What should be done to a plumbing vent that is too short?

A plumbing vent serves a critical role in a drainage system by allowing air to enter the plumbing system, which helps maintain proper pressure and prevents unwanted siphoning of water from traps. If a plumbing vent is too short, it will not effectively perform this function, leading to potential issues like slow drainage, gurgling sounds in the fixtures, and the possibility of sewer gas entering the building.

Extending the vent to the required height above the roof or the highest point of the building is essential for compliance with plumbing codes and to ensure that the vent allows for proper airflow and pressure balance within the system. This height requirement is typically set to prevent wind from blowing in fumes or odors back into the building and to ensure that the vent can effectively release gases without obstruction.

While replacing the vent or installing a cap could be potential considerations in different contexts, those solutions do not address the fundamental need for the vent to be at the proper height for optimal function. Leaving the vent as it is would not remedy the issue and could lead to persistent problems in the plumbing system. Therefore, extending the vent to the appropriate height is the most effective and compliant solution.