My house has a woodstove on the top floor, with the chimney running
pretty much straight up through the roof. It was there when I bought
it; the house has a peaked roof built ON TOP OF (!!) a flat roof, full
of "pellet" insulation.
I just changed insurance companies, so they sent somebody around to
inspect the woodstove. No problems, except that I need to have a
chimney that extends 2' above the highest point within 10' of the
chimney. I haven't gone up there to measure myself (March + Quebec icy roof, sudden death), and I'm not sure how they figured that out,
but I might be a bit short.
I don't want to reinstall the chimney, though... but everything looks
like it's kind of set as is. I clean the chimney myself, so I've seen
it up close several times (and I have no idea how he knew it was short,
you have to stand at the side of the house Is there any way of just
extending the top of the chimney? I figure I must be close to 2', if
not actually there... I just need another 6" or so.
It's a steel prefab chimney. I'm not sure if it's insulated or
triple-walled, but it's basically a thick exterior (about 12") with a
5" hole, IIRC, inside it.