One supply pipe feeding two terraced houses
The property
An Edwardian terrace where one old metal pipe, metered at the pavement, runs under two front paths before splitting to each house.
The problem
The water company wrote about continuous flow. Neither household could find a drip indoors, and each suspected the pipe under the other's path.
How we found it
With both stop taps shut the dial still turned, so the leak was outdoors. The ground microphone was loudest just past the split, on one house's branch; tracer gas between the slabs agreed.
The outcome
We marked and photographed the spot, giving both households the same evidence of which branch leaked. That owner then had the repair quoted separately.