In the installation of building structures, in addition to the basic properties and operational qualities of the materials used, auxiliary elements play an important role. Among them, insulators occupy a special place, ensuring the integrity of the main structure. The function of this component in roofing is significant. Thanks to the insulating layer, a barrier is formed before precipitation and other external influences. Different means of providing such protection are presented on the market, but the most effective material is waterproofing diffusion membranes, which are laid directly in the roof structure. But roofing systems are not limited to the scope of this coating. For example, an insulator is also used in laying floor and wall materials.
General information about diffuse insulators
Builders use waterproofing sub-roofing films specifically to preserve the technical and physical properties of the roofing. Most of them are implemented 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 makes it possible for their structure to pass water vapor. In the language of experts, this parameter is called the density of the diffusion flux. In practice, the use of vapor permeability determines the intensity of the passage of moisture through the roof into the premises used. Thus, diffusion membranes minimize the possibility of sediment and its derivatives penetrating under the roof. Almost all specialized waterproofing agents perform similar functions, but membranes also include the ability to withstand the intense effects of rainfall in gusty winds. Also, if ordinary insulating layers form only basic protection against raindrops and snow, the diffusion film becomes an effective barrier to water vapor.
Membrane principle
A common problem with many waterproofing systems is the accumulation of moisture in one place - usually in front of an impermeable layer. Proper installation provides for special channels for draining the liquid, but this method does not eliminate all the problems of operation. According to another principle, diffusion membranes included in the composition of roofing "pies" work. It acts not passively, but actively, that is, it does 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 position 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 two layers. The fleecy fabric acts as a moisture collector and transfers it to the perforated areas. Further, through the microscopic holes, droplets of steam seep onto the outside of the web. In such a dehumidification scheme, there is a risk of liquid contact with the metal elements of the roof structure. To prevent corrosion processes, a polypropylene non-woven bulk diffusion membrane is used. Also, films with increased throughput will help to save moisture-sensitive materials - they provide faster moisture removal, 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 isolators are isolated. The first category includes diffusion membranes, which consist of 2-3 layers with a reinforcing mesh. Such a material has the average ability to conduct water vapor, but as a universal means of protection against precipitation can be the best solution. Highly permeable materials exhibit a higher level of throughput, which is why they are also called superdiffusion films. Again, the high speed of moisture does not allow it to condense, which helps to protect the insulation layer from destruction. For this reason, builders simplify insulating layers, eliminating them from ventilation gaps.
Also, in some cases, special types of vapor-permeable films are used, among which the mentioned bulk membranes. This material is commonly used to insulate seam and metal coatings. Mount volumetric separation diffusion membranes with the provision of an upper ventilation gap on roofs made of aluminum, steel, titanium and other metals.
Characteristics of diffuse membranes
The main operational indicator of such materials is vapor tightness. But when choosing, other characteristics are also taken into account - for example, grammar, water resistance and temperature resistance. As for the grammar, 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 increases. On the market you can find films whose grammar varies from 60 to 270 g / m 2 . Also important is the resistance of the coating to water pressure. This characteristic indicates the water resistance that a diffusion membrane has in a particular design. There are different methods for assessing this parameter, but the simplest system is one that provides marking according to classes W1-W3. So, the belonging of the membrane to the W1 category indicates that the material can 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 also damage waterproofing films. As standard, such materials withstand peak temperature effects in the range of 80-100 ° C. As for UV resistance, 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.
Roofing Application
As part of the roof, an 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 wrong to attribute the tasks of this material to the insulation of the building. The main functions of the membrane still extend to the protection of the insulation layer, which, in turn, regulates the humidity, and in some cases temperature conditions. During the design of the membrane device, it is necessary to prevent the possibility of water draining from the film surface to the heat insulator at the joints. As a rule, a subroofing diffusion membrane is adjacent to ventilation channels, chimneys and chimneys, antenna posts and other third-party components, intersections with which must be isolated.
The use of membranes in flooring
Ensuring reliable insulation is required in the premises themselves. So, floor surfaces retain decorative and technical qualities only in conditions of optimal temperature and humidity conditions. Of course, there are materials that are not sensitive to the same effects of 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 be significant. The most demanding is the lower level in a private house, especially if it connects living quarters with a basement.
Application in wall and facade cladding
Using a diffusion film, they also provide protection against weathering and moisture of the heat-insulating materials that are part of ventilated facades. The membranes are placed on the outside, thus providing the possibility of excess moisture and steam passing through the ventilated gap in the lining. 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 construction, a bulk diffusion membrane is optimal, which will create a natural moisture sink without the risk of corrosion. If you plan to use siding or lining for decoration, the film must be fixed close to the outer side of the insulation under the decorative lining. This is one of the simplest ways to use diffuse insulators, since it requires minimal effort in terms of installation - just use a construction stapler or galvanized studs and fasten the material to the supporting structure.
Mounting the diffusion membrane
With the external method of placing the material, it is desirable to perform the operation in dry weather and together with fixing the heat insulator. The membrane should be rolled out over the entire working surface and fixed with studs or brackets. The classic roof installation involves laying with horizontal stripes 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 the individual pieces of material are fixed using butyl rubber or acrylic tape. Ventilation clearance is not required if diffusion membranes are planned to be installed on the roof, but when installing the insulator on facade surfaces it is better to provide for it. In winter, the load on the insulation material increases significantly, so it is recommended in the autumn to perform a revision of the roof for a tight fit of the membrane to the insulator. If the rafters have a thickness exceeding that of the heat insulator, then the vapor-proof material should be pressed to their side with slats with a size of 2x3 cm. Also, construction brackets can be used to perform this task. In the course of work, you should focus on the fact that the lower edge of the membrane provides unhindered removal of moisture in a special drain trough.
Manufacturers
Non-woven vapor-proof material is represented on the market by different manufacturers, many of which are domestic. In particular, the Technonikol diffusion membrane allows for waterproofing, which simultaneously protects structures from contact with moisture and allows surfaces to “breathe”. The material of this line is presented in several versions, including with reinforcing fibers. The users also gained trust in the Technonikol superdiffusion film, which is made of a three-layer microporous material. The difference between this insulator is the bilateral use of non-woven polypropylene, which performs a protective function for the main layer. It is advisable to use such a membrane in roofing coatings, 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 Du Pont, which specializes in the protection of wall and roofing systems through air and water filtration. Under this brand is Tyvek diffusion membrane, which is a multifunctional waterproofing film. The material has a network structure formed by polymer fibers. Unlike competing insulators, Tyvek coatings are environmentally friendly. That is, they can be used both in the exterior decoration and in the structure of the internal facing coatings. In both cases, the inclusion of a diffusion film of this brand will ensure dryness and durability of the finish.
Conclusion
Conventional methods for arranging insulating interlayers usually do not require special installation conditions. It is enough to select a sheet or plate of the appropriate size and fix the material on the work site. According to this principle, both insulation material and waterproofing are usually mounted. The diffusion membrane, in turn, guarantees a higher operational effect than conventional insulators. But to achieve it, it is important to observe the rules for the location and fastening of vapor-tight films with respect to the insulation layers. Roofing constructions in this regard are the most complex, since the moisture-removing material can come into contact with other coating components and roof systems. Also, communications for a drainage system with which diffusion material will interact should initially be provided. From the point of view of installation, the installation of insulators on walls and facade structures looks somewhat simpler. In such cases, the task of preserving the ventilation properties of the coating, which are realized due to the inclusion of a vapor-tight membrane in the insulation layer, still comes first.