Efflorescence is not a rock band. That’s Evanescence. Efflorescence is the white, chalky substance that appears on concrete, pavers, brick, and stucco. It is residue that is left behind when hard, ...

A powdery substance called efflorescence will sometimes appear on stone, concrete or tile surfaces. This shows up as irregular, whitish blotches and is especially frequent around joints and grout ...

Dear James: Our house has a rather strange bathroom with some glossy and some dull ceramic tile. There is a lot of dark mildew on the grout. What is the best and safest method to clean the grout? - ...