Quel rôle joue l'humidité dans la cause de l'efflorescence?
Reading time: 2'

What role does moisture play in causing efflorescence?

The Intricate Dance of Moisture and Efflorescence

A Glimpse into Efflorescence

Before diving deep into the role of moisture, it's essential to understand what efflorescence is. It's that white, powdery deposit of salts that often appears on masonry surfaces, including bricks, concrete, and stone. At Maçonnerie Montréal, we've encountered numerous instances of efflorescence, and our clients frequently ask about its origins and prevention.

Moisture: The Catalyst of Efflorescence

1. The Journey of Water

Efflorescence is born when water infiltrates masonry materials. As this water moves, it dissolves soluble salts present within the masonry. When the water eventually reaches the surface and evaporates, it leaves behind these crystallized salts, which we recognize as efflorescence.

2. Sources of Moisture

Moisture can find its way into masonry from various sources:

  • Groundwater: If the masonry is in contact with the soil, it can absorb moisture, especially if drainage is poor.
  • Rain: Especially in areas with heavy rainfall, water can penetrate masonry if not adequately protected.
  • Internal Sources: This includes leaky pipes or high internal humidity.

Why Moisture Management is Crucial

1. Beyond Aesthetic Concerns

While efflorescence is often viewed as a cosmetic issue, the moisture causing it can signal deeper problems. Persistent moisture can weaken masonry, making it more susceptible to damage over time.

2. Potential for Structural Issues

Moisture, especially when it freezes and thaws, can lead to:

  • Cracking: Expansion during freezing can cause masonry to crack.
  • Spalling: This is when the surface layer of masonry breaks off, often due to freeze-thaw cycles or salt crystallization.
  • Corrosion: In reinforced masonry, moisture can cause the metal reinforcements to corrode.

Strategies for Moisture Management

1. Proper Drainage

Ensuring that the ground around masonry structures slopes away can prevent water from pooling and being absorbed.

2. Waterproofing

Applying a high-quality waterproofing agent can create a barrier against moisture infiltration.

3. Regular Maintenance

Routine checks for potential sources of moisture, like leaks or poor drainage, can prevent long-term issues.


The relationship between moisture and efflorescence is intricate. While efflorescence itself might be a cosmetic concern, the moisture causing it can have more profound implications. At Maçonnerie Montréal, we're dedicated to ensuring the longevity and beauty of your masonry structures across Greater Montreal, Laval, Longueuil, South Shore, and North Shore. Trust in our expertise to guide you through understanding and addressing all masonry-related concerns.