The standard set of protective materials for the walls of the house includes insulation and waterproofing. The first regulates the temperature regime, and the second does not allow the passage of moisture. But in the complex, the "work" of the two layers can form condensate, which adversely affects both the insulating material and the protected base. The vapor barrier of the walls helps to exclude such phenomena, which delays and prevents the spread of water vapor.
The principle of operation of the vapor barrier
To understand how a vapor barrier works, you should refer to the concept of "dew point". This is the temperature level at which moisture passes into the dew state - that is, the process is the opposite of evaporation. For this phenomenon, a combination of several microclimatic indicators is necessary, with which the insulator works. At home, the level of humidity and temperature is always higher than the street, which causes the tendency of moisture to go outside. This process just leads tocondensation on the walls of the house.
Here it should be emphasized that moisture is not only directed naturally upwards, but exits through any cracks and gaps in the building frame. And even a heater with a waterproofing agent cannot act as a full-fledged obstacle to this process. How does the vapor barrier of the walls of the house help? This layer, thanks to the sealing function, creates conditions for moisture to escape with minimal losses, leaving no condensate (dew) on building materials and insulation.
Vapour barrier film
The most common material for providing the vapor barrier function is film. On average, these insulators maintain a throughput of 0.5 g/m2 per day. That is, there is no question of ideal sealing, but the film completely provides protection of walls and structures from direct exposure to steam with consequences in the form of dampness. Manufacturers produce film vapor barrier walls in yellow, green and blue. Depending on the conditions of use, materials with reinforcement, that is, a reinforced structure, can also be used if there is a threat of mechanical damage. Expensive film insulators have a fiberglass treatment that improves both external strength and tensile strength.
PVC vapor barrier membrane
There are a lot of options for combined insulation on the market, which combines waterproofing and a vapor barrier. Such coatings are characterized by a thick structure and versatility. One of the layers of hydrovapor barrier is a membrane. It effectively regulates the passage of water vapor, and also protects the adjacent insulation from moisture.
But there are also separate polyvinyl chloride (PVC) membranes that can be used as self-protection against water vapor. If a completely sealed vapor barrier is planned inside on the walls, then it is quite possible to give preference to polymer membranes. The fact is that they are fixed not with a standard shell or hardware along the edges of the waterproofing, but by means of a thermal pile. The melting of the material eliminates cracks and gaps in the insulation structure. In terms of other qualities, polyvinyl chloride is also not inferior to a conventional vapor barrier film. Its top layer is protected by a textured coating that gives the material strength and resistance to damage. The main composition includes modifiers and additives that improve the susceptibility to high temperatures and UV rays.
How to choose the right material?
Despite the same function and principle of operation, the materials for vapor barrier are not the same. There are different characteristics that you should rely on when making a choice. One of the main ones is protective qualities. We are talking about mechanical protection, which is provided by the already mentioned layer of reinforcement, foil and other coatings. The next thing to consider is durability. This is a complex parameter that depends on the internal structure of the material, resistance to aggressive environments, physical influences, etc. What is also important is the compatibility of the wall vapor barrier with adjacent temperature and humidity controllers.materials. Jointing with metallized coatings is completely excluded, as is the combination of synthetic and natural organic insulators. It is advisable to select a film or membrane from a series of one manufacturer.
General recommendations for the installation process
Before insulating work, you should consider the overall structure of materials that regulate the microclimate of materials. As a rule, the vapor barrier is laid between the thermal and waterproofing. That is, it separates the humid environment and the dry, retaining heat. The most important task during installation is to ensure high-quality fixation. There are different ways of fastening the material, determined by its structure and operating conditions. The simplest method is with the help of self-adhesive strips, which the manufacturer himself applies to the surface of the insulator. Such installation of wall vapor barrier has disadvantages in the form of low strength and fragility, but under the condition of a tight clamp from the side heat and hydropanels, it may well justify itself.
As already mentioned, to ensure the maximum sealing effect, it is better to use membranes that are laid and fixed by heat welding. But this option will require the use of special equipment, not to mention the skills of handling the burner. As for the use of traditional fasteners, this option is suitable when performing a vapor barrier of the wall from the inside, where third-party damaging factors will not affect the film. Rigid fixation of a self-tapping screw or screws with screws in combination withholding profiles, of course, is more reliable, but there is a risk of gaps at the very line of passage of the mounting elements.
Which side to lay the insulator?
The fundamental question that determines the most effective configuration for the placement of vapor barrier material. If glassine is used as an insulator, then it is better to lay it with the inside to the insulation. The bituminous black surface should face the room. A simple single-layer film is fixed by any side to the heat insulator. It has no pronounced protective properties, with the exception of reinforcement, but in this case, reinforcing fibers equally maintain the strength of the overall structure. But there is also a special fleecy vapor barrier of the walls. Which side to mount it on? These are two-layer materials that are installed tightly to the insulation with a smooth surface, and the pile turns outward. Almost all metallized and foil coatings are attached with the protective side to the room. The same foil will act as both a mechanical barrier and a heat reflector, so it is oriented towards the outer space.
Vapour barrier technology inside
Requirements for interior decoration are not as high as outside. It is enough to think over the components of the insulating "pie" and make the installation. For frame houses, it is recommended to use a construction stapler for fastening. It allows you to securely fix thin layers of insulation, hydro and vapor barrier. Installation should be carried out to the strapping or to the racks of the frame. Directly the material of the walls should not be mated with the mount. According to experts, the correct vapor barrier of the walls does not allow the tight convergence of the two protective layers. It is for the effective removal of condensate between the hydro and vapor barrier that there must be a small gap for ventilation. By the way, for this purpose, manufacturers of film materials do not provide materials with absolute sealing, leaving air allowed.
External vapor barrier technology
The problems of insulating a house from the outside are in a whole range of threats that affect the facade. Therefore, proper physical protection is indispensable. A frame structure is formed, including a crate. Its skeleton is made of a metal profile or wooden bars with counter rails. It should be noted that outside the vapor barrier of the walls is arranged in two layers. The first is placed under the crate. It is enough to glue the edges of the material, and fix the wooden or metal frame on the outside. In the very niche of the crate, heat insulator plates and hydroprotection are placed. This is followed by a closing counter-batten with panels on which the second layer of vapor barrier is laid. The installation is completed with facade cladding.
Features of vapor barrier of wooden houses
Solid wood is more susceptible to the negative effects of moisture and condensation. Dampness is a direct factor due to which the processes of biological destruction of walls begin with the appearance of fungus and mold. How to make a vapor barrier for wallswooden house? The structure of the insulation system will be the same, but the difference lies in two points:
- Laying the vapor barrier layer should be comprehensive. It is necessary to isolate not only walls, but also floors with a ceiling structure, an attic and other surfaces of the house. If the rotting process begins in one damp corner, then in the future it should be expected to develop in places protected by an insulator.
- Before installation work, a comprehensive treatment of wood with protective impregnations should be carried out. It is also necessary to seal the log structure, since "cold bridges" often trigger the destruction of material that is constantly under cold and damp.
Seaming
Laying can be done butt and overlap. It depends on the method of fastening and the type of the insulator itself. At the final stage, after the installation is completed, it is necessary to examine the coating in order to detect insufficiently sealed areas. These are not technological tolerances for air circulation, but gaps left as a result of a technical error or improper installation. How to eliminate such defects? The choice of materials for embedding depends on the design itself. For example, vapor barrier of wooden walls can be performed with the addition of viscous mixtures with butyl rubber, polymer compounds and butylene. Slots on flat surfaces, on the contrary, are recommended to be eliminated with hard mats and panels. Products made of polyethylene foam are usually used, which alsoreinforce the insulating pie.
Vapour barrier manufacturers
There are a lot of insulation and waterproofing products on the market, but a specialized water vapor barrier is a narrow segment. In Russia, the most famous brand is Izospan, which offers funds for external and internal protection. The main thing is to choose the right label. For example, vapor barrier for the walls of a wooden house can be performed with Izospan B. Axton offers several options for vapor protection - in particular, a non-woven membrane is produced for building structures that protects surfaces from moisture and steam. Premium materials are developed by the American company Tyvek, which focuses on external protection. For complex insulation, combined wind and vapor barrier films are recommended.
Conclusion
The targeted water vapor barrier device has become fashionable not so long ago. Previously, such functions were entrusted to waterproofing and thick plastic film. Today, it is possible to provide reliable vapor barrier of walls at minimal cost with the thinnest layers of polymeric materials. And again, do not forget that the walls are only part of the frame, the protection of which will not matter without proper insulation of adjacent structures. Another thing is that in each case an insulator with suitable characteristics, protective properties and optimal bandwidth is selected.
