Finish coat materials commonly used for plastering include which of the following?

• A. Portland cement-based plaster
• B. Lime-putty
• C. Gypsum-based finish plasters
• D. All of the above

Answer: (D)

Finish coats in plastering come in several material families, each chosen for how it behaves with the backing and the environment. Cement-based finish coats are durable and moisture resistant, making them a solid choice for exterior stucco and interiors with higher humidity or exposure. Lime-based finishes, including lime-putty mixes, are highly breathable and flexible, which helps on historic or breathable walls and in climates where moisture management is important. Gypsum-based finish plasters provide a very smooth interior surface with a fast set, ideal for dry, stable interior walls. Because all three types are commonly used in different plastering systems, the best answer is that finish coat materials can be cement-based, lime-based, or gypsum-based. The choice depends on the substrate, climate, and performance needs of the project, but all are valid finish coat options.