The impact of moisture negatively affects the condition of wall and floor structures, therefore, waterproofing is performed as a mandatory measure for their protection. At the same time, in some rooms, like basements and attics, condensate can accumulate, releasing water vapor. Its impact on building materials is also negative, although not to such a high degree. Integrated sealing of structures could eliminate all sorts of problems due to the contact of building materials with moisture. Partly such problems are solved by vapor barrier. This is a material that regulates the permeability of steam, protecting the target surface or even the room from destructive processes. How to install vapor barrier? Installation and fastening of the coating is carried out in several technological stages. In the course of work, both the features of the selected insulator and the conditions for its future use are taken into account.
What representsa vapor barrier?
Most often it is a film material of yellow, blue or white color. There are also membranes with green and gray shades, in which the waterproofing effect is increased. The film may have reinforcing reinforcement in the form of plastic thin fibers, as well as external coatings such as a layer of aluminum foil. The inclusion of protective coatings is carried out in order to strengthen the insulator on surfaces that are subjected to mechanical stress. How to install a vapor barrier to minimize the negative effects of third-party influence? On this score, there are many opinions related to the styling techniques of one side or another. This issue will still be considered, however, it is the protective function that is best manifested in the combined installation of a vapor barrier and insulation, which is often performed in the form of relatively rigid plates.
Types of material
The film or membrane itself can be made from different materials that differ in technical, physical and operational qualities. The most popular films include the following:
- Polyethylene. As a rule, a reinforced fabric with perforations, which can be used in the arrangement of ventilation shafts, where the exclusion of the "greenhouse" effect is required. Modern versions of polyethylene insulators are covered with an aluminum protective layer, although in terms of strength this is far from the best means for a vapor barrier.
- Polypropylene. More resistant to mechanical stress material, characterized byalso inclusions of layers of viscose with cellulose. This makes it possible to retain moisture, preventing the passage of condensate to the insulation.
- Films based on kraft paper. A special category of vapor barriers with a metallized coating. For example, such modifications are present in the Izospan line. The material is quite dense, therefore, it requires a non-standard approach to installation. How to lay the Izospan vapor barrier from kraft paper? Firstly, the coating is used on roofs, where it is necessary to protect the overlap of the truss system. Secondly, rolling is performed on a stable platform, after which it is covered with a wooden crate. The edges are carefully fixed to the supporting frame with a construction stapler.
Non-woven diffusion membranes. A new generation of vapor barriers that "breathe" and effectively regulate the passage of water vapor. That is, two opposite tasks are solved in a balanced way - the "greenhouse effect" is excluded, but at the same time, sufficient throughput of the protective coating is maintained
Preparation for work
Before starting work, it is necessary to prepare a tool with consumables, a workplace and the insulator itself. To work, you will need measuring devices, a hammer, a screwdriver, scissors, the same stapler, etc. It is important to assess in advance what materials you will have to deal with in specific conditions. Sometimes the laying of insulators also affects the mounting structures, for example. With consumables, the same thing - you should sketch out an action plan in advance anddetermine what fasteners are required. For example, how to lay a vapor barrier on a vertical surface? Obviously, fixing devices like wooden planks or even a full-fledged crate will be required. The only thing that is excluded is the use of metal profiles, as water vapor can lead to corrosion damage.
Next, the workplace and material are put in order. The target surface is cleaned of dust, dirt and repaired if there is serious structural damage. The vapor barrier film is checked for integrity, compliance with dimensions and volume requirements.
Material installation instructions
Universal vapor barrier installation technology looks like this:
- Material is spread across the floor or pressed against a vertical surface.
- The edges are fixed with a stapler.
- If adhesive tapes are provided around the edges, then the protective coating is removed and the film is pasted on the target area.
- If it is planned to lay in parts of the canvas, then the joints are overlapped with a grip of 5-10 cm.
- The fixed film is additionally pressed with bars or a wooden crate. But how to lay vapor barrier in interfloor ceilings, if installation by the type of superstructure of wooden planks is impossible? In this case, the material will have to be spread at the level of the draft log or in the niche of the floor frame. This problem is solved at the stage of construction of the building frame. In extreme cases, you will have to lay the insulator without cratesunder decorative flooring.
- The crate is fastened with anchors or self-tapping screws, after which it is covered with sheet wood-shaving material.
Features of laying on walls
In a wall covering, a vapor barrier is most often mated with a heater. In the supporting structure, a batten system is also used, but in this case, a counter-batten is also built in. First, a mineral wool slab is superimposed and fixed on the prepared frame of bars, and then a vapor barrier follows. Which side to lay to the heater? Installation is carried out with the inside to the thermal insulation. There is a simple rule that the protective part addresses the room and covers the insulation. Further work continues according to the general technology - the material is fastened along the edges with small hardware, and then closed with a counter-batten.
Laying roof vapor barrier
Rear vapor barrier of slopes is usually made with glassine. By this time, the fixation points should be marked, since the installation will not be carried out along a specially prepared crate, but to the elements of the truss structure. Moreover, it is important to calculate the places where the intermediate beams pass between the slopes, which will have to be framed by a vapor barrier for the roof. How to lay the material in this case? The difficulty lies in the fact that the work will be carried out on an inclined surface, which is very inconvenient. Fastening is carried out with staples, as well as on an adhesive base. As an addition, the material is clamped with long strips throughoutthe length of the laying line.
Differences in laying single- and double-layer films
Single layer insulation is usually made of polyethylene. These are thin film coatings that need reliable mechanical protection at the installation site. The representatives of this group include the Akston vapor barrier. Which side to lay this cover? If we are talking about non-woven membrane fabric of the "C" series, then fastening can be done on either side. This is a universal single-layer vapor and water insulator, insensitive to external influences. Two-layer coatings have some features that affect their installation. Firstly, it is also a thick and protected material with a wide range of tasks. And secondly, functional layers can be located on different sides. The purpose of each of them will determine the side of the installation. As a rule, one of the coatings has a mechanically resistant base with a heat reflector.
How to lay the vapor barrier on the floor?
In a floor system, the insulation can be placed either under the rough flooring with the crate, or in the underfloor heating structure, and most often under the outer decorative coating. In any case, the same physical effects are taken into account, so the side facing up will have to be covered with a wear-resistant substrate. How to install vapor barrier on underfloor heating? Before pouring water circuits or electric mats, a dense waterproofing layer with a heat-resistant primer is laid. Further, it will be possible to lay the vapor barrier in combination with insulation without fixing, but evenly.
Vapour barrier in a wooden house - what to consider?
Thin polypropylene membranes are ideal for insulating wooden structures. They are good because they effectively protect against condensate and other wet vapors. Since wooden houses are subject to high requirements for thermal insulation, you will have to use a combined installation scheme. Which side to lay the vapor barrier to the insulation in this case? From the side of warm rooms, three-layer polymer sheets are laid with the protected part outward. On the other hand, additional superdiffusion membranes can be installed on the cold side - according to the same principle with external protection.
Recommendations along the way
Experts recommend taking into account the following nuances in the process of working events:
- Cut the canvases not strictly according to the size of the working area, but with slight excesses - by 1-2 cm.
- All joints must be immediately sealed with either adhesive mounting tapes or construction adhesive.
- If cold bridges (circulation of outdoor air) are observed in the finished structure, it means that the vapor barrier is not laid correctly, and a control check of the joints is required. Gaps with a structural gap are more likely to occur.
- Combined laying with other insulators is always carried out closely.
Conclusion
When erecting critical structures, repairing or laying facing material, it will not be superfluousassess whether a vapor barrier is needed in a given place. It practically does not hide free space and is inexpensive, but its function of protecting building materials is very useful. The main thing is to properly install. For example, how to determine which side to lay the vapor barrier? First of all, you need to focus on a protective coating with a heat reflector. It should refer to the room. If it is not there, then you will have to identify the most sensitive side with an open membrane - it is pressed against the installation site. In extreme cases, double-sided thermal insulation can be performed, which will close the vapor barrier on both sides. The outer part can be protected with a waterproofing layer.
