My house is a 1950's brick walkup. There is a chimney that runs from
the basement and up through the kitchen and out the roof. There is no
fireplace or woodstove hooked up to this chimney; just the gas
furnace. The chimney is brick. It appears to have a liner of some kind
of clay or ceramic stuff. There is a metal roof over the top of the
Where the chimney passes through the kitchen, it juts out from the
wall and is plastered over. Just this winter, I have started noticing
water damage in the plaster. It appears moisture is destroying the
plaster from the inside, discoloring it brown and making it bubble up.
The damage does seem to be located more toward the top of the chimney,
near the ceiling of the kitchen.
I have only owned the house for two years, so I don't know for sure if
this is a recurrent problem. I'm guessing it is. It could have been
patched over before we bought the house, and only now starting to show
I went up on the roof to see where water might be getting in. The
concrete crown on top of the chimney looks to be in good shape. All
the brickwork and mortar looks sound up there. There are no obvious
problems with the flashing or the shingles around the base of the
chimney. The flashing material looks to be some kind of brown-painted
sheet metal. Someone has caulked around the edges of the sheet metal
with clear silicone caulk.
Since there are no obvious problems up above, I am wondering if there
may be moisture coming from inside the chimney somehow? It is
suspicous to me that we only started having this problem when the
weather got cold and we were running the furnace. Of course that could
be a coincidence, if the previous owner did a patch job that held for
2 years, and the underlying problem is only now starting to reveal
Does anyone have any suggestions to help me diagnose and repair this
To say for sure, you'd need a reputable chmney inspector. It may be from
condensation. One of the products of combustion of natural gas is water.
With the cold weather, it will condense in the chimney and drip back down.
There may be some blockage from an animal next in there too making it worse.
Liner may have cracked allowing it to seep through.
you 100% guaranteed fix! Replace furnace with direct vent, abandon and
remove chimney to at least below roof level, roof over offending area.
much lower fuel bills, new furnace increasing value of home, never a
chimney problem again EVER!
you can take chimney all the way out and gety more space in your
Yeah I know it costs but long term has many advantages
Well, if it's staining brown, then it is definitely moisture. Where
it's coming from is another thing. Since someone has siliconed the
roof, I'd say it's a re-occuring problem.
It may be coming from a roof opening around the chimney that is hard
to see, but I doubt it. You'll have to go into the attic and look to
see why moisture is pooling where it is, and where it's coming from.
It can be anything, even and improperly vented bathroom fan. You'll
just have to search and hunt for it.
If the plaster is sound ( you can't put your finger through it ) Just
repair it and touch it up. Don't make a months worth of work out of a
2 hour fix.
I agree with Don. No reputable roofer would use silicone on
flashing/roofing. There has been, and probably still is, a problem area.
Attempt to find a reputable roofer experienced with custom flashing. Make
sure anyone you talk with, has a brake to bend flashing in an acceptable
If it were a flashing problem, why is the problem appearing in the
middle of the kitchen wall where the chimney is? Flashing problems
typically result in a roof leak, with water appearing at the ceiling,
not in the middle of the wall.
I'm with Edwin on this one. I'd start with a chimney inspection. It
could be a deteriorated chimney combined with condensation.
Depending on the inspection, you can decide what to do. If it's
condensation related, a steel liner may be a solution. That not only
keeps the water from getting into the house, but also from condensing
to begin with. The liner is much smaller, so the gases have less time
to cool down.
Of course, since a liner is $1K+, if it comes to that, you should
consider Hallerb's idea of going with a new direct vent furnace too.
Of course, if you have a gas WH, then you're looking at having to vent
that anyway or replace it too.
Well, if you would read the post as written, and not put your on thoughts
into it, you probably would've read:
You would also know, no one puts silicone on flashing, unless there's a
problem. And, silicone is the wrong approach to solve any problem with the
You sure do have all kinds of expensive ways to spend this persons money.
Would you spend your own money like this, when the problem is quite
obvious? Of course there's no guaranty it's a flashing problem, but it's
pretty simple to check, if you're know what you're doing.
Yes, obviously I missed that he did say it was near the ceiling.
He has a house that is 50 years old and he's only owned it for 2 years
so he has no history. I don't think it's unreasonable to have that
chimney inspected. Nor is it expensive. That was where both I and
another poster recomended he start.
Yes, I would have my own 50 year old chimney inspected under these
conditions. I'd rather know what's going on inside, how
deteriorated it may be, than to wait till CO leaks into the house or
it falls down. Plus many chimney guys can also give an opinion as
to what's going on with the flashing.
The problem is, you want him to start with a more expensive diagnosis.
You are really going out there on a limb, you got the guy's chimney
emitting CO & falling down. He said it's leaking around the chimney, and
showing up near the ceiling. I didn't read any place where they said the CO
detector was going off, they do have these little meters with alarms which
will tell you this, believe it or not.
You also previously stated: " Depending on the inspection, you can decide
what to do. If it's
condensation related, a steel liner may be a solution. That not only keeps
the water from getting into the house, but also from condensing to begin
with. The liner is much smaller, so the gases have less time to cool
You don't put a liner in the chimney, just to run venting for HVAC. Talk
about a bunch of nonsense, and throwing away money!
You also got the guy buying a new furnace & possibly a water heater! "Of
course, since a liner is $1K+, if it comes to that, you should consider
Hallerb's idea of going with a new direct vent furnace too.Of course, if
you have a gas WH, then you're looking at having to vent that anyway or
replace it too."
Good grief man, give it a rest! You give out some really expensive
information, thank the good Lord, you don't do this for a living.
As far as a chimney guy "giving" an "opinion", I worked with custom
flashing for close to 30 years, and met a lot of trades persons, and worked
side by side with different trades. And, a sheet metal worker will do the
flashing, not a "chimney guy". I for one would not trust a "chimney guy" or
mason, over the work of a sheet metal worker, with an emphasis on roofing
I stand by my suggestion look into new direct vent furnace, OP said it
was the ONLY thing vented into the chimney.
New furnace can pay for itself and is a INVESTMENT in the home.Energy
prices just go up over time/
He also mentioned chimney intrudes in kitchen, no chimney equals more
I too believe a 50 year old chimney is due for a pro inspection!
Perhaps its the FACT we nealy died from carbon monoxide poisioning
from a bad chimney.
when you buy a home its a endless repair cycle.
I provided OPTIONS!
The cheapest patch isnt necessarily the best repair.
Lots of people never even think of removing chimneys, but doing so can
save LOTS of maintence and future expenses.
Around pittsburgh chimney removal has become a industry.
Plus you save the bricks, which often match the home!
Look, can't even reply to a NG correctly. You're messing around with the
This is all fine and dandy, but I'd hate to see what recommendations you
give if someone was asking about paint. You'd say something like buy new
You're information is not fitted for the problem at hand. I'm afraid this
thread is over your head.
You obviously don't believe in preventative maintenance. I do. He
has a 50 year old chimney that he doesn't even know the history of for
48 years. I would have that chimney inspected, whether it was
showing signs of problems or not. And maybe a couple hundred bucks is
a lot of money to you, but to me it's money well spent to know what I
have and any serious problems that may exist.
Obviously, you'd rather wait till you have a CO detector going off.
I'd just prefer to have a 50 year old chimney checked.
Now you show that you really don't know much about chimneys at all.
Steel liners are used all the time in chimneys that serve a HVAC
furnace. A friend of mine just had it done in his old house when his
25 year old oil burner was replaced. There are two very good
reasons. One is many old chimneys were sized for old heating systems,
using coal for example. The chimney is oversized for a modern
furnace and that leads to gases condensing inside the chimney and in
turn causing deterioration in the chimney. The other reason for
using a steel liner is if an inspection shows the interior of the
chimney is deteriorated and it's ability to contain gases is suspect.
((I know, you'd prefer to just ignore those possibilities on a 50 year
old chimney, cause it's still standing and the CO detector isn't going
off) Here's a nice tutorial for you:
Many homeowners never consider the fact that the central heating
system also vents into a chimney. When I point this out and start
talking about health and safety, the expression turns to one of
How heating changes affect chimneys
The original central heating system in most older homes was fueled by
coal or oil. Many homeowners replace these old furnaces with more
efficient, modern systems, or convert to cleaner burning gas heat.
Unfortunately, the chimney is often neglected in this switch, and this
can cause a two-step problem:
Large chimney flues required for coal and oil are often oversized for
modern, more efficient heating equipment. Much of the combustion heat
from older boilers and furnaces was lost up the chimney. This escaping
heat warmed the chimney and created an adequate updraft. As a result,
very little of the exhaust of the heater condensed before reaching the
atmosphere. Today's heating systems extract more of the heat for
distribution into the home. Flue gases now enter the chimney at a much
lower temperature, creating less draft and more condensation.
Condensation from gas fired equipment reacts with the deposits already
inside the chimney flue from the previous type of fuel. This
condensation water combines with fuel emissions to create sulfuric
acid, which can eat away at terra-cotta liners, exposed bricks or
Relining the chimney
Your chimney needs to be relined if:
The interior of the chimney, or the previous liner, has deteriorated
to the point that the emissions from the heating equipment could
escape into the home or cause further damage to the structure of the
The flue is oversized for your current heating system. The relining
will reduce the interior dimensions of the chimney. This creates a
higher temperature inside the chimney, increasing draft and reducing
the possibility of the gases condensing before reaching the top. Your
local building inspector or heating contractor may be able to
calculate the dimensions of the flue needed for your heating
There are three types of chimney liners:
Cast-in-place concrete lining systems. This is the most expensive
option, and the best option for a chimney that needs structural
reinforcement. You can often avoid rebuilding the entire chimney by
installing a cast lining system. These systems can be used for any
type of fuel, but if your chimney is structurally sound, you may be
able to use a less expensive metal liner.
Stainless steel. These lining sleeves are recommended for coal and oil
systems because they resist corrosive acid emissions these fuels
generate. They can be used in chimneys that are structurally sound.
Galvanized or aluminum sleeves. Similar in construction and function
to stainless, this least expensive option can only be used if both the
furnace and the water heater are natural gas. Never use galvanized or
aluminum with a coal or oil system, because the metal will rapidly
You left out the part about:
A: Only CONSIDERING a high eff furnace as an alternative if a chimney
inspection shows that the chimney has serious problems that need to be
addressed. If he needs to, the OP can do the math and cost benefit
analysis of going to a 90%+ furnace, the fuel cost savings (as Hallerb
pointed out) vs putting money into a chimney. Apparently, you think
he should just forget about inspections, safety, cost/benefit, not
make his own decision on all the facts, and only listen to you.
I suppose you think that most homeowners that get a new roof or
chimney have the flashing done my a seperate sheet metal contractor,
right? Only union too no doubt. Flashing is routinely done by
roofing, chimney contractors, etc. And like everything else, there
are good ones and bad ones. With your approach to inspection and
safety, I know which category you likely fall into.
<snipped like a thread should be, when only replying to one paragraph or
You miss the point. The thread/problem is way over your head. You don't
throw parts at a problem, and make recommendations that are completely
irrelevant to the problem at hand.
You gave out some really bad information to solve the problem. In all
honesty, you should refrain from replying to posts to which you have zero
knowledge about. For your sake, just save some face, so when you do reply,
people don't take you as a jerk.
Moe I shudder to think about the condition your home must be in.
If its not collapsing ignore it.
The trouble is LOTS of stuff can be fixed or maintained easily if
checked on a regular basis.
Sometimes its cheaper to replace a furnace than rebulid a chimney.
If say the home has the original 50 year old furnace you can save 1/2
the energy cost by going from the old fuel guzzler to a spify new 93+
furnce while by removing the top of the chimney elminarte forever
flashing etc. while cutting fuel bill by HALF forever:) That might
save 3,000 a year in fuel ANNUALLY!
Whoever buys your home next will have a ton of work.
Pointing out OPTIONS is always a good idea!!!
Moe is the only guy I ever heard of that says it's bad advice to have
an inspection done on a 50 year old chimney with unknown history, that
is exhibiting problems. And then he claims chimney liners are never
used on hvac systems, which of course they are. But the thread is
over my head and I look like a jerk? LOL He may know about
flashing, but he doesn't know much about chimneys, preventative
maintenance, or safety.
Hey dufus, we're talking about a roof leak. Exactly what don't you
understand, that replacing the furnace is not the way to fix the leak?
I see your reading comprehension hasn't improved either. I said the
"Foolish to say the least. Extending a flue pipe is much more economical."
Not only can't you comprehend, you're a down right liar. Please quote where
I said liners are never used.
I'll give you the same opportunity as your twin dufus. I'll post pictures
of the interior & exterior of my home, if you're willing to do the same.
Good grief man, I suppose you put new windows in, if your driveway is
cracked. I bet the contractors you call, love to see suckers like you.
I'll have to look up what other kind of stupid advice you give out on this
NG. Damn, I hurt from laughing so much.
A roof leak that took 2 years to show........IMHO not a really bad
Silicone on the roof shows there was a problem years ago. It should
have been flashed and tarred
The problem is, the leak may be coming from anywhere as water travels
along the rafters.......which is why I said look in the attic.
Trader,In 40 years of construction, I've yet to see the "perfect
house". You can spend your life fixing things and I'll guarantee you
that in less then a year some other problem pops up. If you're gong to
throw expensive fixes at every minor problem, you not only show you
are at best, a first time home owner, or you haven't grasped this
equity thing yet.
"the driveway is cracked.........replace it!
"the foundation is cracked ( lift the house and pour a new basement)
Ya get the idea?
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