North Carolina Plumbing Practice Exam

The primary material commonly used for underground plumbing is PVC (Polyvinyl Chloride). PVC is favored due to its lightweight nature, resistance to corrosion, and cost-effectiveness, making it an ideal choice for buried drainage and waste systems. Its ability to withstand various chemical exposures and its longevity also contribute to its widespread use in underground applications.

ABS, while utilized in some plumbing systems, is not the primary choice for underground plumbing mainly due to its susceptibility to UV light, which can cause degradation over time. Galvanized steel is prone to rust and corrosion, which diminishes its integrity when buried. Cast iron, although strong and durable, is heavy and more expensive, making it less practical compared to PVC for underground installations.