What is the minimum number of plaster coats required?

The minimum number of plaster coats required for proper application is commonly recognized as two. The first coat, often referred to as the scratch coat, is applied to provide a solid base and is typically followed by a second coat, known as the brown coat, which creates a smoother surface and allows for better adherence of the final finish.

The two-coat system is sufficient for many standard applications, particularly in residential settings. While additional coats may be used for greater durability or specific aesthetic finishes, the requirement for at least two coats establishes a foundation that ensures reliable adherence, thickness, and overall performance of the plaster.

Using fewer than two coats may lead to instability, poor finish quality, and inadequate moisture resistance. Therefore, two coats are generally viewed as the industry standard minimum.