If you notice that the house insulated with mineral wool has not become warmer, the rooms remain at a low temperature and the walls are damp, this may indicate that the insulation was not covered by a membrane. Modern housing is becoming more technologically advanced; recently, requirements for insulation materials and the quality of all elements of buildings and structures have been increasing.
The issue of insulation was resolved by the use of multilayer structures, which provide for the presence of fibrous insulation. Houses became warmer thanks to ventilated facades, frame exterior walls, insulated ceilings and pitched roofs. But if you use mineral wool insulation, then it itself needs reliable protection, this is due to the fact that atmospheric moisture and wind pressure, as well as fumes 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 accumulation of condensate in the elements of buildings, then it is worth using special membranes. They became a real breakthrough in building heat engineering, because without them it is impossible to imagine a modern house built using thermal insulation.
The need for a membrane
The hydro-windproof membrane does not absorb moisture, but contains many air channels and pores, which contribute to the movement of moisture 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, insulating characteristics will decrease, even if only 1% moisture accumulates inside. With temperature fluctuations, the water will freeze and thaw, expanding and destroying the internal structure of thermal insulation.
Even if the drainage and enclosing structures work properly, moisture can enter the cotton 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 semipermeable film that separates two media, it regulates the directional transport of substances. Some membranes, called building films, are not at all capable of passing water and steam; 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, has flame retardants. Another solution to the problem is the impregnation of paintings or the application of protective compounds to them.
Application features
Quite often, novice masters wonder about which side of the insulation to install the membrane. If the facade is insulated with mineral wool, then the steam wrap must be installed outside. If we are talking about an insulated roof, then anti-condensate, bulk and diffusion membranes are installed on top of mineral wool. When working with a cold roof, a vapor barrier membrane is laid on the bottom of the rafters. When the walls are insulated from the inside, a continuous vapor barrier is required, represented by a perforated film, laid on top of the room. A hydro-protective membrane is installed from below if the insulated ceiling has a higher cold attic.
Which side to cover the membrane
When working with non-professional masters, quite often a reasonable question arises as to which side to lay the membrane on. As a rule, vapor barrier films are two-sided, therefore it does not matter which side to turn the material to the insulation, but, as in everything, in this case there are exceptions. Anti-condensation membranes are placed 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 toward the living quarters.
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 bilateral 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, then you should answer the question of whether a ventilation gap near the material is required. 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 likelihood of the vapor barrier coming into contact with the inner lining should be excluded. The diffusion hydro-windproof membrane is installed on top of thermal insulation, plywood or OSB coating. Over such membranes, a ventilation gap should be made to drain excess water. In the roofing system, it can be equipped with the method of installation of bars placed in the construction of the counter-lattice.
When working on a ventilated facade, the interlayer is provided with perpendicularly arranged profiles or racks. The anti-condensation film has an air gap of 40 to 60 mm on both sides.
Do I need overlap during installation
The waterproofing membrane for the facade is laid with an overlap, the width of which can vary from 100 to 200 mm. For the roof, the material performs a waterproofing function, so this parameter can vary, depending on the slope of the slopes. An overlap of 100 mm is necessary for 30 °, it increases to 150 mm, if the slope decreases to 20 °, an overlap of 200 mm is required for a roof whose slope is less than 20 °.
The hydro-windproof membrane, the photo of which you can see in the article, also fits in the area of the ridge. 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 deviations along the entire length, the 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 removed to a metal drip or drain chute during installation.
Do I need to glue joints
Hydro-wind-proof membrane is required during insulation works. Which side to lay the material was mentioned above, but it is still important to resolve the issue of the need for gluing joints. Cloths are necessarily 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, foamed polyethylene, butyl or polypropylene. Such tapes are single-sided and double-sided, with their help you can eliminate tears and damage to the paintings. Do not try to save on the use of conventional packaging tape, which, among other things, has a small width. This causes the depressurization of the joints.
Membrane mounting method
Nails with wide hats or staples of a construction stapler can become temporary fasteners. But if you want to get a secure fit, you should use a 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 plates, each of which is fixed by two plate-shaped dowels. A diffusion membrane is laid on top of the insulation, which should be cut in the locations of the brackets. Through a layer of cotton, all this is reinforced with dowels to the wall surface. The minimum number of fasteners per square meter should be four pieces. If you can choose a place, you should drill a hole in the area of the junction of the paintings.
Characteristics of the membrane "Isospan AM"
The Isospan AM waterproofing membrane is a three-layer vapor-permeable material that is used to protect thermal insulation and roofing structures, as well as walls from moisture, wind, condensation and the effects of the external environment. Laying should be carried out on the insulation, without forming a ventilation gap, this will eliminate the additional costs of the crate. The material is characterized by high water resistance and vapor permeability, provides an increase in the life of the insulation and the structure as a whole. The temperature range of application of the material is quite wide and varies in the range from -60 to + 80 °.
Reviews on the membrane "Izospan AM"
The hydro-windproof membrane described above, the reviews of which are only the most positive, is able to protect the material not only from moisture and condensate, but also from freezing temperatures, as well as direct sunlight. According to customers, installation can be carried out by either side, 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 tearing. Within 3 months after installation, the membrane can be left under the influence of ultraviolet radiation. Hydro-windproof membrane “Isospan” is characterized by a high degree of stretching and eliminates tearing and deformation of the insulation.
Conclusion
Despite the fact that the building membrane can cope with the negative effects for several months, it also needs protection. Therefore, it is necessary to make finishing work as quickly as possible, if it comes to the facade. Even if you try to seal all the holes and joints, the material can work effectively only in tandem with a finish coating. Indeed, while waiting for further work, the materials may get wet during rain.