Barrier layers are everywhere needed where components to water or water vapor must be sealed. True appropriate to prevent the water absorption into the component as well as the capillary of water and the diffusion of water vapor through the component.[1] The hydrophobic coatings suspend or restrict the capillary. The capillary component is only slightly affected. (Water silicone-based rock slide the spores, and these are not sealed.) [2]
The application areas and the end to seal Sperrschichten of soil moisture, not drückendes or drückendes water in the DIN 18195 Part 1 to 10 (waterproofing). The seal on roofs is in DIN 18530 (Massifs cover-constructions for roofs) and DIN 18531 (roof seals) provided.
Pillars, walls or chimneys are in addition to the vertical seal against moisture penetrating the side with horizontal barrier layers against rising moisture. For older buildings lack these layers or their function is largely repealed. If at such an exterior wall surface area of capillary and water vapour diffusion current impeded or interrupted, without the need for the missing barrier layers have been appropriate, the walls begin to soak it comes to painting, cleaning or even heavier building. The salt deposition on the surface of a base, for example, is also a barrier. It may well shift to the consequences. If this base by wall tiles or a synthetic resin coating (Figure 1) sealed, increasing evaporation level to the top of the ground floor apartment.
Figure 1:
Heterogeneous multi-layer construction with außenseitiger dense ceramics (1). There is a risk of condensation (2) under the ceramic facade. [3]
Barrier layer for a complete seal against water vapor diffusion be damp and are referred to throughout needed where there is a risk that water vapor in the component condenses. The reason is usually an unfavourable impact layers, but for design reasons can not be avoided.
For interior insulation, for example, even under normal temperature conditions the dew point in the wall cross-section achieved if he is not even in the insulating layer. Against the Wanddurchfeuchtung kondensierenden by water vapor helps usually only have a vapor barrier (Figure 2). (In the heavy concrete walls with interior insulation could brake the steam trap moisture. Cheaper would be an insulating material with a high diffusion resistance, for example sparkling glass, which itself acts as a brake steam.)
Figure 2: steam at a brake interior insulation
a) Where a trained unfavourable external wall
b) If there is no ideal layer structure, but improved.
Damp must be always on the hot side of a design. Contains Insulation this one, they must always on the inside before. At the developed roof and prefabricated houses, they are absolutely necessary. It is a joint leakage and to ensure the flank transmission. The vapor barrier prevents that, in order to Tauwasserbildung in the inner area of the wall. Even the smallest holes, for example, by fixing nails caused reduce the blocking of the vapor barrier. If 1% of their surface water vapour, it is ineffective. [7]
It should be built so that one preferably no steam-barriers it requires since you are always problematic even if they are on the technically right side:
In addition to the steam lock brakes and wind from seal boards, special PE foil or aluminum foil, but also close closing plaster, concrete, metal plates and requires other building panels made of wood and plaster them. However, the material properties such as the sd-value, and the fugues densee assembly. Despite the unity of the optical sheetrock with 12.5 mm is still a steam brake / wind barrier. What, for example, a plastered on both sides wall from gas concrete (7 cm) is not required. How already named above, the steam-brake prevents a drying moist building materials. To solve this problem, had a brake feuchteadaptive steam developed (Figure 3).
Figure 3: Impact of a scheme feuchteadaptiven steam brake with variable diffusion resistance (sd-value), it is sorptiv, that is, water recording.
One assumes that the completely harmless wintry attack of condensation in the roof faces a big potential of an desiccation in the summer. Compared to conventional steam brake with the same restrictive in winter is the dry summer when using steam feuchteadaptiven brake at least ten times greater. [4]
In this picture 4 from an investigation of the overall course of the moisture in the roof and down the course of the humidity of the timber formwork boards over a period of 10 years. With the conventional brake steam rising seasonal fluctuation in the wood moisture quickly. With the moist regulates steam brake, the values always under 20 M.-%. [5]
If you have a roof of an older house knows also knows what a fine dust are translated. To what extent the full functionality after 20 years and later still exists is uncertain.
Even with only a slight excess of wood humidity of 20% over several months (winter), is too much. For wood insects already cheap and wood mushrooms can be found under certain conditions, their living space.
It is very important to maximize air-tightness of the building envelope. In short, it may only air above the appropriate components, such as windows, doors and ventilation systems are exchanged. To measure the air leak is the differential pressure method "Blower Door", where the entire amount of leakage through the building envelope quantified and more localized leaks. [6] There are also fog candles, then you can see whether the air moves and whether they, for example, through an outlet in the sill escapes.
Problem Statement and implementation examples are in the new e-manual toproof-extension with more than 180 illustrations.
Quelle:
[1] Kur, Friedrich; Wohngifte, Handbuch für gesundes Bauen und Einrichtungen, 3. Aufl. Verlag Eichborn, 1993, S. 573
[2] Ettel, Wolf-Peter; unda.; Bautenschutztaschenbuch, Verlag für Bauwesen Berlin-München, 2. Aufl. 1992, S. 199
[3] Eichler, Arndt: Bautechnischer Wärme- und Feuchtigkeitsschutz, 1989, S.95
[4] IBP/rb, Feuchteadaptive Dampfbremse, bau-zeitung 50(1996)10 S. 79
[5] H.M. Künzel, A. Kaufmann; Fraunhofer-Institut für Bauphysik IBPMitteilung 268 , 22(1995)
[6] Geißler, Achim, Hauser, Gerd; Messung und Kennzeichnung der Luftdichtheit von Gebäuden; renova 3(1997)1 S.79
[7] Rauch, Peter; Sanierung, Wärmeisolierung und Wärmebrücken, Leipziger Bauführer 1994 Seite 121 ff.
Ingenieurbüro
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Healthy living building protection advice timber immovable Climate in apartments
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