WHAT IS EFFLORESCENCE?
Efflorescence refers to the formation of a powdery or crystalline deposit on or underneath the surface of various types of masonry. The deposit is usually an unappealing shade of white, brown, gray, or yellow and mars the aesthetic appeal of the walls.
Efflorescence results when water present in the building surfaces dissolves certain salts and migrates to other areas, leaving behind salty deposits as it evaporates. Efflorescence is among the most challenging waterproofing problems to solve. Unfortunately, efflorescence cleaning is a major problem when it comes to concrete surfaces.
Concrete efflorescence can be triggered by faulty waterproofing, humidity, rain, and condensation. While exterior efflorescence is tricky enough, treating interior efflorescence is considered even more challenging.
Common Causes Of Efflorescence:
- The presence of certain salts in the construction materials used
- Improper raising of masonry following repointing
- Incomplete hydration process/improper curing of concrete
- Improper flashing or caulking
- Excessive water added to the concrete
- Improper drainage
- Inadequate provisions for ventilation
- Sulfation of pyrites in clay
- Improper ground storage
Two Kinds of Efflorescence
1. Primary Efflorescence
This type of efflorescence occurs when concrete is in the curing phase. If water with soluble salts or lime emerges to the surface and evaporates, leaving a powdery residue, it is known as primary efflorescence.
2. Secondary Efflorescence
Secondary efflorescence occurs after the concrete has hardened. When external moisture migrates to a concrete surface and infiltrates it causing the appearance of powdery deposits, it is known as secondary efflorescence.
The problems posed by efflorescence aren’t just aesthetic. Left untreated, it can lead to structural damage as well. While there are many traditional methods for efflorescence cleaning, these are seldom effective.