Question: Hi. I have a question. We have a vermont castings resolute that will fit comfortably in our existing fireplace (we need to remove the stove from the room where it now stands). I will be able to run a flexible pipe from the exhaust opening at the top of the stove up into the chimney with no problem. The question is this: There will be a lot of space on each side of the flexible tube and I assume that cold air will be able to come down through the chimney and into the house. How can I close off that opening surrounding the flexible tubing? Stuff it with insulation? Any thoughts would be greatly appreciated. Answer: Make a template out of cardboard- and make the final piece out of sheet metal - thin- 24 gauge or so will do. Cut a hole for the pipe. Seal around the pipe with furnace cement and around the plate with silicone. Another option is to line the entire flue with stainless steel pipe and seal it off at the top. Even in this case, the plate at the bottom makes sense as it keeps the chimney insides separated from the home.