Efflorescence

 

Efflorescence is a white powder which forms at the surface when there is excess moisture.

Efflorescence is a white powder which forms at the surface when there is excess moisture. Humidity dissolves the mineral salts contained in masonry and brings them up to the surface where they accumulate after water evaporation (alkalis).

Causes

  1. Water or moisture in masonry.

Solutions

  1. Prevent water infiltration and let surface dry. Apply muriatic acid on surface. Depending on use, it is preferable to apply a water-based paint if possible; they allow the paint film to breathe and offer better adherence to masonry.
  • If a solvent-based covering is to be applied on a concrete floor, start by testing for moisture: the humidity rate should not exceed 6 %.
  • Alkalis can reduce the adherence of adhesives and chemical or water-based sealants. In such cases, use solvent-based products.