Shared supply under the passage between two terraces
The property
Two Victorian terraced houses in the inner town, both lived in by their owners, fed by one old pipe from a single pavement meter that splits under the passage between them.
The problem
Both households had letters about water passing all the time. Neither could find anything wet, indoors or out, and both had checked every tap and cistern.
How we found it
Both stop taps were closed and the pavement meter kept moving, which put the loss on the shared length. The ground microphone peaked under the passage, and tracer gas rose through its paving at the same point.
The outcome
One report went to both households, with the spot in the passage marked and photographed. We quoted the repair separately; how to share it was for the neighbours to agree.