Gypsum plaster and cement plaster are two commonly used materials in the construction industry, each with its own characteristics and applications. The strength of these plasters can vary depending on a number of factors, so the specific requirements of the building project must be considered.

Gypsum plaster:

Gypsum plaster, also known as plaster of paris, is a building material made from gypsum, a soft sulfate mineral. It is widely used in interior wall finishes and decorative elements. Gypsum plaster is known for its smooth and white surface, making it a popular choice for aesthetic purposes. However, in terms of strength, gypsum plaster is generally not as strong as cement plaster.

The strength of gypsum plaster is affected by factors such as the ratio of gypsum to water during the mixing process and the thickness of the plaster. Because gypsum is susceptible to water damage, gypsum plaster is not recommended for use in areas exposed to moisture or external weather conditions.

Cement plastering:

Cement stucco, often called Portland cement stucco, is a mixture of Portland cement, sand and water. It is commonly used for interior and exterior wall finishes. Cement stucco is known for its durability and strength, making it suitable for a wide range of applications, including areas of high stress.

The strength of cement mortar is affected by the quality of materials used in the mixture, the curing process and the thickness of the mortar applied. Cement stucco is more resistant to moisture and exterior elements than gypsum plaster, making it the first choice for exterior surfaces.

Strength comparison:

Generally speaking, cement plaster is considered stronger than gypsum plaster. The cementitious properties of Portland cement help improve the overall strength and durability of stucco. Cement stucco is often chosen for areas that require high resistance to wear, impact, and weather conditions.

Things to note when choosing plaster:

Strength Requirements: Consider the specific strength requirements of the application. If high strength is a priority, cement mortar may be a better choice.

Aesthetic preferences: Gypsum plaster is preferred for its smooth and white surface, making it suitable for interior walls where aesthetics play an important role.

Moisture Exposure: If the plastered surface is exposed to moisture or external weather conditions, cementitious plaster is a more suitable choice due to its waterproof properties.

Location of application: Consider the location of application (interior or exterior) and the potential impact on the performance of the plaster over time.

While gypsum plaster has its own set of advantages, including its aesthetics, cement plaster is generally stronger and more durable. The choice between the two should be based on the specific requirements and conditions of the construction project.