good evening all. First post here but have been reading for the last 2 weeks researching how to install my 1960s Whopper Stove. A lot of useful information out there already so thank you. My question is on a 6/12 pitch how much insulated metalbestos pipe will I need above the roof line? I get the 10’ rule but get confused when I see the 3’ and 2’ part. Any help would be greatly appreciated before I cut a hole in my roof.