A clue in the timing
The kitchen ceiling dripped when the upstairs showers were used and stopped when they were not. There was no visible leak in the bathroom.
Following the waste water
ADI used thermal imaging and moisture checks, then introduced dye into the shower waste. Green dye appeared through the ceiling, confirming the route.
A small ceiling opening, made with permission, allowed an endoscope inspection. The engineer identified a leaking waste fitting and a partial blockage at the shower trap.
What was repaired
The faulty section was replaced with new pipe and fittings. Retesting showed the system functioning at the visit.
Professional clearing of the waste system was still recommended. The recorded blockage was a separate follow-up issue, not work reported as completed.