It's employed for skirting wagon tax (8)
I believe the answer is:
wainscot
'it's employed for skirting' is the definition.
I can't judge whether this definition defines the answer.
'wagon tax' is the wordplay.
'wagon' becomes 'wain' (wain is a kind of wagon).
'tax' becomes 'scot' (I've seen this before).
'wain'+'scot'='WAINSCOT'
Can you help me to learn more?
(Other definitions for wainscot that I've seen before include "Lower part of interior wall" , "Wood panelling on lower walls of room" , "Panelling on lower part of interior walls" , "Wooden board at the bottom of a wall" , "Wooden panelling on lower wall of a room" .)