In any case, I tried consulting with Thunder Bay Fireplaces again about the situation, and together we fleshed out the notion that the cabin is perhaps still SO draughty that it is sucking smoke out of the stove before it has a chance to go up the chimney, at least when the stove is fairly closed up and not producing huge draught of its own.
I happened to describe one spot in the cabin I already knew to be subject to air leakage issues - that leaky chimney boot. That's when together we brainstormed up the notion of enclosing the insulated chimney pipe up in the attic. I had stuffed some Roxul into the chimney boot, but this is a theoretical no-no. So to maintain proper installation, the next best thing will be to put the chimney in that area into its own air-tight room.
I've been sick for the past five weeks or so - I caught a terrible cold and/or sinus infection that made me fear for my ability to take on even the simplest of tasks - I was wheezing and coughing and it was all I could do to catch my breath at times. So this process is only about half finished so far, but I wanted to get an update onto the blog.
As of this writing, I have managed to put up the two walls perpendicular to the existing outside wall. The final wall will be a bit more of a challenge - it isn't any sort of regular shape really - it will have to match the contour of the roof.
Once the walls are finished, I will line them with closed cell foam, and then spray foam around the edges of that to seal it up air tight. I'll also spray foam around the edges of the walls themselves as they will butt up against the existing spray foam, which isn't a flat surface either.
|You can barely make out the tall wall to the left of the stove pipe.|
|You can see the studs of the tall wall, and a view of the short wall from here.|
|I've learned to always try to wear lung protection nowadays.|
|A better view of the short wall?|
|This is my non-kosher seal to try to slow down heat loss. Not so effective. I'll remove all this once I box in the pipe.|
|I'll lay pieces of closed cell foam here and seal it with spray foam. Then I think I may actually lay more Roxul on top of the closed cell foam for even better insulation from below. I can put a number of inches of insulation up that boot.|
|Good view of the short wall. You can see I'm just using 2x3 studs.|
|And you can see the rough connection at the top of the large wall, I'll just seal that with spray foam.|