Thermal insulation can reduce heating costs, so it is mounted during the construction of a variety of houses. In the process of arranging the insulation, vapor barrier is used. This material has certain characteristics. There are many varieties of this film. What is vapor barrier, what properties does it have, will be discussed later.
general characteristics
What is vapor barrier? Builders were able to get acquainted with this material relatively recently. Today it is used in the process of repair and installation works. Vapor barrier is used during the arrangement of the thermal insulation layer. In this case, different varieties of material can be used. It is necessary to choose the right vapor barrier. It depends on the features of the operation of the building, the tasks that set before the insulation. When choosing a vapor barrier, the budget allocated by the owners for the repair and construction work is also taken into account.
Considering what a vapor barrier is, it is worth noting that the final result of the work depends on the correct installation of this material. If you make a mistake, the insulation will not fulfill its responsibilities. Therefore, you need to consider how to choose and install a vapor barrier. To understand how to apply the presented material, you need to consider its functions.
The humidity level in the room may vary. Various factors can influence this, for example, the presence of a large number of plants, the operation of ventilation, the presence of linen that is dried on a battery, etc. Condensation may appear on different surfaces when the temperature changes. Dew falls in the insulation layer. This phenomenon is explained by a certain ratio of temperature and humidity level. Due to such fluctuations, the dew point may shift inward. For this reason, condensation can be observed.
It is also worth noting that many building materials have the ability to “breathe”. They let steam through. Only glass, metal and some other materials are deprived of this ability. At a certain temperature inside and outside the room, steam can turn into condensate. This happens more often during the cold season.
Condensation will form inside the walls if certain temperature characteristics are established. In addition to walls, condensation can occur in roofing materials, accumulating in the structure of thermal insulation. The danger of this phenomenon is that when saturated with water, the insulation ceases to cope with its duties. Heat begins to quickly leave the room. To maintain comfortable indoor conditions, you will need to spend more energy for heating. Costs in this case increase markedly.
In severe frost, water in the structure of the material may freeze. This leads to the destruction of the thermal insulation structure. Moreover, this process irrevocably violates the functions of the insulation layer. With the onset of heat, the ice will melt, and water will begin to seep through the external walls of the house. This leads to the destruction of the interior finish, yellow streaks, stains and stains remain on the walls. Because of this, repairs will be required.
To avoid adverse effects, when arranging the insulation layer, vapor barrier is used. Its main purpose is to prevent steam from entering the thermal insulation. It is important to know which side the vapor barrier is mounted on the base. In this case, the dew point is shifted, which prevents the destruction of the insulation.
In addition, mold does not form on the materials. The fungus will not appear indoors. This not only extends the life of wooden structures, but also allows you to maintain the correct microclimate in the room. The fungus can be dangerous to human health. Therefore, the use of vapor barrier is necessary in the process of creating a layer of insulation for buildings and structures of various types.
Vapor barrier and waterproofing
Considering what vapor barrier is, you need to pay attention to its difference from waterproofing. This will allow the correct use of both types of films. Waterproofing and vapor barrier are structured. This determines their scope. Vapor barrier protects buildings and thermal insulation from condensation that may occur due to vapors. They form inside the house. Moreover, the throughput of such a membrane is different.
Most vapor barrier varieties have micropores. In addition, vapor barrier for insulation is a multilayer material. Each of them performs a number of specific functions. This is a complex system that significantly improves the performance of the insulation. Professional builders have no doubt whether vapor barrier is necessary in the process of arranging thermal insulation.
Waterproofing is a slightly different material. This is a uniform film that has no pores. Its surface is tight, so water or steam does not pass through it. Waterproofing, in contrast to vapor barrier, is needed to protect the rabbit, walls from moisture coming from outside. It can be water that gets on the walls during rainfall. Waterproofing prevents the penetration of moisture from the outside into the base insulation layer, roof, walls.
Another area of application of waterproofing is to prevent groundwater from entering the foundation. They leak through the soil, which can eventually lead to destruction of the base. This significantly reduces the life of the house. Therefore, when building the foundation, a waterproofing layer is required. In this case, the base of the structure will be reliably protected from groundwater, which during the season of melting snow or heavy rains can come close to the surface.
Knowing the difference between these materials, it is possible to understand whether vapor barrier is needed and in which construction work it is used. When creating a layer of insulation, both types of films are needed. But the sequence of their installation will be different.
Varieties of vapor barrier
Vapor barrier for the walls of the house can be different. Several types of this material are on sale. The choice depends on the conditions in which the film will be used.
Vapor barrier differs in certain parameters, which affect not only the scope of its application, but also the principle of its installation. In order not to make a mistake in the choice, you need to consider what options for vapor barrier are used today in the course of construction and repair work. The main options are:
- Glue based vapor barrier.
- Films in rolls that are impregnated with different compositions.
- Liquid varieties of coating materials.
- Polyethylene films.
- Materials with a foil layer.
- Breathable membranes that pass a certain amount of steam through themselves.
The vapor barrier device of some varieties involves the installation of a certain side. It is impossible to confuse landmarks, since the film in this case will not fulfill the functions assigned to it. Each type of vapor barrier material differs in scope. It is necessary to clearly understand for what purposes it is acquired. Otherwise, difficulties of a different nature will arise during operation.
Roll types of vapor barrier can have impregnations of bitumen or other similar substances in the structure. These types of vapor barrier are used as temporary material. At the same time, mounting such varieties of films is problematic, since the joints are sealed with a special burner.
Liquid formulations are quite expensive. Such varieties of materials are used to create the floor in the bath or shower. It is used for finishing the base at the places of communications, at the junctions of various building materials. If you apply the coating for a complete surface treatment of walls, ceilings, the budget for repair work will increase significantly. Moreover, the procedure for applying liquid vapor barrier is quite difficult.
Polyethylene film
Vapor barrier for insulation can be made of polyethylene. This type of material is used in rooms with high humidity. However, in some cases it is used in dry rooms. The advantage of polyethylene vapor barrier is its relatively low cost. Therefore, this kind of materials is used quite a bit when arranging thermal insulation. But this type of materials is not suitable for all works.
The sides of the vapor barrier are identical. Therefore, for this material it does not matter how to deploy it during installation. The structure of this material is characterized by certain features. This determines the scope of the material. Most often it is used as temporary protection in the process of construction work. The film protects open materials from moisture, precipitation. Under certain conditions, condensation may occur on such material. It is important to carry out the installation in accordance with existing standards and requirements. Otherwise, the film will not be able to protect structures from decay and premature destruction.
The duration of operation of plastic films is quite short. Under the influence of various external factors, the material quickly collapses. If the owners of the house do not want to deal with the installation of a new insulation, you need to choose a different type of vapor barrier. Polyethylene films are a temporary option that is used during construction work. Vapor barrier of the type presented is often used in the arrangement of concrete floors.
Membrane
Which side of the vapor barrier to the heater is mounted, it is important to know when installing membrane materials. They have a perforation of a certain configuration. The shape of such cells, their size determines the speed with which steam will pass through the membrane.
This film is a layered structure, which has an important ability to "breathe". In such a vapor barrier, each layer performs a specific function, ensuring the proper functioning of the membrane. Each layer has openings through which steam passes further. So that he does not come back, the holes have different diameters. In the lowest layer, the pores have a minimum size. They cut off part of the moisture without passing it inside the insulation layer.
Some types of membrane types of vapor barrier have a reinforcing layer. This ensures a long life of the film. Reinforcement does not allow the material to deform due to changes in ambient temperature. Due to the presence of this layer, the film will last a long time, but its cost will be an order of magnitude higher. It is worth remembering that, despite the high price, this option is preferable in the harsh northern climate. Such a film quickly pays off during operation. The insulation in this case will be used longer.
Not all membranes have a reinforcing layer. Therefore, you need to find out if it has a vapor barrier for the walls that you plan to buy.
The top layer of the membrane type material presented also has pores. Their diameter is larger than that of the lower layer. This feature provides steam movement in only one direction. This contributes to the appearance of traction, which moves air masses saturated with moisture at a certain speed. Thanks to this device, water does not stagnate in the structure of the insulation.
The top layer often has a rough texture. It is important to know how to install this material. When installing such membranes, it is important to leave a technological gap between the film and the main finish. Its width should be from 2.5 cm or more. Moisture may accumulate in the rough layer if improperly installed. Therefore, for its removal in the natural way during the construction process, a ventilation gap is laid.
Features of combining the membrane with thermal insulation
In some cases, the use of a vapor barrier during the insulation process is not mandatory. The fact is that not all types of thermal insulation use different materials of the type presented. You need to familiarize yourself with the recommendations of specialists about when a vapor barrier is needed.
It is worth noting that today in the process of construction work different types of insulation are used. Such materials may have a porous structure. In this case, they are able to greatly absorb moisture. Because of this, the initial operational characteristics of the material are markedly reduced. This is primarily true for mineral wool. This is one of the most common heaters. If it gets wet, heat easily leaves the room in the external environment. Therefore, for mineral wool or other varieties of insulation with a porous structure, it is necessary to apply vapor barrier without fail.
But do you need a film when arranging thermal insulation from polystyrene foam, polystyrene foam, polystyrene foam and other similar materials. These are synthetic heaters that are not able to absorb water. In addition, they do not allow steam. Therefore, many builders believe that vapor barrier is not needed for this material. But this is not so.
Although the material does not allow steam to pass, joints form between the plates during installation. Steam is able to penetrate even the thinnest gaps. It should be noted that polystyrene foam is mounted on glue. Even when using special compositions, a small layer of air remains between the sheets and the base. It is impossible to tightly attach the material to the base.
In such a gap, condensation may occur under certain conditions. This leads to the development of mold and fungus, rotting processes occur. Materials will be destroyed. Steam will also seep through the joints of the insulation. Therefore, even when using materials that repel moisture, vapor barrier must be used.
Laying a vapor barrier is not required only when using polyurethane foam as a heater. It forms a tight connection with the base, without letting moisture into the insulation. There are no gaps in this thermal insulation, which allows you to reliably protect the walls from condensation and steam.
Choosing a film for a balcony
During installation, it is important to understand where it is especially important to apply vapor barrier, which side to the heater it should be mounted. For different surfaces, the use of such films and membranes is required to a greater or lesser extent. If you plan to carry out insulation on the balcony, loggia, you can not do without vapor barrier.
Such constructions are a barrier between external conditions and the house. A large temperature difference can be observed here. Because of this, condensation appears with all the negative consequences. The windows on the balcony have a significant area. They have a low temperature during the cold season. Therefore, moisture can spread inside the insulation. To prevent such unpleasant consequences, it is necessary to use a correctly selected vapor barrier when arranging the insulation.
In this case, you need to use a three-layer membrane. Moreover, the material should have a foil layer. It should be directed to the room. The foil reflects infrared rays back into the room. This allows you to reduce the cost of heating the loggia.
Walls
If the thermal insulation is mounted indoors, vapor barrier is necessary. It is necessary to put it to the heater with the side not covered with pile. Smooth surface should be directed towards the insulation. The rough side of the vapor barrier should be directed into the room.
When creating thermal insulation outside the premises, vapor barrier is not needed. No vapor is formed in these layers. If condensation occurs here, the vapor does not penetrate into the structure. Only creating an external finish for the bath, you need to apply a membrane.
Floor
In most cases, a membrane is not needed for flooring. For floors, you need to apply waterproofing. But when arranging the floor in the bath, vapor barrier should be used during construction work. In such rooms there is a lot of steam, therefore, membranes in this case are appropriate.
Roof
When arranging the roof, vapor barrier is necessarily applied. How to mount such a material? The ceiling passes a lot of steam through itself because it rises. Even in dry rooms, membranes must be used.
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