1.What is the building membrane?
As stated in the us patent of 2003, building membranes or architectural fabrics are part of the structure of a building. They protect the buildings from weather elements such as wind, sun, and rain. They can be a permanent part of the structure or temporary. They must be water-tight, fire-resistant, UV-resistant and have an attractive appearance.
Membranes, for use in structures-on the facade, in the system of thermal insulation of the hinged ventilated facade, and under-roof-in the "roof pie" system are divided by type into vapor - insulating and wind – moisture – proof (or "breathable", vapor-permeable).
The main function of the membranes is to protect the rock wool insulation from wind, moisture and steam condensation, as well as from the emission of fibers from the insulation. The greatest effect of the membrane properties is shown in extreme conditions of a long frosty winter with high humidity and strong winds.
An additional important property of the membranes is the protection of rock wool insulation from being humidified by rain during installation and from solar ultraviolet radiation during a long break, before being closed by a hinged facade. It is known that UV radiation quickly degrades the silicone water repellent and synthetic binder of the insulation fibers.
2.Why does mineral wool need protection?
Rock wool has two main advantages:
it does not burn and it allows steam to pass through perfectly. Yet the main disadvantage is unlimited in and out airflow.
It is known that still air is the best heat insulator after vacuum, if it is located in closed cells of the insulation. Such insulaters are polystyrene foam and polyurethane foam, which in turn burn well and do not have the necessary vapor permeability.
What if the air walks freely in the insulation?
From inside the building, humid warm air enters the rock wool insulation through the wall (exfiltration), from the outside, frosty wind blows the rock through the ventilation gaps of the facade (infiltration). Opposite vortex flows occur in the insulation, where moisture condenses and becomes water.
It is known that during the winter insulation, even protected from the wind by a layer of vapor-permeable plaster, gains water up to two kilograms per square meter of wall area. It is clear that in this case you can forget about insulation in winter.
Calculations show that without a windproof membrane, the thermal insulation properties of the insulation are reduced by four times.
With cyclic freezing-thawing, aging of the binder occurs over time. Defects are possible in any material during its production, catastrophic processes of increasing destruction develop in the weak points of the insulation. Weak spots accumulate, their number increases, their areas expand. And now the walls are freezing, mold, fungus appear, allergens spread through airborne droplets throughout the premises, and people get sick, without knowing what caused them.
But one has only to cover the insulation with a windproof "breathing" vapor-permeable Izolteks NG 200 from the side of the frosty street, as the infiltration stops, the warm zone in the insulation will be sharply fenced from the outside cold, the steam will freely come out of the insulation and condense in the outside air.
If the membrane increases the immobility of the air in the insulation, then the issue of the quality and properties of rock wool as a heat insulator will lose its sharpness.
For these reasons, it is recommended to use a "breathing / vapor permeable / wind resistant / fireproof" Izolteks NG 200 membrane in rock wool insulation.
On installation scheme:
1. Composite material
2. Non-flammable membrane Izolteks NG 200
3. Dowel disc
4. Wall Bracket
6. The outer wall
1. Mounting brackets for mounting the hinged facade.
2. The plates of the insulation are fixed with a minimum number of dowels (1 - 2 per plate).
3. Izolteks NG 200 is rolled out with stretch (without a gap) vertically along the surface of the insulation. Holes are cut out in the exit points of the brackets in the building membrane. The membrane can be mounted either side to the insulation.
4. Izolteks NG 200 is permanently fixed with the required number of dowels to the wall. The number of dowels recommended for fixing the building membrane Izolteks NG200 is at least 4 per 1 m2. The minimum distance of the dowel from the edge of the membrane sheet is not less than 70 mm. The overlap of membrane sheets is 150 - 200 mm.
For better fixing, it is recommended to position the dowels in the points of sheets overlapping.
In the case of membrane sheet tearing, it is recommended to use dowels.
If the membrane is not stretched, acoustic claps are possible. In the places of bordering with windows and doors it is recommended to use dowels. Membrane Izolteks NG 200 should cover the entire surface of the insulation, including the ends. For this purpose the building membrane must be bend tuck under the insulation.