If you notice that a house insulated with mineral wool has not become warmer, the temperature in the rooms remains low, and the walls become damp, this may indicate that the thermal insulation was not covered with a membrane. Modern housing is becoming more technologically advanced, the requirements for insulating materials, the quality of all elements of buildings and structures have recently increased.
The issue of insulation was solved by using multilayer structures, which provide for the presence of fibrous insulation. Houses have become warmer thanks to ventilated facades, frame exterior walls, insulated floors and pitched roofs. But if you use mineral wool insulation, then he himself needs reliable protection, this is due to the fact that atmospheric moisture and wind pressure, as well as vapors from the premises, reduce the thermal characteristics of the material and the building as a whole. If you want to maintain the design efficiency of the structure, eliminating the formation and accumulationcondensate in building elements, it is worth using special membranes. They have become a real breakthrough in building heat engineering, because without them it is impossible to imagine a modern house built using thermal insulation.
Membrane required
The hydro-windproof membrane does not absorb moisture, but contains many air channels and pores that help moisture move inside and retain it in the structures. If cotton wool absorbs moisture, then its mass will increase by 5% of its own weight. Water will displace air, insulation performance will decrease even if only 1% moisture accumulates inside. When the temperature fluctuates, the water will freeze and thaw, expanding and destroying the internal structure of the thermal insulation.
Even if the drainage and enclosing structures work properly, moisture can get into the wool from the premises. That is why there is a need to use building membranes that protect structures from atmospheric moisture and wind. Physically, any membrane is a semi-permeable film that separates two media; it regulates the directional transport of substances. Some membranes, called construction films, are not capable of passing water and steam at all, they consist of perforated layers of polyethylene on a mesh basis.
The fire resistance of such films is also a very topical issue, which is solved in several ways. The non-combustible hydro-windproof membrane, the photo of which is presented in the article, containsflame retardants. Another solution to the problem is to impregnate the fabrics or apply protective compounds to them.
Application Features
Quite often, novice masters ask themselves which side of the thermal insulation to install the membrane on. If the façade is insulated with mineral wool, then the vapor film must be installed outside. If we are talking about an insulated roof, then anti-condensate, volumetric and diffusion membranes are installed on top of mineral wool. When working with a cold roof, a vapor barrier membrane is laid below the rafters. When the walls are insulated from the inside, a continuous vapor barrier is required, represented by a perforated film laid on top from the side of the room. A hydro-windproof membrane is installed from below if the insulated floor has a cold attic above.
Which side to cover the membrane
When carrying out work, non-professional craftsmen quite often have a reasonable question about which side to lay the membrane. As a rule, vapor barrier films are double-sided, so it does not matter which side to turn the material to the insulation, but, as in everything, there are exceptions in this case. Anti-condensate membranes are laid inside the room with a textile absorbent layer. On sale you can also find metallized coatings, which are one-sided. They have a foil layer that faces towards the living areas.
The hydro-windproof membrane, which has steam-removing characteristics and is called diffusion, is laid according to the instructions. In the assortment of the same company, you can find unidirectional or double-sided films. The reference point will be different coloring of the sides, one of which has a pronounced marking. Most often, the colorful side faces outward.
Installation recommendations
If you are still not familiar with the technology, you must answer the question of whether a ventilation gap is required near the material. At the bottom there should be an air gap, the thickness of which is 50 mm, it will be needed to weather possible condensate. The possibility of contact of the vapor barrier with the inner lining should be excluded. Diffusion hydro-windproof membrane is installed on top of thermal insulation, plywood or OSB covering. A ventilation gap should be made on top of such membranes to drain excess water. In the roofing system, it can be equipped by installing bars that fit into the construction of the counter-lattice.
When working on a ventilated facade, the layer is provided by perpendicular profiles or posts. The anti-condensation film has an air gap of 40 to 60 mm on both sides.
Do I need an overlap during installation
The hydro-windproof membrane for the facade is laid with an overlap, the width of which can vary from 100 to 200 mm. roofing materialperforms a waterproofing function, so this parameter may vary, depending on the slope of the slopes. An overlap of 100mm is required for 30°, this increases to 150mm if the slope drops to 20°, an overlap of 200mm is required for roofs that slope less than 20°.
The hydro-windproof membrane, the photo of which you can see in the article, is also laid in the ridge area. If we are talking about diffusion material, then the overlap for it should be equal to 200 mm. In valleys, the material overlaps by 300 mm, with slight slopes along the entire length, a second layer should be laid, using an additional strip, it will go 300-500 mm.
For reference
The hydro-windproof membrane, the advantages of which were highlighted above, should cover not only the total area, but also the end parts of the thermal insulation. A roofing membrane should be brought out onto a metal drip or drain chute during installation.
Do I need to glue joints
Required for insulation works hydrowindproof membrane. Which side to lay the material was mentioned above, but it is also important to resolve the issue of the need to glue the joints. The fabrics must be glued together. As a result, you should get an absolutely tight joint, for which special self-adhesive construction tapes are used. They are made on the basis of non-woven materials such as polyethylene, butyl rubber, foamedpolyethylene, butyl or polypropylene. Such tapes are single-sided and double-sided, with their help, tears and damage to the canvases can be eliminated. You should not try to save money on using ordinary packing tape, which, among other things, has a small width. This causes depressurization of the joints.
Membrane attachment method
Temporary fasteners can be wide-head nails or staples from a construction stapler. But if you want to get a reliable fastening, then you should use the counter-lattice system. More complex work may seem when arranging hinged facades. As soon as the bracket is in place, you should start laying the insulation boards, each of which is fixed with two dish-shaped dowels. A diffusion membrane is laid over the thermal insulation, which should be cut through at the locations of the brackets. Through a layer of wool, all this is strengthened with dowels to the surface of the wall. The minimum number of fasteners per square meter should be four pieces. If it is possible to choose a location, a hole should be drilled in the area where the sheets meet.
Characteristics of the membrane "Izospan AM"
Izospan AM hydro-windproof membrane is a three-layer vapor-permeable material used to protect thermal insulation and roof structures, as well as walls from moisture, wind, condensate and the effects of the external environment. Laying should be carried out on a heater, without forming a ventilation gap, this will eliminate additional costs for the crate. The material is highly water resistant andvapor permeability, provides an increase in the life of thermal insulation and the structure as a whole. The temperature range of application of the material is quite wide and varies from -60 to +80°.
Reviews about the membrane "Izospan AM"
The hydro-windproof membrane described above, reviews of which are only the most positive, is able to protect the material not only from moisture and condensate, but also from negative temperatures, as well as direct sunlight. According to buyers, laying can be carried out by any party, and this will not affect the quality of the vapor barrier. The material is based on a special film, which is characterized by high resistance to aggressive environmental influences.
Buyers emphasize that the membrane is able to protect the insulation from mechanical damage and ruptures. Within 3 months after laying the membrane can be left under the influence of ultraviolet light. The hydrowindproof membrane "Izospan" is characterized by a high degree of stretching and eliminates ruptures and deformation of the insulation.
Conclusion
Despite the fact that the building membrane can cope with negative influences for several months, it also needs protection. Therefore, it is necessary to carry out finishing work as quickly as possible when it comes to the facade. Even if you try to seal all the holes and joints, the material can only work effectively in tandem with the top coat. After all, while waiting for further work, the materials may get wet during the rain.
