I own a property that has a brick chimney that extends maybe 10 feet or so
above where it comes through the roof at the back of the house. The
property that I own is a "twin" home -- meaning two single family homes that
are attached with a common wall in between -- I own the home on one side and
my neighbor owns the home on the other side. My side is a rental property
that I have rented out to a family, and my neighbor on the other side owns
his half and lives there.
The chimney is actually two chimneys in one. It goes up along the inside of
the back wall along the party wall line, and my half of the chimney is for
my home and the other half is for the neighbor's home. The combined chimney
was originally brick and it now has stucco over the brick on all four sides.
The stucco is starting to deteriorate in a few places and the chimney looks
like it may be leaning a little. So, I am going to have a chimney person
look at it and tell me what he thinks it needs etc. It may just need to
have the stucco repaired or redone or it may need a lot more than that.
What I am wondering is, if it turns out that the best thing to do is to take
down the existing chimney and replace it, are there other types of chimney
construction that could be used for the replacement other than brick or
block? Both houses have aluminum siding and no brick, and the chimneys in
the back, so there is no need for a new chimney to be made of brick or
anything fancy. Even metal chimneys would be fine with me (and probably my
neighbor) if there is such a thing for this type of application.
The heaters for both houses are gas-fired steam radiator heat and the hot
water heaters are gas hot water.
I found the following link that gives some guidelines for how high the
chimney is typically supposed to be in relation to the roof:
http://www.solidflue.com/concerns.htm#Common . I didn't do any measuring,
but if it needs a new chimney and it is legal and safe to have the new
chimney be less high than the existing one, I would go with that.
I'll be asking the chimney person these same questions, but I thought I'd
also post the questions here beforehand to get any ideas or suggestions
anyone may have.
I'd go with brick or stone myself, but there may be other factors I don't
see from here. In my area, there are a lot of houses build in the mid
1700's and up. The original chimneys are, for the most part, still intact
and working proving the durability of masonry. Some have been relined. A
good chimney guy is the best to see and assess the situation though. Metal
may be a less costly alternative if it has to come down.
There may be a reason for the height also. Prevailing winds or other
topography may affect the draft. so check things before you arbitrarily
Ya know, a lot has happened in the last few years. Major thing
is that houses have gotten tighter, so there is not as much air
coming around doors and windows to supply the air that would
go up the chimney.
So if you don't already have it, I suggest pipes to supply adequate
combustion air into the firebox. Consider whether the inner size
of the chimney portions is really needed. Masonry holds up, it's up
to you to decide what, if anything, is needed to be done differently.
Remember that the standard fireplace is seen by utility companies
as a negative heat source.
In the process, I'd consider the age and efficiency of the existing
and the water heaters. At some point, if you were to go with new
that are direct vent, you'd no longer need the chimney to be
though you'd probably still have it for aesthetics.
Along the lines of Michael's sizing issues, if you replace the boiler
with a direct vent, the chimney will be too
large for just the water heaters and will need to have a chimney liner
installed. Just some factors to keep in mind as you go through the
There is no such thing as a condensing Steam Boiler that release low
temp exhaust in his size. The best you get is 83% in the homeowner
range. Commercial even at 1,000,000 btu are best 83%. Industustrial,
im sure they have them. Convert to HW? then you can get leaks as steam
is 2-4lb and water is 15-35lb.
Hey, with no fireplaces along the way, I'd make
the chimney go away. Even if it had to be replaced
by a couple of vent pipes, that may barely have to
go a foot beyond the roof penetration..
Got a roof replacement coming up anytime soon?
I agree with your observation. When I suggested considering
a high efficiency direct vent, I was thinking hot water, not
steam. You're right, in the home class units, looks like there
is no such steam animal. Which I guess makes sense
because to extract all the heat out, it has to go to someplace
colder. With the higher the temp of the fluid, eg hot air, water,
steam, the harder it gets to do that.
Same here. Although I know a guy in South Dakota that has
some secondary heat exchanger setups to get some of the
waste heat before it is lost in the stack, on a unit that is easily
well over 60 years old. He swears by the name of Dan Holohan.
Thanks for all of the replies. I guess I'll need to wait and see what the
chimney person tells me as to what my chimney may need, what the options are
if it needs to be taken down and rebuilt, etc. I haven't found anything
much on the Internet regarding non-masonry (a.k.a. factory built)
Maybe all I'll need is to have the stucco around the chimney repaired.
Since the chimney extends fairly high above the roof line, I have a hunch
that this may end up costing more than I had hoped, but I'll have to wait
I won't be replacing the heating system or converting it from steam to hot
water (it's a one-pipe steam system now).
I assume you have no working fireplaces?
If so it might be cheaper to upgrade furnace and hot water tanks in
both units and just remove the top of the chimney completely.
thats pretty popular around here, far cheaper than rebuilding and
relining, no flashing or chimney to maintain, lower utility bills,
with condensing furnace.
the roofer just drops he debris and bricks down the now no longer used
chimneys, plywood over the hoe once the chimney is below roof level.
many do this all the way to the ground, to get more interior space....
of course you have the other owner to deal with. but you should at
leastprice all the alternatives
There is no condensing steam unit that I know of for a homeowner, he
needs a chimney. There are condensing boilers , but at 140 is peak
efficiency, at 180f you save only maybe 5% at steam or over 212 you
Thanks for the ideas. I'm sure I won't be doing the option of eliminating
the chimney completely. Even if there is such a thing as a high efficiency
direct vent steam heat boiler (I don't know if there is), it would mean both
me and my neighbor getting new heaters and I know my neighbor will never do
that. In fact, most likely, whatever I have done with the chimney(s), I
will rpobably pay for the whole cost myself.
I know what you mean about the chimney removal process. I removed and old
no-longer-in-use chimney that way in another property. In that case, as I
worked from the top down I dropped everything down the chimney into a
walk-out basement. Then I had someone wheelbarrel it all out onto a trailer
and haul it away.
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