Efflorescence is that salty substance that appears on walls and slabs and sometimes even ceilings, a sign of moisture coming through the surface. By itself, it isn’t a structural defect, but it’s a sign that something’s going on that needs further investigation. What Efflorescence Actually Is Efflorescence is the salt that is left on the surface after moisture migrates through your cementitious, blockwork, or brickwork surface. The moisture dissolves salts out of the brickwork, blockwork,…