I suggested that she could scrape off the bits and pieces of double-sided tape still adhering to the concrete in various locations, using the old filling knife I keep for just that sort of task.
I got home from work to find all the remnants removed - bonus
When I asked how she had been able to do such a great job she told me it was easy using "that metal thing with the handle".
"That metal thing with the handle" just happens to be the brand spanking new professional plasterer's finishing trowel that I'd treated myself to at the weekend, at a cost of nearly Â£50.
The once perfect edges of that trowel now look like rip-saw blades