Question: I am looking to install a fireplace insert in my open brick fireplace. I am going to line the chimney with 6" pipe myself. Do I have to tear the complete damper out or can I cut brick out and work around damper? Do they make a flexible pipe, if so is this recommended? This project seems to be simple enough for a prominent diy. Answer: Most jobs I've seen use flexibly for the first 5-10 feet so as to get thru the damper (it can be slightly ovalived), and up into the smoke chamber. After that point straight can be attached. The pipe must be dropped down from the top, because it is difficult to make connections when working from the bottom. 11/2007 It has become fairly common practice to fully line chimneys with flex liner. It reduces the number of joints/possible points of failure that are inside of your chimney and is easier/less time consuming to install.