Kitchen Plumbing Rough-In Inspection

Per UPC/IPC, kitchen supply lines require 1/2" minimum hot and cold lines with shutoff valves. Supply stubs for kitchen sink should be 18–20" above floor, centered on sink location. Dishwasher supply requires hot water line with dedicated shutoff. Refrigerator ice maker requires 1/4" supply with saddle valve or dedicated stop. Hot on left, cold on right.

1. Verify hot and cold supply stubs at correct height (18–20" AFF for under-sink access)

2. Confirm shutoff valves installed for sink hot, sink cold, dishwasher hot

3. Check ice maker supply line location behind refrigerator (1/4" with shutoff)

4. Verify pipe sizing: 1/2" minimum for sink and dishwasher

5. Confirm hot is on left, cold on right at sink location

6. Check all valves are accessible after cabinet installation

- Supply stubs too high or low for cabinet configuration

- No dedicated dishwasher shutoff — must turn off sink hot to service dishwasher

- Saddle valve for ice maker (prone to clogging) — dedicated stop valve preferred

Per UPC/IPC, kitchen sink drain requires 1.5" minimum (2" recommended). Drain stub-out should be 16–18" above floor. Garbage disposal requires same drain size. Dishwasher drain connects via air gap or high loop to disposal or sink tailpiece. Drain slope minimum 1/4" per foot. Grease waste may require grease interceptor in some jurisdictions.

1. Verify drain stub-out is 1.5–2" diameter at correct height (16–18" AFF)

2. Check drain slope: minimum 1/4" per foot to main drain

3. Verify dishwasher drain connection point is accessible (high loop or air gap)

4. Confirm P-trap can be installed with proper clearance in cabinet

5. Check if garbage disposal drain is properly sized for the disposal unit

6. Verify vent connection within code distance of trap

- Drain stub-out at wrong height — P-trap doesn't fit in cabinet

- No air gap or high loop for dishwasher — backflow contamination risk

- Drain slope insufficient — kitchen sink drains slowly, food particles accumulate

Per NFPA 54 (IFGC), gas line for kitchen range requires 1/2" or 3/4" black iron or CSST (corrugated stainless steel tubing) with proper BTU capacity. Gas shutoff valve must be within 6 feet of the appliance, accessible without moving the appliance. CSST must be bonded per manufacturer requirements. All gas joints must be tested for leaks.

1. Verify gas line size provides adequate BTU capacity for planned range/cooktop

2. Check shutoff valve location: within 6' of appliance, accessible in emergency

3. Confirm gas line material is code-approved (black iron, CSST, or copper where permitted)

4. Verify CSST bonding to grounding electrode system per manufacturer specs

5. Test all joints with gas leak detector or soap solution — zero bubbles acceptable

6. Check gas line is properly supported and protected from physical damage

7. Verify drip leg (sediment trap) installed before appliance connection

- Gas line undersized — range burners produce weak flames, oven slow to heat

- Shutoff valve behind range (inaccessible) — code violation, safety hazard

- CSST not properly bonded — lightning strike can arc through tubing

- Missing drip leg — debris damages gas valve

Per IRC M1503 and IMC, kitchen range hoods should vent to the exterior through approved duct (smooth-wall metal). Minimum duct size per manufacturer specifications (typically 6" or 7" round). Maximum equivalent duct length per CFM rating. Duct must have backdraft damper. Recirculating hoods do not require ductwork but are less effective.

1. Verify duct routing from hood location to exterior wall or roof

2. Check duct size matches hood CFM rating (6" for ≤400 CFM, 8" for 600+ CFM)

3. Confirm duct material: smooth-wall galvanized steel or aluminum (not flexible vinyl)

4. Count elbows and calculate equivalent duct length — verify within hood's rated maximum

5. Check wall or roof cap location and verify exterior termination is feasible

6. Verify makeup air provisions for hoods >400 CFM (per IRC M1503.6)

7. Confirm backdraft damper at exterior termination

- Flexible duct used (high friction, accumulates grease) — must use smooth rigid duct

- Duct vented into attic instead of exterior — moisture and grease buildup, fire hazard

- No makeup air for high-CFM hood — negative pressure pulls CO from furnace/water heater

Per UPC/IPC, all new plumbing must pass pressure testing before walls are closed. Supply lines: 50 PSI above working pressure for 15 minutes minimum. Gas lines: per NFPA 54, test at 3 PSI for 10 minutes (or per local code). DWV: air test at 5 PSI for 15 minutes. All tests must be documented and witnessed by plumbing inspector.

1. Supply lines: pressurize and hold for 15 minutes — no pressure drop allowed

2. Gas line: pressurize to 3 PSI, hold 10 minutes — gauge must not move

3. DWV: air test at 5 PSI for 15 minutes

4. Check each connection while under pressure — visual inspection for leaks

5. Document test results with photos of gauge readings

6. Confirm inspector witnessed and signed off on all tests

7. Repair any failures, then retest from beginning

- Slow gas leak — barely perceptible gauge drop, use soap test on every joint

- Threaded connections not sealed properly (use yellow Teflon tape for gas, not white)

- Push-fit water connections not fully seated — leak under test pressure