What is the minimum height that vents must rise vertically above the flood level rim of the highest fixture served before turning horizontal?

The minimum height that vents must rise vertically above the flood level rim of the highest fixture served before turning horizontal is 6 inches. This requirement is in place to ensure that the vent effectively removes gases and allows for proper air circulation within the drainage system. By maintaining this height, it helps to prevent potential backflow issues, which can occur if the vent is not positioned correctly.

The 6-inch height standard also serves to ensure that any potential condensate does not accumulate in the vent line, which could lead to blockages or functional impairments in the plumbing system. This guideline is part of the plumbing code to maintain the safety and efficiency of waste disposal in plumbing systems.