Some efflorescence ( encrusted white powder or deterioration of the brick face) is visible to the brickwork. Effloresce is generally caused from rising damp and can also be called salt damp. Rising damp can make buildings unsightly and unpleasant to occupy. The situation is made much worse if there are appreciable quantities of soluble salts present in the soils, for the damp will carry dissolved salts up into the masonry to where it evaporates. There the salts are left behind (for salts can’t evaporate) and can often be seen as a white efflorescence or flowering on the wall surface.
Damage is done when evaporation takes place just below the surface, leaving the salts to grow as crystals within the pores of the masonry.The growth pressure of developing crystals is very high and sufficient to disrupt even the strongest masonry material. Crystal growth leads to either grain-by-grain loosening, which produces fretting and crumbling of the surface, or to delamination of a complete surface skin. The source of rising damp should be further investigated and controls put in place to stop further damage.