North Carolina Building Contractor License Practice Exam

What type of wood may be used if it is continuously below ground water level or submerged in fresh water?

1. Pressure-treated wood

2. Plastic lumber

3. Composite wood

4. Untreated wood

The correct answer is: Pressure-treated wood

Pressure-treated wood is specifically designed for applications where it will be exposed to moisture and potential decay, such as in environments that are continuously below ground water level or submerged in fresh water. The treatment process involves infusing the wood with preservatives that help protect it from rot, insect infestation, and fungal decay, which are significant risks in such wet conditions. This makes pressure-treated wood a suitable choice for areas like pilings, posts, and other structural elements that require durability and longevity when in contact with water. The other materials listed possess characteristics that make them unsuitable for extended exposure underwater or in consistently damp conditions. For instance, plastic lumber and composite wood may not offer the same structural strength or long-term stability when continuously submerged, and untreated wood is highly vulnerable to moisture, leading to decay and structural failure. Thus, when considering materials for submerged or continuously wet environments, pressure-treated wood is uniquely equipped to handle such challenges effectively.