Gas and Oil Home Heating Furnaces - Titanium/Steel liner for furnace chimney?

Hi - first time post. This site looks wonderful - my compliments to those who run it and the contributors. I hope this question hasn't been asked - I searched the archives several ways and didn't find it.

(actually not a do-it-yourself question, but I will have plenty of those in the near future, I promise!)

I bought an 80-year-old house back in May (first home). Before purchase, my inspector noted that I should get the chimney (for the gas furnace and gas water heater) tuckpointed, as some gaps were starting to appear between the bricks (on the roof of a one-story rambler). I had a chimney guy out last week to give me an estimate for the masonry work, and while on the roof he peered down inside the chimney with a flashlight. He informed me that he could see at least one terra cotta tile missing and several others chipped or damaged. In any case he said the integrity of it was breeched. The missing tile is ~12 feet down, which would put it about at the middle of the main floor of the house.

He warned that this breech means carbon monoxide (CO) can seep into the house through the bricks. So in addition to an estimate for the tuckpointing, he quoted me $1,200 to install a Titanium/Stainless Steel liner for the chimney, including connecting it up to my furnace and water heater per code.

My questions (advice on any or all appreciated!):

- how likely is it that significant amounts of CO would seep into the living space of the house (ie, through bricks of chimney and through/around wallboard), assuming the top of the chimney is kept free of blockage? Doesn't the gas follow the "path of least resistance", so to speak?

- is this a real worry given that it's an old house that probably "breathes" fairly well? (I still have old sashcord-style windows for example)

- if I take him up on the liner offer, is Titanium/Steel the recommended way to go? Will that be an advantage down the road when/if I replace my 20-year-old furnace with a new high-efficiency model (which I intend to do when it wears out)?

- would the Ti/Steel liner be a selling point for the home in the future, or is it sort of a passing gimmick?

I can afford the $1,200 if it's worthwhile, but I want to make sure I'm not just filling in work during this fellow's slow season (though he seemed quite nice and on the up-and-up). To anticipate one obvious suggestion - there is a "gas detector" (does that mean CO or only natural gas?) mounted at the top of the basement stairs, which tests as functioning and has not sounded an alert so far in my time in the house. I'll probably get a second detector for near the bedrooms, but in any case since it's not furnace season yet (only my water heater is exhausting through it at the moment), a real leak test wouldn't be until December. By then it will be busy season for them and I might have a hard time getting it worked on. Which is why I'm trying to decide on this now.

Sorry for the long-winded and perhaps naive question. My first choice for a handle was "Neophyte" - but that was taken.

PS - the previous owners were a couple both working in environmental issues, had two small children and seemed conscientious, which makes me skeptical that they wouldn't have been on top of any hazard (but maybe they simply didn't know about it)

I'm an insulation contractor and although I am not in that field, I have seen problems on the job.

If you have problems you can SEE. How many problems can't you see. And, carbon monoxide does kill, why take the chance.

Titanium. As a former journeyman machinist, I can't see why it would be better than stainless steel. Got any mechanical engineer friends? Ask them.

Might want to ask your local building inspector. Sometimes they find out things before others.

Thanks the reply, rbisys. I tend to want to err on the side of caution, so your point is well taken.

I actually am so naive on this that I don't know when/whether chimney liners are necessary to begin with. Did the original terra cotta tiles laid in by mortar(?) really create a hermetic seal against gases? I probably need to read up on basic chimney construction so I can ask a more intelligent question...

Assuming that a liner of some sort is advised, I am curious how many of these Titanium/Steel ones are out there, if they have a track record, etc.

$1200!!!!! you gotta be kidding! how tall is the chimney, and how difficult to work down through the top of it? material costs do not reflect such a price. atlanta ga cost @ $450, with 30 ft. liner. sounds like you do need a liner, shop around, standard flue liner kit has 20 yrwarranty, good luck

He quoted 23 feet for the liner. It looks like a narrow chimney to me, but what do I know.

Thanks for chiming in, HVAC4U. I should be getting two more quotes here shortly, maybe I'll also get a better feel for how necessary it is (though it is sounding like a good idea, from both the responses here).

Thanks again for the help.

I got thinking about this material.
As a former machinist I can think of a couple of advantages, but, not $1200.00 worth. Titanium is expensive.

It sounds like this may be a new product, even to the pros here? A search on "titanium steel chimney" on google.com gave me these vendor links in the first few pages:

http://www.americanboa.thomasregister.com/olc/americanboa/metal3.htm

http://www.protechinfo.com/hiflex.html

http://www.stovesdirect.com/chimney/masonry.shtml

Not sure what diameter my contractor was quoting for, but assuming 4" or 6", hvac4's estimate of $450 was about right. At $1200 then that quote sounds like it was figuring an awful lot of labor.

Was thinking I might find a page from the EPA/DOE/CDC/etc to know if they're recommending this for new homes, or if it's just a passing gimmick in the industry.