What is the minimum height an open vent pipe should extend above the roof?

An open vent pipe is crucial for the proper functioning of plumbing systems, as it allows sewer gases to escape and ensures that water can flow smoothly through pipes. The minimum height for vent pipes above the roof is established by building codes to prevent backdrafts and to minimize the risk of blockages caused by snow or ice.

Extending the vent pipe at least 6 inches above the roof provides a sufficient height to ensure that the gases can vent away from the building effectively, while also reducing the likelihood of the pipe being obstructed. This height helps maintain the necessary air pressure in the plumbing system and prevents the potential for harmful gases to enter living spaces.

Choosing a height that is lower than 6 inches may lead to issues such as inadequate venting or blockages, which can compromise the plumbing system and create health risks within a home. Therefore, 6 inches is the correct minimum height to ensure both safety and effective ventilation of the plumbing system.