Schedule and Pass the Rough-In Inspection
The rough-in inspection is the gate between everything-still-fixable and everything-buried-behind-tile-and-drywall. Pass it cleanly and the rest of the project moves fast. Fail it and you're tearing things out a week later. Most failures are predictable, here's how to catch them before the inspector does.
Quick Summary
Inspection length
30–60 min
Schedule lead time
1–2 weeks
Typical re-inspection fee
$50–$150
Prerequisites, what must be done first
Don't schedule the inspection until every item below is complete. Inspectors will not pass partial work; they'll require you to call them back and pay another fee.
- Plumbing rough-in: all supply and drain lines installed, pressure-tested, fixture stub-outs at correct heights
- Electrical rough-in: all wiring run, boxes installed, GFCI/AFCI breakers identified, exhaust fan ducted to exterior
- Framing: any new walls built, blocking installed for fixtures and grab bars, headers sized correctly
- Backer board: cement board or Hardie board installed in wet areas, screws every 6–8 inches, seams ready for tape
Self-inspection checklist
Walk through this list with a tape measure and a critical eye before the official inspection. The same items the inspector will check, in the same categories.
Plumbing
- Drain slope is 1/4 inch per foot, no more, no less
- P-traps installed under every fixture (toilet, sink, shower)
- Vent stack tied in correctly, no flat horizontal runs over 6 feet
- Toilet flange flush with planned finished floor height (account for tile)
- Supply line pressure test holds for 15+ minutes
- No drain lines passing through floor joists in restricted zones
- Pipe support every 4 feet horizontal, every 10 feet vertical
- Sweat joints clean and fully soldered, PEX connections crimped per manufacturer
Electrical
- GFCI protection on all bathroom outlets
- Outlets at least 6 feet from any water source
- Dedicated 20-amp circuit for receptacles
- Switch boxes at code-required height (typically 48 inches)
- Light fixture boxes rated for the fixture weight
- Exhaust fan vented to exterior, not into the attic
- AFCI/GFCI breakers identified and installed (per current NEC)
- Wire nuts secure, no exposed copper
- Box fill calculations don't exceed code limits
Framing
- Blocking installed for shower fixtures, grab bars (even if not installing now), towel bars, and any wall-mounted vanity
- Stud spacing 16 inches on center for walls receiving tile backer board
- Headers sized correctly for any new openings
- Notches and bored holes within code limits (no more than 25% of stud width in load-bearing walls)
- Bottom plates pressure-treated where in contact with concrete
- All structural changes match stamped plans (or documented as approved deviations)
Backer board / waterproofing prep
- Cement board or Hardie board installed in all wet areas (no paper-faced drywall behind tile)
- Screws every 6–8 inches with corrosion-resistant fasteners
- 1/8 inch gap at all panel joints (will be taped with mesh and thinset)
- Tub or shower flange integrated correctly with backer board
- No gaps at corners, around fixtures, or at floor
Day-of-inspection checklist
- Permit card visible and unobstructed
- Stamped plans available for inspector reference
- Path to bathroom clear and well-lit
- Plumbing pressure test set up and ready to demonstrate
- Power available to test electrical (or scheduled to be on)
- Homeowner or contractor present and available
- Phone or camera ready to document any deficiencies
- Pets secured
Most common failure points
Drain slope wrong. 1/4 inch per foot is the only acceptable slope. Too flat won't drain; too steep causes the water to outrun the solids and clog. Verify with a level on every horizontal run.
Exhaust fan vented into attic. Bathroom fan must vent to the exterior, through the roof, gable, or soffit. Venting into the attic creates an enormous moisture problem and is an instant fail.
Missing blocking. Inspectors check for blocking even when you're not installing the fixture today. Adding blocking later means cutting drywall and tile. Block for grab bars (24 inches each side of toilet, around shower), shower fixtures, towel bars, and any wall-mounted vanity.
GFCI distance miscalculated. All bathroom receptacles must be GFCI-protected, and outlets within 6 feet of any water source need extra attention to splash-zone code. Measure from the source, not the receptacle face.
FAQ
When during the renovation does the rough-in inspection happen?
After all rough-in work is complete (plumbing, electrical, any framing changes, exhaust fan ducting, and backer board installation) but BEFORE waterproofing membrane, tile, or drywall closes the walls. Once an inspector signs off, you can proceed with waterproofing and tile. Schedule it the moment all four trades are done, every day you wait is a day workers can't move to the next phase.
What does the inspector actually check?
Bathroom rough-in inspections cover four categories. Plumbing: drain slope (1/4 inch per foot minimum), proper venting, pressure test on supply lines, drain pipe support, fixture rough-in heights to spec. Electrical: GFCI protection within 6 feet of any water source, proper box height for switches and outlets, dedicated 20-amp circuit for receptacles, AFCI/GFCI on bathroom circuits per current NEC, exhaust fan wired and switched. Framing: blocking for grab bars (even if you're not installing them now, easier to add now than retrofit), correct stud spacing, header sizing for any new openings. Waterproofing prep: backer board screws every 6–8 inches, no paper-faced drywall in wet areas, tub/shower flange properly integrated.
What are the most common failures?
(1) Drain slope wrong, slope must be 1/4 inch per foot, no more, no less. Too steep is also a fail. (2) Missing GFCI on bathroom outlets or improper distance from water sources. (3) Toilet flange not flush with finished floor height (account for tile thickness). (4) Plumbing not pressure-tested or pressure dropping during inspection. (5) Exhaust fan vented into the attic instead of to the exterior, duct must terminate outside. (6) Missing blocking for shower fixtures, grab bars, or cabinet anchoring. (7) Improper stud notching or boring (a 2x4 can't have more than 25% of width removed in load-bearing walls). (8) Waste line dry-fit with glue not yet applied, must be permanently joined.
How long does the inspection take?
30 to 60 minutes for a typical bathroom renovation. The inspector will walk through the entire work area, photograph anything notable, check measurements, and may ask for the pressure test to be demonstrated live. Larger remodels with combined permits (kitchen + bathroom + addition) can take 90 minutes. Don't schedule another contractor or appointment for the same day, sometimes the inspection runs long, especially if there are deficiencies the inspector wants to walk you through in detail.
What if the inspector fails some items?
First, don't argue with the inspector. They'll provide a written list of corrections needed. Read it carefully and ask clarifying questions about anything unclear, most inspectors are happy to explain because they want the next visit to pass. Schedule the corrections immediately and request a re-inspection within a week if possible. Some jurisdictions charge a re-inspection fee ($50–$150) for second visits; subsequent visits get more expensive. Plan as if you'll fail one item, most projects do, and budget time and money for one re-inspection.
Can I do the rough-in inspection if I'm DIY-ing the renovation?
Yes, homeowner-pulled permits work the same way as contractor permits for the inspection. The advantage is you control the timing and don't have to coordinate with a contractor's schedule. The disadvantage is that DIY work is sometimes scrutinized more carefully, especially on plumbing and electrical. A homeowner doing their own bathroom should self-inspect twice as carefully and consider hiring a licensed plumber and electrician just for the connections that require certified work, many jurisdictions require a licensed plumber for any work behind walls and a licensed electrician for any new circuits.