Massachusetts Plumbers Journeyman Practice Exam

What is the minimum diameter required for a vent extension through a roof according to regulations?

1. 1"

2. 1.5"

3. 2"

4. 2.5"

The correct answer is: 2"

The minimum diameter required for a vent extension through a roof according to regulations is 2 inches. This specification is crucial for ensuring that the vent line effectively allows for the proper escape of gases from the plumbing system, which helps to maintain the efficiency and safety of the drainage system. A vent that is too small may not provide adequate airflow to prevent pressure build-ups, leading to potential drainage issues or even dangerous situations with sewer gases. In plumbing code, the standards for vent sizes are set to ensure that they can effectively handle the necessary outflow and provide the required ventilation for sewage systems. Choosing the correct diameter ensures compliance with safety regulations and promotes the proper functioning of the plumbing system.