Where roofers work for free (2,3,5)
I believe the answer is:
on the house
'free' is the definition.
(something on the house is given free of charge)
'where roofers work' is the wordplay.
I cannot quite see how this works, but
'work' could be 'use' (work can mean to use or operate) and 'use' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
Can you help me to learn more?
(Other definitions for on the house that I've seen before include "Roof tiles so" , "Where roof slates should be going" , "With the management's compliments" , "for no money" , "Free" .)