The vendor of this property had recently paid a contractor to clear her gutters and gulleys. They seem to have overlooked this one!
Rainwater from the rear roof slope of the main building discharges into this box gutter via the downpipe at the top of the photo. Not only had this box gutter been poorly constructed with no incline towards the scupper, but the lead flashings hadn’t been adequately chased into the brickwork.
Our recommendation? Rip it all out and start again.