What is the minimum pipe size that can be used for a wet vent?

The minimum pipe size that can be used for a wet vent is 2 inches. This specification is based on plumbing codes and standards that ensure proper drainage and venting in plumbing systems. A wet vent serves to both drain wastewater and vent air to prevent vacuum conditions, ensuring that the system can function effectively without creating pressure issues.

Using a pipe size smaller than 2 inches could lead to inadequate venting, which may cause slow drainage, the potential for water backups, or even the release of sewer gases into the building. Therefore, a 2-inch minimum diameter is critical to maintain proper flow and venting efficiency in wet vent systems. The specified pipe size is designed to handle the cumulative flow from multiple fixtures without compromising the system's performance.