General Regulations, Permits, and Inspections
Permits
A plumbing permit is required before new installation, alteration, or replacement of piping and fixtures, and before most water heater change-outs. Applications state the scope, fixture count, and valuation; plans are required for commercial work and for systems beyond prescriptive limits. The permit is issued to a licensed contractor, or to an owner-occupant where the jurisdiction allows it, and the permit holder requests inspections.
Inspection points
- Underground and slab piping before backfill.
- Rough-in of drainage, waste, vent, and water piping before walls, floors, or ceilings are covered.
- Gas piping pressure test before the system is energized.
- Water piping test at 100 psi, or working pressure if higher, held for the code-specified period.
- Drainage test with a 10-foot head of water or an approved air test.
- Final inspection after fixtures are set and tested.
Worked example
A bathroom remodel: pull the permit, demolish, rough in the drainage and water lines, request rough-in inspection, and only after approval close the walls. If the installer hangs drywall the day before inspection, the inspector can require the wall be reopened. Concealed work cannot be verified, and the code places the cost of exposure on the permit holder.
Traps that cost marks
Skipping a permit because the job looks small; treating a passed rough-in as a final; failing to have gauges and test water in place at inspection time; and forgetting that blocked access can trigger a re-inspection fee or an order to uncover work.