What is the minimum height above the roof that a vent pipe must extend?

• A. 12 inches
• B. 24 inches
• C. 6 inches
• D. 18 inches

Answer: (A)

Vent terminals must rise above the roof surface enough to stay clear of weather, snow, and debris so sewer gases can vent freely. The minimum height specified is 12 inches. This ensures the vent remains exposed above potential snow cover and rain runoff, reducing the chance of blockage or water intrusion into the vent opening. Heights like 6 inches can be overwhelmed by snow or wind-driven rain in many climates, while 18 or 24 inches go beyond the minimum without providing additional practical benefit for typical residential installations.