"maxit solaren" exterior wall coating convinces in demanding façade renovation in Raschau
A good façade coating contributes significantly to maintaining the value of buildings. This guiding principle was also followed by the Raschau housing association in a renovation project in Raschau-Markersbach (Saxony). The task here was to renovate the façades of a residential complex. Thanks to the "maxit Solaren" façade coating, the dowel marks that had appeared on a composite thermal insulation system (ETICS) installed around 20 years ago could be permanently eliminated. The success of the applied facade coating is based on a combination of silicone resin emulsion with microfine hollow glass beads. In addition to beading off raindrops and dirt particles, it contributes to the even distribution of temperature and moisture on the façade. Thus, the entire surface is evenly and optimally protected against algae and moss growth. Furthermore, this special façade coating can permanently fill and seal small hairline cracks in the plaster layer from bottom to top.
In the 1990s, the individual buildings were successively renovated. Bathrooms were newly tiled, old wooden windows were replaced with double-glazed plastic windows. Above all, the structural thermal protection was to be significantly improved. From 1995 to 1998, the 24-centimetre-thick brick exterior walls were covered with an eight-centimetre-thick composite thermal insulation system (ETICS) consisting of dowelled polystyrene insulation boards. The exterior walls were then coated with a thin layer of rubbing plaster. After a few years, however, this showed a strong algae formation in some areas of the façade. The resulting light-coloured dowel marks were particularly noticeable. They formed due to a higher heat transmission that occurred in places on the façade: Directly above the ETICS plugs, the façade dried faster and thus prevented algae infestation. As a consequence of these punctual thermal bridges, bright circular spots appeared that stood out clearly from the surrounding algalised surface.
After unsatisfactory trials with other paint products, an effective solution to the problem was finally found in the form of the "maxit solaren" façade coating. In contrast to conventional façade coatings, this coating takes a completely new approach to protecting against algae formation. Quite deliberately, no unencapsulated algaecides and fungicides are used, which are washed out by precipitation after a relatively short time and pollute the environment. Instead, the developers of the maxit Group (Azendorf/Krölpa) rely on the physical properties of microscopically small hollow glass beads for the functional coating "maxit solaren".
In combination with the silicone resin emulsion, the coating provides a particularly smooth surface that repels raindrops and dirt particles. At the same time, the microporous, diffusion-open structure contributes to a balanced moisture balance of the façade - comparable to a breathable multifunctional jacket. The same applies to the temperature balance. In summer, for example, a steep angle of incidence of the sun's rays leads to a reduction of the heat input through reflection. In winter, on the other hand, absorption results in an increase of up to 20 percent due to flatter angles of incidence. The complex façade renovation began in 2015, and the workers of Malerwerkstatt Lötzsch from Annaberg-Buchholz proceeded very methodically. In addition to thoroughly cleaning the façades, they also carefully repaired the plaster coating where necessary. Subsequently, areas with algae infestation were pre-treated with "maxit prim 1120". This was followed by hydrophobisation using the primer "maxit Solarfarbgrund". This was necessary due to the tendency of the mineral rubbing plaster to absorb a lot of moisture. The water vapour permeability of the substrate was fully preserved. Before the final two coats of "maxit solaren" façade coating, the applicators made sure that the primer dried out completely. In this way, they ensured a secure bond between the substrate and the paint coating. To make the appearance of the housing estate more lively, the individual building blocks were also painted in different shades (yellow, blue, brown). Embedded in green meadow areas with park benches, the housing estate now looks inviting and friendly with the new colour scheme. However, the redevelopment project is not yet complete: After the first nine building blocks, 13 more residential buildings will be visually upgraded with "maxit solaren" over the next three to four years and sustainably protected against weathering and algae formation.