Master Plumber Practice Exam

The minimum height a plumbing vent should terminate in relation to an air intake is crucial to ensure that no harmful sewer gases are drawn into the ventilation system of buildings, which can pose health risks. According to plumbing codes, terminating the vent at least 10 feet away from an air intake helps to prevent the possibility of backdrafts or cross-contamination of air supplies.

This separation distance is particularly important because air intakes are designed to bring fresh air into a building, and plumbing vents emit gases that need to dissipate safely into the atmosphere. The 10-foot requirement creates a necessary buffer that significantly reduces the risk of vented gases re-entering the building through the air intake.

The other options present values that either do not comply with the health and safety regulations regarding air intakes or focus on different contexts that are unrelated to the direct impact of venting on air quality. For example, while the roof height and the distance from windows may be relevant in other situations, they do not address the specific interaction between plumbing vents and air intakes essential for maintaining indoor air quality and safety.