Newbie here with a question on concentric chimney flues. I finished my upstairs that was originally framed up but never sheetrocked. The chimney flue from a downstairs fireplace ran through an upstairs wall at an angle, but that wall wasn't framed all the way. When I sheetrocked, insulated, and ran electrical in the walls upstairs, I had to complete the framing of this wall so I removed the chimney flue. It was spring in south Louisiana so I just figured I'd put it back later. It's later now, and my wife wants me to put the flue back. problem is that I now have walls in the way where the flue used to go up to the chimney cap. I have tried to re-route the flue to no avail. I have called a fireplace installer and he said no straight run flues will work but doesn't deal with flexible flues. I have looked up flexible flues and found "liners" but not flues, and then again, I have no clue if I can use them. So, here is the question, are concentric flexible flues available, and are they safe?