Question: I am planning new construction via a subdivision production builder who puts in pre-fabbed fireplaces with 6-inch triple-wall flues. Do I need to specify 8-inch flues to accommodate Vermont Castings stoves? Thanks. Answer: The Vermont Castings Intrepid and Acclaim take 6 inch. Also the Dutchwest small and large take 6" flues. The Defiant Encore and large Dutch take 8".<p> Other newer Vermont Castings take 6"...<p> In short, decide on your stove first and then have the correct size prefab chimney installed.