A shower leak starts from 1 of 5 sources.
- Failed waterproofing (also called the tray or membrane)
- Water leaking through holes in the wall around the pipes (tap spindles and rose)
- Leaking pipes or tap washers inside the wall cavity
- Leaking waste pipe (drainpipe) which can be the pipe or the waterproofing around the pipe
- Leaking shower screen (if leak gets outside the bathroom then the waterproofing has also failed)