General Contractor Practice Exam

Which material can be directly influenced by humidity levels during construction?

1. Concrete

2. Wood

3. Steel

4. Drywall

The correct answer is: Wood

Wood is significantly affected by humidity levels during construction due to its hygroscopic nature, meaning it can absorb and release moisture from the surrounding environment. When humidity levels are high, wood tends to absorb moisture, causing it to swell and potentially warp or crack. Conversely, in dry conditions, wood releases moisture and may shrink. This behavior can lead to challenges in maintaining proper dimensions and structural integrity if not accounted for during construction. While concrete can also be influenced by moisture content, especially regarding its curing process, it is primarily concerned with the water-to-cement ratio rather than direct absorption of humidity. Steel is not affected by humidity in the same way, though it may be prone to corrosion in damp environments. Drywall, made from gypsum, can also suffer damage from excessive humidity but is not directly influenced by moisture levels in the same structural manner as wood. Therefore, wood stands out as the material most directly influenced by humidity during construction.