Scaffolder's prompt -- taking roof off (6)
I believe the answer is:
rigger
'scaffolder's' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for rigger that I've seen before include "Sailing ship; fraud" , "Scaffolding worker" , "'Long, pointed brush used by artists (6)'" , "Scaffolding erector" , "oilman" .)