Damp high on a landing wall under the loft
The property
A Georgian brick townhouse with lime plaster. A cold water tank in the loft feeds the taps below through old pipes buried in the walls.
The problem
A damp patch high on the top floor landing kept spreading downwards. The gutters had been checked, yet the water meter never quite stopped.
How we found it
Moisture readings peaked near the ceiling, so the water came from above. Closing the valve under the loft tank stopped the meter; tracer gas in that pipe then came through the plaster.
The outcome
After marking and photographing the spot, we left the opening up to the owners' builder: a small section of lime plaster, with the rest of the old wall untouched.