What is the difference between crack-resistant mortar and ordinary cement mortar?-HUALIAN TOP TECHNOLOGY,Redispersbile polymer powder,RDP

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What is the difference between crack-resistant mortar and ordinary cement mortar?

Release time:

2025-12-10

Crack-resistant mortar and cement mortar both belong to the category of pre-mixed mortar. Crack-resistant mortar is mainly a polymer-modified, cement-based plastering crack-resistant mortar, used for surface reinforcement and protective coating on mortar walls and insulation (EIFS) systems.

What is the difference between crack-resistant mortar and ordinary cement mortar?

Crack-resistant mortar and cement mortar both belong to the category of pre-mixed mortar.

Crack-resistant mortar is mainly a polymer-modified, cement-based plastering crack-resistant mortar, used for surface reinforcement and protective coating on mortar walls and insulation (EIFS) systems.

Cement mortar is used for plastering concrete substrates and cement-based substrates, and can be used for base-layer protection and surface leveling.

Crack resistance:
Cement mortar has relatively weak crack resistance. It is prone to cracking under temperature changes and substrate deformation. Crack-resistant mortar has excellent crack resistance. The addition of fibers and polymer emulsion (RDP) can effectively reduce cracking and improve the mortar’s flexibility and adhesion.
Bond strength:
Cement mortar has average bond strength. On substrates with poor flatness or high water absorption, debonding may occur. Crack-resistant mortar has higher bond strength; over time it is less likely to deform, so the bond remains stable.
Flexibility:
Cement mortar lacks flexibility. When the substrate undergoes small movements, it cannot deform accordingly, which can lead to cracking. Crack-resistant mortar has better flexibility and can tolerate a certain degree of substrate deformation while maintaining integrity.
Application method:
Cement mortar is usually applied in a thick layer. If the temperature is too high or drying is too fast after application, cracking may occur. Typical thickness: 5–12 mm.
Crack-resistant mortar is usually applied by thin-coat troweling/scraping. The surface is smoother and it has high strength with better crack resistance. Typical thickness: 3–5 mm.
Scope of application:
Cement mortar is suitable for leveling and patching walls/floors, and for the surface of building components or substrate materials.
Crack-resistant mortar is suitable for interior and exterior walls, insulation systems, masonry/brickwork, and wall construction areas where crack resistance is needed.
Cost estimation:
Although the unit price of crack-resistant mortar is higher, its overall cost-effectiveness can be better because the required application thickness (and therefore material consumption) is lower, while still meeting performance needs.