Building drying
By building drying technical drying of various building structures after construction or after penetration is called due to water damage. A distinction is made between the technical drying of screed insulation layers, separating layers of screeds on separating layers, composite screeds, cavities, walls and ceilings.
In addition to a technical drying process, moisture measurements are carried out. For this purpose, when drying with process air, the relative humidity and temperature of the incoming and outgoing air can be measured. The measured values can then be converted into an absolute value, grams of water per kilogram of air, using an HX diagram or an HX table. Differences between supply and exhaust air of up to 3 g / kg indicate that the normal household humidity has been reached. When drying wall surfaces with condensation and adsorption dryers , non-destructive, electronic moisture measurements are mainly carried out for control purposes.
Drying of screed insulation layers and screed floors
Screed insulation layers can be dried successively by blowing in dry warm air, so-called process air (overpressure method). Nowadays, the overprint process should no longer be carried out due to microbial contamination and various pollutants. In addition, there is a risk that with some types of screed such as B. mastic asphalt or anhydrite screed in the overpressure process, the material is damaged. In the case of sensitive, dust- and particle-forming insulation layers, moist air is therefore preferably sucked out of the floor structure (vacuum method). To do this, access to the insulation layer must be created. The process air is dried using condensation or adsorption dryers.
Drying via core drilling
Here, core holes with a diameter of 50 mm are drilled into the screed slab through the top floor. Appropriate nozzles (screw-in, press-in nozzles or blow-in plates) are inserted into these bores, to which the process air hose is then connected. To Einflutung the process air or exhaust the moist air will ring blower used. Prior to implementation, it must be clarified whether pipelines (e.g. underfloor heating) or electrical installation lines have been laid in the floor structure.
One variant is drying using overhead boreholes, whereby the boreholes are drilled through the floor slab under the screed insulation layer without damaging the floor surface. However, these holes should only be drilled in exceptional cases, because it involves interference with the statics, the vapor barrier may not be able to be restored and the hole must in any case be provided with a fire protection plug again. In addition, with this variant, before drilling the holes, it must be ensured that no pipes or electrical cables are damaged.
Joint cutting process
In this process, a special wet saw is used to make approx. 30 cm long cuts in the joints of the top floor through the screed slab down to the insulation layer. Injection plates with a circumferential rubber sealing lip are fixed on these cuts. After drying is complete, the incision is closed again.
Joint nozzle or edge strip method
In the case of floating screed panels, there is an edge strip filled with cardboard strips or foam strips to separate the rising masonry from the screed panel. The process air is introduced into the screed insulation layer through nozzles inserted into the edge strip or boxes sealed on the edge strip. The air flows out on the opposite side, all other joints are sealed. Expansion joints can be used in a similar way . The process is not suitable for vacuum processes. The process is non-destructive, but less effective compared to drying via core drilling.
Cross joint method
With this method, holes with a diameter of 3 to 5 mm are made in the spacers between the tiles in tiled floors. Nozzles are inserted into these bores, through which process air can be flooded. The air exits via the edge joint or additional outlet holes. This procedure is rarely used because the disadvantages clearly outweigh the disadvantages. Due to the large number of holes in their grid-like position, the statics of the screed slab may be weakened. Due to the small size of the holes, in comparison to other methods, not enough process air can be flooded in, which leads to comparatively long drying times. Since each individual nozzle has to be provided with a hose, the room in which the process is used is no longer accessible.
Drying of screed floors on a separating layer
Screeds on a separating layer are dried in a similar way to screed insulation layers, but the process air must also be blown under the separating layer made of foil or oil paper.
Drying of bonded screeds
Bonded screeds are dried using condensation dryers or adsorption dryers as well as axial fans. The room air humidity is reduced, the screed plate releases the stored moisture to the dried room air.
Drying cavities
Cavities occur particularly in drywall and wooden beam ceilings . The procedure is the same as for screed drying. After creating entrances, process air is flooded in or extracted.
Drying of wall and ceiling surfaces
Wall and ceiling surfaces are dried by installing condensation or adsorption dryers and axial fans. In individual cases (e.g. with damp brick masonry) it is necessary to heat the areas to be dried. This is often done with infrared heaters. The use of gas heaters, which emit their exhaust gases directly into the room to be dried, is excluded, as water is produced when gas is burned.
supporting documents
- ↑ a b c Information on the website of a provider ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Website of a provider ( Memento of the original dated August 2, 2009 in the Internet Archive ) Info: The archive link was inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Website of a provider ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Information from a provider ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 923 kB)
