Easy now. No need to be Self-righteous, posing or any other self-ism that leads you to bouts of anger over anothers thoughts. I have read this post For quite some time, never posted because I dont have anything to say. Not my house, not my fire.
First, set all your R-values aside, I have the cough lovely opportunity cough to work with engineers all day long. dealing with more issues then heat and a metal box to make a fire. No offense, as I wanted to be one, maybe still do, you all suck. Read a book get a pencil and a calculator and provided you paid attention in school you to can do the same math. (ask them to do finance math, like watch monkeys drive) Now dont assume im beating on those who are, you make the world..move. But if you get focused on how to add up some arbitrary numbers to get some 'magical' one, you are preforming a simple human trick. Every item you add up has been doctored to some 'safety factor'. every manufacturer, dealer, joe home-blower adds his own to call it GOOD. so your adding on someones inflated guess. Thats like trying split wood without anyone telling you how to cut it down, buck it up, and thusly split it. People for ohhhhh I dont know, since the beginning of time, where building fires. cave men, Neanderthal, all sorts of indigenous peoples 'discovered' and utilized it all their own. And I will venture a guess that a whole mess load of humans died in the long arduous process of taming one of the four elements. but along the way lots of them figured it out. This runs along the lines of worrying intently on "draft settings" "re-load times" " what temp do you____" when we forget that its fire.
With that, rant, my point. I agree with whom ever said, your building afire in your house. you said it in as many words as I did in the above.
Dont knock the guy for trying something out of the box thats how people came up with EPA stoves with burn tubes cats and little eleves that blow on the fire to keep flames. If it works for you then damn, you just completed something many only grasp at, Maslow highest, Self-actualization (not one of the Self-ism mentioned above) and good for you, its that same felling some of you and I get when we fell a tree, buck, split, stack, stare, carry, stoke, and warm our Souls knowing 'WE' did it ourselves.
To End, dude dont burn you mother f'in house down. if you give it a good look and in the back of your mind you second guess if its right, tear it out. Whats fours days of work worth? What do you make an hour? What would Carls Chimney or Harrys Home improvment cost and hour? Just venture a guess (I dont know you maybe your bill gates rich) but even still I bet its not worth more then your home, family, dog, cat, goldfish, or even the peace of mind that a nice warm sleep with a clear conscience.
Do it the right way, over do it if ever unsure, K-I-S. Whatever gets you to the point, that you stand back, look at at your work and truely feel good, not asking a bunch of weirdos (sorry guys and gals here) on the Internet so that when you look at your work and second guess it you have "well that forum site said..." in the back of your head. Good Luck.
Crap rambled so much I need to put another log in