Case Background
In the construction of an exterior insulation finishing system (EIFS) for a project in the United States, traditional putty materials suffered from low adhesive strength, insufficient flexibility, and a tendency to crack, leading to issues such as bubbling and detachment of the decorative layer. To address these problems, the construction team decided to use putty modified with redispersible polymer powder.
Application Plan
Material Selection
White Cement
Redispersible Polymer Powder
Other Additives: Cellulose ether, defoamer, quartz powder, heavy calcium carbonate, etc.
Formulation Design
Based on the requirements of the exterior insulation finishing system, a flexible putty
formulation was designed, focusing on enhancing adhesive strength and flexibility.
Construction Process
Mixing: Combine the dry powder materials with water and mix thoroughly to form a uniform putty paste.
Application: Apply the putty evenly to the wall surface, controlling its thickness.
Drying: Allow it to dry naturally, then sand the surface for finishing.
Performance Improvement
Adhesive Strength: The modified flexible putty achieved a significant increase in strength.
Flexibility: When the dosage of redispersible polymer powder reaches a certain level, the flexibility of the putty reaches an ideal state, effectively preventing cracking.
Resistance to Dynamic Cracking: The putty's resistance to dynamic cracking was significantly enhanced.
Water Absorption: The water absorption rate was significantly reduced.
Construction Performance: The putty's water retention was improved, the open time was extended, and the workability during construction was enhanced.
Construction Results
After actual construction, the exterior putty layer showed no cracking, bubbling, or detachment. The surface flatness and smoothness were excellent, meeting the decorative requirements of the exterior insulation finishing system.
Conclusion
The addition of redispersible polymer powder significantly improved the adhesive strength, flexibility, and crack resistance of the wall putty. It also reduced water absorption and enhanced construction performance. This modified putty is particularly suitable for exterior insulation finishing systems, effectively addressing common issues associated with traditional putty.
