Paves the way to halt Spa's work (8)

'paves' is the definition.
(asphalting is a kind of paving)

'the way to halt spa's work' is the wordplay.
'the way' becomes 's' (Compass direction - South).
'to' says to put letters next to each other (I've seen this in other clues).
'work' is an anagram indicator.
'halt'+'spa'='haltspa'
'haltspa' with letters rearranged gives 'asphalt'.
's' put after 'asphalt' is 'ASPHALTS'.