Flowering
Efflorescence is the formation and deposition of small, white crystal crusts on the masonry.
The salts are dissolved by water or moisture and transported to the surface during drying, where fine crystals are formed. The cause of this may lie in binding or antifreeze agents, in the mortar sand, in the mixing water or in improper storage of building materials. Failure to covering of finished components by precipitation or concrete water can also also lead to efflorescence.
Façade stains of the type mentioned above are usually triggered by the action of water, which allows the discolouring substances to dissolve and discolouring substances from the masonry to the façade surface. A distinction must be made distinction must be made between two forms of ‘efflorescence’ or discolouration. I addition to efflorescence, which is caused by permanently water-soluble compounds (collectively referred to as ‘water-soluble salts’), there are deposits - especially coloured ones - that form according to the same principle, but quickly become insoluble in water on the surface of the façade (metallic discolouration).
The white-coloured blooms are most often caused by sulphates of the the elements found in almost all raw materials in the building building stone/earth sector.
Other common terms for the technically the technically incorrect term ‘wall salts’ are ‘saltpeter’, “wall corrosion” or ‘saltpetre corrosion’, but the correct term is is ‘efflorescence’.
Wall saltpetre can be found on both natural and artificial stone, but but also on concrete structures as a whitish superficial deposit on building parts. These are crystals of calcium nitrate that form when the water in the building materials evaporates. These crystals absorb water (water of crystallisation), which leads to an increase in volume (which damages the building).
If efflorescence occurs repeatedly, a specialist should be a specialist to remove it. Salt efflorescence can over time only be removed from by a professional fagfolk. Hydrofobisering to avoid.