Q&A About Chimneys
Wood Stoves in A-Frame Buildings
Hi, are there special considerations for wood stoves in A Frame houses? I am looking for the best installation method. Thanks so much.
Yes there are some important issues to deal with. First, don't attempt to place a stove against one of the sloping walls and run the chimney out through the wall/roof far down the slope. If you try that you'll end up with a very tall chimney outside the building and providing stability will be difficult if not impossible.
You do need to penetrate the sloping roof in order to keep the venting system inside, but do it near the peak. By far the best approach is to locate the stove near one of the gable ends and mount the chimney in the roof just below the peak. That will keep the venting system mostly inside the building where it will stay reasonably warm and will provide the most stable, least ugly chimney installation. It will also mean you can do the installation from ladders instead of scaffolding.
Boosting efficiency with a flue pipe mounted heat reclaimer?
I'm curious whether there are after market secondary heat exchangers available as accessories for residential use to be used to upgrade older pre-high efficiency wood furnaces. I'm just trying to find a way of harnessing those hot flue gases before they all escape out my chimney. Is ther anything short of actually buying a new furnace? Our old one still works but is extremely inefficient and sends a lot of hot gases up the chimney (especially in the coldest weather when we've got a large fire going.
Retrofit flue pipe mounted heat reclaimers used to be popular until it was learned that all they do is plug up with creosote. In Canada they are banned outright because of the hazard they represent. Advanced technology, high efficiency heaters don't achieve higher efficiency by extracting more heat from the flue gases, but by burning the wood more completely. Moreover, the chimney is the engine that drives a wood combustion system and it needs heat to work. You'll boost efficiency more by concentrating on burning the wood completely without smoke than by lowering flue gas temperature. You'll get higher efficiency by using the ideas you'll find in our Tips section.
BBQ starter as a chimney primer?
Hi! On occasion my basement will fill with smoke when I try to light a fire - fortunately, this doesn't happen too often, even though the woodstove is located in the basement and the metal chimney runs up the outside of the house from the basement (lucky me!).... Anyways, I was wondering if it would be okay to use one of those electric BBQ starters to warm the chimney up? (fyi - the kind of electric BBQ starter I'm talking about is a coil of metal that gets red hot when plugged in). Thanks!Rich
p.s. I love your site & visit it often!
I suspect an electric BBQ lighter might work, but it is rather energy intensive and maybe time consuming. And depending on how powerful your backdraft is it might not even work because the rush of cold air coming down the chimney prevents the hot air from going up. I have heard of people having success with hair dryers, usually pointing them up a chimney cleanout door, because the fan helps to drive some hot air upward.
But the normal approach to correcting a cold backdraft before attempting to light a fire is to open the closest window or door. This neutralizes the negative pressure due to stack effect that sucks cold air down the chimney. In most cases with the window or door open, the chimney flow will turn around immediately. Once the fire is lit and a little heat gets into the chimney, you can close the window or door.
Try the open window approach. It tends to be quicker and consumes no energy except for a little heat loss.
I have a franklin stove in my basement, which is in the new addition of my home. The chimney is stainless, triple wall and runs inside the house along the outside wall. I have a terrible problem with downdrafts, until the chimney warms up. The new addition is not as tall as the old section of my house, so the chimney is a lot lower than the peak of the old section. I've seen when it really got cold that the chimney above the stove has been white with frost and the damper frozen solid. Should I raise my chimney up or what?
I would really like to use my stove, but my wife hates to get up in the middle of the night to smoke detectors and a house of smoke when the fire burns out. Any ideas will be much appreciated
You are suffering from a classic type of chimney failure. You have diagnosed it exactly right. At standby with no fire in the stove, your house acts like a better chimney than the chimney. That is, the stack effect created by the warm air in the house creates a slight negative pressure down where the stove is and because your chimney is shorter than the house, it cannot compete, so it flows backwards. The phenomenon is explained in our Chimneys section.
Chimney physics is working against you. The only sure-fire reliable way to fix the problem is (believe it or not) to change the relationship between the chimney and house by moving the stove to the part of the addition next to the tall part of the house and run the chimney up through the warm space. This will make the chimney outperform the house as a chimney when it gets cold outside.
Just raising the chimney is not likely to work. mainly because heat loss in a tall chimney exposed to the cold is so great that the chimney still can't compete with the house. A theoretical alternative is to 'trick' the chimney into thinking it is inside the house and at the same time raise it to be taller than the house. This would involve building an insulated chase around the chimney.
But your chimney is air-cooled, which means it will be cooling itself, whether you have a fire on or not. Air-cooled chimneys can be very bad, and your case is a good example of why they should never be used. The only benefit of an air cooled chimney is that it is cheap. But it is a truly lousy chimney.
Filling the house with smoke in the middle of the night is just totally unacceptable, not to mention hazardous. And besides, Franklin fireplaces are truely awful wood burners that smoke and overfire and tend to disappoint their users. If that were my system, I'd take it out and start again. And I'd use a solid-pack chimney.
Fireplace Chimney Problem
I have a problem with the chimney for my 40-year-old split-level house in Toronto, Canada. The chimney is outside the house and has three flues (2 for two fireplaces [main floor and basement], 1 for natural gas furnace/water heater). The chimney has been rebuilt by a previous owner above the roofline once before. The bricks are spalling above the roofline and breaking apart. We have installed glass doors on the main floor fireplace to prevent smoke from escaping into the room. We currently don't use the basement fireplace.
I am planning to have the chimney replaced above the roofline with matching bricks, new crown, rain cap and install a stainless steel chimney liner for the furnace. While we get this work done I was wondering what we could do to make the fireplaces more functional? The chimney is on the lower half of the split-level - should the height of the chimney be higher than the roof of the taller side of the split-level?
Would you recommend installing a new hearth? Will the basement fireplace ever be able to be used practicably or would it be better to convert to gas? Is it feasible to expect that we not need the glass doors, as they do not allow the heat to escape?
Sorry for all the questions but I hope you can help. Thanks, Darren
This chimney has both of the worst possible characteristics. First, it runs up outside the house and second, the chimney penetrates the house envelope below its highest level. Both of these problems are explained in detail in our Chimneys section.
There is no good solution because both problems are created by the relationship of the chimney to the house. You're not alone; these problems plague North American housing.
By all means, install a liner for the gas furnace. Better still, replace the vertically vented gas furnace with a condensing or sidewall vented one so there is less risk of exhaust spillage into the house.
As for the fireplace, considering you are in a city, you might want to consider a direct vent gas fireplace insert; do not let someone talk you into a B vented insert, which tends to be a little cheaper. If you want wood and you want heat, install an EPA certified fireplace insert with a full liner. I would suggest you forget about glass doors or an open fireplace, unless you don't highly value your health and safety.
Outside chimney causes problem?
I just bought a home with a 40', metal, outside flue for the fireplace. It's in Vermont, USA. Am I in trouble from the get go here? From what I've read, I have two things working against me.
1. The flue is outside.
2. It gets to -15 deg F here sometimes.
Any thoughts, help, leads?
Hello, I think your assessment is correct. When the temperature in the flue falls a few degrees below room temperature, the house will begin to function as a better chimney than the chimney, and air will be sucked down the chimney by the negative pressure low in the house due to stack effect. The actual frequency and severity of cold backdrafts in any given system depends on a lot of factors, but the taller the system and the colder the weather, the stronger the backdraft and the harder it will be to correct.
Some people recommend installing a chase around the chimney to keep it warm, but I've seen enclosed chimneys backdraft because the chase leaked cold outside air and because, without heat input from the house, even the inside of a chase will eventually cool. If you have a very strong backdraft, I wouldn't recommend a chase, unless you want to spend a lot of money on it.
I would investigate re-installing the system inside the house. I know that sounds outrageous, but it can, and has been done. On the other hand, if this is a cheap factory-built fireplace, then its poor performance wouldn't likely justify the expense, even if it worked to its potential. You could save up your money and install a good EPA certified fireplace and be able to view the spectacular fire and heat a good part of the house with it, but only if you relocate the chimney.
But, I guess the best thing to do is try it this coming winter and see how much of a pain it is to live with. With a system like yours, with a high potential for strong backdraft, my worry is that, even if you could get a fire burning, as it recedes to a coal bed the system could go into a hot backdraft and fill the house with smoke and carbon monoxide. This is why correcting a cold backdraft by temporarily opening a nearby window to neutralize stack effect is sometimes not such a good idea. Good luck with it.
Chimney Height and Draft
Could you tell me the right way to draft a chimney? Is the higher the better or the lower height or how high above the roof should it be?
The chimney should extend at least 3 feet above the roof surface it penetrates and 2 feet higher than any roofline or other obstacle within a horizontal distance of 10 feet.
Two things determine chimney draft:
1. chimney height
2. flue gas temperature
Taller chimneys make more draft, but chimneys exposed to outside cold don't. See our section on chimneys.
Proper Height of Flue
We have inherited a good woodburning freestanding fireplace to install in a section of our home but we don't know how high the flue should be. The flue outlet is around 22cm square. The hearth/grate is 80 x 50 x 50 cm. The room has a flat roof about 2.7 metres from the floor. Is there an equation to calculate height and size of flue needed? We don't want a very tall flue unless its is absolutely necessary as we get high winds in winter and want to avoid excessive bracing. Your help will be appreciated
First, the top of the chimney must be at least 1 metre above roof level to prevent excessive turbulence. Secondly, a good rule of thumb suggests that system height from hearth level to the top of the chimney should be at least 4.6 metres. It looks like you'll need at least 2 metres of chimney projecting from the roof. Flat roofed single-storey buildings are always a problem with chimney height, but I would strongly recommend meeting the 4.6 metre objective to help prevent smoke spillage into the house.
But the more important issue is that freestanding fireplaces are terribly inefficient and usually smoke into the room. I would suggest that you take the fireplace to the dump and buy yourself a decent appliance.
Can a woodstove share a central single flue masonry chimney with other natural gas appliances (boiler furnace and water heater)?
In a word, no. Most codes prohibit co-venting wood and gas, and for good reason: their draft requirements are entirely different and incompatible. The draft hoods on the gas appliances bleed off draft to the point where you could hardly get the stove to run at all, and it would smoke like crazy if you opened the door. Gas appliances prefer almost zero draft at the burner and wood stoves like lots of draft.
A wood stove needs its own chimney. And besides, a wood stove should never be put in a furnace room. Wood stoves are space heaters and so should be installed in the space to be heated, not hidden away someplace in the basement.
Suppliers of Chimneys
We're interested in installing a woodstove and are wondering what places (online, presumably) are best for us to learn about and purchase the stove pipes we will need. Is there possibly a Canadian company, where we might get a better deal with a favourable exchange rate? Thanks, Lisa
When you say stove pipes I assume you mean chimney, as distinct from the flue pipes that run between the appliance flue collar and the chimney. I think you should read our chimney section before going any further.
Price should not be your first concern – safety is what is important.
By the way, I have never seen anyone, including me, install their first chimney perfectly. Anything less than perfect might not be safe. I would strongly recommend that you ask the most experienced person you can find to give you a quote, then take it from there.
Yes, there are Canadian companies and Canadian suppliers all over the country. I don't know why you are concerned about exchange rate. People in Canada rarely install US chimneys, unless they are part of a fireplace.
Money Saving Wood Stove Chimney? NOPE!
Hi, I am planning on installing a wood stove this fall and have a question on the chimney. I will be installing the chimney in a 25 foot tall framed chase with inside dimensions of 18 inches by 60 inches. A chimney installer informed me that I could use a stainless steel liner with a zero clearance (some sort of fiberglass wrap) instead of the costly triple insulated stove pipe. This sounds great to me if it is an safe substitute for the stove pipe.
Thank You, Scott
The plan sounds hazardous to me. Are you sure your chimney installer wasn't thinking about relining a masonry chimney? It is inconceivable that any responsible installer would suggest that you could install an insulated liner in a framed chase, considering the house would likely burn down in short order. These are liners, not chimneys; they need to be installed in a brick enclosure.
I do hope you reconsider. Your plan to save money sounds extremely dangerous to me. If you value your house and your family's safety, save up your money and buy a proper solid pack insulated metal chimney. Maybe you should seek out someone else to advise you.
Adapting Chimney Sizes
I've taken over a "hippie homestead" in Manitoba, and in order to get insurance I'm going to have to upgrade the chimneys to the "2100" type (2-inch insulation). Fair enough - I'm all for safety!
The main heater is a Triumph with an 8" collar which has been adapted to a 7" chimney. (The stove had a label, which is now gone, so I can't offer specifics.) I may want to, or have to, replace this stove as well, as I would think there are better designs available now, and I'd like to keep emissions to a minimum. Something EPA certified or whatever.
It seems, from a cursory investigation (there are no serious stove dealers within 200km of here) that newer stoves most commonly have 6" collars. Maybe this impression is skewed due to the small data sample. ;-)
I don't want to put in a shiny new chimney that's inappropriate for the present stove or a later stove acquisition. The two goals may be incompatible.
Question: Presumably it's best to have the same chimney size as the stove collar. If forced to adapt sizes, which is the lesser of two evils - large stove into smaller chimney or visa versa? (If nothing else, this will tell me something about the quality of the existing situation.)
My technician's guess (I've no experience in wood heat systems) is that, to a point, a smaller chimney would have greater flue-gas velocity and be less prone to creosote accumulation, even though at first blush the idea of a slightly oversized chimney is intuitively appealing to the neophyte. One way or the other, I suspect that if the size difference is too great, one eventually gets into trouble of a different kind.
I'm thinking I should bite the bullet and buy stove and chimney at the same time, but as I know so little and the suppliers are at such a distance, I don't want to rush into this. Meanwhile the nights are getting chilly.
BTW, I'd love to hire a qualified stove supplier / installer to take care of this but they're not easy to find here, and I shudder to think what it would take to get one out here from a distance. When you ask about installers, people look at you as though you're from Venus. The idea that you wouldn't put in your own chimney is borderline bizarre to them. But they've grown up doing this stuff, whereas I've grown up with thermostats. ;-)
Your intuition is right. Better to use the smaller 6" chimney. Best to install a new EPA certified stove with it, but barring that use the 8" Triumph on the 6" chimney, adapting from 8" to 6" at the bottom of the chimney (ie use 8" smokepipe to the chimney base) for pretty much all the reasons you mentioned.
Thanks very much indeed. Just yesterday the insurance company in question confirmed this as well.
The old Triumph doesn't seem like a bad stove, though I know a newer unit would be a good investment. I've just moved in here though, and I'm trying to spread the cost of upgrades out a bit! That much more important not to close doors on myself.
Thanks sincerely for your help.
I'm attempting to find the usual operating flue temperature ranges of woodstoves and fireplaces. Also if clay liners have a tested operating temperature.
Flue temperatures are highly variable because of differences in appliances, venting systems, fuel and operating conditions, but the range would be from ambient up to about 2100°F. A system operating normally will run between 200°F to 1000°F, depending on where and when in the burn cycle you measure it.
The clay liner standard only says that they must not soften at 2100°F. There is no performance test for clay liners. They tend to fail because of thermal shock caused by rapid temperature changes like those that happen during a chimney fire.
Odor Busters Please!!
I have a "heat-a-lator" type fireplace installed in the basement of my single story home. The chimney is a masonry type with clay liners and brick exterior on an outside wall. The liners are 12" as recommended by the fireplace manufacturer.
I didn't use the fireplace for many years after it was installed until I finished the family room in this area. After the first fire I burned and the chimney had cooled down- I had a very strong sooty smell enter my fireplace and family room from the chimney-even with the damper closed! The chimney worked properly while the fire was started and burning. It had plenty of draft and is covered at the top with a chimney cap.
My question is: Do I just need to burn more fires to "condition" the chimney to burn out excess moisture, etc. that may have settled in over the many years of not being used? and Are there any chemicals that can be used in the fireplace to help eliminate these odors? (I know after reading your articles that my main problem is the chimney is located on an outside wall and is not insulated)
Any comments would be appreciated- because I love a burning fire and no odors afterwards and my wife said divorce court was next if those ghostly odors entered the house again. Thank you! Ron
I'm sorry to say there is no simple solution to your problem because it is, as you say, caused by the relationship between the chimney and the house. You can use baking soda or equivalent to reduce the smell, but this only works if you clean the system thoroughly and then don't use it any more. Here are some options;
- install a sealing damper at the top of the chimney to stop the backdraft between fires (Lymance and Locktop are popular cable operated brands) (fireplace throat dampers don't seal well at all)
- install a fireplace insert with a full stainless steel chimney liner; this will reduce backdraft volume and intensity, convert the fireplace to a serious heater and the chimney liner will tend to isolate the flue from outside cold.
Those are my best suggestions. Good luck with it and I hope it doesn't end in divorce.
What's best: masonry or metal chimneys?
I want to know what the lifespan would be for an outside the house woodburning chimney made of block and tile as opposed to insulated stainless pipe.
The life span of a masonry chimney depends a lot on how it is used and maintained. A severe chimney fire can blow the tile liner instantly and a failure to maintain the cap or crown every year or two can allow water in. If you live in an area with freezing temperatures, this can lead to rapid deterioration. Well built and maintained, a masonry chimney can last a long time. Note that concrete block shells are not nearly as good as brick because a) they absorb water and break up with freeze/thaw cycles and b) they are less stable because there are fewer interlocking joints that key the structure together.
On balance, of all the chimneys that are acceptable under building codes, a concrete block chimney is the worst. The fact that you intend to put it outside, which we strongly discourage, makes it a truly lousy option.
Metal chimneys are well proven and most have parts warranties. They tend not to need the same level of maintenance as masonry in order to last a long time.
In short, either option can be effective, although on balance, we tend to favor metal over conventional masonry because it tested, certified and has some insulation to keep the liner warm.
A question about steel chimney liners
Hello, I found your site helpful and interesting. Our home in Massachusetts is entirely heated by wood. The house is very well insulated, and it is only 15 years old. I had the local chimney sweep come to clean, and he says we need a steel liner installed inside our chimney -- for about $3000 (two flues). We do normally burn with the choke pretty tight, so it's not very hot in the chimney. But I am surprised that such a young house would need that kind of repair. What is your take on steel chimney flue liners? How do I get an unbiased opinion? Andy
Stainless steel chimney liners are widely used and have been for more than thirty years. They are a great way to upgrade failing masonry chimneys. Masonry chimneys can fail in as little as three years, depending on how they are used. I would recommend that you get another liner estimate, just to make sure the price you have been quoted is fair.
Choking down woodburning equipment is the main way to destroy chimneys, both by being the main cause of chimney fires, and also by permitting water condensation in the chimney, which is really destructive. You should try to avoid smoldering fires because of the damage they do to your system and to the environment. You might want to read the articles in our Tips sectioin.
Connecting to a two flue chimney
I would like some info. on connecting wood stove to my chimney, which has two inserts. I already have a gas furnace in one of the inserts, so can I put a woodstove in the other one?
To get the terminology correct, you have a chimney containing two flues which are the holes through which flue gases flow. Chimney liners (not inserts) surround the flues.
In answer to your question, yes, you can connect a wood stove to the other flue, provided it meets code requirements. You really need some local assistance to make sure the connection would be effective and safe. Chimney sweeps are good at checking out existing chimneys.
Bad smells from a basement stove
In the past 2-3 months we have been having problems with our wood stove. It is located in our basement. We have been awakened in the middle of the night to the heavy smell of creosote. My husband has cleaned the flue and replaced the pipe from the stove to the flue. We have had the stove for 3 years now and this is the first time we have had this problem. Also, since he replaced the pipe this last time, it is dripping creosote where the pipe fit together.
Thanks for your help.
It is difficult to diagnose this kind of problem without seeing the system and the house, especially since you haven't given much information. It sounds like you are suffering a cold backdraft, normally linked to installations in which the stove is installed low in the house and the chimney runs up the outside wall. See articles in our Chimney section.
If someone in your household likes to sleep with their bedroom window open a little for fresh air, this may be the problem. Any leaks high in the house will make a cold backdraft more likely and more powerful. I would strongly recommend that you get a chimney sweep or stove/fireplace specialist to inspect the system and advise you.
Also, since you report dripping creosote, it is likely that the stove is being allowed to smolder. You might also look for sources of high moisture in the house, like a large amount of firewood or laundry hanging to dry. Low flue temperatures due to smoldering is a common reason for failures to vent smoke properly. You might want to read the articles in our Tips section to learn how to keep flue gas temperatures higher.
Joe's got an outside chimney – NOW what can he do?
So I blew it and built a metal chimney outside the house enclosed in a frame chase. I assume I will have the backdraft problems you spoke about in your "evil outside chimney" paper. What can I do now? Would putting some kind of blown in insulation into the chase around the pipe help?
Yes, your system will be prone to cold back drafting, but before responding I need to deal with the issue of insulation around the pipe. If you really did that, rather than just use fiberglass batts in the spaces between the framing studs of the chase, you would likely burn your house down. The air space around chimneys must be maintained or they will overheat. Please do not blow insulation into the cavity. If you want to insulate, only put it between studs. Also, insulation and air barriers in chases must be contained by sheathing to prevent them from heating up and falling against the chimney.
A number of things affect how strong cold backdrafting can be, and how big a problem it is, such as:
- How cold is your climate? The colder the climate [or weather], the stronger the backdraft. Houses in Canada and northern tier US states suffer powerful backdrafts. People in southern states don't [but, of course, they have other problems]
- How tall is your house and chimney? Taller houses and chimneys backdraft more aggressively. This is why basement stove backdrafts seem stronger than main floor stove backdrafts
- Where are the leaks in your house? The higher the leaks, the stronger the backdraft. If you have a leaky attic hatch, lots of high level recessed light fixtures, forced air heating ductwork in the attic, or you like to sleep with the second floor bedroom window open, you'll have stronger backdrafts.
The really bad thing about outside chimneys is that the remedial measures are either ineffective or unappealing or expensive or all three, which is why we tend to be strident about not installing chimneys outside in the first place.
Consider the following comments in the context of the three points made above.
Insulating the chase might help some, but a large component of heat loss from typical chases is from leakage, so sealing it [including top and bottom] is at least as important as insulation. The only way to really fix an outside chimney is to trick it into thinking it is inside. That would mean a chase that is the same temperature inside as the house is so the chimney stays warm enough to compete with house stack effect. With a really well sealed and insulated chase, you could vent it into the house, with a couple of passive vents at top and bottom of each storey, so that a convection current would keep the inside of the chase nearly as warm as the house. That strategy is the only one sure to work, and then only if it is done well
On the other hand, if your climate is reasonably mild and your house is reasonably short and if its leaks are relatively low and you keep fires burning most of the winter and you burn the wood bright, hot and clean, you might never have a problem with cold backdrafting.
When it's windy, we have a smoky house
We installed a new woodstove with an existing chimney when we moved into our house three years ago. Last spring and this winter, we have been having problems with smoke coming into the house through the stovepipe joint where it enters the ceiling. When it first happened last spring, we thought it was possibly because of a pressure inversion. This winter, however, we seem to have a smoky house any time there is a wind. Our chimney is straight, inside in a one story addition to a one and one half story house. We clean the chimney frequently (approximately 5 or 6 times/winter). Do you have any diagnosis for the problem, where we can get help, and how we can fix it? We didn't have this problem the first winter we were here.
Problems of this kind are so complex that I could spend a long time writing to you about possible contributing factors. I can't do that. But here are a few ideas.
1. A chimney installed in a single storey section of a two storey house has to compete as a stack with the house, especially when no fire burns or when chimney temperatures are low like when the fire smolders. This may not be the main cause, but it weakens the chimneys ability to flow air and gas up under all conditions.
2. You need to pay attention to which wind direction leads to the problem. If spillage happens when wind blows from the single storey side, you need to look for leaks on the downwind side of the house on the two storey side, especially high level leaks like open second floor bedroom windows or a leaky attic hatch. This situation can depressurize the house and suck flue gases down the chimney into the room.
3. Smoldering fires are a key cause of this type of failure. Make sure that you burn small, hot fires and don't let the fire smolder. The wood should be flaming until it is reduced to charcoal.
4. If there is no cap on the chimney, get one; open chimneys are extremely vulnerable to adverse winds. Raising the chimney might help to get the top of it up out of a zone of positive pressure caused by a wind effect.
Ideally you could contract with someone who can come to your house and diagnose this, but such people are hard to find. Check first with local chimney sweeps or long-time stove and fireplace retailers.
Stainless steel liner in a masonry fireplace chimney
What options are available for fireplace flue repair? We are working on a project where there are two existing fireplaces, roughly 75-80 years old. The owner would like the fireplaces restored. Can stainless steel liners be used on wood burning fireplaces? Jim
Yes they can, but it is not an elegant solution because the connection above the throat and damper are difficult to do and rarely done well. Since we at woodheat.org think wood should not be wasted just to watch it burn, but should provide an energy benefit by delivering heat to the room, we would recommend the installation of a fireplace insert with a full stainless liner to the top of the chimney. In this case the liner is sized to the insert, not to the fireplace, and the connections can be secure and permanent. An additional benefit of an insert is that it would improve resistance to smoke spillage into the room and reduce outdoor air pollution from the fireplace. This is the only environmentally responsible solution, in our opinion.
If your client insists on retaining the conventional fireplace for historical or nostalgic reasons, a far better solution than stainless steel is a solid-set poured-in-place lining system. This insulating cementatious material greatly improves the structural integrity of the chimney and improves performance by insulating it.
You need to find a supplier of SolidFlue, Arens, Golden Flue, Supaflue and there may be a couple of others that I can't think of at the moment. Chimneys sweeps can usually tell you if there is a local supplier.
A fireplace cannot share a chimney
I bought an old house in Philadelphia. The heating system is gas, hot air. There are two chimneys. One vents the heating system and air conditioning; that one is in the living room. The other vents the hot water heater. I would like to add a fireplace in the living room. I would prefer wood. It would need to be very small, as the living room is 14 X 16.
Is there some way to utilize the chimney that vents the heating system? If not, how expensive would it be to install a new chimney for a wood burning fireplace (ball park figure is OK). The house is two stories and very small.
Am I better off with a direct vent gas fireplace? Any advice would be greatly appreciated!!! Susan
“Is there some way to utilize the chimney that vents the heating system?”
No, you can’t use a chimney for both a fireplace and heating system.
There are many factory-built fireplaces on the market of all shapes and sizes. They don’t need a foundation, can be put almost anywhere and routing a chimney up through the house is done all the time without problems. You need to visit a few fireplace retailers, see what they have and what they have to say.
“Am I better off with a direct vent gas fireplace?”
We are not the right people to ask about gas fireplaces. Since most everyone else will advise you to go gas, including most fireplace retailers, I will suggest that if you want a real fire, the only option is wood.