The traditional material for building houses is wood. It began to be used in the distant past. In an effort to obtain environmentally friendly housing, modern people increasingly pay attention to this material. But the installation process still became different. And precisely because of this, today we have 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 you need vapor barrier?
In the old days, a house made of wood 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 simply “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 conservation standards. And this led to a change in the very concept of a "house made of wood." Currently, it is understood most often as a “pie” of several layers of building materials.
Naturally, it is difficult for air to get through all these layers. Its free circulation is broken. Steam lingers inside this “pie”. As a result, condensation builds up that accumulates inside. As a result, it turns out that the insulation layer is wet.
The materials used to warm the house, under the influence of moisture lose their properties, are deformed. In addition, condensation causes mold and mildew on the tree. As a result, the structure of the material is disturbed. The wood begins to "twist", the joints of the logs are broken.
Understanding the above process necessitated the use of a protective layer. For this, vapor barrier for the walls of a wooden house is used.
What does a wall-mounted “pie” look like?
To fully understand why 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 under construction of a frame type, then the “pie” looks like this:
- finishing finishing of the room;
- vapor barrier of the interior walls of a wooden house;
- insulation layer (from wind, moisture);
- exterior decoration of the house.
Vapor barrier for the exterior walls of a wooden house is also carried out to protect the structure from wind and moisture.
Building a building from solid logs
The use of logs changes the fixation order of building materials, typical for frame-type buildings. In these cases, vapor barrier for the walls of the wooden house is laid outside, not inside.
An insulating layer is lined on top of the logs. Next, a frame for a heater is constructed. To do this, most often use a wooden beam. Next, a waterproofing layer is attached. On top of all this, a finish layer is laid. As the latter, any suitable building materials may 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 the vapor barrier for the walls of a wooden house for siding is attached.
Types of vapor barrier
As a vapor barrier layer, several types of building materials can be used:
- A polyethylene film that has a thickness of just one millimeter. This is the easiest and cheapest option. But it has one significant drawback. The fact is that the film completely blocks the normal circulation of air. As a result, the walls cannot “breathe”. Use this type of material very carefully. He easily breaks. Do not pull it too tight. Otherwise, the inevitable seasonal expansion of materials can damage the film.
- The vapor barrier mastic perfectly passes air and retains moisture, preventing it from penetrating inside. It is applied immediately before the finish of 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, we dwell on its characteristics.
Optimal option
A vapor barrier membrane is an innovative material that appeared not so long ago. Its main advantages are:
- Excellent moisture protection.
- Air passes through the membrane, which prevents the appearance of the so-called greenhouse effect.
- Absolutely safe for people.
- Does not emit harmful and dangerous substances.
Even at the stage of choosing building materials, it is worth paying attention to the issue of membrane strength. To reduce cost, some manufacturers reduce this figure. When applied, such a membrane easily breaks. And who needs a damaged vapor barrier for the walls of a wooden house?
Which side to lay the membrane with is another important nuance. It should be strictly monitored so that the vapor barrier lies exactly as the manufacturer requires. If you expand it on the other side, it will not bring the desired effect.
Methods of fixing the protective layer
For the construction of housing can be used timber of various types. Depending on this, the vapor barrier for the walls of a wooden house outside can be fixed 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 cross section, this option is not suitable. In such situations, a rake about two and a half centimeters wide is packed on the log itself. Between them, an interval of the order of one meter is observed. The vapor barrier is attached to the installed rails.
Use of vapor barrier indoors
Moisture protection is provided not only outside the building. The vapor barrier for the walls of the wooden house from the inside is also laid. In this case, the whole process will look as follows:
- On the inner side of the wall is a wooden crate. To do this, use bars five centimeters wide.
- Next, a layer of waterproofing is lined. 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 of the crates through the waterproofing.
- Insulation is formed between the cells formed between the profiles.
- From above everything is closed with a vapor barrier membrane. She laid out the lap. Joints are sealed.
- Finishes the “pie” exterior cladding, which is covered with a finish.
The vapor barrier thus laid out for the walls of a wooden house indoors will prevent condensation in the “pie”.
What you need to remember during installation
It is very important to properly prepare a wooden wall before fixing the vapor barrier. To do this, all joints and crevices must be 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 preserve the openings between the vapor barrier and the finish. They are necessary 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 mounted between the bars from which the frame is assembled. As a result, two-thirds of the entire wall is insulation. Therefore, it must be carefully protected from moisture. Otherwise, the material will lose all its heat-insulating properties and other features. Deformation of the insulation will lead to cracks.
Rules for installing a vapor barrier
To achieve the maximum effect from the use of a vapor barrier membrane, compliance with some simple rules will help:
- The pattern on the membrane should be facing you, not the wall.
- Individual parts of the insulation are lapped. They must face each other by at least ten centimeters.
- Material is rolled only in the horizontal direction.
- All joints are sealed. To do this, they are glued with a tape, the width of which should be more than ten centimeters.
- The tape also glues elements of complex construction: corners, niches, ledges, openings of windows and doors, and so on. All adjacent surfaces are glued with tape. This will improve the tightness.
- It is necessary to provide a membrane reserve near the windows so that during deformation the insulation is not damaged. The stock is made in the form of folds.
- The material must be fully protected from the sun. This is especially true near window openings.
- The method of attaching the vapor barrier depends on the material selected. Polyethylene and polypropylene films are fixed with a conventional construction stapler or nails. So that the material is not damaged, 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 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 errors are:
- Installation is inaccurate. This means poorly sealed joints, the presence of a large number of folds, and damage to the material mechanically.
- The material is not selected correctly. When choosing insulation, it is necessary to consider where it will be attached: inside or outside. For example, a diffuse membrane is only suitable for internal use.
- The effect of double vapor barrier. It arises due to non-compliance with the installation technology. Some types of materials are mounted tightly on the wall. For others, it is necessary to collect the crate.
Manufacturers of vapor barrier materials
Many modern companies produce vapor barrier films. The most popular of these include the following:
- Utah with the trademarks Yutafol and Yutavek (Czech Republic).
- DuPont and their films Tyvek (USA).
- "Dorken" producing vapor barrier under the Delta brand (Germany).
The vapor barrier for the walls of the Isxpan wooden house from Gexa is worth mentioning separately. This company produces several types of vapor barrier materials. They can be used inside or outside the premises, 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.