Choosing the Right Putty: Gypsum-Based, Cement-Based, or Gray Calcium-Based?

When it comes to wall finishing, putty is far more than just “white filler.” It’s a scientifically engineered material that plays a crucial role in surface smoothness, paint adhesion, durability, and even indoor air quality. Depending on its key binder, putty is generally categorized into gypsum-based, gray calcium-based, and cement-based types—each with distinct properties, benefits, and applications.

1.Gypsum-based putty uses calcium sulfate hemihydrate (construction gypsum) as its main inorganic binder. It offers fast drying, good workability, and high strength, making it ideal for indoor base-level wall leveling. Due to its air-hardening nature, gypsum putty cures quickly without being affected by ambient humidity, and its natural composition contributes to better indoor humidity regulation and sound insulation. However, it is not recommended for wet areas due to limited water resistance.

2.Gray calcium-based putty, made with hydrated lime (gray calcium powder), is widely used as a finishing layer. It provides excellent whiteness, smooth texture, and better water resistance compared to gypsum. Its fine particles and strong polishing performance make it a preferred choice for high-end interior walls. It hardens by absorbing CO₂ from the air, a slow but steady process that ensures dimensional stability and a refined finish.

3.Cement-based putty, primarily composed of white Portland cement, is designed for strength and weather resistance. It performs exceptionally well in exterior applications or damp environments like kitchens and bathrooms. While it offers superior durability and water resistance, its coarse texture and slow curing time can make it difficult to sand or achieve a smooth finish, limiting its use in decorative interiors.

In short, no single type of putty fits all purposes. Gypsum-based is fast and smooth for indoor leveling, gray calcium-based is ideal for fine finishing, and cement-based is built to withstand the elements. Choosing the right type based on your environment and performance needs ensures better results, fewer repairs, and longer-lasting wall protection.