Hi all, I've been meaning to ask about my chimney setup, so here goes. Last fall I removed the old 7" interior diameter insulated chimney. It was older and the walls were 1" thick, what is referred to as "Class A chimney" up here in Canada - a style that is no longer acceptable for wood burning applications. There were two 3' sections for a total of 6', with half in the (crawl in) attic and half outside the building envelope. The new chimney I've installed is modern Selkirk-Metalsbestos 6" ID (stove didn't require 7") and I replicated the old setup's two 3' sections for a total of 6' of chimney. However the new ceiling support protrudes further into the room than the old one did (check out my avatar to see what the old ceiling support looked like - that single wall was about 2" from the very combustible pine ceiling), so I suspect the chimney height vis-a-vis the roof peak is no longer adequate (if it ever was) and I plan on adding a 1' section. The stovepipe is about 5' and completely vertical. So my questions are: Will another 1' of chimney improve the draft much? Could the chimney be too cold? There's only about 6" of chimney in a heated part of the cabin. The attic may be sheltered compared to outside, but it's still freezing in the depths of winter. Do these manufactured chimneys fail often? I'm pretty confident of the installation, clearances, framing, etc, but I have to say that the way those sections are connected to each other and the ceiling support doesn't inspire a lot of confidence. Is it possible/advisable to build a sort of internal chase around the chimney in the unheated attic - let's say with Durock and other non-combustibles? Would there be any reason not to do this? I'm thinking even if it wasn't completely sealed it would keep the chimney warmer and perhaps offer a small measure of safety in the event of chimney failure. Also, it might stay warm enough to allow a smoke detector to be installed inside. As I understand it most/all smoke detectors need to be in an environment that is at least 40 degrees F or 4 celsius.