Which side to lay the hydro and vapor barrier. Which side is the correct way to lay a vapor barrier? What is the difference between anti-condensation film and “anti-condensation side”

The floor in a wooden house is a multi-layer structure, an important part of which is vapor barrier. It allows you to protect the insulation, boards and floor joists from steam, which, penetrating into the underground, condenses and turns into a full-fledged liquid. And since in any residential building something is constantly being cooked, washed and washed, a floor without a vapor barrier risks becoming a source of constant dampness. This, in turn, leads to the appearance of fungus, mold and rotting of wooden structures. Vapor barrier of the floor in a wooden house will allow you to avoid these bleak prospects, extend the life of the structure and increase indoor comfort.

What materials are used for floor vapor barrier?

Convenient to use as vapor barrier materials for wooden floors various films, which, due to their structure, do not allow steam and water to pass through. You can select the type of vapor barrier from the list:

1. Polyethylene film

The most famous and inexpensive vapor barrier is polyethylene film, which is sold in wide rolls. Since polyethylene sheets themselves are quite fragile and tear easily, they are reinforced with fabric or thin reinforcing mesh.

Reinforced polyethylene, along with its affordable price and strength, has high vapor barrier properties

Reinforced films can be perforated or non-perforated. The first type, due to micro-holes, is characterized by a fairly high vapor permeability (Sd = 1 - 2 m). This means that the perforated films allow a certain amount of steam to pass through. Therefore, in damp rooms such films are more often used in waterproofing systems. A completely different matter is non-perforated polyethylene with vapor permeability values ​​Sd = 40 - 80 m, which serves as an excellent barrier even for fine vapor.

2. Aluminum laminated polyethylene film

There is another type of film - polyethylene sheets with an aluminum reflective layer. In addition to high vapor barrier properties (Sd = 200 m), this material also has thermal insulating qualities, reflecting infrared radiation and retaining heat indoors. This type of vapor barrier for a wooden floor is most often used for very humid or hot rooms, where preservation is important. existing microclimate. These can be kitchens, showers, baths and saunas.

Vapor barrier film with foil coating creates an excellent vapor barrier and has thermal insulation properties

3. Polypropylene film

Compared to polyethylene, polypropylene is more durable. Materials with an anti-condensation layer, which have low vapor permeability (Sd = 50 -100 m) and prevent the formation of condensation on the surface, are considered especially high quality. inner surface films.

The anti-condensation layer of polypropylene film is formed by interweaving viscose fibers and cellulose

Polypropylene films may not have an anti-condensation layer, but in this case, condensation often forms on their surface, which is located in close proximity to the insulation.

Which side should I attach the vapor barrier?

The vapor barrier of the floor must be installed according to strict technology. One of the most important moments is which side the insulating film will be laid. If you do not pay due attention to this point, the vapor barrier will not work. The basic rules for installing vapor barrier are as follows:

• When using double-sided film, it must be laid smooth surface inside the “pie” (on top of the insulation), and the rough one – outside, towards the steam. The rough side will retain steam and condensation, preventing moisture from entering the insulation.
• Polypropylene films with a one-sided laminated coating are also placed with a smooth surface towards the insulation, and a wicker surface towards the room.
• Foil films tend to reflect infrared radiation thermal radiation. Therefore, it must be laid with the aluminum side outward, towards the room.

These styling principles almost always work. But manufacturers of modern vapor barriers still reserve the right to change this order. For example, the well-known vapor barrier Izospan B is recommended to be installed with the rough side facing the insulation, and the smooth side facing outwards. Therefore, always, before you start laying out the vapor barrier roll, read the instructions for its use.

Place of vapor barrier in the floor “pie”

The main role of the vapor barrier film is to prevent moisture vapor from penetrating the wooden floor structures and insulation. Therefore, a vapor barrier is always installed between the finished floor and the insulation. Typically, the floor design also includes a second layer of vapor barrier - it is laid behind the insulation, between it and the subfloor. This layer prevents the penetration of moisture and steam from the soil. However, this vapor barrier layer is sometimes replaced with a waterproofing film or membrane. The bottom layer of insulation is especially relevant on lower floors wooden houses, the subfloors of which are located directly above the ground or above damp basements.

Classic scheme for thermal insulation of a wooden floor - floor pie

Step-by-step instructions for installing a vapor barrier

1. Preparing the subfloor

Before laying a vapor barrier on the floor, it is necessary to treat all wooden base structures (boards, joists, cranial bars) with antiseptic compounds against rot, insects and fungi. If it is decided to install a new vapor barrier in an existing floor covering, the finished floor boards, as well as old heat and vapor barrier materials, are removed. All debris and dust are removed, the wooden elements of the subfloor are primed with antiseptics and installed in place.

2. Laying a vapor barrier on the floor

The first layer of vapor barrier film is laid for vapor and waterproofing, that is, to prevent moisture and steam from the ground from entering the insulation.

A roll of vapor barrier film is unrolled and the sheets are laid on the floor frame. The individual strips are overlapped by 15-20 cm and connected to each other using a special double sided tape or mounting tape. This solution eliminates the occurrence of cracks and gaps through which unnecessary moisture can penetrate into the insulation. The canvas is attached to the joists with a stapler or galvanized nails.

3. Laying insulation

Insulation with a thickness of at least 50 mm is laid on top of the film, between the joists. These can be polystyrene foam mats, polystyrene foam, mineral wool. The insulation should fit snugly to the joists and vapor barrier film without creating cracks and gaps.

Insulation mats are laid tightly between the joists, without gaps

The second layer of film plays the role of a direct vapor barrier, creating a barrier for wet steam coming from the room and preventing it from reaching the insulation.

The film is laid on the joists in such a way that ventilation gap between the vapor barrier and the finished flooring. The film strips are connected to each other with tape or mounting tape.

5. Finished flooring

Finished floor boards are mounted on top of the logs, on which the finishing material is subsequently laid. flooring, for example, parquet, laminate, linoleum, etc.

Installation of finished floor boards on top of a vapor barrier film

Video example of the work

When settling in protective layers insulation, the use of vapor barriers is necessary in any case. The range of products is large, it is difficult to understand the purpose, scope, and characteristics. In addition, you should know which type of materials is suitable for a wooden base, and which one is needed for concrete slabs ceilings Let’s look at the questions in more detail, let’s figure out how to install a vapor barrier on the ceiling and whether it’s possible to do the work yourself.

If the room is located so that one side of the ceiling is constantly warm, and the second plane faces outward, where the temperature drops to sub-zero levels, for example, a room under an unheated attic or roof, then condensation will collect in a certain area of ​​the structure. This area is called the dew point and it is important to move this point beyond the insulation layers. Otherwise, the overlap bearing structures and the thermal insulation will begin to get wet, rot and in a short time will become unusable.

Vapor barrier material protects the main structural units, floors, load-bearing beams from damage, prevents rot, and increases the energy efficiency of the house. A correctly laid insulator layer will release moisture out, but will not let it back in - this is due to the special structure of the material.

Advice! In rooms with variable humidity, laying out a vapor barrier is a necessary condition. The suspended water rises to the top; it is necessary to ensure timely release of steam so that mold does not form in the room.

Types of vapor barrier materials

The product range is large:

1. Reinforced polyethylene films. They have zero moisture absorption and cope well with protective functions. For zones high humidity It is better to use films with perforations, and non-perforated products are suitable for rooms with normal moisture levels. The availability and versatility of the material are advantages, but the ability to collect condensation on the surface is a disadvantage.
2. Polypropylene tapes with viscose coating - an option that is suitable for all types of premises. Viscose absorbs moisture without forming condensation. Increased strength and ease of installation are advantages; the high cost of the material can be a disadvantage.
3. Foil-coated insulation It is made of foamed polyethylene or thick cardboard, covered with foil (on one or both sides). High quality, reliability, durability and ability to display heat are advantages. In addition, the products are small in thickness and are indicated for installation in baths and saunas.
4. Vapor barrier membranes. Modern material, consisting of several layers: perforated fabric, polymer film, polypropylene. The main quality is 100% vapor barrier. The membrane collects all the moisture without giving it back. Two-sided insulators are considered especially effective, as they successfully remove all moisture to the outside. For processing concrete surfaces Varnishes and mastics with a membrane effect are offered.
5. Glassine is a durable cardboard impregnated with bitumen. It is distinguished by its plasticity, light weight and is used to protect wooden buildings.

When choosing a vapor barrier, you should pay attention not only to the cost of the material, but also the purpose, scope, protective characteristics and base materials for which the product is best suited.

Operating principle of vapor barrier products

Regardless of the type of product, all insulation has one purpose - to prevent the accumulation of condensation on insulating materials. But the principle of operation of the products differs. For example, the film does not allow moisture into the insulation, and the membrane allows steam to pass into the layers of thermal insulation, helping to evaporate excess moisture. And this is the main difference.

Important! When purchasing membrane sheets, you need to know how to properly install a vapor barrier on the ceiling - unlike film products, membrane rolls installed incorrectly will release moisture inside without allowing it to pass out.

What materials are better to choose

The type of insulation is selected depending on the base material, humidity level in the room, evenness base ceiling and many other factors.

For wooden ceilings

Basic requirements: to protect the wood from moisture and to ensure ventilation of the structure and the “insulation pie”.

Suitable:

• films of polyethylene, polypropylene;
• foil-type insulators;
• glassine;
• membrane vapor barriers.

To eliminate condensation on films, it is necessary to provide ventilation gaps - this way the moisture will gradually evaporate without damaging the wood structures.

For concrete ceilings

You should choose products that are attached directly to the base: varnishes, mastics, paints, insulators with a foil layer. The latter are mounted both on floor slabs and on wooden frame– this is convenient for forming a suspended, suspended ceiling.

Features of vapor barrier installation and fastening technology

Before starting work, the ceiling is cleaned of old coating, dirt and dust. Then like this: if used roll materials, the surface must be puttied, eliminating defects, unevenness, filling cracks, but before coating with liquid paints, bituminous materials It is enough to level concrete floor slabs with a ready-made repair compound. After puttying and leveling base surface primed in 2-3 layers with preliminary drying of the previous layer before applying the next one.

On a note! The wooden ceiling must be treated with an antiseptic, fire impregnation, and only then prime it.

On a wooden ceiling base

Rolled sheets are attached to the prepared base with a stapler and staples. When laying out film products, in order not to deform the sheets, it is better to place small pieces of cardboard or thick paper under the bracket.

Lay the strips overlapping each other by about 15-20 cm, and glue the joints with reinforced construction tape. In the areas of junction with the walls, the film is not cut, but is lowered 10-25 cm onto the wall panel.

Important! When using a vapor barrier membrane, first consider the material and determine which side to place the vapor barrier on the ceiling. The smooth side is laid out towards the ceiling, and the rough surface is “turned” towards the room.

After installing the insulation, a lathing is formed so that the sheets are held tighter; in addition, the structure will create the necessary ventilation gap so that drops do not collect on the ceiling vapor barrier, and will serve as the basis for finishing ceiling. Attach the sheathing with self-tapping screws, sewing it to the base base.

On concrete ceiling bases

Preliminary preparation of concrete slabs will reduce the risk of the thermal insulation layers getting wet. Most often, the sheets become moistened due to cracks at the junction of the plates, so it is important to properly seal all the seams, inspect the areas where the ceiling meets the walls - putty and prime the surface.

Once the base has dried, you can apply vapor barrier materials. Polymer mastic is considered a good solution - the mixture protects well from moisture vapor, and also does not allow water to pass through from above if there is a gap left somewhere in the ceilings. The mastic is applied according to the instructions from the manufacturer; all information is written on the packaging; it should be carefully studied.

When using rolled or sheet materials, a lathing is formed on the base from wooden beam or metal profile. The size of the cells must correspond to the size of the insulation sheets. Many craftsmen prefer to measure insulation rather than vapor barrier materials - first the insulation elements are laid out in the cells, and then the membrane or film.

How to attach a vapor barrier to the ceiling:

• on wooden sheathing staples (a construction stapler will come in handy);
• on metal structure with tape.

On a note! Foil materials are laid out only end-to-end, membrane and film with the sheets overlapping each other by 15-20 cm. However, in both cases the seams are secured with tape.

After the installation of the ceiling vapor barrier is completed, the sheets are pressed against another sheathing frame so that the necessary ventilation gap remains. If the ceiling is then covered with a tension fabric, then to form the second frame of the sheathing it is permissible to take thin dies so as not to burden the entire structure. And in case of formation suspended ceiling or hemming the surface with plywood, gypsum board, the timber must be strong enough, otherwise false ceiling will collapse.

Why does condensation appear on vapor barriers?

Having figured out how to properly install a vapor barrier on the ceiling, many owners are still faced with the formation of drops on the surface of the materials.

There are several reasons:

1. Sheets of foil products are laid overlapping one another. This is not true. Lack of clearance and ventilation leads to moisture accumulation on the surface of the insulator.
2. Wrong product selection. In rooms with high humidity film insulators will collect all the moisture on the surface, which will then flow down. To avoid this phenomenon, replace regular film with materials with a viscose layer - this will eliminate the appearance of condensation.

AND main mistake – vapor barrier membrane laid out on the wrong side. Recall: to the ceiling surface ( rough ceiling) the smooth side is turned, and the rough side “looks” into the room. If you are afraid of making a mistake, take a 2-sided foil insulator; in addition to protection from moisture, the product has the ability to retain heat, which is an additional advantage of the insulator.

“Izospan B” (which side to lay it towards the insulation, you will learn from the article) is a material that acts as a vapor barrier when there is a need to protect thermal insulation or other structural elements that can become saturated with moisture vapor during operation. The vapor barrier can be used in buildings for any purpose. Its structure consists of two layers, one of which is smooth, while the other is rough. The last layer allows the material to retain drops of moisture, which then evaporate.

Need for use

The use of vapor barrier material “Izospan V” allows you to maintain the performance qualities of thermal insulation for a long time. The material prevents the formation of excess moisture, protecting building components from corrosion and damage by microorganisms. Another additional function of vapor barrier is that it protects the room from penetration of insulation fibers.

Which side to cover

Quite often, Izospan B has recently been used as a vapor barrier. You should ask which side to lay it towards the insulation before starting installation. At the first stage, the consumer should decide where the smooth and rough surfaces are located. According to the instructions, the smooth side should be facing the surface of the insulation; this advice must be followed strictly. The membrane is installed on the load-bearing elements of the frame or on the rough sheathing. It is necessary to use a stapler as fastener.

If the premises will have finishing material in or lining, then “Izospan V” is strengthened along the frame with wooden slats with a section of 4x5 cm. Installation work provide for tight joining of thermal insulation with the film. If the material is used as a material, then the horizontal strips must be overlapped, and this work must begin from the bottom. Horizontally and vertically, the overlap should be approximately 15 cm.

Used to conduct interior work material "Izospan B". You now know which side to lay it towards the insulation. However, during installation there are many nuances that must be observed. For example, vapor barrier can be used in the construction of floors. In this case, the canvases must be laid along the ceiling joists. The material must be placed between the subfloor and the finishing floor. Between the thermal insulation and top layer membrane, as well as between the membrane and the finished floor, a gap of up to 5 cm should be left.

If you also decide to use when carrying out repair work“Izospan B”, which side should be placed towards the insulation, it is important to ask even before the start of manipulations. For example, if working surface is represented by plasterboard, the membrane must be fixed to the galvanized profile. It should be tightly mounted with the smooth side facing the thermal insulation. All resulting joints and places where the membrane will be connected to other materials must be glued with connecting tape from the same manufacturer. Do not forget to leave a ventilation gap of 3 cm, which is necessary to prevent displacement and reduce the likelihood of excess moisture accumulation.

Quite often, people wonder which side to place the vapor barrier against the insulation, if the latter is reinforced on the outside of the wall. In this case, “Izospan B” should be installed indoors, and its rough part should face inward. To fasten the material in all cases, you can use a stapler or slats, the latter of which are nailed. Both solutions are good, the main thing is to purchase galvanized fasteners, which will last a long time and will not cause rust spots.

Overlapping

After you have figured out which side to place Izospan on the insulation, you need to pay attention to one more point, which is the need to form an overlap of 20 cm wide between the sheets, which will prevent air from penetrating under the material. If fixation is carried out to vertical profiles, then the material should be tensioned to prevent it from sagging. A slight weakening is possible, but its fluctuations should not exceed 50 mm.

Specifications

Izospan vapor barrier is quite common today. Which side to lay it towards the insulation was mentioned above. However, you may also be interested in specifications, as well as purpose. For example, areas of use in in this case the following:

• insulated sloping roofs;
• interior walls;
• frame walls;
• basement floors.

The material is produced in widths that can be 1.4 or 1.6 m. The area of ​​one roll is 35 or 70 m2. The composition contains 100% polypropylene, its breaking load (transverse and longitudinal) is 107 and 130 N/cm, respectively. Resistance to vapor permeation square meter is 7 Pa/mg. The water resistance of the material is 1000 mm water. Art. Within 4 months, the surface of “Izospan B” will be able to undergo impacts ultraviolet radiation. It can be operated in a temperature range from -60 to +80 °C.

Technology for performing vapor barrier work

If you also decide to use Izospan V, which side to lay it towards the insulation, you need to decide before starting work. This was discussed in more detail above. However, not only correct location material in relation to thermal insulation is a guarantee of a successful procedure. It is also important to follow all the rules of technology. Thus, it should be taken into account that the vapor barrier coating is laid according to the principle that is used when installing a waterproofing layer. The coating must be laid entirely, there should be no gaps minimal amount. In those places where the covering is adjacent to the wall, it is important to place it on a vertical surface by about 15 cm to prevent the thermal insulation from getting wet. The vapor barrier should also not be moistened during work.

Adjacent sheets should be laid overlapping, and it is important to prevent the formation of voids and holes. “Izospan B” is becoming more and more common today. It is important to understand for yourself which side to lay it towards the insulation. But it is also necessary to remember that in winter such work should be carried out in warm places. The surface where the vapor barrier will be installed must be prepared, cleaned of dirt, dried and heated. If the rolls were stored in the cold, then they must first be kept warm for at least a day. The material should not be transported from place to place in the cold.

Which side should Izospan A be placed on?

You may be interested in the question of which side to lay Izospan A to the insulation. This material located on the outside of the wall or roof, after facing material walls or roofing. Rough surface should be adjacent to the thermal insulation, while the smooth one is located on the side roofing material or external wall cladding.

Conclusion

Floors can be vapor-insulated using the Izospan material. Which side to lay the material towards the insulation in this case was mentioned above. Using this vapor barrier, you can carry out work inside and outside buildings, the main thing is to figure out which type of membrane to choose.

During construction country house or a private bath, an important step is thermal insulation various surfaces. In addition, the insulation itself needs high-quality and reliable vapor barrier protection.

To prevent negative impact external factors and the formation of condensation on the heat insulator, any homeowner should have general idea about how to properly install a vapor barrier to ensure a long service life of the entire structure.

Membrane structure and operating principle

The most popular for their performance characteristics are breathable multilayer membranes, which are designed to create reliable vapor barrier protection.

They consist of three layers, each of which performs an important function. The first layer prevents the penetration of steam into the insulation, the second provides the necessary strength of the base, and the third protects against moisture from the outside.

Each individual layer has the necessary perforation for good air exchange. The first layer removes excess moisture, allowing dried air to penetrate. The reinforcing layer retains warm air masses inside thanks to a special weaving of threads. The third layer provides a sufficient level of traction inside the structure.

Some types of membranes have an additional anti-condensation layer based on viscose or cellulose. It retains excess moisture deposited on the paper fibers. To naturally remove moisture from the membrane, a technological gap of 2.5 cm is provided between the vapor barrier and the finishing surfaces.

Features of vapor barrier installation

An important stage in protecting insulating materials is laying a reliable vapor barrier layer. All work is carried out during the repair or reconstruction of a finished building or during the construction of a new building. To correctly install a vapor barrier, you need to understand how to connect membrane sheets and which side to fix them to the insulating base.

Preparatory work

On at this stage work is being carried out to select the appropriate type of vapor barrier, taking into account the features of the installation process, performance characteristics and material requirements.

Before laying a vapor barrier, careful surface preparation will be required. It is important to consider the type of material used in the construction of floors, walls, ceilings and roofing structure.

1. During the construction of a log house, everything structural elements treated with protective antiseptics and fire retardants.
2. When carrying out repair and reconstruction work, complete dismantling of the finishing, cleaning and preparation of surfaces is carried out:

Wooden elements are treated with compounds against aging, rotting and burning. Concrete, block and brick surfaces are treated with deep penetration antiseptic compounds.

Proper preparation of surfaces will ensure a long service life of the insulating material and the entire structure.

Technology for laying vapor barrier on the ceiling

If the roof structure and interfloor covering are made of wood, then the installation of the membrane for waterproofing is carried out on a prepared base.

Roll or block insulation is installed in the space between the rafters and joists, the best option– mineral or basalt wool. Next, you can lay vapor barrier protection on the ceiling surface.

When the thickness of the insulation is equal to the height of the logs, an additional slatted counter-lattice is installed to maintain natural ventilation.

It is necessary to install a vapor barrier on the ceiling with a slight overlap on the walls around the perimeter, while Special attention should be given to the corners. It is better to place the joints on the joists and glue them on both sides with tape on a reinforced base.

Important! When installing a vapor barrier, sagging and deformation of the panels should be avoided.

For thermal insulation flat roof or concrete ceiling is mounted from the inside waterproofing film on self-adhesive tape, then a lathing made of wood or metal is installed.

The height of the sheathing is determined based on the thickness thermal insulation material and minimum technological clearance for ventilation. The installation step is 3 cm narrower than the width of the heat insulator, which allows for high-quality installation of the insulator into the prepared sheathing cells.

Technology for laying vapor barrier on the floor

The installation scheme for vapor barrier protection on the floor is similar to how the material is laid on wall and ceiling surfaces.

The wooden floor is insulated using joists, on which a waterproofing layer is laid. Next, insulation is placed in the space between them - wool on a mineral or basalt basis. After this, vapor barrier material is laid.

The rolled material must be laid with an overlap of 12 cm, with the joints carefully sealed with metallized tape on both sides. A properly laid vapor barrier should completely cover the floor surface with an overlap of up to 10 cm on the walls.

To install vapor barrier protection on concrete base, you will need to install a sheathing, in the cells of which a waterproofing layer and a heat insulator will be laid.

Choosing a side for installing a vapor barrier

Once the material for the vapor barrier has been selected, you should consider important question– which side to attach the vapor barrier to the insulation. Such materials can be fixed as follows:

• Polyethylene films (reinforced and plain) are laid on any side, which does not impair the protective properties of the material.
• Foil films are installed with the reflective side inward to effectively reflect heat.
• Anti-condensation films are mounted with a fabric surface inside the room, treated - to a heat-insulating base.
• Membranes of any type are attached with a smooth surface to the heat insulator, and with a rough surface - inside the room.
• Foam-based insulators are laid similarly to membrane materials.

Important! Before laying the vapor barrier to the insulation, it is recommended to spread the prepared material on flat surface to correctly identify the inside and outside.

The face or the back of a vapor barrier?

If a breathable membrane is used to create a protective barrier, the main thing is to determine which side to lay the vapor barrier on - face or back.

The vapor barrier cake must be placed so that the protection is directed towards the heat insulator on both sides with the smooth back side, and with the rough front side facing the inside of the room.

The rough surface provides protection from moisture penetration into the insulation, and the smooth surface promotes maximum heat accumulation.

Determining the width of the overlap when installing the membrane

There are special markings along the edge of the insulating membrane to determine the width of the overlap of the sheets, which ranges from 8 to 20 cm.

The vapor barrier strips on the roof should be laid in a horizontal plane from bottom to top, overlapping each other with a width of 15 cm. At the ridge the overlap is 18 cm, at the valley - 25 cm.

On walls, ceilings and floors, the canvases are mounted with an overlap of 10-15 cm.

Is a layer required for ventilation?

In the lower part membrane vapor barrier There is a 5-centimeter ventilation gap, which helps prevent the formation of condensation on surfaces and heat insulation.

Diffusion membranes can be attached to insulation, plywood sheets or OSB. In a membrane with an anti-condensation layer, gaps up to 6 cm wide are located on both sides.

To create a gap for ventilation when insulating the roof structure, a counter-lattice is used. In the process of fastening a ventilated facade, a technological gap is created when installing racks located perpendicular to the vapor barrier.

Elements for fastening vapor barrier

To reliably fasten a membrane or film vapor barrier, nails with wide heads or metal are used construction staples. Most practical option fasteners - counter rails.

To increase the tightness of the structure individual elements vapor barriers are additionally sealed with double-sided adhesive tape or wide metallized tape.

To ensure long service life modern insulation materials, you will need high-quality vapor barrier protection. Otherwise it will be difficult to obtain optimal ratio temperature and humidity indicators in the premises. The main thing in this matter is to choose the right one suitable material and know how and which side to lay to the heat insulator.

will penetrate into layers of material and slowly destroy it. This property is especially relevant in cold period years when the temperature difference between indoors and outdoors is significant.

For this reason, a volume of steam is formed in the house, which must leave it without obstacles. In order to correctly carry out the installation of materials that prevent the accumulation of moisture, you need to know which side to lay the vapor barrier.

During preparatory work it is necessary to make a choice of the one that will be used in the vapor barrier.

Today on the market of materials suitable for moisture protection are: various options, which are suitable for work on floor slabs, ceilings, under the roof, on walls or even on the floor:

• When installing a vapor barrier on wooden structures: ceiling, walls or floor, it is preferable to use films with a membrane designed for such cases.
• For floors made of any material - mastics based on polymers and bitumen.
• The universal “Izospan” is suitable for ceilings, various surfaces of walls and floors; it has excellent construction against moisture and condensation accumulation.
• For concrete or wooden walls Foil, polystyrene foam, and mega-isol are suitable.

If the surfaces are not properly prepared, the vapor barrier will not be effective. Complex preliminary work depends on the specific material from which the house is built, whether the walls, floor or ceiling are erected, and also on whether a new building is planned or a major renovation of a dilapidated one is planned.

Surface preparation options depending on the material:

• If it is being built wooden house from scratch, you first need to saturate all parts with special insect repellents, this is important for the subfloor, ceiling and walls. It is also worth using impregnations against fungi, mold and fires. When this work is completed, you can do the vapor barrier.
• During major repairs They dismantle outdated floor coverings and all layers of insulation. All surfaces are cleaned, impregnated with products, and only then a layer of material is applied to protect them from moisture.

Concrete buildings do not require separate surface treatment with special substances; it is enough to clean the walls, floor or ceiling.

Vapor barrier helps prevent the formation of mold, mildew and rot in wooden buildings. does not require great skill, it is enough to properly prepare the surfaces and know a few nuances of the work.

We put a vapor barrier on the ceiling

During work, the question very often arises, which side should the vapor barrier be placed on the ceiling and how to lay it correctly? You will find the answer to this question in this article.

First, you need to determine where the front and back sides of the vapor barrier are. Typically, vapor barriers have a smooth side and a rough side. More uneven surface always faces the insulation layer, and is smooth on the outside.

If in doubt, you can take a small piece of material and cover the mug with it. hot water. Condensation will settle on the side that remains waterproof.

Instructions for installing vapor barrier on the ceiling

Before starting work on the vapor barrier of the ceiling, it is necessary to clean out all irregularities that do not exceed 5 mm, then clean it of dust and dirt, and then prime it and dry it.

The installation of the material depends on its characteristics; most often, vapor barriers are installed indoors on the inner surface of the ceiling or ceiling.

If the climate is such that in winter the temperature can drop to low levels, and the walls are not too thick, then it is recommended to install a vapor barrier inside and outside.

• The vapor barrier is usually attached to the surface using a stapler.
• Special attention should be paid to the corners; the material should slightly overlap the walls around the perimeter of the ceiling.
• The material must be whole; the use of several pieces is not allowed. It is important that the edge of the canvas overlaps the corner.
• When laying a vapor barrier film, its surface should be as stretched as possible. It is placed only after the insulation layer has already been laid.
• The film, which is laid between the ceiling beams, is secured using nails with a special wide head; a distance of about 30 cm must be maintained between them.
• The film sheets on the ceiling must be placed overlapping each other. The joints are hermetically sealed using tape.

Sometimes a vapor barrier is laid on the ceiling without a layer of insulation; in this case, the film can be attached using strips of plastic or wood, which are fixed to the ceiling with screws. The step between the slats should be small, and the attachment points themselves should be located at a distance of no more than 30 cm.

When insulation material is placed on top of a vapor barrier, there is no need to attach the vapor barrier layer separately. You can record everything at once.

Attaching various types of vapor barrier to the ceiling

Sheet vapor and thermal insulation requires a special approach during installation.

First, a special frame of profiles is installed.

These can be wooden blocks or special aluminum slats. The latter are much easier to work with, since they are designed for these purposes.

They have special grooves into which sheets are secured. To eliminate the gaps between the ceiling and, it is necessary to capture a small part of the wall.

There is a type of vapor barrier made from roofing felt; this type of work is called lining. This material is laid on the prepared floor surface. During pasting, heated bitumen or mastic is used, which is applied without missing areas.

If there are joints in the ceiling or corners, then it is necessary to introduce the material with a slight overlap and secure it with nails with large heads on a special rail. The edges of the material are folded under the insulation.

If a painted type of ceiling vapor barrier is used, then most often they use bitumen-kukersol mastic, varnish or hot bitumen. The varnish must be made on the basis of chlorinated rubber or polyvinyl chloride. A layer of mastic is applied using a special sprayer.

The varnish coating is applied twice, and you must wait until the first layer has dried before applying the second.

Features of laying vapor barrier to insulation

When carrying out work, it is very important to consider which side to lay the vapor barrier to the insulation. If you make a mistake at this stage, the thermal insulation will not be effective.

For all film-type materials, one rule applies: the film is placed in such a way that the smooth surface is on the insulation side, and the rough surface is on the inside.

This rule is suitable for protecting walls, ceilings and floors from moisture, but only if the material has a structure consisting of two layers. When working with a vapor barrier with an aluminum side, it is necessary to place the shiny surface inside and the rough surface against the wall.

Using polypropylene material, also the rough side should face the room, and the smooth side should face the insulation. As a rule, high-quality vapor barriers have instructions and installation guidelines.

Installation of vapor barrier on the floor

Vapor barrier materials must be laid only on a prepared base. For this type of work optimal solution will use isospan. You will also need a construction stapler and adhesive tape suitable for the following purposes:

• If the film is two-layer, then its first layer is laid directly on a wooden or concrete floor.
• The material should be laid with an overlap of approximately 5-10 cm on the walls, and secured with a special tape.
• In places where the film is glued together from two canvases, it is necessary to additionally fasten the layers with a stapler. When laying, the result should be a single canvas, without defects. It should completely cover the floor area.
• Any insulation material is placed on top of the vapor barrier: mineral wool, polystyrene foam, expanded polystyrene and others. After the layer of thermal insulation, it is necessary to put a second layer of material to protect against moisture.
• The vapor barrier is placed with a smooth surface against the insulation.
• In the first layer, the rough side faces the base of the floor, and in the second layer, it faces the room.
• After the materials have been correctly laid, the main floor is installed.

When using a film with a foil side, it is laid end-to-end. To fasten the canvases, you need to use a special tape with an aluminum surface.

A layer with a metallic sheen is placed towards the room, then all the heat will be reflected from it and returned to.

Sometimes special rubber is used to vapor barrier the floor. liquid state. The subfloor is prepared in advance; its surface must be dried and cleaned of dirt.

Then the mastic is applied using brushes or a roller. After time, the impregnation dries and forms a dense film that completely matches the texture of the floor.

Types of vapor barrier

An important stage in carrying out thermal insulation work is right choice material.

Not so long ago, the most popular way to protect against moisture was to use glassine or roofing felt.

Today the market is saturated with offers, and technological progress has gone far ahead - you can buy combined materials that are reliable and durable:

• The film is an excellent vapor barrier and prevents condensation from forming on the walls, roof and insulation itself.
• Film with a layer of aluminum foil. The metal surface has the ability to reflect heat and has excellent vapor barrier properties. This type of material makes sense to use in wet areas: bathrooms, swimming pools, saunas and baths.
• Film with a membrane - has a limited ability to transmit steam. Depending on its condition, it can change its properties. As the humidity level increases, the film begins to allow steam to pass through; in a dry state, this property is much lower.
• Mastic based on bitumen - allows air to pass through and retains moisture.

Vapor barrier materials can also be produced in sheets and rolls. Depending on this, the installation technology differs.

When using the material in rolls, they should be rolled out in the direction from bottom to top. The fabric is secured using wooden slats or profiles in the horizontal direction.

The hole for ventilation is left in the gap between the vapor barrier layer and the finishing inside; its size must be at least 4 cm. The fastening must be strong.

The vapor barrier in sheets is mounted in a pre-prepared profile frame, and then the material is installed into it from the bottom up.

Features of vapor barrier

Vapor barrier materials are necessary for normal circulation of moisture in the room. A special membrane in the film prevents the insulation from accumulating moisture. Therefore, it is very important to observe several conditions when laying the layer:

• If a membrane with wind and waterproofing properties is used, it must be in close contact with the insulation. If there are gaps, the material will cool to a temperature that will be lower than that of the steam being released. Then the membrane film can be covered thin layer ice and cease to be effective.
• It is necessary to provide a gap for steam removal of at least 40-50 mm. But the size may vary depending on climatic conditions. It is especially important to maintain a balance for large roofs or with obtuse angle slopes, in which air circulation is worse.
• The amount of steam passing through the system should be kept to a minimum.

Vapor barrier has one important function - it prevents moisture from entering the insulation layer. But that’s not all, when silicate or polystyrene foam materials are used in houses to retain heat, the membrane will serve as a barrier to the entry of individual fibers and volatile substances into the house, which can be harmful to health.

Air does not escape through cracks and gaps in structures, and the house remains at a pleasant temperature.

Recommendations for proper installation of vapor barrier materials

Planning work on installing a vapor barrier begins with identifying the most critical areas where special attention is needed. Laying material that protects against moisture is needed where the surface becomes the boundary between warm and cold air.

Most often such places are basements, ceilings, roofs, attics, attics and walls. Wooden structures require special attention when performing vapor barrier work:

• The layer protecting against moisture must be laid with the smooth side facing the insulating materials, in this case there will be no influx of steam, rot or fungus will not begin to form, and heat will not be lost. This is especially important for wooden buildings.
• If the walls are insulated from the outside, then the vapor barrier is placed outside the room. At indoor installation For thermal materials, a layer of film that protects from moisture should also be located on this side.
• The most common mistake is a loose fit of the film to the insulation.
• When gluing the seams of vapor barrier sheets, it is necessary to use wide tape of at least 10 cm.
• When work is carried out in places window openings, then they often forget to leave a small supply of film, which is needed in case of deformation or shrinkage. This should be a fold 2-3 cm in size.
• The film must be protected from exposure sun rays, in just one season the exposed surface can become unusable.
• To connect the joints of the film to the foil surface, you need to use metallized tape.

On the one hand, vapor barrier work does not require great skills, but there are still a number of nuances that need to be taken into account. The main condition correct installation film - installing it with the correct side to the insulation. As a rule, it is not difficult to determine the reverse and face of a material. The video shows how to install Izospan: