What is Efflorescence?

Efflorescence is a common problem that occurs in masonry and concrete structures. It is a white, powdery substance that forms on the surface of these materials, often appearing as a crystalline deposit. Efflorescence is caused by the migration of soluble salts to the surface of the material through capillary action. When water evaporates from the surface, it leaves behind these salts, resulting in the formation of efflorescence.

Causes of Efflorescence

Efflorescence can be caused by various factors, including:

1. Moisture: Excessive moisture in the masonry or concrete can lead to efflorescence. Water acts as a carrier for the soluble salts, allowing them to migrate to the surface.

2. Soluble Salts: The presence of soluble salts in the materials used for construction can contribute to efflorescence. These salts can be present in the cement, aggregates, or even in the water used during the mixing process.

3. Temperature Changes: Fluctuations in temperature can also trigger efflorescence. When the temperature rises, the water within the material expands, causing the salts to be pushed towards the surface. As the temperature drops, the water contracts, leaving behind the salts.

4. Poor Construction Practices: Improper construction techniques, such as inadequate curing or improper mixing of materials, can increase the likelihood of efflorescence.

Effects of Efflorescence

Efflorescence is not only an aesthetic issue but can also have negative effects on the structural integrity of the masonry or concrete. Some of the effects of efflorescence include:

1. Discoloration: Efflorescence can cause unsightly white stains or discoloration on the surface of the material, diminishing its visual appeal.

2. Deterioration: Over time, the accumulation of salts on the surface can lead to the deterioration of the material. The salts can react with the components of the masonry or concrete, causing it to weaken and crumble.

3. Reduced Lifespan: The presence of efflorescence can accelerate the aging process of the material, reducing its lifespan and durability.

4. Moisture Related Issues: Efflorescence is often an indication of moisture-related problems within the structure. The presence of excessive moisture can lead to mold growth, water damage, and other structural issues.

Prevention and Treatment of Efflorescence

Preventing and treating efflorescence requires a multi-step approach. Here are some methods that can be employed:

1. Proper Drainage: Ensuring proper drainage around the structure can help prevent the accumulation of moisture, reducing the likelihood of efflorescence.

2. Waterproofing: Applying a waterproofing membrane or coating to the surface can create a barrier that prevents water from penetrating the material and carrying the salts to the surface.

3. Efflorescence Cleaners: There are various efflorescence cleaners available in the market that can be used to remove the white deposits from the surface. These cleaners typically contain acidic or alkaline solutions that dissolve the salts.

4. Sealing: Sealing the surface with a penetrating sealer can help prevent the migration of salts to the surface, reducing the occurrence of efflorescence.

5. Proper Construction Practices: Following proper construction practices, such as adequate curing and proper mixing of materials, can minimize the chances of efflorescence.


Efflorescence is a common problem in masonry and concrete structures, caused by the migration of soluble salts to the surface. It can have negative effects on the appearance and structural integrity of the material. Preventing and treating efflorescence requires a combination of proper construction practices, drainage, waterproofing, and the use of efflorescence cleaners and sealers. By taking proactive measures, it is possible to minimize the occurrence of efflorescence and ensure the longevity of the structure.