How To Reduce Efflorescence of Coloured Mortar

Efflorescence is caused by water-soluble salts present in the mortar. When rain water or ground water migrated into the mortar, it dissolved the salts and carried them to the mortar surfaces. The moisture will then evaporate off and caused the salts to crystallized and deposited on the surfaces, resulting in efflorescence.

Coloured mortar is made with a combination of Portland cement, hydrated lime, sand and colour pigments. It is usually applied on the exterior wall of building. After the colour mortar cured for a period of time, patches of whitish colour salt deposits (efflorescence) may appear on the surfaces which caused discoloration. When this happened, repairing and cleaning work are required to restore the colour mortar to their original colour which will incur extra cost.