Plaster is a wall covering that has been tried and tested for thousands of years, especially on masonry. As an exterior plaster, it usually consists of two layers: the base and the top plaster. The wide range of possibilities in terms of material, the combination of base and top plasters and the surface design enable a very versatile use of exterior plaster in new and old buildings.
Types of concealed plaster:
When choosing an exterior plaster, it is important to take into account the constraints resulting from the substrate (material, bulk density, salt/moisture load) and, if necessary, other requirements (e.g. monument protection, increased exposure to the weather). The properties of the concealed plaster, in particular its dry bulk density and strength, must be matched both to the properties of the respective substrate and to the intended top plaster. [...]
Source: bauwion
While the base plaster always consists of mineral raw materials, there are a variety of options in terms of material and surface design for the top plaster. The properties of the top plaster, in particular water vapour permeability, dry bulk density and strength, must be matched to the properties of the base plaster.
Types of top plaster:
Pasty top plaster:
Mineral top plasters:
Top plaster is usually applied to a mineral base plaster. The properties of the top plaster, in particular water vapour permeability, dry bulk density and strength, must be matched to the properties of the base plaster. A distinction is made between thin-layer and thick-layer finishing plasters. Thin-layer top coats are applied in grain thickness, i.e. usually up to 5 mm. According to DIN 18350 (VOB C), the grain size for thin-layer top coats is at least 3 mm, if this is not the case, additional measures are required, e.g. fabric filling. For normal plasters, the average plaster thickness of the system consisting of bottom and top plaster must be a total of 20 mm, and in some places it is permissible to fall short of up to 5 mm. For single-layer plasters made of mortar, an average thickness of 15 mm applies. Here, too, a shortfall of 5 mm is possible in individual places. [...]
Source: bauwion
