In addition to the basic properties and performance of the materials used, auxiliary elements play an important role in the installation of building structures. Among them, a special place is occupied by insulators that ensure the integrity of the main structure. The function of this component in roofing is essential. Thanks to the insulating layer, a barrier is formed against precipitation and other external influences. There are various means of providing such protection on the market, but the most effective material is waterproofing diffusion membranes, which are laid directly into the roof structure. But roofing systems are not limited to the scope of this coating. For example, the insulator is also used in laying floor and wall materials.
General information about diffuse insulators
Specially to preserve the technical and physical properties of the roofing, builders use waterproofing roofing films. Most of them are sold in the form of rolls, which outwardly practically do not differ from each other. Such insulators can be evaluated according to various criteria, including vapor permeability. Actually, this is the main quality of polymer films, which determines the ability of their structure to pass water vapor. In the language of specialists, this parameter is called the diffusion flux density. In practice, the vapor permeability determines the intensity of the passage of moisture through the roof into the rooms used. Thus, diffusion membranes minimize the possibility of penetration of sediments and their derivatives under the roof. Similar functions are performed by almost all specialized waterproofing materials, but the membranes also include the ability to withstand the intense effects of precipitation in gusty winds. Also, if ordinary insulating layers form only a basic protection against raindrops and snow, then the diffusion film becomes an effective barrier to water vapor.
The principle of operation of the membrane
A common problem with many waterproofers is the accumulation of moisture in one place - usually in front of an impervious layer. Proper installation provides for special channels for draining fluid, but this method does not eliminate all the problems of operation. Diffusion membranes included in roofing "pies" work according to a different principle. It does not act passively, but actively, that is, they do not provide a stationary barrier, but due to a special layer it conducts moisture from the insulation to the place of future runoff or weathering. Therefore, it is very important to place the material in the working area with the correct side.
The very structure of the functional web of such insulators resembles a capillary pump, which is formed by twolayers. The fleecy fabric acts as a moisture collector and transfers it to the perforated areas. Further, through microscopic holes, drops with steam seep to the outer side of the web. In such a moisture removal scheme, there is a risk of liquid contact with metal elements of the roof structure. To prevent corrosion processes, a bulk diffusion membrane on a polypropylene non-woven base is used. Also, films with increased throughput will help to preserve moisture-sensitive materials - they provide moisture removal faster, reducing the chances of destructive processes.
Varieties of membranes
Coatings of this type differ according to several criteria, but the degree of vapor permeability is considered the main one. In particular, low- and high-vapor permeable insulators are distinguished. The first category includes diffusion membranes, which consist of 2-3 layers with a reinforcing mesh. Such a material has an average ability to conduct water vapor, but as a universal means of protection against precipitation, it can be the best solution. Highly vapor permeable materials exhibit a higher level of throughput, which is why they are also called superdiffusion films. Again, the high rate of conduction of moisture does not allow it to condense, which helps to protect the insulation layer from destruction. For this reason, builders simplify the insulating layers, eliminating ventilation gaps.
Also, in some cases, special types are usedvapor-permeable films, among which are the mentioned volumetric membranes. This material is usually used to provide insulation for seam and metal coatings. Volumetric separating diffusion membranes are mounted with an upper ventilation gap on roofs made of aluminum, steel, titanium and other metals.
Characteristics of diffuse membranes
The main performance indicator of such materials is vapor permeability. But when choosing, other characteristics are also taken into account - for example, grammar, water resistance and temperature resistance. As for the grammage, it denotes the mass of the film, which increases in proportion to the thickness of the material. Also, as the weight increases, the mechanical strength of the insulation also increases. On the market you can find films whose weight varies from 60 to 270 g/m2. Also important is the resistance of the coating to water pressure. This characteristic refers to the water resistance that a diffusion membrane has in a particular design. There are different methods for estimating this parameter, but the system that provides for marking according to classes W1-W3 is considered the simplest. Thus, the belonging of the membrane to category W1 indicates that the material will be able to withstand the pressure of a water column, the height of which is 20 cm, for 2 hours.
In addition to precipitation and humidity, warm sunny weather can cause damage to waterproofing films. As standard, such materials withstand peaktemperature effect in the range of 80-100 °C. As for resistance to ultraviolet radiation, for example, the TechnoNIKOL diffusion membrane in the basic version can be exposed to direct sunlight for 3 months. For enhanced modifications, this time period increases to 4 months.
Used in roof structure
As part of the roof, the insulating membrane provides protection for the insulation and internal parts of the structure. The layer performs several functions at the same time - in addition to protecting against moisture and steam, it also protects the roof elements from weathering. It is incorrect to attribute the tasks of this material to the insulation of the premises of the building. The main functions of the membrane still extend to the protection of the insulating layer, which, in turn, regulates the humidity, and in some cases, temperature conditions. In the course of designing the scheme of the membrane device, it is necessary to prevent the possibility of water runoff from the film surface onto the heat insulator at the joints. As a rule, under roof diffusion membrane is adjacent to ventilation ducts, chimneys and chimneys, antenna posts and other third-party components, intersections with which must be isolated.
Using membranes in flooring
Providing reliable insulation is also required in the premises themselves. So, floor surfaces retain their decorative and technical qualities only under conditions of optimal temperature and humidity conditions. Of course, there are materials that are not sensitive to the same influences.moisture, but wood surfaces are not. Usually, the use of diffusion membranes in floor coverings is limited to the creation of an auxiliary substrate for insulation. However, the floor on which the work is performed may matter. The most demanding is the lower level in a private house, especially if it links the living quarters to the basement.
Use in wall and facade cladding
With the help of a diffusion film, they also provide protection against weathering and moisture of heat-insulating materials that are part of ventilated facades. The membranes are placed on the outside, thus allowing excess moisture and steam to pass through the ventilated gap in the cladding. Installation is carried out directly on the facade of the house along with heat-insulating panels. By the way, if a metal supporting frame is used in the design, then a volumetric diffusion membrane is optimal, which will create a natural moisture drain without the risk of corrosion. If you plan to use siding or lining in the decoration, then the film must be fixed close to the outer side of the insulation under the decorative cladding. This is one of the easiest ways to use diffuse insulators, as it requires minimal effort in terms of installation - just use a construction stapler or galvanized nails and fix the material to the supporting structure.
Installation of the diffusion membrane
When the material is placed outside, it is desirable to perform the operation in a dryweather and together with the fixation of the heat insulator. The membrane should be rolled out over the entire work surface and secured with nails or staples. The classic installation on the roof involves laying in horizontal strips with an overlap of about 15 cm. In this case, the vertical joints of the ends should be placed on the rafters. All points and lines of gaps between individual pieces of material are fixed with butyl rubber or acrylic tape. A ventilation gap is not required if diffusion membranes are planned to be installed on the roof, but when laying the insulator on facade surfaces, it is better to provide it. In winter, the load on the insulating material increases significantly, so it is recommended to inspect the roof in the fall to check the tightness of the membrane to the insulator. If the thickness of the rafters exceeds that of the heat insulator, then the vapor-tight material should be pressed against their side with slats with a standard size of 2x3 cm. You can also use building brackets to perform this task. In the course of work, you should be guided by the fact that the lower edge of the membrane ensures the unhindered removal of moisture into a special drainage chute.
Producers
Non-woven vapor-proof material is represented on the market by various manufacturers, among which there are many domestic ones. In particular, the diffusion membrane "TechnoNIKOL" allows you to arrange waterproofing, which at the same time protects structures from contact with moisture and allows surfaces to "breathe". The material of this linepresented in several versions, including those with reinforcing fibers. Also, the TechnoNIKOL superdiffusion film, which is made of a three-layer microporous material, won the trust of users. The difference between this insulator is the double-sided use of non-woven polypropylene, which performs a protective function for the main layer. It is expedient to use such a membrane in roof coverings, which require not only high-quality performance of insulating tasks, but also the preservation of the strength properties of the structure.
A fairly well-known manufacturer of vapor-tight waterproofing is the Du Pont company, which specializes in protecting wall and roof systems through air and water filtration. Under this brand comes the Tyvek diffusion membrane, which is a multifunctional hydro-windproof film. The material has a mesh structure formed by polymer fibers. Unlike competing insulators, Tyvek coatings are environmentally friendly. That is, they can be used both in exterior decoration and in the structure of internal facing coatings. In both cases, the inclusion of this brand of diffusion film will keep the finish dry and durable.
Conclusion
Traditional ways of installing insulating layers usually do not require special installation conditions. It is enough to pick up a sheet or plate of the appropriate size and fix the material in the working area. According to this principle, it is usually mounted andinsulating material, and waterproofing. The diffusion membrane, in turn, guarantees a higher operating efficiency than conventional insulators. But to achieve it, it is important to follow the rules for the location and fastening of vapor-proof films relative to the insulating layers. Roof structures are the most difficult in this regard, as the moisture-removing material can come into contact with other roofing components and roof systems. Also, communications for drainage should initially be provided, with which the diffusion material will interact. From the point of view of installation, the installation of insulators on walls and facade structures looks somewhat simpler. In such cases, after all, the task of maintaining the ventilation properties of the coating comes first, which are realized due to the inclusion of a vapor-tight membrane in the composition of the insulation layer.
