Efflorescence of bricks, causes, and prevention

Efflorescence of bricks refers to the white or grayish powder-like substance that can appear on the surface of brickwork or masonry. This is caused by the migration of soluble salts to the surface of the bricks, where they combine with moisture and air to form the powdery deposit. 

Efflorescence is a natural process that can occur in any masonry structure, and while it does not usually indicate structural problems, it can be unsightly and may detract from the appearance of the brickwork.

Let us understand what is the efflorescence of bricks with this simple example.

Imagine you have a brick wall that gets wet during rain. Over time, you may notice a white or grayish powder-like substance forming on the surface of the bricks. This is efflorescence, and it is caused by soluble salts within the bricks that are brought to the surface by moisture.

Causes of efflorescence of bricks

1. High levels of soluble salts in the brick or mortar used in construction.
2. Moisture penetrates the brickwork, either from rain or groundwater.
3. Poor ventilation can lead to excessive moisture buildup within the brickwork.
4. Incorrectly installed or damaged flashing, can allow water to penetrate the brickwork.
5. Inadequate curing time for the mortar used in construction.
6. Improper mixing of mortar or other construction materials.
7. Poor drainage or improper grading around the foundation of the building.
8. Use of high-pressure water cleaning or acidic cleaning products that can damage the surface of the bricks and increase the risk of efflorescence.

How to prevent of efflorescence of bricks

1. Properly mix and cure the mortar and other construction materials.
2. Use low-salt content materials in construction.
3. Ensure proper ventilation to prevent moisture buildup within the brickwork.
4. Install proper flashing and ensure that it is correctly installed and maintained.
5. Use a waterproof membrane behind the brickwork to prevent moisture penetration.
6. Properly grade the area around the foundation to ensure adequate drainage.
7. Avoid using high-pressure water or acidic cleaning products that can damage the bricks and increase the risk of efflorescence.
8. Apply a silane/siloxane water-repellent coating to the surface of the bricks to prevent moisture infiltration.

Also read: Spalling of bricks, signs, causes, and prevention