What is the required clearance above a flood rim for a plumbing vent?

The required clearance above a flood rim for a plumbing vent is indeed 6 inches. This regulation is in place to ensure that the venting system effectively functions without being compromised by potential water flooding. Adequate clearance helps prevent the entry of water into the vent system during heavy rains or floods, which can lead to sewer gases escaping into occupied spaces or create a blockage in the vent. It is part of maintaining a safe and effective plumbing system according to plumbing codes, which are designed to promote public health and safety. Therefore, adhering to this 6-inch clearance is essential for the proper operation and safety of plumbing systems.