Classic silicate or mineral paints are known for their high-quality design and indestructibility. The reason for this is the mineralogical binding agent, water glass, and the fact that it has been used for numerous applications on outstanding architectural monuments, in particular early modern structures.
Toward the end of the 19th century, water glass-bound painting and coating systems represented a new chapter of paint chemistry and technology, both in terms of quality and quantity, and enabled adequately durable and weather-resistant artistic façade designs.
In principle, water glass is simply glass dissolved in water. A differentiation is made between potassium water glass and sodium silicate. Only potassium water glass is suitable for manufacturing paints (water glass paint). A silicate paint dries when the water evaporates and carbon dioxide is absorbed from the air. During this process, the water glass silicifies and binds pigments to the subsurface.
To ensure that no ‘over-hard’ surfaces are created here, only firm render surfaces should be coated with silicate paints. Silicate paints are some of the most breathable paints available. They are usually hydrophobic for use on façades. One general exception is when they are used as a coating in the in-fills of timber-framed buildings. Silicate paints and lime paints are the materials of choice when coating modern indoor insulation systems, i.e. systems that need to be completely capillary-active.