Damage makes building material fade badly on top (10)
I believe the answer is:
defacement
'damage' is the definition.
(defacement is a kind of damage)
'building material fade badly on top' is the wordplay.
'building material' becomes 'cement' (cement is a kind of building material).
'badly' is an anagram indicator.
'on top' means one lot of letters go next to another (down clues only).
'fade' is an anagram of 'defa'.
'cement' put after 'defa' is 'DEFACEMENT'.
'makes' acts as a link.
(Other definitions for defacement that I've seen before include "act of vandalism" , "Distortion" .)