Bout halfway through the install and decided i really wasnt sure what was best idea to finish the job! haha Anyhow I have installed a wood stove into and existing fireplace opening. Stove itself will be sitting in opening of fireplace with front of it sticking out of wall. Now i have purchased a flue liner 6" and the opening of fireplace flue is around 12x12. To cover the excess opening around the flue without getting cold air back thru chimney, what would be ways you guys would go about this?? For sure my first time installing so would appreciate any input from others who have experience on this. Thanks