DIY vapor barrier: tips and recommendations

Even if it seems that the air inside the house is very dry, and even air humidifiers are specially purchased, it still contains a large number of moisture vapor. Before the appearance of energy -saving materials in the construction, no one paid attention to this. Modern thermal insulation materials based on mineral wool were ineffective and lost most of their fragmentary qualities due to gradual wetting. Therefore, special films appeared on sale, some of which are mounted only on the outside and are wind and moisture-proof, and the latter are located from the inside, from the side of the room and prevent the penetration of steam. The article will talk about the correct vapor barrier of the house.

Content:

What is vapor barrier in the house for

A house without vapor barrier can be if it is insulated with polystyrene, foam or does not have a heat -insulating layer, such as foam block and brick.

But to save on heating and to improve thermal protection characteristics of houses in modern construction, natural heaters made of cellulose (ecowata) or basalt wool are almost always used. But here we must remember the constant moisture exchange, which occurs in the living room.

So, if the house is too wet, then the water vapors will inevitably be absorbed by the walls and the ceiling, and, conversely, with excessively dry air, this moisture will turn to the rooms. From which it follows that if the insulation in the wall is not protected by a vapor barrier film, then moisture will accumulate in it, filling all the air cavities between the fibers of the mineral wool, thereby depriving it of all its thermal insulation characteristics.

Tip: the exception is internal partitions in the house. One of the most important factor in which a mineral -based insulation absorbs steam is the difference in temperature that happens in the outer walls. In this case, condensate accumulates inside, which is most dangerous for the material. But in the interior partitions there is no such effect, so they are not closed with vapor barrier material.

Those cases when the installation of vapor barrier is required

When the walls bordering the street are insulated with mineral wool outside;
if the wall of the wall consists of several layers, one of which is a cotton insulation. In this case, the vapor barrier film is mounted on the inside. The most striking example of such a device is frame houses;

when arranging ventilated facades. Mineral insulation should be closed outside with a hydraulic protection film, and a vaporizard. The first will protect thermal insulation from water and air flows, and the second from the interior of the steam. A clear example is a wooden house, sheathed with siding or wooden lining.

Steamed films are released in several types and divided into wall and roofing:

vapor barrier of the roof. It is attached from the side of the dwelling, protecting thermal insulation from rising vapors. This is an important stage, since the evaporation of moisture rises with warm air up and can fall into the insulation. It threatens this not only with a loss of heat, but also the formation of mold and fungus. It is needed only when arranging an operated and heated attic. If the attic is cold, then the vapor barrier is not done, limited to the windproof membrane under the roofing material itself, which protects it from the formation of condensate;
vapor barrier of the walls of the house. It should be carried out by special materials that, on the one hand, should not let steam pass to insulation, and on the other hand, unhinderedly remove it if the moisture somehow got inside. This happens due to possible cracks or incorrectly made joints of rolled materials. It is better to choose special diffusion materials, instead of the usual polyethylene films or parcham;
vapor barrier of the inter -story floor. It must also necessarily be done, as condensate from rising ups ups can accumulate $

steamed flooring. It is necessary in rooms with high humidity or in houses where the floor is insulated with mineral wool. In this case, a waterproofing film is placed on the bottom, and vapor barrier is laid on top. Equip a vapor barrier when concrete floor slabs are located directly above the ground.

If the question is whether vapor barrier is needed in a wooden house, then again you need to rely on the presence of insulation. If it is not, and the wall of the house consists entirely only of a beam or log, then it makes no sense to mount a vapor barrier film.

Types of vapor barrier materials

Until recently, the only vapor barrier material used in Russia was Permamin. But with the development of technology, it gradually began to start from him, preferring more durable and high -quality materials.

Polyethylene films. They are best used for vapor barrier of the ceiling in a living room. Most often, inter -story ceilings are insulated with mineral wool, since it has the best soundproofing properties. The plastic film will reliably protect it from even a small amount of moisture. On sale you can find ordinary materials reinforced or with a foil layer.

Polypropylene films. It is best to use to warm the ceiling on a residential attic. They are distinguished by increased strength to mechanical damage and resistance to UV radiation. When arranging it, you can safely repair the roof, not afraid that moisture will leak inside the house.
Membrane. This popular and often used type of vapor barrier is produced in the form of a single -layer or multilayer roll material. These non -woven materials can be one -sided or bilateral, this will depend on this. The use of inexpensive bilateral non -punctured membranes is considered optimal.
Breathing films or breathing membranes. They completely exclude the possibility of penetration of water vapor inside to thermal insulation, but at the same time do not at all prevent their exit from the inside. They can save on living space, since their functioning does not need to equip a ventilation gap.
An ordinary vapor barrier film. Its function consists in creating a vapor barrier from the inside of the walls and roofs. It protects thermal insulation material from steam from the inside of a heated room.
Vapor barrier membrane with a reflex coating. It is able to partially reflect heat back into the room. This helps to increase the thermal protection of the room and roof to 10%. Regarding standard analogues, they have large vapor barrier characteristics, so it is advisable to use them in rooms with high humidity.

Vapor barrier membrane with limited permeability. They have diffusion abilities that make it possible to remove pairs from the premises that are used irregularly. For example, it can be a garden house that is actively operated in the summer, and in winter it can only be heated a few times.
Vapor barrier with variable vapor barrier properties. Ideal for repair work, as they can be mounted from the outside without dismantling the internal cladding.

Manufacturers of vapor barrier films

Technonikol

This well -known company guarantees that its vapor barrier films will last more than one decade. On sale there are 3 main types of these products:

the vapor barrier film is techno -nicol. Used for internal work. Pretty universal material that is suitable for insulating walls, ceiling and pitched roofs of the attic. The price of the roll is 1,500 rubles.;

diphuszial membrane films Technonikolintended for the isolation of a subcutaneous insulation from the formation of condensate in it. It is a non -woven polymer canvas and the protection of both sides of polypropylene canvases. Unlike conventional vapor barrier materials, this is a breathing film. The cost for a standard roll is about 3200 rubles.;
unperformed vapor barrier film Technonikol. Narrowly targeted material for a roof steam gun. Protects both from water and dust. For the greatest strength, it has reinforcement with a special mesh fabric. The approximate cost is 1200-1500 rubles/roll.

Isospan

This is the rare case when a domestic company represents high -quality world -class material at an affordable price.

Isospan with. This is a two -layer film Protective insulation from the inside of the room. It can also be used as a subcutaneous film on unsolded roofs. One side of it has a roughness, the role of which consists in holding excess moisture and with its further evaporation. The second side is smooth, it is mounted on the insulation.
Isospan in. An analogue of the previous material, it is also chosen for vapor barrier of the walls of a frame or wooden house from the inside.
IsospanD.. This is the most universal pair -protective film from the entire presented line of products of Isospan. It has an anti -condensate coating that can protect mineral wool as from the inner pair, so from external moisture and wind. Its strength is so high that it can be used as an independent roofing for 3 months even in the winter. When installing it on the walls from the outside, it is allowed to postpone the arrangement of the finish cladding for up to 6 months. Rolon price 2500 rub.

Installation of vapor barrier walls in a wooden house

The technology of installation of vapor barrier implies its fastening from the inside of the house between the insulation and the crate, to which the facing material is mounted. If modern membrane material is used, then it is placed with the smooth side close to the insulation. In this case, the vapor barrier will evenly distribute wet air flows, bringing it to the ventilation system.

The method of attaching vapor barrier depends on the purpose of the premises in the house. In low -extracted or non -residential rooms, in which low humidity is allowed to use a unilateral method of arranging a ventilationzor. In all other cases, professionals advise to provide bilateral ventilation, which is much more effective. Often, the manufacturer of the membrane on the package indicates the recommended installation method.

Stages of work

If the house is not new, but repair work is carried out, then at first they dismantle the entire cladding to the wooden frame of the wall. If possible, inspect the insulation or wood for damage, if necessary, eliminate them.
Walls and thermal insulation should be carefully dried. It is advisable to perform work in the warm season, since in the winter an irrigation can form, which by closing vapor barrier will turn into a large amount of moisture over time.

If the house is frame, then the membrane is rolled out along the length of the entire wall and cut off so that in the corners the overlap on the adjacent wall of 10-15 cm is obtained. It is fixed in stages to each verticlier board of the frame with a stapler. Skews, cracks or folds should not form. Therefore, the work is better to do together. The tension should be so strong that the insulation in the wall is located tightly, without falling out of the wall.

On top, again with an overlap, the next layer of vapor barrier is rolled and attached in a similar way. After that, the joints are glued with tape. On top, a frame is stuffed from the racks, which tightly presses vapor barrier and at the same time serves as a frame for facing. Subbus represented spinning slats, which are attached to self -tapping screws with a step of 60 cm (the distance corresponds to the width of the insulation and the frame of the walls of the house). In addition, the film is also fixed along the perimeter of all door and window openings.

If vapor barrier of the house from the beam is made, then the frame is primarily stuffed to the walls under the insulation and tightly laid it there. Further, all work is performed according to a similar scheme.

With your own hands vapor barrier in the house

Most often, it is done if the floor ceiling is made of wooden lag and insulated with mineral or basalt wool. To perform this work, two people will be required, it will be extremely difficult to make one.

Before starting work, the ceiling should be disassembled and consist only of the lag.
Then, from below, that is, from the side of the living room, vapor barrier is attached to the lags. This must be done along the longer side of the room to form as few joints as possible.
The required length is measured and cut off on the floor and already with a prepared segment rises to the ceiling. It is convenient when 2 masters are located on the opposite sides of the room. This allows you to properly arrange vapor barrier and make sure that it does not distort it during fastening.
For the convenience of work, at first it can simply be grabbed in several places (but do it firmly). And making sure of its correct location, it is already thoroughly fixed.
So the whole ceiling pass, not forgetting about the overlap and their gluing.

From below to the lags, it is attached with wooden rails, regardless of what the ceiling coating will be.

Tip: the work is rather painstaking and often happens when an accidental anguish occurs in the already fixed area. In this case, a patch from the membrane with a allowance along the edges 10-15 cm is cut out. It is inserted into the resulting hole and glued along the edge with glue. This creates a rather sealed layer. On top is additionally glued with tape.

Having finished fastening the vapor barrier, from the side of the second floor, the insulation is laid in the formed cells.

Errors during vapor barrier in a frame house

Poor -quality installation. At first glance, it seems that it is simply impossible to make an error when fastening a vapor barrier film. What could be easier than pulling it well, attach it to the frame and glue the joints. But it is precisely because of the apparent simplicity, some builders neglect accuracy during work. As a result, ruptures or folds are formed. But the improper location of the membrane, or rather the wrong side, may be the worst mistake, as a result of which it begins to work incorrectly. If all this was already closed by the interior decoration, then the consequences of such work can be guessed only after a couple of seasons, when the thermal insulation layer begins to work worse.
Installation of a vapor barrier film from the outside of the house. This gross error leads to the fact that the steam, leaking from the inside at home and passing through the insulation, rests on a vapor barrier and settles with condensate on it. During a very short period, the insulation damps it, unable to ventilate. For external protection, it is necessary to use exclusively windproof films that are able to skip excess moisture out.

Lack of vapor barrier in a frame house. There are a number of materials that allow the absence of a vapor barrier. This is a foam or extruded polystyrene foam. Most often it is made in houses from sandwich panels. But, to remove excess moisture from the house, in this case it is necessary to mount a high -quality forced ventilation system. When warming an ecowide or mineral vapor barrier, must be present in all cases.
Double vapor barrier. It happens that if a vapor barrier layer is placed in rooms with high humidity, and a facing material with low vapor -permeable properties is laid on top, for example, plastic panels or tiles. It turns out that having passed through the seams of grout or joints of the panels, steam falls between vapor barrier and tiles, without the possibility of exit to the outside. Therefore, for facing in such rooms, it is recommended to make a crate on the wall that borders on the street.

Or just refuse vapor barrier in this place, but there will be a risk that, getting into the insulation, the steam will not have time to disappear through the windproof membrane from the outside. This is permissible only for frame houses that are used as summer cottages.

Selecting the method of installing vapor barrier. In total, 2 methods of using a vapor barrier are used. In the first case, the film is attached to the frame of the wall, and on top of the same load -bearing wall boards, sheathing material (drywall, lining, etc.) is mounted. In the second version, the film is similarly nailed to the wall frame, but under the lining material of the walls, a frame is additionally made from the racks 2-3 cm thick. Which way is to consider more correct?

The first option has the right to exist, but only if the materials of the highest quality are used for decoration. Otherwise, the repair will quickly become worthless, due to the lack of ventilationzor. Or apply this method when the construction has an economic purpose and is not used year -round. But here it is necessary to do ventilation wiring throughout the room.
The second option with the arrangement of ventilation fence is more acceptable for houses intended for permanent residence. This helps to eliminate the risk of unnecessary humidity in the air.

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