What is the best vapor barrier for a frame house. A Guide to Reliable Vapor Control for Hardwood Floors

The construction of a frame country house is inexpensive, but such a building need to be insulated.

Since wood passes water vapor well, and with the accumulation of moisture it can rot, you need to carefully protect from the action of water vapor and drops.

Thermal insulation materials can also absorb water vapor and cause wood to rot when in contact with wood.

Obviously, even before the start of construction, the future owner needs to understand the properties of vapor barrier materials and the procedure for warming so that the house is warm and does not collapse fungus and bacteria.

There are such groups of vapor barrier materials:

1. Reinforced polyethylene film. For greater tensile strength, it contains a mesh sealed inside, which takes on the mechanical load. This is the cheapest material. When buying, you should make sure that it is strong enough to tear. Mounting it is convenient and simple, since the edges of the panels can be securely sealed with construction tape and a vapor barrier of a sufficiently large area can be obtained. The reinforced film can be laid on either side of the insulation, since the properties of its surfaces are the same.
2. Bitumen-cookersalt mastic. Other mastics are also used for vapor barrier, but this one is the most popular. It consists of lacquer "Kukersol", bituminous resin, rosin and Portland cement. It is a ready mix that does not need to be mixed or diluted. Although it contains strong-smelling substances ( bitumen, rosin), the finished mixture is practically odorless. This means that it can be applied to the wall not only outside, but also inside. After the walls are treated with this mastic in several layers, the wood acquires water-repellent properties, but passes steam well. The dried layer of this material has elastic properties, so it does not break when bent. This allows the mastic to be applied to plywood that can bend under load. Cracks are not formed, and the layer is not destroyed.
3. Ruberoid. Affordable vapor barrier, which is laid only on the outside due to the specific smell. It retains water well and passes steam, but for its laying you need a crate of bars, which are attached in increments of no more than 50 cm.
4. Specialized film vapor barrier membranes, which may consist of several layers and contain reinforcing meshes for reinforcement. To work with them, they offer double-sided and reinforced tape or mastic for sealing joints. The surface of such membranes may be covered with foil or pile to retain condensate. Such films are chosen for a specific task. For instance, foil membrane needed for vapor barrier baths. Here, it not only retains steam, but also reflects heat inward, reducing its loss. Such a vapor barrier is more expensive than a reinforced polyethylene film. Foil film is always laid with foil inside the room. Membrane with a rough anti-condensation coating lay the rough side to the fibrous insulation at a distance of 2-6 cm from it.
5. Diffusion vapor barrier membranes. These materials differ from others in that they do not have permanent properties. In some conditions, they prevent the penetration of steam, and in others, they accelerate its removal. They are needed where there is a high probability of moisture accumulation and destruction of the frame. For example, a diffusion membrane is laid on a heater when "wet" finishing of the facade. If a little moisture gets on the wall, the film does not let it through into the insulation, and the water from the wall evaporates in dry weather. But where water constantly flows under a layer of finishing material into a heater (for example, under a window sill), the diffusion membrane becomes vapor-permeable and passes steam through a wooden wall into the house. Indoor steam must be removed through ventilation slot between the wall and interior finishing material. After the rains stop and the insulation dries out, the diffusion membrane becomes vapor-tight again, protecting the thermal insulation from steam. Such a membrane is more expensive than a specialized one.

Regardless of the chosen type of material, it must be mounted so that its panels are hermetically connected overlap with an overlap of at least 15 cm or end-to-end (for metallized film) with gluing the edges with construction tape. Only in this case a reliable vapor barrier layer is formed.

Operating procedure

The vapor barrier of the frame house is carried out in the course of work on insulation and wall decoration. For the installation of a vapor barrier layer, you will need such tools and materials:

• tape measure or measuring tape;
• scissors for cutting film materials;
• double-sided construction tape (metallized tape for mounting metallized films);
• a stapler with brackets for attaching films or a hammer with nails when installing roofing material;
• wooden slats with a section of 40 × 50 or 50 × 50 mm, if you want to create a ventilation layer;
• vapor barrier material.

The work is done in this order.:

1. In dry weather, the wooden frame and slats are treated several times with a compound that protects the wood from decay and ignition. After it is completely dry, proceed to the next step.
2. The walls are measured and parts of the required size are cut out of the material, taking into account that at the point of contact of the panels, films without a metal coating will overlap with a width of 15 cm, and metallized ones - butt.
3. The film is laid from the foundation to the roof, overlapping the next sheet. The edge of the top panel is glued with double-sided tape to the bottom. Metallized films are laid end-to-end, the joints are glued with metallized adhesive tape. Materials are fixed on the wall with a stapler or nails. It is not recommended to overstretch the films, because at low temperatures they will shrink and tear.
4. After installing the vapor barrier, proceed to the insulation and finishing.

Vapor barrier outside

In this case mounted on the wall, then a vapor-permeable insulation (for example, mineral wool) is laid, the insulation is covered with a windproof vapor-permeable membrane, through which moisture is removed from the insulation.

finishing(siding or facade panels) are mounted with an air ventilation layer. Inside, vapor barrier is not made, but the finish (wooden panels or drywall) is mounted on the crate.

In this case, between the wooden wall and the finishing material is formed ventilation layer through which moisture is removed from the wood of the wall.

Vapor barrier from the inside

Such wall protection method from moisture is also possible. The film is fixed on the walls from the inside. Finishing panels are also mounted on the bars of the crate. The air gap between the wall and the panels ensures the evaporation of the condensate that forms on the film. Outside, the wall is not isolated from steam.

Laid on the wall vapor-permeable insulation, a windproof vapor-permeable membrane and cladding panels with a ventilation layer are mounted. In this case, the moisture from the wood penetrates through the insulation and is vented through this layer, as well as the moisture condensed in the insulation.

Mounting errors

For independent developers, the most typical such mistakes:

1. Fixing the vapor barrier layer on top of the heat insulator from the outside. In this case, the builder believes, the insulation will be reliably protected from water and vapors and will always be dry. However, water vapor seeps from the inside through the finish and the wooden wall, and then condenses and accumulates in the insulation. Thermal insulation at the same time loses its properties and moisturizes the wood, which begins to rot.
2. Installation of vapor barrier on the inner and outer surfaces of the wall. However, no film isolates wood from steam perfectly. Vapors seep into the wall and accumulate in it. The result is rotting walls. It must be remembered that the vapor barrier is needed only on one side of the wall, and there must be air access to the second side.
3. No vapor barrier. At the same time, no materials, except for heaters and finishes, are mounted. If outside the role of a heater is played by mineral wool, then the steam seeping out of the rooms condenses in it at the dew point. At the same time, the mineral wool is moistened and then freezes. Thermal insulation deteriorates, and wood can rot. If the foam serves as a heat insulator, which itself plays the role of a vapor barrier, then moisture accumulates between it and the wall.
4. Low quality installation. If gaps form in the vapor barrier during installation, then heat leakage and rotting of the walls will occur there. For this reason, you can not stretch the film, somehow glue the joints or leave places that are not protected by the film. Minor imperfections can cause the load-bearing wooden parts to rot, and then the walls to collapse.

Wooden structures of a frame house require not only insulation, but also proper vapor barrier. If you do not protect the wood from moist air, the house will break down quickly.

Protect wooden structures from water vapor only possible on one side. The second side must communicate with air to remove moisture. Vapor barrier materials must be laid exactly following the technology. Poor installation of the vapor barrier also leads to the gradual destruction of the building.

How easy it is to lay a vapor barrier for the walls of a frame house in hard-to-reach places, look at the video:

For a long service life of the insulation in a frame house, attention should be paid to such an element of the overall design as the vapor barrier of the frame house and its quality. It is important to follow this already during the construction of the structure. Although many are still wondering: do I need a vapor barrier for a frame house?

Do I need a vapor barrier in a frame house? A well-thought-out and well-equipped vapor barrier of the internal walls of a frame house is needed for warm and at the same time humid rooms. A large amount of moisture and steam is generated in the frame house, which must be removed from the building in order to maintain optimal humidity, high quality and the appearance of a do-it-yourself frame house.

Moisture in the process of its formation and accumulation tends to go out through the walls or ceiling. First of all, moist air rises, so the vapor barrier of the floors will stop the movement of air and prevent the insulation from getting wet. If the correct vapor barrier of the frame house is not installed, then the humidity in a short time will destroy or cause quite serious damage to the construction site, and also create an unfavorable microclimate.

Vapor barrier of walls and ceiling.

Vapor barrier from inside the house is a barrier designed to protect the surface of walls, floors and ceilings from moisture, therefore, it ideally protects them from subsequent wetting.

Proper vapor barrier of a frame house is an event that is mandatory not only for baths and basements, but also for other premises built or finished using a special technology. Among the main buildings and structures where insulation is needed, it can be noted:

1. Buildings insulated from the inside, especially if mineral wool or glass wool can be used as insulation. Insulation ideally retains the overall heat, but at the same time does not remove moisture at all. It gradually accumulates in heaters, whereby the base gradually loses its main purpose, and the structure of the heater is also lost.
2. Structures with multilayer wall insulation. These are frame buildings with special internal insulation, respectively, protection from steam is simply necessary here.
3. Frame houses with ventilated modern facades. The windproof membrane will play the role of wind protection. The installed wind protection seriously doses and softens the directed flows of external air masses.

On a note

The advantage of a well-equipped vapor barrier from inside the house is its ability to normalize heat transfer in the room.

The main mistakes of the vapor barrier

If you listen to the opinion of professionals, you can find out what difficulties and mistakes you may encounter when solving such an important issue as vapor barrier for the walls of a frame house. Among the most common shortcomings are:

The device of external walls.

• Installation of vapor barrier on the outside of the frame house. Steam will pass through the entire finish, and accumulate in the insulation. The vapor barrier layer must be located inside the building, wind protection will be sufficient from the outside;
• Installing poor vapor barrier in a tiled bathroom. In this situation, water and steam penetrate through the tile joints. All this automatically leads to a violation of not only tightness, but also the strength and reliability of fixing the finishing material in the frame house;
• Lack of moisture protection in walls insulated with mineral wool and its analogues. The absence of vapor barrier layers is permissible only if the walls are insulated with foam;
• Carrying out poor quality work. The processes associated with the installation of vapor barrier in a frame house must be carried out as clearly as possible, following the instructions. Even the most minor flaws and neglect of the rules will lead to damage.

Frame houses are known for their comfortable microclimate for everyone. For long-term preservation of it and for a serious increase in the time period of the object's service, it is worthwhile to competently carry out all the work and activities related to construction and subsequent professional finishing.

We insulate the ceiling.

Vapor barrier materials

Modern manufacturers offer a huge variety of vapor barrier materials. What vapor barrier to choose for a frame house? The most popular of them include the following options:

• Reinforced polyethylene. A material that is becoming increasingly rare and popular solely because of its affordable cost. It is used in such a process as the vapor barrier of the floor of a frame house. In the process of its use, maximum care and strict adherence to the instructions is required. Otherwise, the frame house can turn into a steam room, that is, humid air will accumulate in the house, making living not very comfortable.
• Various types of masks. These are special mixtures that are applied to the walls of the structure before the external finishing of the frame house. Bituminous kukersol mastic, which is ideally breathable, and is sold at an affordable cost, is popular. Any type perfectly collects and retains water, completely preserving the frame of the house in its original form. This is possible only with the correct installation of the vapor barrier of the frame house.

Partition wall insulation.

• Ruberoid. Suitable for finishing modern frame buildings. The main feature of the material is the need for preliminary arrangement of a wooden crate 50 by 50 mm. Modern roofing material is universal and affordable.
• Vapor barrier films. This is a unique option with which you can create a high-quality vapor barrier for the walls of a frame house. Vapor barrier films reliably protect the structure and insulation from moisture. All this ensures the most comfortable stay in buildings built using frame technology.

All of these materials not only provide an excellent level of protection, but are characterized by such positive properties and qualities as the possibility of long-term use, ease of installation, reliability during use and perfect functionality.

Vapor barrier for walls

To equip the vapor barrier layer of modern frame objects, you will need to prepare special tools and the necessary materials. Proper vapor barrier of a frame house requires a certain sequence of work. The tools that the technology of vapor barrier of a frame house provides include:

• Adhesive construction tape with a double-sided special coating is construction tape;
• Various measuring instruments and standard scissors;
• We need metal staples, a hammer, as well as nails;
• The main vapor barrier material.

Frame wall pie.

If the installation of the vapor barrier of a frame house is carried out using the adhesion of the main layer, which protects against water and steam with the main frame with nails, you need to purchase slats made of wood or galvanized material as an addition. At the same time, it is not necessary to make a vapor barrier of the internal walls of a frame house, because there is no temperature difference in the partitions, which means that there is no air movement from hot to cold.

Vapor barrier of the floor in a frame house is simply necessary to avoid wetting of the mineral insulation, which at the same time loses its insulating properties. A vapor barrier layer is laid out on the logs, which must be glued at the joints. The counter-rail is stuffed directly on top of the lag, and only then the floor covering is mounted.

On a note

The arrangement of the vapor barrier of the walls of the frame house should be carried out after the installation of the outer layer of wind protection, as well as the layer of insulation.

Wall vapor barrier sequence

1. The slats and the frame itself are carefully treated with special disinfectants.
2. Walls are being measured.
3. According to the obtained dimensions, elements of vapor barrier materials are cut out. In this case, an overlap of 10 mm must be taken into account.
4. The material is fixed. Fasteners are installed strictly around the perimeter, and rails and a construction stapler are used here. It all depends on the base used. Installation must be done from the bottom and up. Material elements must be placed strictly horizontally. At the joints, you need to use adhesive tape, and it is important to overlap the material itself.

The vapor barrier of the walls and interfloor ceilings of the frame house was made in accordance with all the rules, and after that it is worth taking care of the ventilation in the frame house with your own hands. By the way, the vapor barrier of the partitions of the frame house is not required, because in the internal neighboring rooms the temperature does not differ from each other. But ventilation should take place between the finish and the protection layer. This will help prevent condensation from building up in the interior of the overall design pie.

Basalt wool in insulation.

Vapor barrier between floors

The division of the frame house by interfloor ceilings involves the division of the volume of the premises into parts. In these rooms of frame construction, temperature and humidity may differ. Thermal air vapors will rise upwards, thereby forming condensate on parts of the floors. To protect the load-bearing structures and insulation from moisture, a vapor barrier of interfloor ceilings is made.

Interfloor pie.

It is very important to make a vapor barrier according to all installation rules. The vapor barrier of interfloor ceilings is overlapped by about 100 mm. The joints must be glued with a special tape so that even small gaps do not remain. Only in this case, the vapor barrier will perform its functions.

Proper vapor barrier

In order to achieve an optimal result in working with vapor barrier and in the process of vapor barrier work, it is worth using special insulating and at the same time windproof membranes. The vapor barrier of a frame house with a membrane on the outside will help release moisture to the outside.

If you do not fix high-quality protection on all sides of the mounted insulation, the structure will get wet and lose its basic thermal insulation qualities. If there is no vapor barrier, and the installed insulation layer is tightly closed only with external finishing materials, the cotton wool insulation will get wet very quickly and, accordingly, will immediately lose its advantageous features.

Specialists strongly advise builders and owners not to save on the purchase of building materials, as this will require material investments over time. High-quality materials, as well as proper vapor barrier in a frame house, will provide the most comfortable indoor climate and will retain the overall performance of the building for a long time.

Vapor barrier in a wooden house. Everyone who builds a frame wooden house asks about this first of all! I already wrote about vapor barrier and waterproofing, but I decided to separately cover the topic of combating steam, since errors in vapor barrier are very critical for the future home.

• What is vapor barrier
• Which side to lay (lay) the vapor barrier?
• Vapor barrier for the walls of a frame / wooden house
• Vapor barrier of partitions
• Vapor barrier between floors
• FAQ. Film FAQs

What is vapor barrier?

vapor barrier- this is any film with low vapor permeability, which is mounted in a frame house from the INSIDE to prevent steam from getting into the insulation and keep the latter from constant wetting.

Do not confuse it with waterproofing, which is placed outside and is needed to protect the wooden frame from moisture! They use special membranes.

Do I need a vapor barrier for a frame house

Yes. The technology of frame housing construction necessarily implies the presence of vapor barrier materials in the walls, in the floor and ceilings! We must create a complete contour of the vapor barrier, which is why often the framers are called "thermos houses".

Why do you need a vapor barrier film:

• does not allow the insulation to get wet (does not let moisture into it)
• stabilizes the climate in the frame house

For this, a special vapor barrier material is used, spunbond and other films will not work.

Which side to lay (lay) the vapor barrier?

And you take an ordinary vapor barrier film, then you won’t need to look at the wrong side. But if you have already taken a specialized steam film, then look at the instructions. EVERYTHING is written there. Just don't be lazy or force the builders.

In addition to the manufacturer, no one knows how to properly lay the vapor barrier of his production, each of them has its own notes. But it is logical that a part with his brand be inside and we can see it, they did their best for us!

At Izospana-B everything is simple. A rough surface inside, moisture remains on it, the smooth side of this vapor film is placed against the insulation.

This concludes the questions about how to lay the vapor barrier. You can go to the website of the vapor barrier film manufacturer and see the exact information there, for example, on the Yutafol website (Isospan does not have a normal website).

Vapor barrier for the walls of a frame house

In the walls of a wooden or frame house, steam is isolated BEFORE the wall, that is, inside. You can’t lock it from the outside, the walls will rot.

Vapor barrier of frame house partitions

Partitions do not need to be vapor-insulated, with the exception of damp rooms. It's really better to put a PE film on the inside! But not on both sides of the wall.

If you are worried that the insulation will collect dust and get into your lungs - put a vapor-permeable membrane in the partitions on both sides!

Vapor barrier floor and ceiling in a frame house

You can vapor barrier the floor with a film (standard), but it can be a little easier - lining under the laminate + plywood or OSB on the floor gives a good result. Or even linoleum. The floor is not the place where most of the steam goes, because the steam goes mostly up!

The ceiling is more difficult. The ceiling needs to be vapor-proofed exactly with a film, because all the steam goes up. I have a text about how it looks in my house - Installing a wooden crate on the ceiling.

Vapor barrier of the ceiling in a frame house

It is NOT necessary to vapor barrier the ceiling between floors, as there is warm air from above and below. But the upper floor is another matter, there we work the same way as with the ceiling.

FAQ. Frequently asked questions about the vapor barrier of a frame house

Vapor barrier. Inside or outside?

Of course inside! Steam goes from hot to cold.

What vapor barrier to choose for the walls of a frame house

For walls, and in general, the best vapor barrier for a frame house is an ordinary plastic film 200 microns thick (not thinner).

But if you really want that you can buy Isospan or Yutafol vapor barrier, but for me it's a waste of money. Americans usually use polyethylene and without any brands.

Is it possible to have a frame house without vapor barrier?

In some climates, such as southern climates, it is indeed possible to build frame houses without a vapor barrier film. But these options are individual and you need to calculate pies and dew point very clearly. I wouldn't experiment like that

Do I need to glue the vapor barrier and how?

Yes! The film can be glued either with special butyl rubber tape or with glue. The only way is right, it is impossible not to glue the vapor barrier.

How to make vapor barrier on video:

Thermal insulation in frame houses is the main means of retaining heat. The walls are 75% made of insulation, for which special conditions must be created. It loses its positive properties under the influence of moisture from the inside. It is important that the thermal insulation fits snugly against the frame. To do this, it must always remain dry, which also requires a vapor barrier of the frame house: walls, floor, ceiling and roof.

The use of vapor barrier in the frame house insulation system

Vapor barrier characteristics

A vapor barrier is a porous membrane that can significantly reduce the negative process of moisture accumulation in thermal insulation. The porous layer allows the house to "breathe", providing air exchange. In this case, the greenhouse effect is excluded. Up to 35% of air is let through by wooden structures.

The mistake of many owners is to protect the frame house from the inside with plastic wrap. Over time, water accumulates under it, causing rotting of wooden structures.

The vapor barrier is not a film with many holes, but a complex multilayer porous package. It is tightly laid with the rough side inside the house, and the smooth side - to the insulation. This is necessary so that moisture settles better on a rough surface, and subsequently evaporates freely.

Features of laying vapor barrier when insulating a house

The film is the same on both sides. Then there is no difference which side it will face the thermal insulation. In any case, before installation, read the instructions for the specific type of membrane.

Many membranes have a specific structure. They can have a specific purpose: for residential and non-residential buildings or for rooms with different humidity. The material is selected depending on the way buildings are used, the characteristics of the region, the conditions of use, etc.

In rooms with a humid environment and elevated temperatures, membranes are needed that differ in properties from those used in ordinary homes. For example, reflective aluminum screens are used in saunas and baths.

Vapor barrier of the walls and ceiling of the bath

Thus, the vapor barrier protects the structure of the house from water vapor only partially.

Features of vapor barrier frame houses

Vapor barrier for the outer walls of a frame house is made according to a scheme that is in many ways similar to other types of houses. The only difference is that the supporting structures do not perform the function of insulation here.

Walls in cross section look like this:

• external finishing with siding, clapboard or OSB boards;
• waterproofing film;
• frame;
• thermal insulation;
• vapor barrier;
• crate;
• interior decoration.

At first glance, it seems that the vapor barrier is easy to lay, you just need to fix it by turning it in the right direction. Fixation is carried out using a construction stapler or galvanized nails, with sealing of joints with adhesive tape.

Fastening the vapor barrier with a construction stapler

Basic rules to follow:

• it is unacceptable to leave membrane ruptures;
• the number of folds should be minimal;
• gluing and sealing of seams must be of high quality;
• the places of contact of the tree with the vapor barrier are treated with an antiseptic;
• the diffusion membrane can be laid directly on the thermal insulation, in other cases a gap of about 5 cm is left between them;
• it is not allowed to confuse the sides of the membrane when laying.

Any miscalculation will lead to the fact that the insulation will cease to perform its functions after a short time. As a result, you will have to re-insulate the house. Not all owners or builders are able to show the necessary accuracy during installation, and it lasts for 2-3 seasons, after which the insulation gets wet and stops working properly.

The installation technology provides for laying the vapor barrier from top to bottom. The overlap is made at least 100 mm with sizing tape designed for it. The connection to wooden structures should be carefully checked.

Depending on the type of insulation, sometimes a vapor barrier is not required. A similar decision is made when foam, ecowool and polyurethane foam are used. When using such thermal insulation, the exit of moisture from the premises is difficult. Therefore, it is necessary to create their high-quality ventilation. In such a situation, forced air intake and exhaust are needed.

Vapor barrier is not required in houses without additional insulation, when the walls are built of brick or foam blocks. Also, it is not done on the interior partitions of the house. The insulation absorbs steam in the event of a temperature difference on the outer walls.

Frame house vapor barrier schemes

Differences in the construction of houses provide different conditions for the removal of moisture from the premises.

Double vapor barrier

If the wall is finished on both sides with poorly “breathable” materials (tile, oilcloth, plastic), moisture can accumulate between them. To eliminate this negative effect, a ventilation gap is made between the wall and the cladding. At the same time, you need to make sure that air circulates in it and leaves somewhere.

Basic vapor barrier schemes

Moisture protection in frame houses is usually done in two ways:

1. The membrane is attached to the racks of the frame, and then the interior is finished (Fig. a below).
2. On top of the vapor barrier film, a horizontal or vertical crate is installed, on which the cladding is attached. As a result, a ventilation gap of 4-5 cm is formed inside (Fig. b).

Ways of vapor barrier of the walls of a frame house

The latter option is preferably done with permanent residence in the house, when there is a risk of moisture accumulation between the walls. Without an air gap, it is allowed to build buildings for temporary visits. They are ventilated with the installation of a box. Be sure to make an extract from rooms with high humidity.

When equipping a house with effective ventilation, the role of vapor barrier is reduced. Here it serves only as an additional insurance against the accumulation of moisture in the walls.

Vapor barrier for external insulation of the house

The vapor barrier cannot be laid on a smooth wooden surface.. First, slats 2.5 cm thick are stuffed onto the wall in increments of 1 m, and a membrane is attached to them with a stapler. It should be facing the rough or fleecy side outward, and the smooth side to the wall. Then a crate is stuffed on top, thermal insulation is laid on it, and a waterproofing film is stretched on top. After that, the final exterior decoration of the house is carried out.

External insulation of the house

The method provides a special microclimate in a house made of logs, timber or a frame structure, since there is no need to cover the tree inside with a finishing material.

The disadvantage of this option is the need to dry the structure, which takes several years. Additional work is also added to protect the joints with sealant and seal the grooves on both sides. Only hydrophobic materials can be used for insulation.

Vapor barrier of the floor in a wooden house

Hydro and vapor barriers are needed for an insulated floor due to the action of two factors:

• moisture from the basement or basement passing through the ground;
• steam from the premises.

When insulating the floor, waterproofing is first laid in the space between the lags on the subfloor. Film strips are placed with overlapping and gluing with special adhesive tape.

Plates or rolls of insulation 15 cm thick are placed in the cells of the frame, and then covered with a vapor barrier film. It also requires overlapping and gluing joints.

Boards 30 cm thick and in increments of 40-60 cm are placed across the log. They are fastened with self-tapping screws or other suitable fasteners. Due to them, a ventilation gap is created between the floor and the vapor barrier.

Across the crate, a tongue-and-groove floorboard of 25-30 mm or edged board of 40-50 mm is tightly laid and fastened. From above the finishing floor covering is arranged.

Floor insulation on the first floor

The use of vapor barrier for the floor is effective only together with a breathable insulation. Styrofoam and similar materials are not suitable here. It is advisable to use mineral wool with a density of 37-57 kg / m3, since there is no load on it in the floor structure.

Ceiling insulation and vapor barrier

Up to 80% of frame houses are insulated with mineral wool. In addition to it, expanded polystyrene, ecowool, expanded clay, etc. are used.

The ceiling is insulated as follows:

• A vapor barrier film is stretched onto the beams from below and attached to them with a stapler. Then the board is stuffed in increments of about 40 cm.
• Mineral wool is laid tightly on top of the entire ceiling. At the same time, the walls are lapped. With a thickness of 50 mm boards, they should be laid in three layers to create a standard size of 150 mm. They are stacked in a checkerboard pattern, and the ceiling beams are covered with the top layer.
• From above, the insulation is covered with a vapor barrier film if the attic is made warm. It is rolled out over the entire ceiling with an overlap of at least 10 cm and sealing of the joints. If the attic is unheated, such protection from above can be omitted.
• The floor is laid on top of the insulation. Between it and the vapor barrier there should be a ventilation gap of about 5 cm.

A properly laid ceiling “pie” prevents the accumulation of moisture in the insulation both from below and from above.

Roof insulation and vapor barrier

The roof is insulated like walls, but there are some features here. Waterproofing is laid on top of the rafters. It is fixed by a crate on which the roof is attached. After that, insulation boards are inserted between the rafters. It is better to take them rigid so that the material does not deform.

Plates are installed with a gap from the waterproofing film. It is necessary for ventilation and removal of moisture that forms under the roof. For better circulation, two conclusions are made from the gap - from different sides of the house. It is advisable to choose a fireproof material.

Roof insulation

Waterproofing must be airtight, otherwise moisture will get on the insulation, and it will lose a significant proportion of its useful properties.

From the inside, a vapor barrier is nailed to the rafters and a crate is installed. A facing material is attached to it. These can be QSB-plates, drywall, etc. For cladding, a frame of profiles is installed, as for walls.

With high-quality insulation and reliable protection against moisture in the attic, you can install a heating system. Then at any time of the year it will be a full-fledged living space.

Video: frame house insulation

Laying vapor barrier in a frame house is carried out taking into account the sequence, the specifics of installation, as well as the features of the technology. If there is a non-residential premises under the roof, it can not be insulated, but thermal insulation significantly reduces noise during rain.

The correct choice and installation of vapor barrier membranes fully ensures their useful functions in protecting the frame house from moisture.

I was led to this article by total illiteracy both on the part of builders and on the part of buyers, as well as the phrase “steam hydro insulation” that increasingly flickers in commercial offers - because of which all the pandemonium then begins, lost money, problematic structures, etc. .P.

So, you have probably heard about waterproofing, wind protection and vapor barrier - that is, about films that are placed in insulated roofs and frame walls to protect them. But here further, often begins a complete "steam-hydrodisgrace".

I will try to write in a very simple and accessible way, without diving into formulas and physics. The main thing is to understand the principles.

Steam or hydro?

Let's start with the fact that the main mistake is to mix steam and moisture into one concept. Steam and moisture are completely different things!

Formally, steam and moisture are water, but in different states of aggregation, respectively, having a different set of properties.

Water, it is also moisture, it is also “hydra” (hydro from ancient Greek ὕδωρ “water”) - this is what we see with our eyes and can feel. Tap water, rain, river, dew, condensate. In other words, it's a liquid. It is in this state that the term "water" is commonly used.

Steam is the gaseous state of water, water dissolved in air .

When an ordinary person talks about steam, for some reason he thinks that it is necessarily something visible and tangible. Steam from the nose of a kettle, in a bathhouse, in a bathroom, etc. But actually it is not.

Vapor is present in the air always and everywhere. Even as you read this article, there is steam in the air around you. It underlies the very humidity of the air, which you have probably heard about and complained more than once that the humidity is too high or too low. Although no one saw this moisture with their eyes.

In a situation where there is no steam in the air, a person will not live long.

By taking advantage of the different physical properties of water in liquid and gaseous states, science and industry have been able to create materials that allow steam to pass through but not water.

That is, this is a kind of sieve that can pass steam, but will not let water in a liquid state.

At the same time, especially smart scientists, and then manufacturers, figured out how to make a material that will conduct water in only one direction. How exactly this is done is not important to us. There are few such membranes on the market.

So, a construction film that is impervious to water, but passes steam equally in both directions - is called waterproofing vapor permeable membrane. That is, it passes steam freely in both directions, but does not pass water (hydra) at all or only in one direction.

vapor barrier- this is a material that does not let anything through, neither steam nor water. Moreover, at the moment, vapor barrier membranes- that is, materials that have one-sided vapor permeability have not yet been invented.

Remember as "Our Father" - there is no universal "parohydro membrane". There is a vapor barrier and vapor permeable waterproofing. These are fundamentally different materials - with different purposes. The use of these films in the wrong place and in the wrong place can lead to extremely sad consequences for your home!

Formally, vapor barrier can be called vapor barrier, since it does not let water or steam through. But using the term is a path to dangerous mistakes.

Therefore, once again, in frame construction, as well as in insulated roofs, two types of films are used

1. paro insulating- which do not let steam or water through and are not membranes
2. Waterproofing steam permeable membranes (also called windproof, due to extremely low air permeability or superdiffusion)

These materials have different properties and using them for other purposes is almost guaranteed to lead to problems with your home.

Why do you need films in the roof or frame wall?

To understand this, you need to add a little theory.

Let me remind you that the purpose of this article is to explain “on the fingers” what is happening, without delving into physical processes, partial pressure, molecular physics, etc. So I apologize in advance to those who had five in physics 🙂 In addition, I will immediately make a reservation that in reality all the processes described below are much more complicated and have a lot of nuances. But we need to understand the essence.

Nature has already ordered that in the house the steam always goes in the direction from warm to cold. Russia, a country with a cold climate, has an average heating period of 210-220 days out of 365 a year. If you add to it the days and nights when it is colder outside than in the house, then even more.

Therefore, we can say that most of the time, the steam movement vector is directed from the inside of the house, to the outside. It doesn't matter what we are talking about - walls, roofing or lower floors. Let's call all these things in one word - enclosing structures

In homogeneous designs, the problem usually does not occur. Because the vapor permeability of a homogeneous wall is the same. The vapor easily passes through the wall and out into the atmosphere. But as soon as we have a multilayer structure consisting of materials with different vapor permeability, everything becomes not so simple.

Moreover, if we talk about walls, then we are not necessarily talking about a frame wall. Any multi-layer wall, even brick or aerated concrete with external insulation, will already make you think.

Surely you have heard that in a multi-layer construction, the vapor permeability of the layers should increase as the steam moves.

What will happen then? Steam enters the structure and moves in it from layer to layer. At the same time, the vapor permeability of each subsequent layer is higher and higher. That is, from each subsequent layer, steam will come out faster than from previous.

Thus, we do not form an area where the vapor saturation reaches the value when, at a certain temperature, it can condense into real moisture (dew point).

In this case, we will not have any problems. The difficulty is that to achieve this in a real situation is not easy enough.

Vapor barrier of roof and walls. Where is it placed and why is it needed?

Let's consider another situation. Steam got into the structure, moves outward through the layers. Passed the first layer, the second ... and then it turned out that the third layer is no longer as vapor-permeable as the previous one.

As a result, the steam that got into the wall or roof does not have time to leave it, and a new “portion” is already supporting it from behind. As a result, before the third layer, the vapor concentration (more precisely, saturation) begins to grow.

Remember what I said before? Steam moves from warm to cold. Therefore, in the region of the third layer, when the saturation of the steam reaches a critical value, then at a certain temperature at this point, the steam will begin to condense into real water. That is, we got the "dew point" inside the wall. For example, on the border of the second and third layers.

This is what is often observed by people whose house is sewn up from the outside with something that has poor vapor permeability, such as plywood or OSB or DSP, but there is no vapor barrier inside or it is made of poor quality. Rivers of condensate flow along the inner side of the outer skin, and the wool adjacent to it is all wet.

Steam easily enters the wall or roof and "skips" the insulation, which usually has excellent vapor permeability. But then it "butts" against the outer material with poor penetration, and as a result, the dew point is formed inside the wall, right in front of the obstruction to the steam path.

There are two ways out of this situation.

1. It is long and painful to select the materials of the “pie” so that the dew point does not under any circumstances end up inside the wall. The task is possible, but difficult, given that in reality, the processes are not as simple as I describe now.
2. Put a vapor barrier on the inside and make it as airtight as possible.

It is along the second path that they go to the west, they make an airtight obstacle in the way of steam. After all, if you do not let steam into the wall at all, then it will never reach the saturation that will lead to condensation. And then you don’t have to puzzle over what materials to use in the “pie” itself, in terms of the vapor permeability of the layers.

In other words, the installation of a vapor barrier is a guarantee of the absence of condensation and dampness inside the wall. At the same time, the vapor barrier is always placed on the inner, “warm” side of the wall or roof and is made as tight as possible.

Moreover, the most popular material for this "they" is ordinary polyethylene 200 microns. Which is inexpensive and has the highest vapor permeability, after aluminum foil. Foil would be even better, but it's hard to work with.

In addition, I pay special attention to the word hermetic. In the west, when installing a vapor barrier, all joints of the film are carefully glued. All openings from the wiring of communications - pipes, wires through the vapor barrier, are also carefully sealed. The overlapping vapor barrier installation, which is popular in Russia, without gluing the joints, can give insufficient tightness and, as a result, you will get the same condensate.

Unglued joints and other potential holes in the vapor barrier can cause a wet wall or roof, even if the vapor barrier itself is present.

I also want to note that the mode of operation of the house is important here. Summer country houses, in which you visit more or less regularly only from May to September, and maybe several times in the off-season, and the rest of the time the house is without heating, can forgive you some vapor barrier flaws.

But the house for permanent residence, with constant heating, does not forgive mistakes. The greater the difference between the external “minus” and the internal “plus” in the house, the more steam will flow into the external structures. And the greater the likelihood of condensation inside these structures. Moreover, the amount of condensate as a result can be calculated in tens of liters.

Why do I need a waterproofing or superdiffusion vapor permeable membrane?

I hope you understand why you need to make a vapor barrier from the inner wall - in order not to let steam inside the structures at all and to prevent conditions for its condensation into moisture. But the question arises, where and why to put a vapor-permeable membrane and why it is impossible to put a vapor barrier instead of it.

Windproof, waterproofing membrane for walls

In American wall construction, the vapor permeable membrane is always placed on the outside, on top of the OSB. Its main task, oddly enough, is not to protect the insulation, but to protect the OSB itself. The fact is that Americans make vinyl siding and other facade materials immediately on top of the slabs, without any ventilation gaps or crates.

Naturally, with this approach, there is a possibility of external atmospheric moisture getting between the siding and the slab. How - this is the second question, heavy slanting rain, construction flaws in the area of ​​​​window openings, adjoining roofs, etc.

If water gets between the siding and the OSB, then it can dry out there for a long time and the slab can begin to rot. And OSB in this regard is a filthy material. If it began to rot, then this process develops very quickly and goes deep into the plate, destroying it from the inside.

It is for this that, first of all, a membrane with one-tonne penetration for water is installed. The membrane will not allow water to pass to the wall in case of a possible leak. But if somehow, water got under the film, due to one-sided penetration, it can come out.

Super diffusion waterproofing membrane for roofing

Don't let the word superdiffusion fool you. In fact, this is the same as in the previous case. The word superdiffusion only means that the film passes vapor very well (vapor diffusion)

In a pitched roof, for example, under a metal tile, there are usually no plates, so the vapor-permeable membrane protects the insulation from both possible leaks from the outside and from blowing by the wind. By the way, that is why such membranes are also called windproof. That is, a vapor-permeable waterproofing membrane and a windproof membrane are usually one and the same.

In the roof, the membrane is also placed on the outside, in front of the ventilation gap.

In addition, pay attention to the instructions for the membrane. Since some membranes are placed close to the insulation, and some, with a gap.

Why is it necessary to put a membrane outside, and not a vapor barrier

But why not install a vapor barrier? And make a completely vapor-tight wall on both sides? Theoretically, this is possible. But in practice, it is not so easy to achieve absolute tightness of the vapor barrier - anyway, somewhere there will be damage from fasteners, construction flaws.

That is, some meager amount of steam will still fall into the walls. If there is a vapor-permeable membrane outside, then this minuscule has a chance to get out of the wall. But if the vapor barrier, it will remain for a long time and sooner or later, it will reach a saturated state and again the dew point will appear inside the wall.

So - a windproof or waterproof vapor-permeable membrane is always placed outside. That is, from the "cold" side of the wall or roof. If there are no plates or other structural materials outside, the membrane is placed on top of the insulation. Otherwise, in the walls, it is placed on top of the enclosing materials, but under the facade finish.

By the way, it is worth mentioning one more detail, for which films are used, and the wall or roof is made as tight as possible. Because the best insulation is air. But only if it is absolutely motionless. The task of all heaters, whether it is polystyrene or mineral wool, is to ensure the stillness of the air inside them. Therefore, the lower the density of the insulation, the higher, as a rule, its thermal resistance - the material contains more stationary air and less material.

The use of films on both sides of the wall reduces the likelihood of wind blowing through the insulation or convection air movements inside the insulation. Thus, forcing the heater to work as efficiently as possible.

What is the danger of the term vapor barrier?

The danger lies precisely in the fact that under this term, as a rule, two materials are mixed, with different purposes and with different characteristics.

As a result, confusion begins. Vapor barrier can be installed on both sides. But the most common mistake, especially in roofs, and the most terrible in terms of consequences, is when the result is the opposite - the vapor barrier is installed on the outside, and the vapor-permeable membrane is on the inside. That is, we calmly let steam into the structure, in unlimited quantities, but do not let it go out. This is where the situation shown in the popular video appears.

Moreover, this can happen both with the floor, and with the wall or with the roof.

Conclusion: never confuse the concepts of vapor-permeable waterproofing membranes and vapor barrier - this is a sure way to construction mistakes that have very serious consequences.

How to avoid mistakes with films in a wall or roof?

Fear has big eyes, in fact, with films in a wall or roof, everything is quite simple. The main thing to remember is to follow the following rules:

1. In a cold climate (most of Russia), vapor barrier is always placed only on the inside, "warm" side - be it a roof or a wall
2. Vapor barrier is always made as tight as possible - joints, openings of communication penetrations are glued with adhesive tape. This often requires a special adhesive tape (usually with a butyl rubber adhesive base), as a simple one can peel off over time.
3. The most effective and cheapest vapor barrier is 200 micron polyethylene film. It is desirable "primary" - transparent, it is easiest to glue the joints on it with ordinary double-sided tape. Buying "brand" vapor barriers is usually not justified.
4. Vapor-permeable membranes (superdiffusion, windproof) are always placed on the outside, cold side of the structure.
5. Before installing the membrane, pay attention to the instructions for it, as some types of membranes are recommended to be installed with a gap from the material to which it is adjacent.
6. Instructions can be found on the manufacturer's website or on the roll of the film itself.
7. Usually, in order to avoid mistakes with “which side” to mount the film, manufacturers roll the roll so that when “rolling out” it outside by design, you automatically mounted the correct side. For other applications, before starting installation, consider which side to place the material.
8. When choosing a vapor-permeable membrane, you should give preference to quality manufacturers of the "first and second tier" - Tyvek, Tekton, Delta, Corotop, Juta, Eltete, etc. As a rule, these are European and American brands. Membrane manufacturers of the "third tier" - Izospan, Nanoizol, Megaizol and other "isols", "brains", etc. as a rule, they are much inferior in quality, and most of them generally have an unknown Chinese origin with the brand of a trading company stamped on the film.
9. If in doubt about the use of the film, go to the manufacturer's website and read the instructions or recommendations for use. Do not trust the advice of "sales consultants". Refers mainly to the materials of the "first and second echelon". There are often a large number of errors in the instructions of manufacturers of the third echelon, since in fact they only sell films, without producing them and without doing any kind of development, so the instructions are written “on the knee”

PS If you are interested in a little more information about the difference in vapor permeable waterproofing membranes, I recommend reading this small document.

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The vapor barrier of the frame house must be installed on the inner surface of the insulation layer to protect it from vapors, which leads to damage and loss of all properties. This rule applies to frame buildings erected in cold and temperate climates.

The vapor barrier of a frame house is simply necessary, because if excess moisture comes out through the walls, the thermal insulation will definitely get wet, and in cold weather this is fraught with its complete destruction.

The very procedure for installing the vapor barrier is very simple: you need to attach the vapor barrier membrane to the frame racks and strapping using adhesive tape and a stapler. However, this simple step in practice carries the greatest danger to the construction of a frame house.

What is vapor barrier film for?

For a better understanding of why a vapor barrier film is needed in a cake, you need to understand the physics of the movement of air vapor. You can often hear on the news about the humidity, which is close to 70-80% in wet weather. During cold weather in the house, many people turn on humidifiers to increase the humidity. Usually there is a feeling that outside the house the humidity is higher than inside it. For cold and temperate climates, this statement is incorrect.

Humidity parameters directly depend on air temperature. The higher the temperature, the greater the concentration of water vapor in the air around us. If the air in the street with humidity from 75-80% is heated to the usual temperature in the house, then the amount of moisture will be the same, but its percentage will decrease, since air humidity is a relative parameter and depends on temperature.

In temperate climates, there is more moisture inside than outside. This is due to the fact that you cook food, breathe, wash, take a bath, etc.

To even out the difference in vapor concentration outside and inside the house, all excess moisture is looking for exits: open windows and doors, ventilation ducts, ceilings and walls. Ideally, the ventilation system, which is designed for constant air exchange in the house, copes with excess moisture.

You can ventilate the rooms from time to time by opening doors and windows. If the ventilation fails or you do not have the opportunity to ventilate the premises often, then the vapors begin to try to get out through the ceilings and walls. For a frame house, this is a very dangerous process, since the frame wall consists of 70-75% insulation. Moisture vapor, after entering the insulation, causes it to become very wet, which leads to a loss of thermal insulation properties.

If at the same time the temperature outside is below zero, then the freezing of water in the insulation leads to its complete destruction. In order to minimize the release of vapors through the thickness of the frame wall, a vapor barrier is made at home. Air vapors are isolated inside the room, and a previously completed ventilation system is responsible for their removal.

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Errors in the vapor barrier device and their consequences

Installation of a vapor barrier on the outside. Moisture vapor, passing through freely, condenses on the surface of the vapor barrier. The heater gets wet. In a classic wall pie, a windproof membrane with high vapor permeability should be placed outside. It is she who freely removes moisture vapor. A similar situation is obtained if extruded polystyrene foam is installed on the outer surface of the facade, which has a high vapor barrier and is a vapor barrier membrane.

Duplicated vapor barrier in. This can be done by placing a vapor barrier inside and outside the frame wall. However, the vapor barrier layer is not completely sealed and is able to reduce, but not stop, the release of excess moisture to the outside. That is, the membrane cannot completely isolate, but slows down the movement of moisture vapor.

Even a small amount of water, getting between the vapor barrier films, will affect the insulation (it will become damp), and it simply will not have a chance to dry out. By cutting off one of the vapor barrier films, you can see the black boards of the frame due to the creation of ideal conditions for the development of mold: dampness and heat. To prevent this situation, you need to remember a simple rule: the vapor barrier must be installed from the inside, the wind protection must be on the outside.

The second duplication option is associated with the installation of a second barrier on the vapor barrier, for example, ceramic tiles. The tile itself is an excellent vapor barrier. Couples, having got through the seams of the tile, are locked between the vapor barrier layers, which, in turn, leads to the peeling of the tile from the wall. To avoid this, it is necessary to leave a ventilation gap between the layer of vapor barrier film and drywall or not to make a layer of vapor barrier film at all.

Vapor barrier is not done. Compared to the two above, this is not the worst option, but if you use mineral wool for insulation, this can lead to rather unpleasant consequences. The frame house cake is heterogeneous and is made from a set of different building materials with different vapor permeability parameters.

Depending on the constant temperature of the air, moisture vapor, passing through the pie of the frame wall, finds the dew point, namely the area where vapor condensation occurs at a certain temperature. Worst of all, if moisture condenses on the inside surface of OSB boards or plywood. For summer, there are no problems in the absence of a vapor barrier for a frame house, but for winter, it is on the border of the insulation and the outer skin that the vapors leaving the house will condense.

Some heaters are highly resistant to the destructive effect of condensate, for example, foam plastic and ecowool, so a vapor barrier film is not required for such a frame house. There are big savings. But many people forget that in the absence of a vapor barrier, the outer skin is at risk, because it is there that the vapors run into a barrier made of less vapor-permeable materials, dew falling on the inner surface.

To minimize condensation on the cladding of a frame house, you can apply additional insulation of the building with foam plastic along the crate or finish a wet facade. It is also possible to insulate the building with ecowool or polyurethane foam, which have high vapor permeability and minimize the possibility of condensation in the frame cake.

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Poorly made vapor barrier

So, a vapor-tight membrane is a high-quality polyethylene film, which is fixed with a stapler to the strapping and wooden. For high-quality sealing of joints, it is necessary to glue each hole very carefully. For this, adhesive tapes, mastics and glues are used.

The work of installing a vapor barrier is not difficult, but a hastily mounted vapor barrier will not be able to fulfill its direct function. It's best if you do your own vapor barrier on your home or have it checked before installing drywall.

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Choice of vapor barrier film

Ordinary polyethylene (PE). This is the simplest, but reliable vapor barrier. It is quite cheap and is sold at any hardware store. The choice should be made in favor of high-strength polyethylene (strength is measured in micrograms). When buying a film, you need to make sure that it is tear-resistant. PE has its advantages - it is perfectly glued with adhesive tape, which makes it easy and quick to create a reliable vapor barrier.

Specialized vapor barrier membranes. These membranes cost significantly more than polyethylene film. For their device, double-sided tapes, reinforced tapes and mastics are offered. There are vapor barriers with a foil coating, reinforcement, a condensing surface, etc. You can choose the right membrane for certain tasks. For example, a reinforced vapor barrier can be installed without outside help, since a sheet stuck with a stapler can be easily pulled to the other end of the room and not spoiled.

A foil vapor barrier membrane is recommended for use in baths where it is necessary to reflect energy deep into the room. A specialized vapor barrier membrane is an advanced polyethylene film that provides a tight vapor barrier. It performs the functions of a vapor barrier very well, provided that the sealing is of high quality. Before buying, you must carefully study the properties of specialized vapor barrier membranes.

To ensure reliable protection of the floor from moisture, hydro- and vapor barrier must be made. The first material protects against moisture in liquid form, and the second does not allow steam to destroy structures. Vapor barrier for a ceiling with a wooden floor is especially relevant when it is planned to be insulated, that is, in the thickness of the structure there is a transition between positive and negative temperatures (condensation point).

Where to put the insulation

This question is very important, because if you put the material in the wrong place, it will not work or it will be wrong. It is important to remember one rule: vapor barrier is always laid on the side of warm air, and waterproofing on the side of cold air. Usually these materials work together, providing reliable protection of the floor in the house from any type of moisture.

Vapor barrier film is laid on top of the floor insulation

Thus, it turns out that the vapor barrier of the wooden floor of the first floor should be carried out after the installation of heat-insulating material, and the protection against moisture in the air for interfloor ceilings or attic is laid from below.

The vapor barrier film of interfloor and attic floors is laid below the insulation

If you lay the material correctly, then you can not worry about the safety of structures.

Vapor barrier functions

Vapor barrier when attached to the structure of the ceiling or floor in the house performs not only the above purpose. Laying material allows you to talk about the following:

Ceiling vapor barrier options

Reliable waterproofing can eliminate many problems with floors and roofs. The choice of material in a private house depends on the financial capabilities and wishes of the future owner. Previously, as a hydro-vapor barrier, polyethylene film was used almost everywhere, but it is not able to fully perform both functions when laying in the ceiling.

Polyethylene film cannot simultaneously act as a vapor barrier

It is better to give preference to more modern materials that guarantee high quality protection of the ceiling and ceilings in the house. There are several forms of release of materials. The following types of mastics for coating structures are on the market:

• cold asphalt;
• hot on the basis of bitumen;
• polyvinyl chloride;
• lingo-sulfonate based on bitumen;
• rubber;
• bitumen-based kukersolnye.

The processing of the ceiling in the house with such materials is complicated by the fact that the waterproofing of the ceilings is applied to a horizontal surface located above the height of a person. The worker will have to constantly be with his head up. Such working conditions significantly reduce the quality. To ensure reliable protection, it is recommended to consider an option such as vapor barrier membranes (not to be confused with vapor diffusion, which act as a waterproofing and release water vapor to the outside).

The following types of materials can be attributed to modern membranes for protecting the ceiling and ceilings in the house:

Features of wood ceiling vapor barrier

Installation of any material is quite simple. Due to the diversity, it is difficult to give one universal way. Most often, the manufacturer indicates the exact recommendations for the use of his material and the requirements for the performance of work.

Manufacturers most often produce both hydro and vapor protection at the same time. It is best to choose two films (vapor barrier and waterproofing) from the same company to isolate insulation and wood from moisture. This will allow us to talk about reliable protection and compliance with technology.

Regarding the fixing of the material inside the room (and it is always attached precisely from the inside, protecting the elements from the warm air of the room, regardless of which structure is being finished), the following recommendations can be given to home craftsmen:

• Do not forget about the multilayer design of the ceiling. If you list the layers fixed from the inside from the bottom up, you get the following sequence: sheathing, vapor barrier, floor frame, insulation, waterproofing, floor construction. This order is suitable for interfloor and attic floors. When laying the material from the side of the attic, the location of the vapor barrier, insulation and waterproofing does not change relative to each other.
• Before laying the material, it is required to prime the surface with compositions that include antiseptic components.
• It is possible to fix subsequent layers only after the primer has completely dried.
• The vapor barrier should extend onto the wall by at least 20 cm. It is also necessary to ensure that the material sheets overlap (at least 10 cm) and the junctions and attachments to the frame are glued with adhesive tape.
• A crate is mounted on top of the vapor barrier, on which the ceiling sheathing will be attached. The crate can be either wooden or metal profile.

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

Why do you need a vapor barrier in the house

A house without the use of vapor barrier can be if it is insulated with foam plastic, foam plastic or does not have a heat-insulating layer at all, for example, foam block and brick.

• But in order to save on heating and to improve the heat-preserving characteristics of houses in modern construction, natural insulation made from cellulose (ecowool) or basalt wool is almost always used. But here we must remember about the constant moisture exchange that occurs in the living room.

• So, if the house is too humid, then water vapor will inevitably be absorbed by the walls and ceiling, and, conversely, if the air is too dry, this moisture will return 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 mineral wool fibers, thereby depriving it of all its thermal insulation characteristics.

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

Cases where the installation of a vapor barrier is required

• When the walls bordering the street are insulated with mineral wool from the outside;
• if the "pie" of the wall consists of several layers, one of which is a cotton wool 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 from the outside with a waterproof film, and from the inside with a vapor barrier. The first will protect the thermal insulation from water and air currents, and the second from the side of the interior from steam. A good example is a wooden house sheathed with siding or wooden clapboard.

Vapor barrier films are produced in several types and, according to their purpose, are divided into wall and roofing:

• roof vapor barrier. It is attached from the side of the dwelling, protecting the thermal insulation from rising vapors. This is an important stage, since the evaporation of moisture rises with warm air and can get into the insulation. This threatens not only with loss of heat, but also with the formation of mold and fungus. It is needed only when arranging an operated and heated attic. If the attic is cold, then vapor barrier is not done, limited to a windproof membrane under the roofing material itself, which protects it from condensation;
• house wall vapor barrier. It should be carried out with special materials, which, on the one hand, should not allow steam to pass to the insulation, and on the other hand, freely bring it out if moisture somehow gets inside. This happens due to possible gaps or incorrectly made joints of rolled materials. It is better to choose special diffusion materials, instead of the usual plastic films or glassine;
• floor vapor barrier. It must also be done, as condensate can accumulate from rising vapors $

• floor vapor barrier. 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 underside, and a vapor barrier is laid on top. A vapor barrier is also equipped when the concrete floor slabs are located directly above the ground.

If the question is whether a vapor barrier is needed in a wooden house, then you must again rely on the presence of a heater. If it is not there, and the wall of the house consists entirely of only timber or logs, then it makes no sense to install a vapor barrier film.

Types of vapor barrier materials

Until recently, glassine was the only vapor barrier material used in Russia. But with the development of technology, they gradually began to build on it, preferring more durable and high-quality materials.

• polyethylene films. They are best used for vapor barrier ceiling in a residential area. Most often, interfloor ceilings are insulated with mineral wool, as it has the best soundproofing properties. The polyethylene 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. Best used for ceiling insulation in a residential attic. They are distinguished by increased strength to mechanical damage and resistance to UV radiation. With its arrangement, you can safely repair the roof without fear that moisture will seep inside the house.
• Membrane. This popular and frequently used type of vapor barrier is produced in the form of a single-layer or multi-layer rolled material. These nonwoven materials can be single-sided or double-sided, depending on their location and functionality. The use of inexpensive double-sided non-woven membranes is considered optimal.
• Breathable films or breathable membranes. They completely exclude the possibility of water vapor penetrating inside to the thermal insulation, but at the same time they do not in the least prevent their exit from the inside. They allow you to save on living space, since their operation does not require equipping a ventilation gap.
• Ordinary vapor barrier film. Its function is to create a vapor barrier on the inside of the walls and roof. It protects the heat-insulating material from steam ingress from inside the heated room.
• Vapor barrier membrane with reflex coating. Able to partially reflect heat back into the room. This helps to increase the thermal protection of the room and roof up to 10%. Compared to standard counterparts, they have great 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 allow steam to be removed from rooms that are used irregularly. For example, it can be a garden house that is actively used in summer, but in winter it can be heated only a few times.
• Vapor barrier with variable vapor barrier properties. Ideal for renovation work, as they can be mounted from the outside without dismantling the inner cladding.

Manufacturers of vapor barrier films

TechnoNicole

This well-known company guarantees that its vapor barrier films will last for decades. There are 3 main types of this product on sale:

• vapor barrier film TechnoNikol. Used for interior work. A fairly versatile material that is suitable for insulating walls, ceilings and pitched attic roofs. The price of a roll is 1500 rubles;

• diffusion membrane films TechnoNikol designed to isolate the roofing insulation from the formation of condensate in it. Represents a nonwoven polymer fabric and protection of both sides from polypropylene fabrics. Unlike conventional vapor barrier materials, this is a breathable film. The cost for a standard roll is about 3200 rubles;
• non-perforated vapor barrier film TechnoNikol. Highly targeted material for roof vapor barrier. Protects against both water and dust. For maximum strength, it is reinforced with a special mesh fabric. The approximate cost is 1200-1500 rubles / roll.

Izospan

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

• Izospan C. This is a two-layer film that protects the insulation from the inside of the room. It can also be used as a roofing film on non-insulated roofs. One side of it has a roughness, the role of which is to retain excess moisture and with its further evaporation. The second side is smooth, it is mounted on a heater.
• Izospan V. An analogue of the previous material, it is also chosen for the vapor barrier of the walls of a frame or wooden house from the inside.
• IzospanD. This is the most versatile vapor barrier film from the entire Izospan product line. It has an anti-condensation coating that can protect mineral wool from both internal steam and external moisture and wind. Its strength is so high that it can be used as an independent roof covering for 3 months even in winter. When installing it on the walls from the outside, it is allowed to postpone the arrangement of the finishing cladding for up to 6 months. The price of a roll is 2500 rubles.

Installation of vapor barrier walls in a wooden house

The vapor barrier installation technology 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 a smooth side close to the insulation. In this case, the vapor barrier will evenly distribute the flows of moist air, bringing it into the ventilation system.

The method of fastening the vapor barrier depends on the purpose of the room in the house. In little-used or non-residential rooms in which low humidity is allowed to use a one-sided method of arranging a ventilation gap. In all other cases, professionals advise to provide for bilateral ventilation, which is much more efficient. Often, the membrane manufacturer on the packaging indicates the recommended installation method.

Stages of work

• If the house is not new, but repairs are being carried out, then first the entire cladding is dismantled to the wooden frame of the wall. If possible, inspect the insulation or wood for damage, if necessary, eliminate them.
• Walls and thermal insulation must be thoroughly dried. It is advisable to carry out work in the warm season, since frost can form in winter, which, closing with a vapor barrier, will turn into a large amount of moisture over time.

• If the house is framed, then the membrane is rolled out along the length of the entire wall and cut off so that in the corners there is an overlap on the adjacent wall of 10-15 cm. It is fixed in stages to each vertical board of the frame using a stapler. There should be no distortions, cracks or folds. Therefore, it is better to do the work 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 out and fastened in the same way. After that, the joints are glued with adhesive tape. A frame of slats is stuffed on top, which tightly presses the vapor barrier and at the same time serves as a frame for the cladding. Represents sosboy vertilkany slats, which are mounted on self-tapping screws in increments 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 with rails around the perimeter of all door and window openings.

• If the vapor barrier of the house is made of timber, then the frame is first stuffed under the insulation to the walls and tightly laid there. Further, all work is carried out in a similar way.

Do-it-yourself ceiling vapor barrier in the house

Most often it is done if the interfloor ceiling is made of wooden logs and insulated with mineral or basalt wool. Two people are required to complete this work, it will be extremely difficult to do it alone.

• Before starting work, the ceiling must be disassembled and consist only of logs.
• Then, from below, that is, from the side of the living room, a vapor barrier is attached along the logs. This should be done along the longer side of the room in order to form as few joints as possible.
• The required length is measured and cut off on the floor and already with the prepared segment they rise to the ceiling. It is convenient when 2 masters are located on opposite sides of the room. This allows you to correctly position the vapor barrier and make sure that it does not warp during fastening.
• For the convenience of work, at first you can simply “grab” it in several places (but do it firmly). And after making sure of its correct location, already fix it thoroughly.
• So they pass the entire ceiling, not forgetting about the overlaps and their gluing.

• From below, it is attached to the logs with wooden slats, regardless of what the ceiling covering will be.

Tip: the work is quite painstaking and it often happens when an accidental tear occurs in an already fixed area. In this case, a patch is cut out of the membrane with an allowance of 10-15 cm along the edges. It is inserted into the hole formed and glued along the edge with glue. This creates a fairly airtight layer. The top is additionally glued with adhesive tape.

• Having finished fastening the vapor barrier, a heater is placed in the formed cells from the side of the second floor.

Errors in vapor barrier in a frame house

• Poor quality installation. At first glance, it seems that it is simply impossible to make a mistake when attaching a vapor barrier film. What could be easier than stretching it well, attaching it to the frame and gluing the joints. But it is precisely because of the seeming simplicity that some builders neglect accuracy during work. As a result, gaps or folds are formed. But the worst mistake can be the incorrect location of the membrane, or rather the wrong side, as a result of which it starts to work incorrectly. If all this was already covered with interior decoration, then the consequences of such work can be guessed only after a couple of seasons, when the heat-insulating layer starts to work worse.
• Installation of vapor barrier film on the outside of the house. This gross mistake leads to the fact that steam, seeping from inside the house and passing through the insulation, rests against the vapor barrier and settles on it with condensate. In a very short period, the insulation dampens, not being able to ventilate. For external protection, it is necessary to use exclusively windproof films that are able to let 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 foam or extruded polystyrene foam. Most often it is made in houses from sandwich panels. But, in order to remove excess moisture from the house, in this case it is necessary to install a high-quality forced ventilation system. When insulating with ecowool or mineral wool, vapor barrier must be present in all cases.
• Double vapor barrier. It happens that a vapor barrier layer is placed in rooms with high humidity, and a facing material with low vapor-permeable properties, such as plastic panels or tiles, is laid on top. It turns out that after passing through the joints of the grout or the joints of the panels, the steam gets between the vapor barrier and the tile, without the possibility of escaping. Therefore, for cladding in such rooms, it is recommended to make a crate on the wall that borders the street.

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

Choosing a vapor barrier installation method. In total, 2 ways to use a vapor barrier are used. In the first case, the film is attached to the wall frame, and sheathing material (drywall, lining, etc.) is mounted on top of the same load-bearing wall boards. In the second version, the film is similarly nailed to the wall frame, but under the sheathing material of the walls, an additional frame is made of slats 2-3 cm thick. Which method is 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 unusable, due to the lack of a ventilation gap. Or use this method when the building has an economic purpose and is not used year-round. But even here it is necessary to make ventilation wiring throughout the room.
• The second option with the arrangement of a ventilation fence is more acceptable for houses intended for permanent residence. This helps eliminate the risk of excess moisture in the air.