The minimum required slope for a horizontal vent line is _______________.

The minimum required slope for a horizontal vent line is typically set to ensure that any condensation or water that forms in the vent line can easily drain back toward the drainage system rather than accumulate within the vent pipe. A slope of 1/16 inch per foot is sufficient to achieve this drainage without causing any problems in the venting system's functionality.

This gentle slope is designed to prevent the buildup of debris or liquids in the vent while providing a reliable pathway for gases to escape. Having too steep of a slope could potentially lead to other issues, such as air flow disruptions or backflow into the piping system. Therefore, setting the minimum at 1/16 inch per foot strikes a harmony between effective venting and managing drainage, ensuring compliance with local plumbing codes.

Other options proposed, such as steeper slopes or "none," do not meet the minimum requirements set forth for proper vent line installation, underscoring the necessity of adhering to code standards for optimal plumbing performance.