What is the minimum overall thickness for exposed aggregate plaster bedding coat over concrete or masonry surfaces?

• A. 1/4 inch
• B. 1/2 inch
• C. 5/8 inch
• D. 3/4 inch

Answer: (B)

The minimum overall thickness for exposed aggregate plaster bedding coat over concrete or masonry surfaces is set at 1/2 inch to ensure the proper adherence and performance of the plaster. This thickness allows the plaster to provide adequate coverage over the underlying surface, helping to prevent issues such as cracking or delamination, which can occur if the coat is too thin. The 1/2 inch thickness is also sufficient to encapsulate and support the aggregate materials that give the plaster its finished appearance. This requirement reflects industry standards aimed at achieving durability and functionality in plaster finishes, making them suitable for exposure to various environmental conditions.