Step 5 · Rough-in Inspection

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

Before you can cover any of your work, it must be inspected by your local building official. Schedule your rough-in inspection. To prepare, you must conduct a pressure test. For the DWV system, use inflatable or mechanical test plugs to seal all the openings, including the lowest point connecting to the main sewer line. Leave the highest vent stack opening accessible. Fill the entire DWV system with water up to the point of overflowing the highest vent on the roof or up to a 10-foot head of pressure (a 10-foot vertical pipe attached to the system). The system must hold this water without any drop in level for a specified time (usually 15-30 minutes) to prove it is leak-free. The inspector will verify this test, along with checking all pipe sizes, slopes, materials, connections, and support. They will also inspect the water supply lines for proper installation and support.