Building material church folk accept finally (6)
I believe the answer is:
cement
'building material' is the definition.
(I know that cement is a type of building material)
'church folk accept finally' is the wordplay.
'church' becomes 'CE' (abbreviation for Church of England).
'folk' becomes 'men' (I've seen this in other clues).
'finally' suggests the final letters.
The last letter of 'accept' is 't'.
'ce'+'men'+'t'='CEMENT'
(Other definitions for cement that I've seen before include "Firmly fix" , "Seal; bonding agent" , "material for bonding" , "It hardens when wetted" , "Ingredient in mortar" .)