Appearance of white dust or snow on the painted surface or whitewash that seems to “run” on the wall in the form of a waterfall.

POSSIBLE CAUSES

  • Plaster, brick and concrete salts are transported to the outer surface of the wall through capillaries, cracks and moisture.
  • Plasters do not have the right composition.
  • The wall was primed before the plaster dried sufficiently.
  • The wall was not primed properly (eg excessive dilution in the primer or use of poor quality primer).
  • The paint used does not show good resistance to the “migration” of salts.
THE SOLUTION
  • As a precaution, the above causes that cause restrictions and enhance the phenomenon should be done and the new surface should then be primed with water primer or solvent primer or solvent primer. After acrylic paint, which show increased resistance to the “migration” of salts, compared to other acrylic paints!
  • Suppressively, the painted surface should be cleaned of old paints and salts, plastered where needed, primed and painted with the above proposed painting systems.