Methods to Reduce Efflorescence in Newly Constructed Masonry Walls

Efflorescence, the white crystalline deposit that appears on the surface of masonry walls, is a common concern for many builders and homeowners. However, there are effective methods and techniques available to reduce the occurrence of efflorescence in newly constructed masonry walls.

In this article, we will explore various approaches that can help minimize the potential for efflorescence on bricks.

Reduction Methods for Potential Efflorescence in Newly Constructed Masonry Walls:

1. Reduction of Water Penetration into Masonry Walls:

Proper measures should be taken during the construction process to minimize water ingress into the masonry wall. Some recommended steps include:

• Forming a good bond between masonry units and mortar:

A strong bond can be achieved by using mortar that is compatible with the masonry units. Properly fill the mortar joints, whether solid or hollow units are used, and consolidate the joints to prevent water penetration.

• Preventing water penetration during construction:

Take necessary precautions to avoid rainwater or other sources of moisture from entering partially constructed walls or wall openings. Design and place movement joints appropriately, and ensure they are sealed effectively.

• Sealing the masonry wall-roof interface:

Use flashing to create a watertight seal at the junction between the masonry wall and the roof. Building overhangs can also provide additional protection from rainwater.

• Water repellent treatment:

Consider adding a suitable water repellent admixture to concrete masonry units or applying a water repellent coating to the masonry wall.

• Construction of masonry components:

Construct chimney caps, sills, and copings using solid masonry units, reinforced concrete, corrosion-resistant metals, or stone. These components should extend beyond the masonry wall face and be properly sloped. Provide flashings and weep holes for effective drainage.

2. Expelling Penetrated or Condensed Water Out of Masonry Walls Quickly:

To facilitate the quick removal of water that has penetrated or condensed within the masonry wall, employ the following techniques:

• Installation of weep holes and flashing:

Install durable weep holes and flashing at critical locations, such as below window copings and sills, above lintels, masonry wall openings, roof-wall intersections, and at the base of the wall above ground level.

• Air space drainage:

Incorporate drainage systems within the air space of the masonry wall to facilitate the efficient drainage of water.

3. Preventing Contact Between Bricks with Different Chemical Compositions:

To prevent contact between bricks that have different chemical compositions, consider the following measures:

• Installation of separators:

Place separators between different materials used in the masonry wall construction.

• Provide flashing or separators at interfaces:

Install flashing or separators between the masonry wall and other structural elements built from different materials, such as chimney caps, sills, and copings.

• Cavity wall construction:

If a cavity wall is constructed, ensure a minimum of 5cm separation between the exterior masonry wythe and the interior wall constructed from different materials.

4. Reducing the Quantity of Efflorescence Compounds in Masonry Wall Materials:

Minimize the presence of efflorescence compounds in masonry wall materials through the following approaches:

• Material testing:

Conduct tests on masonry materials, including bricks, water, admixtures, and cleaning agents, before construction begins. Evaluate the combined effect of these materials and construction methods on future efflorescence.

• Proper storage of masonry materials:

Store masonry materials appropriately to prevent moisture absorption and contact with dissimilar materials, as these factors can contribute to efflorescence.

• Protection during delivery:

Safeguard masonry construction materials during transportation to prevent contamination.

• Cleaning procedures:

If cleaning newly constructed masonry walls is necessary, employ appropriate materials and procedures to minimize the risk of efflorescence.

 

Efflorescence in newly constructed masonry walls can be effectively reduced by implementing these methods and techniques.

By addressing water penetration, facilitating drainage, preventing material contact, and minimizing efflorescence compounds, builders can achieve aesthetically pleasing and durable masonry walls.