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

Mortar serves as the primary adhesive between bricks, concrete blocks, or other building materials. However, in practice, mortar often cracks quickly after application. These cracks not only disrupt the appearance of the wall but can also reduce the overall structural strength of the building.

To prevent this from happening in your project, let's understand the causes of mortar cracking quickly and how to properly address them.

1. Incorrect Mixing Composition
The most common error occurs when mixing mortar manually. Unbalanced proportions of cement, sand, and water reduce the mortar's adhesive strength.
Mortar that is too thick will be difficult to stick to, while mortar that is too thin will shrink easily as it dries—both of which can cause cracking.

Solution:
Use instant mortar with a composition precisely formulated at the factory. If mixing by hand, ensure the material ratios comply with technical recommendations.

2. Application Too Dry or Too Wet
During installation, a brick surface that is too dry can absorb water from the mortar too quickly, preventing it from bonding properly. Conversely, if the mortar is too wet, it can take a long time to dry and cause uneven shrinkage.

Solution:
Lightly wet the brick or wall surface before applying the mortar to balance the moisture and optimize adhesion.

3. Drying Process Too Fast
Mortar exposed to strong winds or direct sunlight during the hardening process is prone to hairline cracks. This occurs because the water evaporates too quickly before the mortar has fully set.

Solution:
Protect the work area with a tarp or wet cloth, especially in hot weather. A good curing process helps the mortar dry naturally and strengthen.

4. Uneven Mortar Thickness
Mortar that is applied too thickly or unevenly will shrink differently in each area, leading to cracking.

Solution:
Use an ideal thickness of around 10–15 mm for brickwork. Also, ensure each layer is pressed evenly to eliminate air pockets.

5. Poor Material Quality
Dirty sand, oily water, or clumped cement can significantly affect the strength of the mortar.

Solution:
Use clean, quality materials. Choose SNI-certified instant mortar products to ensure long-term quality and adhesion.

Conclusion
Mortar cracks can be caused by many factors, from composition and application methods to environmental conditions. By choosing quality materials and applying the correct techniques, your walls will be neater, stronger, and more durable.

Want a neat, crack-free wall?
Use high-quality mortar products from PT Intisumber Bajasakti — easy to apply, strong adhesion, and compliant with SNI standards.

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

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