Go ahead with the roof covering (4)
I believe the answer is:
lead
'go' is the definition.
(synonyms)
'ahead with the roof covering' is the wordplay.
'ahead' becomes 'led' (to lead is to go ahead).
'with' is an insertion indicator.
'the roof covering' becomes 'a' (I can't explain this - if you can you should give a lot more credence to this answer).
'led' placed around 'a' is 'LEAD'.
Can you help me to learn more?
(Other definitions for lead that I've seen before include "Be ahead of - guide" , "most important story" , "Precede into dale" , "Toxic, malleable, metallic element" , "Guide; precede" .)