100 year old farmhouse, CT. From cleanout in basement you can see that the brick that’s on the outside is the brick that you see on the inside.
At cleanout in basement small pile of tiny brick ‘exfoliation’ particles
At peak of roof chimney show terracotta flue liner exiting. Appears that chimney was ‘rebricked’ from top of second floor up. Has nifty 30 degree or so slant in chimney above second floor to make it exit dead ceneter of roof.
No trace of there ever having been a fireplace. One flue only.
Currently used to vent one oil fired boiler that was installed in 2004.
Question is – does is need/should have/doesn’t really matter – a stainless steel flue liner installed?
Let’s not confuse the issue with facts!
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Greetings gdcarpenter,
This post, in response to your question, will bump the thread through the 'recent discussion' listing again which will increase it's viewing.
Perhaps it will catch someone's attention that can help you with advice.
Cheers
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Not sure what you mean first sentence about inside/outside.
reason for lining old chimney with SS in new upgrades is mainly to downsize for best draw, but also to keep acids from attacking the masonry.
Older heating units would run more often and less efficiently from a POV of oil useage ( or gas) That means the chimney mass stays cooler, so there is more condensation as gas exits. That condensate contains water and acids which etch the masonry and mortars. Also- say, if the flue is 8x8" but the burner only requires a 5" round, the gases are drafting out more slowly, taking time to deposit even more condensate.
You can study the book ( online if need be, for your particular appliance to see what size exhaust flue is recommended. If you are over sized, you should line it. This is something the better installers do as they replace old burners with more efficient ones. There is no downside for them as they are making a profit on the liner.
But the guys bidding at lowest bottom line, or who do not want to get on the roof, just skip thinking about chimney liners, and throw the new in where the old was
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From cleanout in basement you can see that the brick that's on the outside is the brick that you see on the inside.
That is a problem.
If you do not have a clay tile chimney liner, then you must install a metal liner. Probably says so right in the instruction manual. Probably says so in the fuel gas codebook.
A word of warning- if the boiler is not tuned for proper combustion, the byproducts will eat that stainless liner (and the brick). A combustion appliance cannot be tuned without a combustion analyzer. Anyone that tells you otherwise is not doing it right.
The chimney was probably rebuilt because the old one was eaten from the inside out due to interior condensation. Flue gases condensed on the interior chimney walls in the attic along the slant, then continued to do damage at the exit through the roof. Freeze/thaw cycles busted up the brick.
If that boiler has a draft hood instead of a barometric relief damper + spill switch, odds are it is not venting properly. I would put money on it.
If the flue gases get out of the chimney properly because the draft is good ALL OF THE TIME, a liner is not needed. That is something you cannot guarantee because the operation of a chimney is dynamic. Exterior temperatures and pressures interact with the home in strange ways and change the dynamics of a chimney.
That first line confused me because I was thinking inside of house/outside of house.He meant inside/outside of chiney."If you do not have a clay tile chimney liner, then you must install a metal liner."That is at the cleanout that he sees no clay liner. He does see it at the top. It is common to only have the liner from point of entry of the appliance exhaust, but brick only for the 3-4 feet below that to cleanout.I suspect that his "exfoliation" there is from excess condensates dripping down the inside and soaking the brick at the base - not good sign.
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It is common to only have the liner from point of entry of the appliance exhaust, but brick only for the 3-4 feet below that to cleanout.
The only way to verify that is to remove the vent pipe and look... or go up and look down.
I understand what you are saying, but I have seen brick chimneys without a clay tile liner at the point of the appliance connection. The clay liner may not have been needed in the days of coal or wood fired appliances.
I agree that the main source of the problem is customers seeking low bid contractors... and contractors that do not know what they are doing.