Additives for Reliable and Efficient Gypsum Plastering Formula

April 8, 2025
8:10 AM

The quality of a wall is largely dependent on the performance of the plastering formulation. Modern construction requires plastering solutions that combine speed, reliability and durability. While gypsum is the basic material, a reliable plastering formula is the key, and that’s where building additives come in. At TENESSY, we specialize in high-quality additives that enhance the performance of plaster. Our aim is to help you solve problems in construction and improve application efficiency.

I.Understanding the Gypsum Plastering Formula

Gypsum plaster formulations usually consist of a combination of gypsum, fillers such as bicarbonate of soda and glass beads, and chemical additives. Each component plays a specific role: gypsum is the main binder, fillers improve volume and reduce cost, and additives control workability, setting time, water retention, crack resistance, and other properties.

An efficient plastering formula must have these characteristics:

Smooth consistency and workability.

Adequate open time.

Strong adhesion to a wide range of substrates.

Crack resistance and shrinkage control.

Consistency over temperature and humidity changes.

Lightweight Gypsum Plaster Formula

Raw Materials	weight/kg
Desulfurization Gypsum	750
Heavy Calcium Powder (can be combined with 300 mesh stone powder)	150
Glass Beads	50
Cellulose Ether HPMC	1.5-2.5
Starch Ether	0.5-1
Gypsum Retarder	1-1.5
Volume of Water Added 1：2

Without the addition of suitable additives, gypsum plasters may dry too quickly, be difficult to apply, or have a damaged surface. Selecting the right additives is therefore key to optimizing gypsum formulation.

II.Core Additives for Enhancing Gypsum Plastering Formula

1.Hydroxypropyl Methyl Cellulose HPMC

HPMC is a water-soluble cellulose ether with thickening and water retention properties. In gypsum plastering formula, HPMC significantly improves water retention and is able to fully reflect gypsum and water to prevent premature drying. This results in better hydration, improved adhesion and reduced risk of surface cracking.

In addition, HPMC adjusts the consistency of the plaster mix, making it easier to spread and finish the plaster. It extends the open time and workers have more time to make adjustments and level the plaster.TENESSY offers a range of HPMC grades for different climates and working conditions, ensuring consistent performance across different formulations.

2. Starch Ether

Starch ether complements HPMC by improving the rheology of plaster. It enhances thixotropy and makes the plaster mix smoother when mixing or applying; it becomes more viscous at rest. This property helps to minimize sagging on vertical surfaces and ensures uniform thickness of the plaster layer.

In addition, the starch ether reduces the stickiness of the plaster on tools and improves the efficiency of the work.TENESSY starch ethers are optimized for gypsum systems to ensure compatibility and consistency in a wide range of applications.

3. Gypsum Retarder

Gypsum hydrates quickly and usually sets quickly. In most applications, especially in hot climates or for large areas, it is necessary to delay the bonding time to allow sufficient construction time. Gypsum retarders help to regulate the initial and final setting times.

TENESSY’s gypsum retarder provide a controlled delay without affecting the final strength or surface hardness of the plaster. This ensures flexibility and ease of use in formulations that work well in complex conditions.

4. Defoamer

During the mixing process, gypsum plaster attracts air and forms bubbles, which can weaken the final strength of the plaster and lead to defects such as pinholes on the surface. Defoamer can inhibit the generation of air bubbles while eliminating air bubbles, and it can also make the viscosity of the mixture more stable and reduce shrinkage, thus improving the surface quality.

III.Customizing Additive Solutions to Plastering Formula

No plaster formulations are exactly the same. Factors such as the quality of the raw materials, the climate, local construction methods and the type of substrate all affect performance. That’s why TENESSY offers customized technical support and product matching services to help customers achieve their ideal plastering formula.

Whether you are using natural gypsum, FGD gypsum or synthetic alternatives, we can carry out laboratory testing and formulation adjustments.

IV.Conclusions

High performance gypsum plaster formulations are more than just gypsum and water, they need to be optimized with the right additives. At TENESSY, we manufacture and supply specialized additives including HPMC, starch ether, gypsum retarders and defoamer, each of which contributes to improved workability, condensation control, air management and surface performance.

By partnering with TENESSY, you get access to advanced product technology, expert technical support and consistent quality, all designed to help you develop reliable, efficient gypsum formulations. Contact us today to learn how we can help you improve your gypsum formulation and achieve better results on every project.