Chimney liner necessary AT ALL??

Hello everyone. I am new to the sight, and was referred here due to my interest in using a coal insert in my fireplace.

Forgive me if I am asking a question that has already been asked, but the sight is huge, and I could spend hours trying to find the answer that I need.

I have an existing chimney (probably at least 40 years old) that appears to be in good shape, but I am pretty sure it is not lined, maybe not even with terra cota. I need to have it cleaned, but I need to know straight out- Do I need a liner at all if I am burning coal?? Every chimney sweep I talk to says "Yes, you should have one", but I don't have the money to do it right now. On the other hand, I don't want any saftey hazzards that would jeopardize my family. My house is a rental, so I do need to be cautious.

Thanks for any advice on this.

A chimney as new as yours should have a clay (a type of refractory clay, not really terra cotta) liner in it unless it was built by an idiot. If it wasn't inspected by a code enforcement officer and given a certificate of occupancy (CO) then have it inspected by an expert before you attempt anything with it.

A clay liner is required for three reasons: the thermal properties of the clay, the spacing (insulating) characteristics of the clay liner-in-masonry design, and its ability to be sealed from the house.

If the chimney is unlined and on the outside of the house it could be usable for coal but it may run colder (not draft as well) without any air gap to insulate and possibly having air leaks. If it runs through the house, definitely don't use it until it is inspected.

If it lacks a clay liner or it is damaged, put in a flexible stainless steel one, preferably an insulated one ($400-800). Be advised however that it will deteriorate in a few years (ask other members about this) given the sulfur content of coal effluent which mixes with moisture and creates sulfuric acid.

The chimney could also be relined by a professional with special cement but it may be cheaper to build a new one. I had a new external 21ft chimney built three years ago for $2200. With a cap and care, it should last the rest of my life and more. A pre-fab stainless chimney will yield about ten years under warranty ($1000-1500 installed depending on size).

Thanks for this information. I appreciate it.

A few other questions for you or anyone else:

THe chimney is an outside one. It has the typical flue that goes up on an angle for a foot or so, then straightens out. I shined a light up into the flue the other evening, and I cannot see any kind of terra cota. But does the terra cotta not start until higher up in the chimney?? Also, my chimney does not have a mechanism to open or close the flue. I believe it was removed some time back by someone else.

I'm looking at purchasing a used Gibraltar CFI model. If I put this coal insert into the fireplace, do I need some kind of stove pipe that runs part way up the chimney, or will it just vent out the back and up the chimney. This particular insert has a shield behind it which completely covers the opening of the fireplace.

Thanks for any answers to my questions.

musikfan19681964 wrote: My house is a rental

You might want to ask the landlord first

as long as it's safe, the landlord is OK with it. We already cleared use of the fireplace as long as it's safe for burning.

musikfan19681964 wrote: But does the terra cotta not start until higher up in the chimney?? Also, my chimney does not have a mechanism to open or close the flue. I believe it was removed some time back by someone else.

I'm looking at purchasing a used Gibraltar CFI model. If I put this coal insert into the fireplace, do I need some kind of stove pipe that runs part way up the chimney, or will it just vent out the back and up the chimney. This particular insert has a shield behind it which completely covers the opening of the fireplace.

Thanks for any answers to my questions.

If you can see bricks and mortar or blocks and mortar in the vertical run past the fireplace, then there is no liner. Since it is outside the house, you likely will be ok but I would still bounce this off the code people or an expert installer.

I don't have any experience with inserts. Direct your questions to a stove and hearth shop. I suspect that the fireplace opening, or the chimney flue, will somehow have to be sealed air tight with a plate and also around the stove pipe penetrating that plate. The pipe will probably have to run up the flue a bit. If the chimney dimensions are huge (greater than 100 square inches) then you might not draft as well as you need to because it's a lot of space to heat up especially if it's unlined.

Have you checked to see if the chimney is clear and drafts well using a manometer?

I recommend this thread link since we are re-hashing an older thread: Do I need a stainless steel liner for my chimney?

I'm not the person who should be answering this one ...

....but I've been burning coal for 5 years in a centrally located 100 year old (+ or - ) unlined chimney, with mortar that would fall out if I was to clean it. Haven't cleaned it once in the 7.5 years I've been here. Water used to pour through the ceiling next to the chimney before I installed a chimney cap!

Oh .. and my oil boiler vents into the same flue. Code? What code!

Not recommending this to anyone -- just demonstrating how a little common sense works in a pinch. New chimney would cost me about $3,000 if I were to have someone do it for me (so figure half that if you live outside of MA), & I don't feel ambitious enough to build it myself ... so there it will stay ... until it crumbles to the ground ..... sometime soon.

Hey Smitty,

That is one nasty looking chimney. Or maybe it has a lot of character. Either way it works. Lisa

Most sweeps would say you need a liner... because they get to install it for you. You can install the chimney liner yourself, talk to the guys at http://www.rockfordchimneysupply.com, they'll tell you if you really need one. If you do, they will guide you through the installation process and tell you what components you need for your particular setup.

If the chimney is sound, a liner is just asking for trouble.