Factors That Cause Mortar to Crack Quickly and How to Overcome Them

Mortar plays a crucial role in masonry and plastering, as it acts as a bonding agent between building materials. However, in practice, mortar often cracks quickly after application. These cracks not only disrupt the appearance but can also reduce the overall structural strength of the building.

To ensure a neat and strong finish, let's discuss the causes of mortar cracking quickly and how to address them.

1. Incorrect Mixing Composition
One of the main causes of mortar cracking quickly is improper material ratios. If the mixture contains too much water, the mortar shrinks easily as it dries. Conversely, if there is too little water, its adhesive strength decreases and it cracks easily.

Solution:
Use instant mortar with precisely formulated ingredient proportions. If mixing by hand, ensure the ratio of cement, sand, and water meets technical recommendations for stable results.

2. The Wall or Brick Surface is Too Dry
A brick surface that is too dry can absorb water from the mortar too quickly, impeding the bonding process and causing hairline cracks.

Solution:
Before applying mortar, wet the brick or wall surface sufficiently to prevent it from absorbing too much water from the mortar.

3. Drying Process Too Fast
Exposure to direct sunlight or strong winds can cause mortar to dry too quickly. As a result, the water in the mixture evaporates before the cement hydration process is complete—this is what triggers hairline cracks.

Solution:
Protect the work area from direct sunlight. After installation, periodically curing (light watering) allows the mortar to dry naturally and evenly.

4. Uneven Mortar Thickness
Mortar applied too thickly will shrink unevenly, making it prone to cracking in certain areas.

Solution:
Use a uniform thickness, around 10–15 mm for brickwork. Ensure that the pressure during installation is even to avoid air gaps between layers.

5. Poor Material Quality
Dirty sand, muddy water, or clumped cement can significantly reduce the quality of the mortar. This makes the final product more brittle and prone to cracking.

Solution:
Use high-quality raw materials and clean water for mixing. Choose SNI-certified instant mortar to ensure optimal strength and adhesion.

Conclusion
Mortar cracks are usually caused by minor, often overlooked technical errors. By using quality materials, mixing properly, and paying attention to the drying process, your wall will be much stronger and more durable.

💬 Want a neat, crack-free wall?
Use high-quality instant mortar from PT Intisumber Bajasakti — easy to apply, strong, and meets SNI standards!

📞 Phone: 021-66675999
🌐 Web: intisumberbajasakti.com
✉️ Email: info@intisumberbajasakti.com

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