Jump over arched roof (5)
I believe the answer is:
vault
I believe this clue is a double definition.
'jump over' is the first definition.
(to vault is to jump over)
'arched roof' is the second definition.
(thesaurus)
(Other definitions for vault that I've seen before include "Where bodies may be kept" , "Secure room -- spring over" , "Bank's strongroom" , "Spring - clear - cellar" , "Leap - arched ceiling" .)