Moderate

When the deposit of efflorescence is heavier than slight and does not cover more than 50 % of the exposed area of the brick surface. The deposit should not, thus, powder or flake of the surface.

Heavy

While the deposit of efflorescence salts is heavy and covers 50 % or more of the exposed area of brick surface. The deposit, thus, does not powder or flake of the surface.

Serious

While the deposit of efflorescence salts is heavy and is accompanied through powdering and/or flaking of the exposed surfaces.