How many coats of stucco are typically applied to concrete blocks in commercial applications?

Typically, two coats of stucco are applied to concrete blocks in commercial applications. The first coat, known as the scratch coat, is applied to provide a key for the second coat to adhere properly. This coat is textured to create grooves that help with the adhesion of the finish coat. The second coat, called the brown coat, is used to level the surface and provide a uniform appearance. This layering process is essential because it allows for better moisture management and helps to ensure the durability and performance of the stucco.

The application of only one coat does not provide the necessary structure and finish, while three coats can be excessive for most applications, adding unnecessary thickness and weight. No coats would leave the concrete blocks unprotected and would not serve the purpose of stucco in providing insulation, aesthetic appeal, and weather resistance. Therefore, applying two coats strikes a practical balance that aligns with standard building practices in commercial construction.