NASCLA General Contractor Practice Exam 2025 – Complete Test Prep

The correct choice reflects the typical relative humidity range of 20-50% that is ideal for veneer plaster installation. Maintaining this humidity level is crucial because it helps to ensure proper curing and drying of the plaster. If the relative humidity is too low, it can lead to rapid drying, which may cause cracks or poor adhesion. Conversely, if the humidity levels are too high, it can slow down the curing process significantly, which can lead to surface issues and affect the overall quality of the finish.

Veneer plaster is a thin layer applied over a substrate, and achieving the right balance of moisture in the environment aids in the formation of a durable and aesthetically pleasing surface. Adhering to the recommended humidity helps contractors achieve consistent results and reduce the risk of post-installation problems. Understanding and regulating the relative humidity during application is essential to ensure the longevity and functionality of the plaster work.