to clogging of micro-holes, and the material will stop breathing.
  • The wood must be cleared of bark, treated with a fire-resistant liquid, a solution against pests and fungal diseases. It is prohibited to use wood material that has diseases or defects.

Installation of vapor barrier on the outside of the building

The basis for vapor barrier materials to serve for a long time is the arrangement of the materials in the so-called roofing “pie”.

If the materials are positioned correctly, the “pie” will look like this (from the inside out):

  • Lathing. Mounted on the building using self-tapping screws. Performs additional function ventilation gap. Its thickness can be up to 3 to 10 cm.
  • Vapor barrier film. Attached to the sheathing using a construction stapler. The insulator strips are laid with an overlap of about 10 cm. The joints are sealed with construction tape.
  • Insulation material.
  • Waterproofing film.
  • Lathing. It is attached with long nails that will pierce the entire “pie” and attach it to the wall.
  • Finishing material.

If the insulation is wool, a vapor barrier film must be installed. It will protect the cotton wool from vapors coming from the interior.

Installation of vapor barrier from the inside of the house

If necessary, vapor insulation can be installed from inside the premises. Significant disadvantage such installation is that the outer part of the walls will be susceptible to moisture.

To install a vapor barrier indoors, you must:

  • From the inside of the room, attach the sheathing to the wall using self-tapping screws.
  • Attach to the sheathing waterproofing film. Its installation is carried out using a construction stapler.
  • Install ceiling hangers on the wall.

Installation of hangers should be carried out at a distance slightly greater than the width of the insulation. This will ensure a tight fit of the insulation, reducing its waste and labor costs for cutting.

  • Install insulation into the hangers.
  • Attach to insulation vapor barrier film. The vapor barrier strips should be overlapped 10 cm apart and taped.
  • Install the sheathing using long nails that will pierce the entire “pie” and attach it to the wall.
  • Attach finishing material.

Conclusion

If you install a vapor barrier correctly, this will significantly increase the life of a wooden house, reduce heat loss in the house and create comfort in it. Good removal of generated vapors can be ensured by a high-quality ventilation system.

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. When exposed to steam for a long time, these surfaces are damaged. building structures, which negatively affects the condition of the building 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 the case 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 tight, otherwise the film will simply tear during the next change climatic conditions. 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, there can be no talk of comfortable conditions when living in a home. 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 timber structures, as well as houses built using frame technology, and panel buildings. These insulators provide protection from 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, when strong wind 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 the outside of this material there is an anti-condensation surface. Use of this material in winter time provides its protection against phenomena such as condensation and fungus. In addition, its use eliminates the destruction of 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 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 frame type houses 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, special attention should be paid to vapor barrier. 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 the house itself has an effective ventilation system, 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. Similar option optimal for wooden houses that 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, in the premises of a wooden house there occurs high humidity and designs 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 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 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 become 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.