How do I know if I need a liner?

It seems like half the threads in this forum are about installing stainless liners. Why is this and how do I know if I need one?

My house was built in 1987 and it has a rectangular chimney with what looks like a clay liner in it. The guy who inspected it when I bought the house said the chinned looked like it was hardly even used and looked great.

I have been burning every day in it and everything seems fine. Why would I need a liner And how would I know?

Thanks for the knowledge help.

I get the benefits but most people don't dish out thousands of dollars unless there is something actually wrong with what they have now. I can't see putting in a liner just because it's what all the cool kids are doing.

What I do see is a ton of stories on the internet about chimney companies that push liners on everyone pretty much no matter the condition of their chimney.

What things could be a legitimate reason for for using a liner as a repair? What should I look for in my personal chimney that might be cause for installing a liner?

There is already four inches of terra cotta and cinder block between the chimney gasses and the wood in my house. When I go out into the garage while burning the exterior of the cinder block chimney is ambient temps when my thermometer says the flue gasses are 500*+.

Batman said:

An insulated liner will keep the flue gasses warmer, reducing condensation and creosote deposition. The draft will improve. Most of all, it will provide the peace of mind that comes from knowing that should there be a chimney fire, there is a stainless steel tube and a half inch of ceramic insulation between the fire and the rest of your house.
In a recent thread, someone posted a video of a simulated chimney fire in a terra cotta flue. Worth a look. That said, there are many (most) that don't have liners and live to tell about it.

Click to expand...

begreen said:

Shaggyant, what is this chimney servicing - a fireplace, stove, insert? Does the chimney have 2" clearance from any and all combustibles including framing and drywall?

Click to expand...

It's servicing an old '92 model Quadrafire 3100.

I'm not sure how you would determine that? The chimney is original from when the house was built and it butts up to the backside of my living room inside the garage. It's pretty much a cinder block tower on one side of my garage that pokes out through the roof. The cider blocks touch the garage wall all the way up to the ceiling and then it pokes through the garage ceiling and The roof above it at just about the top of the ridge line of the house.

The living room has a nice hearth area made of natural stone and the single wall stove pipe comes up out of the top of the stove about two feet and then goes back to the wall whith the chimney on the other side where it enters through a big sheet metal thimble about a foot and a half in diameter that covers the surrounding Sheetrock of the living room.

I'm sure it is built to whatever 1987 code was at the time.

kennyp2339 said:

Piece of mind for most, masonry chimney's may meet the right codes of having 2" to combustibles, but during a chimney fire when temps go over 1500deg your depending on mortar joints holding and clay tiles not cracking.
What's puzzling with masonry chimney's is the #1 killer, moisture, yet at least around my area (NNJ) only half the chimney's I see have some type of cap to keep the weather out.
Personally if I had a masonry chimney, I wouldn't want to take the chance of depending on just a clay liner, especially if the house has been built for a while, and its been exposed to the weather, that's me though. Plus an insulated liner like other posters mentioned would keep flue gases warmer, reducing the formation of big bad creosote.

Click to expand...

So, basically what you are saying is that it's unsafe no matter what the condition and you shouldn't be operating a wood burning stove without an insulated stainless steel liner or a class a stainless steel chimney in place?

kennyp2339 said:

No, masonry liners a perfectly safe if there built to today's required clearances, maintained annually, and the user understands them.
It's kind of like new technology, there's nothing wrong with the older stuff if properly working, but there's a reason why there's newer. Just my opinion though

Click to expand...

Ok, how does someone tell if the masonry chimney needs to be repaired or replaced? This is what I'm getting at.

How do I know if it's properly maintained and working aside from burning my house down? There has got to be some sort of way to look at it or test it to see if it is still safe to operate.

It's like this. New cars get better mileage and better emissions and better crash protection but I can't see buying a new car every year just because of that. I want to know how to tell when my old car has bit the dust and actually needs replacement.

bholler said:

have it scanned by a reputable chimney company. Watch the camera as they scan and ask them to point out any flaws. there can be cracked flue tiles or bad mortar joints either of those are reason enough to line the chimney. The lack of clearance to combustibles is also a good reason to install an insulated liner. i am a sweep and i install lots of liners but i also clean allot of clay lined chimneys that work just fine as well. Clay is not bad but insulated stainless is better. And yes there are scammers out there that will go around telling every customer they need a liner that is why you should choose a reputable pro

Click to expand...

Awesome!
This is exactly the info I was looking for. I will call around and see if any chimney sweeps in my area have a camera probe to check my lining. How much should something like this cost?

I'm not opposed to relining or even total replacement of the chimney but I'm just not the type of person who replaces things without a reason. It's good to hear that it is possible that my clay lined chimney may not in fact be so evil that it needs immediate replacement just because.