Camera vs Locate vs Dye First on a Suspected Leak Sequencing Decision Tree

Why this matters

A suspected leak can be a pressurized supply line, a drain/waste line, or surface water with no piping involved at all. Running the wrong tool first burns the truck's time and can give a false negative that sends the customer to a restoration contractor for a problem you could have closed. A camera shows the inside of a drain but tells you nothing about a pinhole in a pressurized copper line. A dye test is decisive on a toilet flange or shower pan but useless on a slab supply leak. This tree sequences the three core leak tools so the first one you deploy is the one that can actually confirm or rule out the most likely source.

Symptom presentation

Sort the call by water behavior before choosing a tool:

• Wet only when water is used (any fixture): drain/waste/vent suspect, dye or camera path.
• Wet continuously, worsens with no usage overnight, pressure drops: pressurized supply suspect, locate/acoustic path.
• Wet at a slab edge or through a floor with a warm spot: hot-side slab supply leak, locate path.
• Wet at a ceiling below a bathroom only during/after a shower: shower pan or drain connection, dye path.
• Wet around a fixture base with no measurable meter movement: condensation or surface water, not a piping leak.

Quick checks

Establish a few facts before any specialized tool:

1. Meter test for supply leaks: shut every fixture, photograph the meter dial or leak indicator, wait 15 to 30 minutes with no draw. Any movement confirms a pressurized-side leak somewhere on the building side of the meter.
2. Static pressure and overnight pressure hold: install a gauge at a hose bibb, isolate the house, and watch for pressure decay. A line that will not hold static pressure with the main closed is leaking on the supply side.
3. Moisture mapping: a pin or capacitance moisture meter across the wet area finds the wettest point, which is usually nearest the source.
4. Usage correlation: ask the customer to reproduce the wetting by running specific fixtures while you watch.

Isolation tree

Branch A: meter moves with all fixtures off (pressurized supply leak). Tool order: locate/acoustic FIRST, not camera, not dye.

• Use acoustic listening on the slab or wall, correlating to the meter movement. Pressurize to amplify if needed.
• For slab hot-side leaks, an IR scan finds the warm path; pair with acoustic to pinpoint.
• A line tracer/locator maps the pipe route so you excavate or open drywall once.
• Camera and dye cannot find a pressurized leak; skip them on this branch.

Branch B: meter holds, wet only when a drain is used (DWV leak). Tool order: dye or smoke/water test FIRST, camera SECOND to characterize the defect.

• Isolation by fixture: run one fixture group at a time and watch the wet area.
• Camera the suspect line after isolation to see the crack, separated joint, or root intrusion, and to footage-mark it for the locator.
• A locator on the camera sonde then marks the exact dig point.

Branch C: wet near a toilet, shower, or tub with no meter movement (fixture-seal leak). Tool order: dye test FIRST.

• Toilet: dye in the tank finds a flapper-to-bowl leak; dye in the bowl with a wax-seal suspect finds a flange leak when you flush and inspect the ceiling below.
• Shower pan: plug the drain, fill the pan 1 inch, dye the standing water, hold 15 minutes, inspect below. A pan that drops level and shows dye below has failed.
• Tub waste/overflow: fill, dye, and run the overflow.

Branch D: no meter movement, no fixture correlation (surface or condensation).

• Confirm condensation on cold supply lines, tank sweating, or HVAC condensate before declaring a plumbing leak.
• Check exterior grading and window/wall intrusion.

Confirming diagnosis

Supply confirmation: a leak indicator that keeps spinning with the house isolated and the water heater inlet closed localizes hot vs cold (close the heater cold inlet; if movement stops, the leak is on the hot side downstream of the heater). Acoustic correlation plus IR pinpoints within a few inches before breaking concrete.

DWV confirmation: a static water test (cap the line, fill to the required head per code, hold) proves the line holds or leaks under a known column of water. Camera then shows the exact defect so the locate marks one dig.

Fixture-seal confirmation: dye appearing below within the hold window is conclusive; absence of dye after a proper-duration hold rules the seal out.

Remediation

• Pressurized supply leak: repair the located section (copper repair, PEX reroute, or fitting replacement). For slab leaks, present reroute vs spot-repair options based on access and pipe condition.
• DWV defect: repair or reline the cracked/separated section identified on camera at the located depth.
• Fixture seal: reset the toilet on a new wax or gasket and proper flange height, or rebuild the shower pan/waterproofing.
• Condensation/surface: insulate sweating lines, correct drainage; document that no piping leak exists.

References

• International Plumbing Code (IPC) 2021 Section 312 Tests and Inspections (water and DWV test heads)
• Uniform Plumbing Code (UPC) Section 712 Testing of DWV systems
• ASSE Series 1000 plumbing performance standards (fixture and trap behavior)
• AWWA M6 Water Meters Manual (meter leak-indicator interpretation)
• ASME A112.18.2 / CSA B125.2 Plumbing Waste Fittings