If you ever remove the entire chimney inside your home you can gain
more usable space too

Need someone to deliver some 'outside of the flue' thinking.

We're installing a new direct vent water-heater/air coil system,
motivated in part by the gain of a very strategic 25 sq. feet in our
kitchen. We're gutting and re-framing the basement at the same time we
re-duct the place as a part of the HVAC upgrade.

Here's the rub: having the chimney out of the way is crucial for duct
runs, etc. of the new basement floorplan, BUT we aren't likely to be
tearing into the kitchen reno for perhaps a year. (Anyone who has
played Jenga might be catching on already...)

I can take the chimney down to the top of the kitchen ceiling from the
roof and attic. That leaves me with a 16' column of chimney blocks (not
bricks, but prefabbed cinder-blocks that are 16"x16"x6" and create an
integral flue when stacked up) standing in the middle of our house.

Calculating the volume of concrete in each one puts it at ~100lbs., so
the inaccessible 8' segment in the kitchen will weigh something like
1500lbs.

(My HVAC contractor told me a horror story of a DIY'er in a similar
situation who began demolishing the stack _from the bottom_. Contractor
arrived one day to find this guy happily working away under the
remaining ton or so of stack, which was being held up only by
fireblocking and roof flashing/jack! Yikes.)

So, how can I lower this part of the column out of its 4x4 chase and
onto the basement slab? (Or,in theory, it could be lifted out?) Hey, I
just realized that I've been assuming that I need get it out right
away--maybe I can support it in place in a way that won't interfere
with basement work and deal with it when we gut the kitchen.

Anyway, that wouldn't be as sexy/elegant/convenient/interesting as
using a winch/car jack/hot air balloon to do it now. The possibilities
seem to break down into:

1. a winch with some sort of roof-top derrick assembly that will safely
spread the weight over enough area

2. a method to effect an 8' lower (i.e. tie into the upper-most
basement block and lower the remainder en masse)

3. a method to effect a series of 6" lowers (i.e., ratchet it down,
removing one block at a time)

The problem with 1. is the engineering. The chimney penetrates two
overlapping roofs (split level house), so it is through the overhang of
the upper and right up against the wall on the lower, which are
separated only by 3'. Too close to the edge to errect a structure on
top and not enough height to do one on the bottom.

There are problems with 3., too: it requires either that the
ratcheting be done at ceiling level (supported 8' off the slab) or, if
it operates at at slab-level that it must be capable of carrying both
floors, to begin with. Either way, the means of attaching to the stack
(probably penetrate through it with some kind of bar) will have to be
done as many times as required by the height of each lower.

No. 2 is my preference, but what kind of apparatus can do an 8' reverse
lift of 1000 lbs.? Oh, and I have free access to only three faces in
the basement, and that only for the first 3'; the next split-level
starts above that with only a 4" fire clearance.

I'll come up with some kind of reward for anyone who clinches this one,
honest.