Which side is the vapor barrier placed on the wall? How to lay a vapor barrier on the ceiling and which side to use correctly. Vapor barrier roll materials

Insulation is a very important stage in the construction or renovation of a house, which determines whether you will be comfortable staying in it. Improper implementation of this “procedure” can lead to unpleasant consequences, for example, the release of condensation and increased humidity in the air. But this will not happen if you take care of the vapor barrier and install it right side to the insulation.

Peculiarities

When insulating a house, you should carefully observe correct sequence actions and use only the most best materials. Unfortunately, often owners who undertake to insulate their home themselves forget about one very important thing: important aspect– about the vapor barrier. They install only insulation and don’t even think about the fact that it comes into contact with too warm or too cold air inside the room, and that condensation in the form of water droplets will soon begin to form on it.

And this not only does not contribute to insulation, but also spoils the material itself - it moisturizes it, and if the steam does not yet have time to evaporate, mold appears and the insulation structure deteriorates. Moreover, taking into account our climatic conditions, a similar situation occurs at least four times a year - when the seasons change and, accordingly, the temperatures in the room and outside “conflict”, and the insulation becomes the battlefield.

That is why important stage insulation is the fastening of a “vapor barrier”. The vapor barrier becomes an impenetrable obstacle to steam, preventing it from turning into water, as it “closes” it inside the room and prevents it from coming into contact with excessively warm or excessively cold air.

Materials

Vapor barrier can be made using several materials. From this set, three main types should be distinguished.

• Film. A solid vapor barrier that does not allow water vapor to pass through. One of the main advantages is low price. As a rule, it is made from polyethylene or butylene, their derivatives. Vapor-condensate films are two-layer with a smooth inner and rough outer surface. Lingering on the outside, drops of condensate do not flow down, but evaporate over time. In the case of a solid vapor barrier, you also need to take care of the air gap in order to avoid the occurrence of greenhouse effect, But more on that later.
• Diffusion membrane. The main difference from film is that the membrane allows some of the vapor to pass through itself - but only the optimal amount that does not linger inside and evaporates instantly. Therefore, the vapor permeability of membranes is usually considered limited. The diffusion membrane is made of polymer film and polypropylene and has two sides.
• Reflective or energy-saving film. The outer layer of such a film is metalized, which allows it to withstand high temperatures. Therefore, it is most often used in baths or saunas, reflecting part of the infrared radiation.

As is known, to insulate houses in modern conditions materials such as mineral wool, polystyrene foam, and ecowool are used. Vapor barrier is also needed in the case of mineral wool insulation.

In fact, a vapor barrier is always needed, no matter how expensive or quality material for insulation you use. Mineral wool or mineral wool Otherwise, it is the cheapest material, but its level of thermal conductivity is low, which reduces the likelihood of heat loss in the room. Rodents, mold, and mildew do not like mineral wool; it has high sound insulation and is easy to install. But it still requires a vapor barrier.

The most commonly used is a vapor-permeable limited diffusion membrane. It is laid against the walls, after which you need to lay mineral wool, and in symbiosis they allow the walls of the house to “breathe”.

The question of vapor barrier also arises when insulating a house with ecowool. In general, ecowool is loose cellulose fibers that have the ability to absorb warm moisture and still remain dry. Fungus and mold do not grow on it, the air in it simply does not get wet (if changes in humidity do not exceed 25% percent). From all of the above it follows that in the case of ecowool, the vapor barrier need not be attached.

Another popular insulation– expanded polystyrene actually has another, easier name: polystyrene foam. He lies down like external surfaces, both internal and in the case of external insulation of loggias, balconies or attic floors, does not require vapor barrier - it itself copes well with this when maintaining the insulation technology. But if you insulate with foam plastic interior spaces, vapor barrier and waterproofing are required to avoid the formation of fungus, mold and wetting of the walls.

Device

Purchasing a set of quality materials is only a third of success. In fact, these materials need to be installed correctly and arranged in the correct sequence. It is for this purpose that you should find out which side the vapor barrier is laid, how it is fixed, in what order, and what to nail first - a vapor barrier or insulation.

First you need to carry out preparatory work. At this stage, the type of coating that you will insulate is determined, it performance characteristics and requirements for insulation and vapor barrier materials.

So, the surface needs to be carefully prepared. This takes into account the type of material from which it is made. Wooden elements V mandatory must be treated with compounds against aging, rotting and burning. In the case of concrete and brick, it is possible to use antiseptic compounds deep penetration. From correct processing Half of the success in its operation depends on the surface.

If you are carrying out repairs or reconstruction, then pay attention to the fact that before insulation, all traces of the previous finishing must be removed and a complete cleaning must be carried out. And if we are talking about a log house, then all elements must be treated with fire retardants and antiseptics.

Vapor barrier on the ceiling

In case of roofing structures And interfloor covering The installation of a vapor barrier is supposed to be on an already prepared and properly treated surface. It is best to use a diffusion membrane here.

The main difference between laying a vapor barrier on the ceiling and laying it on other surfaces is that in this case the insulation is laid first, and only then the membrane. It may be mineral or basalt wool in blocks or rolls. It is mounted between the joists and rafters. If the thickness of the insulation is equal to the height of the logs, you will need to additionally install a slatted counter-lattice so that the ceiling is ventilated. After all this, you can work on the vapor barrier.

It should fall slightly onto the walls around the perimeter, the joints should be fastened to the joists - to ensure that moisture does not get into the space between the membrane and the insulation. Pay special attention to the corners - this problem areas, it is better to seal them additionally. Use reinforced tape or a construction stapler as a fastener.

In the case of insulation flat roof or concrete ceiling You can also use a regular vapor barrier film from the inside. It is attached to self-adhesive tape also after the insulation, and then the sheathing is installed - metal or wood.

Vapor barrier on the floor

In the case of laying a vapor barrier on a wooden floor, additional waterproofing must be installed. The floor is also insulated along the joists. Mineral wool or basalt-based wool is installed in the space between the logs. Further without any additional work vapor barrier flooring is being installed.

If we are talking about a rolled vapor barrier, it is laid with an overlap of 12-15 cm with the joints, gaps and cracks glued on both sides with metallized tape as thoroughly as possible. As in the case of ceiling insulation, the overlap on the walls should be within 10 cm.

For a concrete floor you will need sheathing. You will need to lay waterproofing layer into the cells of the sheathing, a heat insulator on top, and after the mineral wool, the third layer is a vapor barrier.

Vapor barrier on walls

The process of insulation and vapor barrier of walls is a little more complicated than performing the same work on the ceiling or floor and involves a slightly larger number of stages. Let's consider the process of laying a vapor barrier film on the walls.

First of all, a frame is mounted from small cross-section bars. The size of the sheathing is determined by the width of the heat insulator block - the distance between the cells is equal to the width of one slab. Classically, mineral wool is used.

At this stage, you should pay special attention to possible gaps that arise due to the difference in the width of the insulation, frame and vapor barrier. The cracks are sealed with reinforced tape, and the sheets of film are glued horizontally with a 15 cm overlap.

Installation subtleties

When installing a vapor barrier, special attention should be paid to important issues.

Which side should the vapor barrier be laid?

Very often masters find it difficult to answer this question, but everything is not so complicated. Ordinary film has the same front and back sides - and then it doesn’t matter which side it is laid on. But in the case of single-sided films, the situation is a little more complicated.

For example, antioxidant films have a fabric backing, and according to installation requirements, it must face the inside of the room. Vapor condensate films must be laid with the smooth side facing the insulation, and the rough side facing outwards. But with diffusion films, you should look directly at the instructions, since such films can be either one-sided or double-sided. Energy-saving films are laid with the foil side, on the contrary, outward - after all, they should reflect and not absorb heat. The same applies to metal coatings.

How to distinguish the outside from the inside?

This information should be indicated in the instructions or on the manufacturer’s website; you can ask a consultant or technician about this. However, if none of the above suits you, you will have to learn to determine the sides of the vapor barrier yourself.

So, remember: if the vapor barrier has two-color sides, then the light side will always fit against the insulation.

But also pay attention to how the vapor barrier roll is rolled out - the side facing the floor will be the inner side, and it should be placed against the insulation. In the case of a vapor barrier with a different surface, the smooth layer will always be the inner one, and the fleecy or rough one will always be the outer one.

What kind of fastener should I use?

Is an air gap necessary near the membrane?

It is believed that this is a mandatory point - it is absolutely forbidden for the wall to come into close contact with the membrane; a gap of about five centimeters should be left for ventilation. Condensation will not accumulate this way. In the case of a diffusion vapor barrier, the air gap is made with outer side, and the film itself is laid directly on the insulation.

First of all, you must follow the manufacturer's instructions, which clearly describe which side to lay the windbreak on. If there is no such instruction, there are a number of general recommendations, applicable for windproof films:

• the wind protection spreads towards the insulation with the “fleecy” side, unless otherwise specified in the instructions;
• if both sides are the same, the film is attached with the manufacturer’s logo on the outside;
• wind protection without markings and distinctive qualities of one of the sides can be installed in any convenient way.

Manufacturers often roll rolls in such a way that the wind protection can be laid as simply as possible - as the roll unwinds.

Windproof films of different types are laid in different ways:

1. Simple wind protection. These are perforated single-layer films that can be placed on either side of the insulation, as they have double-sided vapor permeability.
2. Wind and moisture protection. These are two-layer films that are laid with the moisture-repellent side facing out. This side is smooth, often with manufacturer’s markings or painted in a different (non-white) color.
3. Superdiffusion membranes. This material has a multilayer structure with high water resistance and vapor permeability. It is necessary to lay the membrane with outside insulation and only the marked side out.

On internal floors The film is spread over the insulation with the markings facing outward and the plain side inward.

And to protect the wooden floor from cold wind blowing from an uncovered base columnar foundation, the film is laid on the subfloor without gaps close to the insulation. In this case, it is laid with the inscriptions down.

Single layer windproof films are laid under the roof on either side. But two-layer ones - only with the smooth side up.

Some films and membranes are UV resistant due to a special coating. The manufacturer must indicate this parameter. This windbreak is attached to the rafters with the colored (protective) side up.

On the walls, wind protection is placed from the outside directly on the insulation (with the markings or the colored side facing out). It is necessary to provide a ventilation gap between the film and external finishing. In order for the windbreak to provide a sufficient level of protection from moisture, it must be mounted horizontally from bottom to top with an overlap of at least 10 cm. Inside, a vapor barrier is laid on the walls - this is very important

IN winter period, when it’s frosty outside, but inside the house it’s cozy and warm, unnoticeable steam forms in the rooms. And this steam must leave the room freely. To accomplish this task, a vapor barrier is installed. You need to know which side to lay the vapor barrier on the floor, walls or ceiling.

Why do you need a vapor barrier?

Vapor barrier material is used for normal moisture circulation indoors. If you ignore the vapor barrier, then moisture in the air can enter the insulation and gradually destroy the material.

If the construction of buildings is carried out from a material that is already insulated, then the vapor barrier will serve as protection against the entry of harmful substances into the premises.

Insulation is a heat-insulating material. Depending on the origin of the feedstock, it is divided into:

• organic thermal insulation - the basis is wood, plants, animal hair;
• inorganic thermal insulation - mineral wool, fiberglass, concrete.

The installation of a vapor barrier layer is carried out to maintain a comfortable temperature inside the house, preventing air from penetrating through the cracks of the building.

When using insulation that absorbs moisture well, you cannot do without a vapor barrier. In its absence, moisture is absorbed into the structure of the insulation and there it turns into water. With time thermal insulation characteristics insulation material will decrease. After a certain period, it will be possible to observe the appearance of fungus and mold. The use of a vapor barrier creates a kind of shield between the insulation and the internal air of the apartment.

Correct installation of a vapor barrier will allow the insulation to last a long time and effectively.

Types of vapor barriers

IN modern construction vapor barrier is successfully used to protect organic and inorganic warm insulating materials. It comes in the following types:

• Film.

Film– a blind vapor barrier material that retains moisture and does not allow moisture to pass through. Due to its low cost and excellent waterproof characteristics, the film is used not only in construction industry, but also for domestic needs. Films vary in thickness, number of layers, and surface quality. It can be smooth on the outside and rough on the inside. Water always remains on the surface of the film.

This type of vapor barrier material consists of polymer film and polypropylene, has limited vapor permeability. Water vapor contained in the insulation immediately evaporates.

resistant to elevated temperatures external environment due to its metallized outer layer. Vapor barrier should be installed in rooms with high humidity and temperature. The material is capable of reflecting infrared radiation.

Permits moisture in two directions. Convenient to use when insulating large surface areas.

The thermal insulation and vapor barrier characteristics of a structure depend on the choice of material. Careful approach to selection necessary products will provide comfort and coziness of the premises and help extend the service life of the entire structure.

Principles of installing vapor barriers to different surfaces

Manufacturers of vapor barrier films, focusing on consumer desires, produce their products in different directions:

• for work on and under the roof;
• on vertical surfaces walls;
• on the floor.

Vapor barriers can be installed on any surface. When using vapor barrier material on wooden structures use a film with a membrane. Polymer or bitumen mastic can be used for any type of surface. On concrete walls It is recommended to install a vapor barrier with a metal outer layer.

Its use will be much more effective if the working side is prepared in advance. Preliminary work depends on the characteristics of the material with which the building is built.

During construction wooden house, to begin with, soak everything wooden surfaces insect repellents and harmful bacteria. Only after completing a set of preparatory work are they started to install the vapor barrier layer.

The highest quality insulation material wooden floors– breathable membranes. The body of the membrane consists of a layer of anti-condensation fibers that absorb and accumulate moisture. There are single-sided and double-sided membranes. IN latest version moisture is absorbed from both sides at once, so a double-sided breathable membrane can be laid with either side facing the floor.

When carrying out a major overhaul, all outdated insulating coatings are dismantled. Surfaces are thoroughly cleaned and impregnated with special disinfectants. Then you can lay the vapor barrier. Concrete surfaces They do not require special treatment with special means; they just need to be cleaned.

Features of installation on various surfaces

Installing a vapor barrier layer is not particularly difficult; you need to carefully carry out the preparatory work and know the main stages of installation.

Laying on the floor

Film – best option insulating the floor from moisture. On the ground floor, the insulation layer below is protected by a device, and closer to the premises - by a roll of insulating film, which is laid overlapping. The joints are taped with metallized tape or tape.

If it is interfloor or attic floor, then the film is unfolded with the smooth side down to protect against water vapor coming from the slab or floor logs.

Ceiling insulation

Used in rooms with high moisture content in the air. These can be bathrooms, showers, baths, saunas. The vapor barrier is securely overlapped and the joints are sealed. The reflective side of the material is directed indoors. Special attention given to the corners of the room, the insulation should overlap slightly on the walls around the entire perimeter of the room.

Vertical surfaces

For such surfaces, diffusion membranes are used, which allow air to pass through rather than moisture. The walls must “breathe”, so impermeable film is not used. In case of external work, the product is laid with the smooth side facing the insulation. When installing, the film is slightly stretched.

Roof mounting

The purpose of the vapor barrier is to protect the rafters from mold and prevent the formation of condensation in the insulating layer. Installation is carried out with an overlap and sealing of the seams. The main condition is to ensure the tightness of the roof in conjunction with the vertical elements of the building.

Basements, balconies and underground structures

Balconies, basements and underground rooms are in contact with cold outside air. For balconies, dense foamed polyethylene is used, the reflective side of which is directed indoors. For other structures, membrane film is used.

When working with vapor barrier materials, it is necessary to find out which side the product should be laid in relation to the insulation. The location of the vapor barrier will determine the degree of moisture absorption by the insulation and its service life. The instructions for the product indicate how to install it correctly. But what if there are no instructions? In this case, the installation method is determined independently, taking into account the following points:

• if there are sides on the vapor barrier material different color, then the lighter one is placed next to the insulation;
• the outer side of the product has a rough surface;
• if in doubt, take a glass with hot water and placed on the vapor barrier area. Condensation forms on the waterproof side.

The polyethylene film is laid with either side facing the insulation, while the diffusion film has one smooth surface, which should lie towards the insulation. By preventing the insulating layer from getting wet, it allows moisture to pass through the smooth side without hindrance.

• By placing the barrier with its smooth side facing the thermal insulation, the influx of steam and the formation of rotting processes in wooden structures are eliminated;
• when installing a thermal insulation layer outside the building, the insulating layer is placed outside the room;
• the film should fit tightly to the insulating layer;
• when sealing joints, use wide adhesive tapes and tapes;
• when working with windows and doorways, it is necessary to leave a small supply of vapor barrier film;
• The film should be protected from direct sunlight;
• Before starting work, the most critical places are determined - areas of interaction between warm and cold air.

When performing work on installing a vapor barrier film, it is important that the product is attached correctly. Otherwise, the error will lead to ineffective thermal insulation.

Any homeowner spends a lot of effort to create for his family comfortable conditions accommodation.

This is maintenance constant temperature into the home, ensuring the flow fresh air, humidity is within normal limits. All life activity of any living creature is accompanied by the release of heat and steam.

Wet cleaning and washing, showering and cooking, boiling water, and even breathing - all this is a source of accumulation in the room. Increased humidity leads to the formation of condensation on various surfaces indoors.

Moisture penetrating deep into the structure in wooden house influences them negative impact, and contributes to their deterioration and even destruction. The materials used for construction are covered, and pockets of rotting form on them. Besides, high humidity does not have the best effect on the well-being and health of people living in the premises.

To avoid damage and deterioration individual elements floor, use a special one. His functional purpose– prevent the harmful effects of moisture. At the same time, it does not interfere with air circulation; it calmly goes outside. This technique allows floor coverings not to lose their working qualities and ensures their long service life.

Almost until the end of the second millennium, the role of vapor barrier material was usually played by roofing material, glassine and roofing felt.

Today we can observe the widest range of insulating materials different types and parties, some of which can also protect from water.

For wooden buildings Various breathable films and membranes are most often used as a vapor barrier layer.

In addition to them, there is another type of insulation - bitumen-polymer mastic, liquid rubber, etc. But these materials are more suitable for protecting and rather than the foundation of the building.

Polyethylene film

Perhaps the most affordable and common type of vapor barrier material for installation. Trade presents two types of synthetic films - perforated and non-perforated.

It is believed that the first is more suitable for, and the second for insulating from steam. Their difference lies in the presence or absence of microscopic holes in the material, and, accordingly, in the level of permeability.

Thanks to innovative technologies Improved versions of familiar materials are appearing on the market. These are, for example, films with a layer of aluminum applied to them. They have much better performance characteristics and high vapor barrier properties.

They are preferably used where extremely high levels of humidity and temperature are possible. These are kitchen facilities, saunas, and so on.

Like any material, film is not without its drawbacks. The main and most significant thing is that it is very easy to tear, which should be taken into account when using and installing. Even if you use a reinforced type of material (reinforced with a special mesh), its strength and durability will not be particularly high.

Polypropylene film

A material such as polypropylene, compared to polyethylene, has better resistance to atmospheric precipitation and has higher strength. At first this type The vapor barrier material was made strictly from polypropylene. Later it was discovered that condensation accumulated on the film on the insulation side. It has a negative impact on the quality of the insulation and provokes its premature failure.

This drawback was eliminated as follows. On reinforced film A special viscose-cellulose layer is applied from polypropylene. It prevents the formation of drops, perfectly absorbing and retaining moisture. During installation, such material is placed with the anti-condensation layer down. Ventilation gap usually done between a layer of this film and.

Diffuse membrane

Breathable diffuse membranes can easily be classified as the most expensive and high-quality vapor barrier materials. This material is extremely high rate vapor permeability, which is ensured by the special microstructure of the material. It is a non-woven fabric made from synthetic fibers.

They are used not only to protect against excess moisture, but also to control it required level. This ability is provided to them by a special quality - the ability to pass air on one side or both. According to this quality, membranes are divided into double- and single-sided. The specific installation method used for each type depends on this. When using single-sided film, you need to make sure which side is facing the layer.

Breathable membranes are also divided according to the number of layers that make them up: there may be one, two or three.

In the manufacture of membranes, a special anti-condensation layer is used, which has the ability to absorb excess moisture, and then gradually evaporate it.

A unique representative of diffuse multilayer membranes is a special intelligent membrane. It successfully combines steam, hydro and thermal insulation properties. This material is able to independently regulate the microclimate in the room (by changing the vapor exchange), based on the level of moisture and temperature present there.

Another invaluable quality of a diffuse membrane is the absence of the need for arrangement between it and. Well, and of course, there are shortcomings, where would we be without them. There is only one, but it is quite sensitive - the high price of such a vapor barrier for the floor covering. But positive properties and the advantages of the material more than compensate for it.

Liquid rubber

Liquid rubber today is a fairly actively used material for arranging vapor barriers. What does this name even hide?

This is a bitumen-polymer cold emulsion prepared at water based. It is convenient to spray it on the working surface. This simple application makes it easy to apply even on surfaces with complex terrain. After final hardening, the mass forms a monolithic rubber carpet that has no seams.

It poses an insurmountable threat to liquids and gases, and is also characterized by sound, hydro- and heat-insulating qualities.

Today's liquid rubber There are different types:

• A special emulsion applied to the surface manually. The working area for application should be no more than several tens of meters.
• An emulsion for which special coatings are used. automated systems. It is used in cases where we are talking about vapor barrier of large floor surfaces: hundreds and thousands of squares in size.

Floor: proper vapor barrier

If you need to install a high-quality vapor barrier system in a house under construction, then there won’t be much hassle with it. All floorboards must be treated with specialized products that protect the wood from pests and insects.

This especially applies to lags and subfloor, which are closest to, in close proximity to it. It is this that will become the basis on which the vapor barrier layer will lie.

If you need to equip an already erected structure with a vapor barrier, then the hassle will increase, and the technology will be different. If you need to carry out major renovation, or replace the vapor barrier layer, you will have to lift and remove the floor covering, remove and remove the heat and vapor barrier.

The screed is thoroughly cleaned with a broom or even a vacuum cleaner. A careful inspection is carried out to determine the presence of possible defects. They can be unevenness, chips, small and large cracks.

If there are a lot of them, then repairs should be carried out. If necessary, the screed must be leveled to prevent possible moisture from entering through the cracks from the outside. You can install an additional one to protect against water penetration from the ground.

If a roll is used for this waterproofing material, then it must be overlapped. All resulting joints are sealed with simple adhesive tape or tape.

The level of each of them must be strictly adjusted so that the surface is perfectly horizontal. All elements and parts made of wood are impregnated with protective. The surface is cleaned of debris and dust, and only then you can begin laying the vapor barrier layer.

Laying vapor barrier

To properly install a vapor barrier layer, you do not need any special knowledge. Usually, widely used film materials are used to create a vapor barrier with your own hands. Their worthy representatives are the Izospan B floor vapor barrier and the Izospan membrane. The vapor barrier layer is carefully laid on the supporting frame, making sure that the material sheets overlap strictly. Its width must be at least 20 centimeters.

Secure the laid layer with construction stapler or special galvanized nails. Often the material manufacturers themselves recommend using a special duct tape, which provides a virtually monolithic coating, without holes and cracks.

So that during work there are no questions regarding possible ways fastenings, it is better to clarify this issue in advance when purchasing the material.

All kinds of junctions, parapets, relief areas and others hard to reach places convenient to protect with bitumen-based coating materials. Laying film vapor barriers in them can be very difficult.

After placing the vapor barrier layer, insulation is installed on top of it. It could be , or . The insulation is laid in such a way that it fits snugly, without cracks or gaps, against the joists.

Another one should be placed on top of it vapor barrier layer, which will become an obstacle to moisture rushing out of the room. You should carefully monitor the location of the membrane - strictly overlapping.

Then the joints are glued, and you can begin laying the main floor. When laying boards, keep in mind that there should be a gap of one to two centimeters between the floor and the vapor barrier.

How to install vapor barrier correctly

How to determine which way to lay a vapor barrier membrane: which side?

If a film of two layers is used in the process, then, according to the instructions, it should be laid with the rough side, which can retain moisture, towards the room, and the smooth surface, which prevents moisture from entering, towards the layer