What is self-leveling gypsum mortar？

Self-leveling gypsum mortar, also known as self-leveling gypsum underlayment or self-leveling gypsum screed, is a type of flooring material that is designed to create a level surface over an uneven subfloor. It is made from a mixture of gypsum powder, aggregates, and various additives that provide the mortar with its self-leveling properties.

Self-leveling gypsum mortar is typically used in interior applications, such as in residential and commercial buildings, where it is applied over concrete, wood, or other types of subfloors. It is a popular choice for flooring installations because of its ease of use, speed of installation, and ability to create a smooth and level surface that is ready for further flooring installations.

Composition of Self-Leveling Gypsum Mortar

Self-leveling gypsum mortar is made up of a combination of gypsum powder, aggregates, and various additives that provide the mortar with its self-leveling properties. The gypsum powder acts as a binder, while the aggregates, typically sand or perlite, provide structure and stability to the mortar. The additives used in self-leveling gypsum mortar can vary, but typically include:

1. Superplasticizers: These are chemical additives that are used to increase the flow and workability of the mortar, allowing it to self-level and fill in low areas.
2. Retarders: These are additives that slow down the setting time of the mortar, giving it more time to flow and level before it hardens.
3. Fiber Reinforcement: Some self-leveling gypsum mortars may also contain fiber reinforcement, which can improve the mortar’s strength and durability.
4. Other Additives: Other additives may be added to improve the mortar’s water resistance, shrinkage, or adhesion to the subfloor.

Application of Self-Leveling Gypsum Mortar

The application of self-leveling gypsum mortar typically involves several steps. First, the subfloor must be thoroughly cleaned and prepared to ensure proper adhesion of the mortar. Any loose material, such as debris, dust, or old adhesive, must be removed.