Brick masonry is an essential component of construction, widely used for its durability, fire resistance, and aesthetic appeal. However, brick structures are not immune to defects, especially when exposed to harsh environmental conditions. These defects can compromise the structural integrity and appearance of the masonry. This guide covers common defects in brick masonry, their causes, and effective remedies to ensure long-lasting, high-quality construction. Additionally, we’ll include relevant Indian Standard (IS) codes to follow for best practices in brick masonry work.
Understanding Brick Masonry
Brick masonry involves laying bricks in a specific arrangement and binding them with mortar to form structures such as walls, columns, and foundations. Although brick masonry is highly durable, certain factors like moisture, salt, and improper construction practices can lead to defects over time. Identifying these issues early on and applying effective remedies can help prolong the life of brick structures.
Common Defects in Brick Masonry & Their Remedies
Here are some of the most common defects found in brick masonry, along with their causes and remedies:
1. Sulphate Attack
- Description: Sulphate attack occurs when sulphate salts in brickwork react with the alumina content of cement or with hydraulic lime in lime mortar. This reaction causes the mortar to expand, leading to chipping, spalling, and cracking in the joints and renderings.
- Causes: The presence of sulphate salts, usually from external sources like soil or water, and prolonged exposure to moisture.
- Affected Areas: Boundary walls, parapets, manholes, and retaining walls are especially vulnerable.
- Remedies:
- Use sulphate-resistant cement or low-alumina content mortar.
- Apply a waterproof coating or surface treatment to prevent moisture from entering the brickwork.
- Ensure proper drainage around the masonry to avoid prolonged contact with water.
2. Crystallization of Salts (Efflorescence)
- Description: Efflorescence is a white, powdery deposit of salts on the brick surface. It occurs when bricks containing excessive soluble salts come in contact with water. As the water evaporates, it leaves salt crystals behind, giving the masonry an unsightly appearance.
- Causes: High salt content in bricks, mortar, or water used in construction, and inadequate ventilation or drainage.
- Remedies:
- Regularly brush and wash the affected surface to remove the salt deposits.
- Avoid using bricks with high salt content, or apply a damp-proof course (DPC) to prevent moisture from rising.
- Improve ventilation around the structure to allow moisture to evaporate more easily.
3. Corrosion of Embedded Iron or Steel
- Description: Embedded iron or steel in brickwork can corrode over time due to the presence of moisture. This corrosion causes the metal to expand, resulting in cracks in the surrounding brickwork.
- Causes: Exposure to damp conditions, lack of protective coatings on metal reinforcements, and poor construction practices.
- Remedies:
- Use corrosion-resistant materials like stainless steel or apply anti-corrosion coatings to metal elements before embedding them in brickwork.
- Ensure adequate waterproofing and drainage to minimize contact with moisture.
- Regularly inspect and maintain masonry structures to identify early signs of corrosion.
4. Cracks in Brickwork
- Description: Cracks are common in brick masonry and can range from small hairline cracks to larger, structural cracks. They can appear in both the mortar joints and the bricks themselves.
- Causes: Foundation settlement, thermal expansion and contraction, and seismic activity.
- Remedies:
- Repair small cracks with high-quality mortar. For larger cracks, consult a structural engineer and consider reinforcing the masonry.
- Use expansion joints in long stretches of masonry to accommodate thermal movements.
- Ensure proper foundation support to prevent settlement-related cracks.
5. Spalling of Bricks
- Description: Spalling is when the outer surface of bricks peels or flakes off. This defect reduces the aesthetic value of the masonry and can weaken the structure.
- Causes: Freeze-thaw cycles, water infiltration, or using low-quality bricks.
- Remedies:
- Replace spalled bricks with weather-resistant alternatives.
- Apply waterproofing to exposed surfaces, especially in regions with freezing temperatures.
- Ensure proper drainage to prevent water accumulation around brickwork.
6. Bulging of Masonry
- Description: Bulging occurs when sections of a brick wall begin to protrude outward, creating an uneven surface.
- Causes: Poor construction practices, inadequate support, or overloading the wall.
- Remedies:
- Rebuild affected sections with proper reinforcement and support.
- Hire experienced masons to ensure accurate and durable construction.
- Avoid overloading walls beyond their design limits.
Tips for Avoiding Defects in Brick Masonry
To ensure high-quality brick masonry, consider the following preventive measures:
- Choose Quality Materials: Use bricks and mortar that meet IS code requirements. High-quality materials contribute to the strength and longevity of masonry.
- Hire Skilled Masons: Experienced masons are essential for quality construction. Skilled workers will ensure that mortar joints are even and bricks are laid properly.
- Implement Proper Curing: Allow adequate curing time for mortar to gain strength, especially in hot or dry climates.
- Provide Adequate Drainage: Water is a primary cause of many masonry defects. Design effective drainage systems to minimize moisture exposure.
- Use Damp-Proof Courses: Apply DPC layers to prevent rising damp in walls. This is especially important for areas exposed to high moisture levels.
Indian Standards (IS) Codes for Brick Masonry
Following IS codes helps in maintaining high standards in brick masonry construction. Here are some important codes related to brick masonry:
- IS 1077: 1992 – Common Burnt Clay Building Bricks – Specification: This code provides specifications for burnt clay bricks used in masonry work, including the compressive strength and water absorption requirements.
- IS 2212: 1991 – Code of Practice for Brickwork: This standard outlines guidelines for the construction of brickwork, including best practices for laying bricks and preparing mortar.
- IS 3495 (Parts 1 to 4): 1992 – Methods of Tests of Burnt Clay Building Bricks: These parts specify methods for testing the compressive strength, water absorption, efflorescence, and warpage of clay bricks.
Conclusion🎯
Brick masonry is a durable and effective construction method, but it’s essential to address any defects that may arise. By understanding the causes and remedies for common issues like sulphate attack, efflorescence, and corrosion, you can ensure that your masonry structures remain robust and visually appealing for years to come. Adhering to IS codes will also help maintain high construction standards, resulting in a safe and sustainable building.