What is the minimum required slope for a horizontal vent line?

The minimum required slope for a horizontal vent line is 1/16" per foot. This slope is specified to ensure that any condensate that might form in the vent line is able to drain freely. Proper drainage is crucial to prevent blockages that could impede the venting process or lead to backflow of gases, which can pose safety hazards.

A slope of 1/16" per foot effectively promotes the movement of moisture and helps maintain the efficiency of the venting system. A steeper slope, such as 1/8" per foot, is generally not required and may not be ideal as it could lead to increased velocity of exhaust gases, potentially causing noise and structural issues. Understanding this requirement is vital for ensuring that vent lines function properly in accordance with plumbing codes and best practices.