I have been doing a lot of research on this but have been getting different information. We are going to be installing a wood burning stove in our house very soon. We have already checked with the insurance company and have the green light from them. I'm very handy and have been doing construction work for years and have remodeled several houses over the years but this will be the first wood stove install. We are going straight out the top of the wood stove, thru the ceiling and right thru the roof. I was just reading on the hearth site that the black stove pipe must keep clear of any combustible walls or ceiling by 18". What do I need to go from my stove pipe to the triple wall chimney and what do I need to pass thru the ceiling? Does the chimney have to stick down 18" into the room or am I missing something here.