The traditional material for building houses is wood. It has been used since ancient times. In an effort to get eco-friendly housing, modern people are increasingly paying attention to this material. But the installation process is still different. And it is precisely because of this that today it is necessary to use additional building materials. These include vapor barrier for the walls of a wooden house. We will talk about what it is and what it is used for in this article.
Why do I need a vapor barrier?
In the old days, a wooden house did not need additional insulation or decoration. Its thermal insulation properties were sufficient to ensure air circulation between the room and the street. The wood just "breathed" and that was enough.
Today all work is carried out in accordance with certain requirements and calculations. Therefore, in addition to environmental friendliness and attractiveness, a wooden house must also comply with energy saving standards. And this led to a change in the very concept of "house made of wood." Currentlyit is most often understood as a “pie” of several layers of building materials.
Of course, it is difficult for air to get through all these layers. Its free circulation is disturbed. Steam lingers inside this "pie". As a result, condensation forms and accumulates inside. As a result, it turns out that the insulation layer is wet.
Materials used to insulate the house, under the influence of moisture, lose their properties, deform. In addition, condensation causes the appearance of mold and fungi on the tree. As a result, the structure of the material is broken. The wood begins to "get out", the joints of the logs are broken.
Understanding the above process necessitated the use of a protective layer. For this, a vapor barrier is used for the walls of a wooden house.
What does a frame-type wall "pie" look like
To fully understand why a vapor barrier is used for the walls of a wooden house, it is best to understand all the layers of the "pie". If the house is being built of a frame type, then the “pie” looks like this:
finishing the room;
vapor barrier of the inner walls of a wooden house;
framework;
insulation;
insulating layer (from wind, moisture);
exterior decoration of the house
Vapour barrier for the outer walls of a wooden house is also performed to protect the structure from wind and moisture.
Building a building from solid logs
Using a log changes the order of fixing constructionmaterials, typical for frame-type buildings. In these cases, a vapor barrier is laid for the walls of a wooden house outside, and not inside.
An insulating layer is laid over the logs. Next, a frame for insulation is constructed. For this, a wooden beam is most often used. Next, a waterproofing layer is attached. On top of all this, a layer of finishing is laid. As the latter, any suitable building materials can be used. Their choice today is very large. It all depends on the preferences and financial capabilities of the building owners. For example, in this way a vapor barrier is attached to the walls of a wooden house for siding.
Types of vapor barrier
Several types of building materials can be used as a vapor barrier:
A polyethylene film that is only one millimeter thick. This is the simplest and cheapest option. But it has one major drawback. The fact is that the film completely blocks the normal air circulation. As a result, the walls cannot "breathe". This type of material must be used very carefully. It breaks easily. Don't pull it too hard. Otherwise, the inevitable seasonal expansion of materials may damage the film
Vapor barrier mastic perfectly passes air and retains moisture, preventing it from penetrating inside. It is applied immediately before finishing the room
Membrane film is the best option. The insulation is reliably protected from moisture, while air circulation is carried out in the prescribed volume
The most common vapor barrier for the walls of a wooden house of the third type. It is a protective membrane. Therefore, let's take a closer look at its characteristics.
Best option
The vapor barrier membrane is an innovative material that has appeared not so long ago. Its main advantages are:
Excellent moisture protection
Air passes through the membrane, which prevents the so-called greenhouse effect
Absolutely safe for humans
Does not emit harmful and dangerous substances
Even at the stage of choosing building materials, attention should be paid to the issue of membrane strength. To reduce the cost, some manufacturers reduce this figure. When used, such a membrane is easily torn. And who needs a damaged vapor barrier for the walls of a wooden house?
Which side to lay the membrane is another important nuance. It should be strictly ensured that the vapor barrier lies exactly as required by the manufacturer. If you turn it on the other side, it will not bring the desired effect.
Methods of attaching the protective layer
For the construction of a dwelling, various types of timber can be used. Depending on this, the vapor barrier for the walls of a wooden house can be attached from the outside in two ways.
The first is used in situations where the logs are round. The protective layer can be attached directly to the log.
For logs with a rectangular or square section, this option is not suitable. In such situations, a rail about two and a half centimeters wide is stuffed onto the log itself. Between them, an interval of about one meter is observed. The vapor barrier is attached to the installed rails.
Indoor use of vapor barrier
Moisture protection is provided not only outside the building. A vapor barrier is also laid for the walls of a wooden house from the inside. In this case, the whole process will look like this:
A wooden crate is attached to the inner side of the wall. To do this, use bars five centimeters wide
Next, a layer of waterproofing is laid. In this case, a gap is formed between the wall and this film. It is necessary for ventilation of the room
Metal profiles are attached to the battens through the waterproofing
Insulation is placed in the cells formed between the profiles
From above, everything is closed with a vapor barrier membrane. She lays herself out. The joints are sealed
Finishing the pie is the outer skin, which is covered with a finish
Vapour barrier for the walls of a wooden house inside the room laid out in this way will prevent condensation in the "pie".
Things to keep in mind during installation
It is very important to properly prepare the wooden wall before starting to fix the vapor barrier. To do this, all joints and cracks mustbe completely sealed.
From the outside of the building, the vapor barrier material should not be fixed tightly to the wooden wall. It is necessary to maintain openings between the vapor barrier and the finish. They are essential for air circulation. Thanks to them, the condensate from the film will go away naturally.
In the case of a frame house, the situation is exactly the opposite. Insulation does not require a rigid wall. It is attached between the bars from which the frame is assembled. As a result, two-thirds of the entire wall is insulated. Therefore, it must be carefully protected from moisture. Otherwise, the material will lose all its thermal insulation properties and other features. Deformation of the insulation will lead to cracks.
Vapour barrier installation rules
To achieve the maximum effect from the use of a vapor barrier membrane, following some simple rules will help:
The pattern on the membrane should face you, not the wall
Separate parts of the insulation are overlapped. They must be at least ten centimeters apart
The material is rolled only in the horizontal direction
All joints are sealed. To do this, they are glued with tape, the width of which should be more than ten centimeters
Tape also glues elements that are complex in their design: corners, niches, ledges, window and door openings, and so on. All adjacent surfaces are glued with adhesive tape. This will improve the seal
At the windows, it is necessary to provide a supply of the membrane so that the insulation is not damaged during deformation. The stock is made in the form of folds
The material must be completely protected from the sun's rays. This is especially true near window openings
The method of fixing the vapor barrier depends on the chosen material. Polyethylene and polypropylene films are fixed with a conventional construction stapler or nails. To prevent damage to the material, it is recommended to nail it using wooden planks. With their help, the vapor barrier is pressed against the crate. From above, all this is fixed. The membrane is more stable and does not tear as easily. But it can also be fixed in a similar way
The most common mistakes
Vapor barrier will not perform its functions if the installation process was performed with violations. The most common mistakes are:
Installation done sloppily. This means poor sealing of the joints, the presence of a large number of folds, mechanical damage to the material
The material was chosen incorrectly. When choosing insulation, it is necessary to consider where exactly it will be attached: inside or outside. For example, the diffuse membrane is only suitable for indoor use
Double vapor barrier effect. Occurs due to non-compliance with the installation technology. Some types of materials are attached tightly to the wall. For others, it is necessary to collect the crate
Producers of vapor barrier materials
So many modern companies produce films for vapor barrier. The most popular of these are:
"Utah" with trademarks "Yutafol" and "Yutavek" (Czech Republic)
Megaizol
DuPont and their Tyvek films (USA)
Houserep
Fakro (Poland)
Dorken, producing vapor barrier under the Delta brand (Germany)
Klober (Germany)
The vapor barrier for the walls of the wooden house "Izospan" from the company Gexa is worth mentioning separately. This company produces several types of vapor barrier materials. They can be used indoors or outdoors, for walls or ceilings, for a pie with or without insulation.
The vapor barrier of a wooden house will help maintain comfortable indoor conditions and significantly extend the life of the building itself.
