What is a key characteristic of vapor vents regarding their outlet?

A key characteristic of vapor vents is that they must extend through the roof. This requirement is essential to ensure that any potentially harmful gases or vapors are safely and effectively dispersed into the atmosphere, rather than being released into enclosed spaces where they could pose health risks. Venting through the roof allows for adequate dispersion and helps maintain indoor air quality by preventing the accumulation of gases within the building.

This approach also addresses concerns about pressure and flow within the plumbing system, as proper venting helps to maintain the integrity of the drainage system by allowing air to enter and prevent vacuum formation. By discharging vapors away from the building, it minimizes the risk of exposure to occupants.

Other options do not align with standard plumbing practices; for instance, discharging directly into the sewer could result in backpressure or contamination, venting to basements poses safety risks by allowing toxic vapors to accumulate in living areas, and while traps prevent sewer gases from entering into the building, vapor vents do not require traps as they facilitate the escape of gases rather than containing liquid waste.