Types of vapor barriers used to protect the walls of a house from moisture. Why is this necessary? Correct styling and fixation of the material. Tips and features for installing vapor barriers with your own hands.
Vapor barrier of walls
Vapor barrier of walls during the construction and finishing of a house is one of the first tasks. Moisture protection will protect the building from destruction and bring warmth and comfort into the house. And also protection against fungus, which negatively affects the health of all household members.
Vapor barrier is carried out using various materials both outside and inside the room. Installation technology requires compliance with the stages of work, as well as compliance with the rules on which the quality of the work performed depends.
Why do you need to install a vapor barrier inside and outside your home?
When finishing the walls of a house inside and outside, insulation materials are often used, which absorb moisture like breathable materials. As a result, a condensate collection point appears. This leads to destruction of the insulation, the appearance of fungus, deformation and damage to finishing materials (detachment of wallpaper, falling off of tiles, deformation of plasterboard sheets).
To create the desired microclimate in the room, a vapor barrier is used that can prevent moisture from reaching the insulation. At the same time, many of these components are breathable, which is necessary for both walls and finishing materials. This feature allows for ventilation, which is necessary for all elements on the walls.
Cases when vapor barrier is required:
- When the walls inside the room are insulated with mineral wool. It is breathable and breaks down when exposed to moisture.
- Walls covered with plasterboard and other cladding. Basically, condensation is created between the rough wall and the cladding, which negatively affects the finish.
- A vapor barrier layer is installed on the outside to protect the walls from external moisture. This is done when insulating the facade of a building.
To create the necessary climate in a room with a vapor barrier, a ventilation system is necessary.
Types of vapor barrier material: which one is better
The construction market is overflowing with types of vapor barriers. It can be either liquid or in rolls. Each material has its own purpose and composition. Some are used for walls outside the house, others only indoors.
Mastic
The mastic has a bitumen-polymer base. It is applied to the surface, creating a layer that protects from moisture and allows the rough base to “breathe.” The mastic is applied to clean, dry walls made of various components (wood, brick, concrete) with a brush in 2 layers. The second time bitumen is applied to the dried first layer. The advantage is that the mixture is already sold in finished form and does not require additional preparatory work by cutting or preparing. The service life of the mastic is more than 25 years.
Membranes
Membrane materials available big choice in the construction market. They have the following properties:
- styling with outside insulation. The membrane protects external wall from precipitation, winds. Siding and lining are installed on top;
The membrane should fit tightly to the insulation and be firmly fixed. Because it can tear due to strong winds.
- For vapor barrier for walls inside the house, Megaizol V is used - a polypropylene film in 2 layers with an anti-condensation surface. The film protects the walls from the appearance of dew points, which leads to the development of fungus and dampness;
- Izospan FD, FS, FX – reflective surfaces used in bathrooms, baths, saunas.
When choosing a wide range of membranes, you need to pay attention to what purposes they are intended for - for the street, a bathhouse or vapor barrier inside the house.
Vapor barrier film
For vapor barrier, a film with a thickness of less than 0.1 mm is used. It is the most used of all listed. It has no perforation and does not allow air to pass through. However, recently breathable films have been produced.
Vapor barrier film is applicable due to solutions to such problems:
- Micro-ventilation of walls and insulation occurs.
- The condensate collected when the outside temperature changes is partially removed.
- In saunas and baths, where there is high humidity And heat, which other vapor barriers cannot withstand.
The vapor barrier film does not allow small drops of water to pass through, but at the same time “breathes”, which allows you to solve problems.
Liquid rubber
This material is sold in the form of a bitumen-polymer liquid product. After application, a “rubber” covering appears on the surface, which follows all the recesses on the wall. The rubber surface prevents moisture from penetrating and provides hydro-thermal insulation protection.
Kinds liquid rubber:
- Emulsion – applied by machine. Applicable on floors for vapor barrier.
- Emulsion applied to the floor manually.
Liquid rubber is also applicable to protect the foundation from the street side.
Installation of vapor barrier material for insulation inside a brick house
Vapor barrier of brick walls is made using several types of materials to choose from. Indoors - these are films and membranes.
Materials based on foil are also applicable. They have reflective properties. In this case, the foil side is placed inside the room.
If brick wall the inside is insulated with mineral wool, then it must be protected on both sides. On the wall side from condensation, and on the room side from vapors penetrating into the insulation.
From protective materials Alufom, penotherm, penofol are used.
First of all, prepare the wall: it is cleaned of sharp protrusions and dust.
Afterwards, the vapor barrier is fixed, the insulation is placed in the created sheathing, and a vapor barrier is placed on top again. In this way, the mineral wool is protected on both sides.
Which side to lay to the insulation inside the building: how to lay
Depending on where the material is being installed, determine which side to lay it on:
- When laying insulation on the street side, the vapor barrier is fixed to the insulation on the street side.
- When treating ceilings and roofs, antioxidant materials are used. They are fixed to the insulation.
- If there is no additional fastening of the ceiling and roof insulation, then the material is attached to the bottom of the rafters.
- If thermal insulation comes with inside walls, then fixation is carried out with outside insulation.
Many materials are used that have the same surface on both sides. Therefore, it makes no difference which side the vapor barrier is attached to.
Which side to attach and nail?
When the question arises which side is used to fix the vapor barrier, nuances arise:
- There are materials that have the same sides. Their use does not affect the protective functions.
- The antioxidant insulator is placed with its smooth side facing the insulation.
- Foil membrane - fixed with a shiny surface inside the room.
- Film materials – smooth side to the insulation.
- When choosing a diffuse component, you need to study the instructions, since they can be double-sided.
The dark side of the material is the outer side.
What to glue
The vapor barrier is fixed in several ways:
- use nails with wide heads;
- use of a construction stapler;
- on top of the layer, wooden planks are fixed at a certain distance.
The joints are glued together with adhesive tape for vapor barrier.
Features of vapor barrier of frame and wooden buildings
For guard wooden walls houses have a vapor barrier both outside and inside. This is necessary, first of all, to protect the wooden beams, since after getting wet, slow drying occurs. During drying, the wood becomes deformed and rots.
IN wooden house It is imperative to fix the vapor barrier layer, because there is the possibility of temperature fluctuations and the appearance of humidity. Especially in the autumn-spring period.
Vapor barrier of walls in frame houses is carried out using a different method.
How to lay it correctly
Vapor barrier of walls wooden house from the street are produced in the following sequence:
- On wooden beams fix the layers with overlap. All joints are sealed with tape or foil tape.
- Next, installation is carried out frame base for insulation.
- After attaching the mineral wool, a hydraulic barrier is attached to the beams on top.
- The last step is finishing Houses.
If the bars create flat surface, then the vapor barrier must be mounted on wooden slats. This will create ventilation.
Vapor barrier inside the house:
- a gap should be made using slats for ventilation;
- material is attached to the slats;
- the next step is the construction of a frame base for the insulation.
- after laying the insulation, fix the hydrobarrier;
- the last stage is finishing.
When laying vapor barrier material frame house you need to follow these rules:
- use membranes to create a ventilation layer;
- Installation of vapor barrier on both sides is not done.
The material is secured with a stapler, the borders are sewn up with tape.
Is additional protection needed?
In a wooden house, additional protection is not required. But in frame buildings applicable material such as: hydro-, wind protection. He is fixed to exterior decoration. Then OSB, thermal insulation, vapor barrier and finishing are applied.
Is it possible to lay several layers
This is not necessary, because the vapor barrier material is created in such a way that it fully performs its functions. In addition, in some cases, in addition to vapor barrier, they use Additional materials protecting the insulation and walls (wind protection, waterproofing).
Attention. Some types of membranes are created from several layers. By using this material, there will be additional protection for walls in damp areas.
How difficult is it to make a vapor barrier with your own hands?
Despite the fact that the vapor barrier of the walls in the house is important point to protect the structure from destruction, it can be carried out independently. To do this you need to follow the rules:
- You need to know how to carry out installation correctly in specific cases (high humidity, wooden walls).
- Before installation work You should familiarize yourself with the technical characteristics of the selected material.
- The roll must be cut by clearly measuring the correct length. The fewer joints there are, the better for the building.
- Fixing the layer cannot be done simply with nails to the surface. Over time, the vapor barrier will tear and weaken. You must use either wooden slats, or a stapler.
Peculiarities
Before installing the vapor barrier, the following features must be taken into account:
- Material. Having studied specifications material, you can understand how suitable it is for working indoors or outdoors.
- Correctness of work. In addition to the fact that the rolled material is laid with an overlap of at least 20 cm, you need to know which side and in what method: vertically, horizontally.
- The joints of the material must be glued to avoid moisture getting on the insulation.
- The material is fixed every 60 cm.
For quality work done, craftsmen recommend purchasing vapor barrier and its components from the same company. Let's say that the tape for the joints should be of the same brand as the material itself.
Vapor barrier of the walls of a house can be carried out not only when a new building is being erected, but also when repair work. The walls of the house are destroyed under the influence of moisture, so to preserve them, the material is installed outdoors and in the house. Only in some cases work is carried out on one side ( frame house). Having studied all the nuances of installation, the vapor barrier will last long term, and the microclimate in the house will not be disturbed by moisture.
Useful video
First of all, you must follow the manufacturer's instructions, which clearly describe which side to lay the windbreak on. If there is no such instruction, there are a number of general recommendations, applicable for windproof films:
- the wind protection spreads towards the insulation with the “fleecy” side, unless otherwise specified in the instructions;
- if both sides are the same, the film is attached with the manufacturer’s logo on the outside;
- wind protection without markings and distinctive qualities of one of the sides can be installed in any convenient way.
Manufacturers often roll rolls in such a way that the wind protection can be laid as simply as possible - as the roll unwinds.
Windproof films different types, are stacked differently:
- Simple wind protection. These are perforated single-layer films that can be placed on either side of the insulation, as they have double-sided vapor permeability.
- Wind and moisture protection. These are two-layer films that are laid with the moisture-repellent side facing out. This side is smooth, often with manufacturer’s markings or painted in a different (non-white) color.
- Superdiffusion membranes. This material has a multilayer structure with high water resistance and vapor permeability. It is necessary to lay the membrane on the outside of the insulation and only with the marked side facing out.
Laying windbreaks on the floor
On internal floors, the film is spread over the insulation with the markings facing outward and the plain side inward.
And to protect the wooden floor from cold wind blowing from an uncovered base columnar foundation, the film is laid on the subfloor without gaps close to the insulation. In this case, it is laid with the inscriptions down.
How to lay a windbreak on a roof
Single-layer windproof films are laid under the roof on either side. But two-layer ones - only with the smooth side up.
Some films and membranes are UV resistant due to a special coating. The manufacturer must indicate this parameter. This windbreak is attached to the rafters with the colored (protective) side up.
How to install windbreaks on walls
On the walls, wind protection is placed on the outside directly on the insulation (with the markings or the colored side facing out). It is necessary to provide a ventilation gap between the film and external finishing. In order for the windbreak to provide a sufficient level of protection from moisture, it must be mounted horizontally from bottom to top with an overlap of at least 10 cm. Inside, a vapor barrier is laid on the walls - this is very important
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Construction work, regardless of purpose, cannot be done without an insulating layer, due to which the quality and service life of the building significantly increases. The most important insulating material is vapor barrier, which ensures the correct microclimate in the under-roof space, as well as in wall structures. Working with it does not cause any particular difficulties, however, every developer should know how to properly attach a vapor barrier.
Types of insulating materials and technology for their construction
There are several types of vapor barrier, and in each specific case it is necessary to take into account the presence of certain characteristics of the material.
The most common materials for vapor barrier include:
- pasting, for the installation of which it is used adhesive composition. The integrity of the insulating layer is ensured by the tight fit of the material to the surface of the structure;
- painting;
- grouting materials.
When working with film, it does not matter how the vapor barrier is attached, that is, it can be turned with either side to the base and nailed with small nails or staples. This insulating fiber does not have a front or inner side, which greatly simplifies working with it.
Installation of film depending on its type
It should be remembered that the film is attached depending on a certain gap and its maximum tension level. Since the material has an impenetrable structure, air freely penetrates through the gap into the insulated space. This type of material has a slightly modified copy - with a rough front side, which serves for the timely release of steam to the outside. If necessary, it is permissible to lay two layers of film, with the glossy side facing each other.
As a more modern insulation, manufacturers offer it, which has wide application possibilities. When laying it, the front side must face outward to allow air to flow to the structural elements and release moisture from them.
To determine the correct placement of the material, just look carefully at its canvas - there is a special mark there. Such films are available in two types: single-sided and double-sided, which are used depending on the characteristics of the work being performed.
Vapor barrier films are offered with reflective properties, and they are also called penofol. On one side of this material a foil layer is applied, due to which the film is widely used in baths and steam rooms. In addition, it is necessary during the construction frame houses, where the main construction material– these are galvanized metal profiles. This insulation is fastened quite quickly and simply, but when working with structures endowed with special properties and characteristics, some difficulties may arise.
Preparation of the primary base for vapor barrier material
Developers who do not have sufficient experience in performing construction work often wonder which side to lay the vapor barrier so that it reliably protects the roof from negative factors. To answer this, you should take the time to Special attention completely to the whole stage.
Initially, a primary base must be prepared, where the insulation layer will be attached. In most cases, this will require ordinary lumber that has been cleaned, dried and primed.
This type of insulation does not require special tension, but the film should not sag in the spaces between the elements of the main structure. Under no circumstances should you use staples, nails or other fasteners that could perforate the material or compromise the integrity of the canvas. Experts recommend attaching such insulation to a strong adhesive tape, which ensures a high-quality connection of the film with the primary base.
The material is supplied to the market in rolls, so it is very convenient to work with it when cutting strips required length. To form a complete layer of material, a slight overlap should be made when placing the cut pieces.
Thanks to this type of insulation, a number of actions are carried out that have a positive effect on the building as a whole:
- evaporation of residual and excess moisture without the formation of condensation in the under-roof or inter-wall space;
- microclimate is regulated as in interior spaces, and in the roofing structure;
- the service life of individual building elements and the entire house or cottage increases.
Installation allowed vapor barrier materials right on top of the roof. In this case, solutions made from bitumen, special varnish and mastic are more suitable. This installation is relevant in the case of arranging some roof structures, most often used for the construction of high-rise buildings and those covered with soft roofing material. Grout insulation materials can be used as a base for cement mortar poured according to building requirements.
Self-installation of insulation film
So, initially, you need to determine how much film will be needed to complete the work. If you miss this stage, then it may turn out that there is not enough material, or too much, which is fraught with additional material costs. To correctly calculate the material consumption, you need to have a clear idea of the total area, and to the obtained value add about 15% for the reserve that will be used to overlap the material, as well as replace damaged pieces (read also: " "). It is impossible to complete the work without special tools, so you also need to take care of their preparation in advance. Stock up on a pencil, tape measure, utility knife, adhesive tape, stapler and other equipment necessary for construction.
It is better to secure the canvas before insulation of the room begins. In order for the insulation system to function effectively, experts recommend checking the correct location of the film in relation to the structure. The material needs to be slightly stretched. Make sure there are no wrinkles on it.
Regardless of which side the vapor barrier is laid on, it is imperative to maintain an overlap of at least 50 mm between the two slabs of material - this is the only way to guarantee the integrity of the insulating layer. To connect each strip, you need to use adhesive tape, the structure of which allows you to securely fasten the insulation without damaging it. To completely prevent damage to the interlayer during subsequent operation, carefully inspect the strips of material - if there are even small defects, it is better to replace the damaged material with a whole sheet. The highest quality insulating layer will be obtained if the strips are laid with a slight overlap not only among themselves, but also on the walls (150 mm is enough), as shown in the photo.
Now we will dwell in detail on how to correctly place the selected insulating film on the base.
Despite the fact that all insulating materials perform the same function, the requirements for their placement do not provide for a single pattern. This fact is explained by the fact that each type of insulation requires a special fastening that ensures reliable fixation of the material to the structure.
When choosing special types of films that are produced without the inside and front sides, the work is greatly simplified. In other cases, if the material is placed incorrectly, the opposite protective effect will be created.
An example is the function of a membrane film - it is to allow wet vapors to pass out and prevent moisture from penetrating inside. If the developer confuses which side to attach the vapor barrier, then a reverse reaction will result, which is fraught with rapid destruction wooden elements. Thus, moist air from the street will be drawn into the room, in which additional fumes will accumulate that have not gained access to the outside. In a word, such a system will lead to a significant reduction in the service life of the building.
Features of installation of roofing and wall vapor barriers
The implementation of insulation work can be the basis of the entire construction, since in the absence of such a protective layer, the frame structure or rafter roofing system will not be able to fully perform its functions, and therefore will be subject to rapid wear.
Depending on the availability and use of thermal insulation, the installation of vapor barrier materials will be determined. If there is no insulation in the under-roof pie, attention should be paid to how to lay a vapor barrier: it is laid as a layer between the sheathing and the rafter system. Thus, the rafters are protected from the accumulation of moisture, due to which fungus and mold will appear over time.
Using attic space as the second residential floor, the roof structure must be installed with high-quality insulation using mineral wool or foam boards. The latter material is dangerous due to the release of chemical particles as a result of strong heating.
So, when performing thermal insulation, a double vapor barrier layer is installed, which will protect not only the rafter system, but also the insulation itself. According to special requirements, we check first correct location sides of the film - this is the only way to be sure of the complete safety of the building material during operation.
If the installation of insulating material is carried out on wall structures, then the installation requirements are completely different. In this case, you need to determine the purpose of the walls in the building, and also pay attention to what they are made of. The most popular are interior partitions, with the help of which a living space is delimited into several zones. Such walls are usually erected from frame structures with double-sided cladding.
For filling interior partitions you will need insulation and soundproofing materials, necessary for a high-quality and comfortable microclimate in the house. This design does not require insulation equipment, only if it does not border the kitchen or bathroom, where steam is constantly generated and moisture settles on the walls.
How to properly attach a vapor barrier, more details in the video:
Let's look at how to properly install a vapor barrier in this case.
Inside the partition itself, where the insulation material, it is necessary to build a protective layer that would prevent the penetration of moist air. The function of such protection is assigned to vapor barrier film, laid on both sides of the thermal insulation so that there are no gaps. To make the fabric complete, you need to connect its individual elements with adhesive tape - it works well not only with two, but also with several insulation elements. The insulating material itself required quantity carefully cut off from the roll; in case of even minor damage, you need to replace it with a new one.
So, installing a vapor barrier is a mandatory stage of any construction work, which will result in a high-quality structure that is ready to last a long period of time.
Insulation of a house can be done using various materials, but always in compliance with technologies, in each of which vapor barrier plays an important role, without which the effectiveness of thermal insulation is reduced to practically zero.
Insulating a house using vapor barrier
Why do you need to install a vapor barrier?
If the ambient temperature were always constant throughout the year and did not change day and night, the need for such technological process would be completely eliminated, since condensation would not form on the surfaces of building envelopes. It is vapor barrier materials that prevent condensation moisture from penetrating into the structure of the insulation and further into walls, ceilings, and elements rafter system made of wood, which significantly extends their service life, and not only. Even hardware buildings suffer significantly from condensation moisture, becoming covered under its influence with a layer of rust, which gradually reduces the ability of structures to withstand loads.
If during the insulation process they are used different kinds mineral wool, moisture that gets into them can reduce thermal insulation characteristics insulation. This is especially true for slag wool and glass wool. Stone species mineral insulation not so susceptible to moisture, but not recommended for them either long time contact her.
Wet insulation is no longer able to maintain its properties, and this leads to excessive consumption of energy, which is used to heat the building. In the premises, as a result of temperature changes, mold, mildew appears on the structural elements of the building, the air becomes humid and hazardous to health residents. The roof truss system quickly deteriorates due to wood destruction and requires major repairs.
However, when carrying out thermal insulation works On their own, not everyone knows which side to lay the vapor barrier on and which material is better to choose. This and other points related to thermal insulation will be discussed below.
Classification of vapor barrier materials
Products designed to perform the function of preserving building and other structures from moisture are divided according to several parameters:
- functionality;
- form;
- material of manufacture;
- installation method.
Functionality of vapor barrier
According to this indicator, vapor barrier materials perform the following functions:
Universal products protect elements of buildings and structures from the effects of moisture of all types - ground, sediment, condensation.
The purpose of a vapor barrier is to prevent moisture from entering structures Materials with a special coating, together with protection of structural elements from moisture, are able to simultaneously reflect heat flows from the enclosing structures, thereby keeping the house warm. And in the same way, frosty air flows are not allowed into buildings.
Products with a vapor transmission effect do not allow condensation moisture to settle on insulating materials, removing it outside the insulated structures.
Shape and materials
Materials intended for vapor barrier are produced in the following forms:
- sheet;
- roll;
- liquid.
Liquid vapor barrier for roofing Drywall sheets, wood chips or wood-fiber products can be used as a vapor barrier. A similar vapor barrier is installed in a specially mounted frame structure, from wooden blocks or metal profiles. The sheets can be secured using self-tapping screws. Sealing of joints is required. When installing a vapor barrier under flooring You can use lining material, which is cut into sheets and mounted end-to-end without overlap. The seams with this method are taped with tape or special adhesive tapes.
Most vapor barrier materials are produced in roll form. This:
- Polyethylene and polypropylene films with combined functionality - wind and moisture protection, hydro and vapor protection:
- Oil-bitumen-based materials - roofing felt, glassine, roofing felt.
Roofing felt can also be used as a vapor barrier - Membranes from non-woven fabric, so-called diffuse or “breathable”, which are capable of passing air but retaining moisture vapor. At the same time, it remains high degree vapor barrier, without the presence of a greenhouse effect. Unlike all other types of film materials, diffuse films are laid without creating a ventilation space between the insulating layer and the vapor barrier.
In turn, vapor barrier membranes are produced in several types:
- with perforated surface:
- porous;
- two-layer;
- three-layer.
Perforated material is made from reinforced film or in combination with non-woven fabric. The surface of such products has tiny holes that can allow moisture vapor to pass through. It is mainly used for vapor barrier installation of non-insulated enclosing structural elements of a building.
A membrane with pores contains a large number of air voids between the fibers of the material. This structure does not allow the material to be used in conditions where the ambient air is very dusty, since dust clogs the pores, which reduces the degree of vapor permeability of the membrane.
The three-layer material, called a superdiffusion membrane, is produced by combining several different layers of film or non-woven fabric, which does not have any holes or pores.
Composition of three-layer vapor barrier film The material does not allow dust or water to pass through and serves as a wind barrier. It is these properties that are the advantage of such a membrane.
A two-layer vapor barrier is a simplified version of a three-layer material. The exclusion of one layer from the composition significantly weakens mechanical strength and reduces the reliability of such a membrane.
In liquid form, vapor barrier is carried out using various solutions made on the basis of bitumen, liquid rubber, varnishes and mastics, which are applied with a brush, roller or sprayed with special devices on top of the thermal insulation. This type of vapor barrier can allow air vapor to pass through, but retain moisture.
How to lay a vapor barrier
Depending on the material used and purpose structural element, the technology for laying vapor barriers may differ.
How to attach vapor barrier to walls
If two- or three-layer diffuse membranes or foil insulation are used, it is first necessary to determine the outer and underside of the material.
Foil vapor barrier is placed with the shiny side towards the room Problems often arise after wall insulation is completed, when the master does not know which side to lay the vapor barrier on. When using films that have sides with different textures, the side that is rough to the touch is applied to the insulation. The foil material should be placed with the shiny side inside the room, but with the obligatory formation air gap between the foil and the finishing coating of the walls. To do this, counter battens are installed on top of the vapor barrier, onto which the finishing coating of the walls is mounted.
The membrane is placed on the surface of the walls vertical stripes with an overlap of 10 cm at the junction of adjacent strips. In this case, the joints must be sealed with a special adhesive tape or metallized tape. Where the membrane is laid directly on a brick or concrete wall, it must be well attached with glue to create an absolute tightness of the coating. You can attach a vapor barrier to wood using galvanized nails or a construction stapler.
Vapor barrier material is laid on top of the insulation The insulation of the external walls of the building is carried out by laying a vapor barrier over the insulation. In cross-section, an insulated wall is a multilayer “pie” consisting of frame elements (wooden or metal), between which polystyrene foam slabs are laid. After this, a vapor barrier film is spread, held in place by the counter-lattice slats. And the final layer of such a “pie” is the finishing of the walls - siding (metal or vinyl), lining, ceramic tiles And so on. Between paper insulation and finishing material There must be an air gap, thanks to which condensation moisture will not penetrate into the structure of the insulation, but will roll down or evaporate.
Sometimes a windproof film is laid directly on the walls before installing the insulation, which protects the walls from condensation moisture.
Installation of vapor barrier when insulating the roof
Vapor barrier in roof insulation The roof is insulated from the attic side. Lay the vapor barrier against the insulation with the smooth side. The film itself is attached to the elements of the roof rafter system using a stapler so that it does not sag. The connection of individual strips of vapor barrier, which are laid with an overlap of 10-15 cm in horizontal or vertical rows, is made with tape and double-sided adhesive tape. In this case, double-sided tape is used to seal the strips on the roof side, and single-sided tape is used on the attic side.
Around all structures passing through the roof (stove and fireplace pipes, ventilation shafts, skylights or lanterns) vapor barrier aprons must be installed.
Correct installation of vapor barrier material on a wooden floor
Vapor barrier, if it is a double-sided film, is spread over subfloor smooth side down. Thermal insulation is laid on top of it, which is covered with a second layer of vapor barrier material and the finished floor is filled.
Vapor barrier is laid on the subfloor The foil film is laid with the shiny side up, that is, towards the room. The exception is Izospan vapor barrier, which is mounted with the smooth side up, rough side to the insulation.
It would be more correct to first study the manufacturer’s instructions, and only then begin laying out the vapor barrier. All types of vapor barrier products are attached to the walls using damper tape. An air gap between the vapor barrier and the finished floor can be created, or you can skip this stage. There is no clear opinion on this matter.
Concrete floor construction with vapor barrier
The vapor barrier membrane is located under the reinforcing mesh The technology of concrete floors is somewhat different from wooden floors in that the vapor barrier is not laid out on the ground. Here it is better to use waterproofing to prevent the concrete structure from being moistened by ground moisture. For this, bitumen-based materials are used - several layers of roofing felt, which are connected with the same type of mastic. Concrete structure insulated with expanded polystyrene boards, which are covered with a vapor barrier and then reinforced with metal mesh. After this they pour cement-sand mortar. In such a “pie” there is the possibility of replacement vapor barrier membranes a simple plastic film, but it should be chosen with a thickness of 200 microns so that it does not tear under the weight of concrete or cement mortar.
The main point of the article
The use of vapor barrier materials in insulating buildings and structures helps to significantly extend their service life building structures. If the process of laying vapor barrier is carried out in accordance with the technology, when the material is laid right side to the insulation, you can expect good effect from insulation. The variety of vapor barrier materials sometimes confuses home craftsmen; in this case, you need to carefully read the manufacturer’s instructions.
