Andy Wojtowski

Chimney and Fireplace Safety

In this episode, the team talks about how important it is to maintain a wood-burning fireplace. This topic was brought up because Bill’s neighbor is dealing with a $20k chimney rebuild.

The show starts with Reuben explaining the structure of chimneys. He then answers some questions:

What involves a fireplace from the place you put the logs all the way up to where the smoke leaves the top of the chimney?

What are the pieces that make it all up? Where would you often find the biggest problems with this whole system?

What’s the lifespan of a concrete cap?

How to know whether you have a mortar cap or a concrete cap?

Which of these masonry chimneys have the most problems?

What is NFPA 211 and why do we use their guidelines?

How much can someone expect to spend on Level 2 chimney inspection?

What is the level of safety we need in chimney inspections?

What is the challenge with the stainless steel liner that allows us to burn woods?

How often should you get a flue cleaned?

Which wood to burn inside a fireplace?


The following is a transcription from an audio recording. Although the transcription is largely accurate, in some cases it may be slightly incomplete or contain minor inaccuracies due to inaudible passages or transcription errors.

Bill Oelrich: People in the great state of Minnesota have an obsession with burning real wood for some odd reason. It’s very important that if you are going to be using your wood-burning fireplace, that you maintain it, and sometimes, in the course of maintaining it, you find that maybe there’s a problem or two.

BO: Welcome everybody, you’re listening to Structure Talk, a Structure Tech presentation. My name is Bill Oelrich, alongside Tessa Murry and Reuben Saltzman. As always, you all can’t see him waving, but they are waving in the background, rest assured.

Reuben Saltzman: Yes.

Tessa Murry: We’re here.

RS: ‘Cause they are very nice waves.

BO: Yes, yes. They were very pageant-like.


RS: Yes.

BO: So thanks everybody for joining today. On today’s episode, we thought we’d dig into chimneys a little bit. As we record this episode, it’s late October, and people in the great state of Minnesota have an obsession with burning real wood for some odd reason, and so I thought we would kinda dig into the topic of chimneys again. It’s a topic we’ve spent some time on, but it’s very important that if you are going to be using your wood-burning fireplace, that you maintain it, and sometimes in the course of maintaining it, you find that maybe there’s a problem or two. And so one of the things that brought this up is I’m looking out of my window at my home in beautiful St. Paul, Minnesota, and my good friend and neighbor across the street is currently rebuilding his chimney to the tune of $23,000. So these things are there, and they are not immune to decay and deterioration, and so, unfortunately, my neighbor is dealing with just that problem. He had called a mason out to do some tuck-pointing on the chimney, just thought it was gonna be one of those quick and easy, tuck point, replace a few bricks, but the first guy that came out looked at it, he said, “Yeah, I think this is a full rebuild.” If you had walked by that chimney, there is no way you would have ever thought that.

RS: No, I gotta ask, Bill. I’m dying to know. I gotta interrupt. Was it covered with stucco?

TM: I was just gonna ask the same thing.

BO: No. This is straight up brick chimney. It’s a unique chimney, I’ll give you that, it’s a big chimney, it’s tall, but the indication that something was going on is that it was beginning to lean. And so…

RS: That’s not good.

TM: No. [chuckle]

BO: And so this chimney itself sticks up on its own, probably 15 to 16 feet in the air, above the roof where it last passes the roof, and then there’s this big metal brace that comes down and ties into the roof to prevent the chimney from kinda getting pushed over in a big, heavy wind. But yeah, they noticed it was leaning, and he got a second and a third opinion, and by the end of the third opinion discussion, he decided, “Yeah, we’re gonna do this,” so…

TM: Wow.

RS: Crazy. That’s a really scary thing when you got a chimney that leans ’cause chimneys have their own foundation. They are independent structures. You should be able to have just about the whole house fall down, burn down, and that chimney should remain standing. So when that thing starts leaning, it’s not like you just re-attach it to the house, it means you’ve got issues down below. That is bad news.

BO: Yeah, I’m not sure… They’re not digging into the foundation of it, they’ve gone down to the house level, they’re rebuilding from there, but still significant.

RS: Okay, so how did it lean if they’re not re-doing the foundation?

TM: Yeah.

BO: Because there’s such this top heavy… There’s this projection into the air, like I said, it’s about 16 feet higher than the roof, just sticking up in the air, and so if you look at it, you could see a little bit of a lean in it. I think it’s just by the fact that it’s so high, and maybe some of that mortar was beginning to decay, and I’m guessing at some point, it was tuck pointed in the past, and maybe somebody just replaced it by… Replaced the mortar and just left it leaning a little bit. Reuben’s got his hand up, so I’m gonna call on Reuben.

RS: [chuckle] Okay. So which way was it leaning? Towards the house or away from the house?

BO: I’ll have to confer, I don’t know. I plead the fifth.

RS: Okay, alright. I’ll bet anything it was leaving towards the house. I sat through a seminar by this guy at one of the ASHI conferences, and he was teaching on old houses, and he said, “They always lean towards the house,” and someone asked, “Why is that?” He said, “I don’t know. That’s just the way they always do.” [chuckle] And I still remember that answer, so I’ll bet anything it’s leaning towards the house. There’s gotta be some science behind it, but I don’t know what it is.

BO: Yeah, I’m sure there is something to what you just said, but that’s also the direction where the supporting posts came from. So I don’t know. We’ll see. I’ll ask ’cause I had a great discussion with him yesterday, it was a five-minute check in, how’s things going, that turned into 30 minutes on our chimney. I’ll get to the bottom of this. But let’s talk about why are people so obsessed with burning wood in the state of Minnesota?

TM: ‘Cause it’s cold. [chuckle]

RS: ‘Cause you feel cozy. We had a wood-burning fireplace, and it was just an event, it’s like, “Alright, let’s go get wood, let’s put the kindling in there, start the paper, it’s nice and cozy in the living room, and you just… ” it feels nice. You go out sledding, you come in and sit by the fire. There’s something to it. I don’t know, romantic, inviting, than a gas fireplace. There’s no question about it.

TM: That’s if it works properly, ’cause growing up, we also had a wood-burning fireplace. The couple occasions we did try to have a fire, I remember my dad lit the fire and opened up the flue, and we had all the smoke pouring into our family room. [chuckle] And the only way we could get the smoke to draft up and out of the chimney was to open up the window in the living room, and it would just get so cold that there was really no point in having a fire anyways. So I think we only did it a couple times.

RS: Yeah, that’s bad news.

TM: Yeah.

BO: Reuben, let me do this. Let’s do a little education on fireplaces, because you’ve seen thousands of them, I imagine, over the years. Give us the high level overview of what involves a fireplace, from the place you put the logs, all the way up to where the smoke leaves the top of the chimney. What are those pieces that make it all up? Where would you often find the biggest problems with this whole system?

RS: Sure. You’ve got the structure of the chimney itself, it’s gonna be made out of bricks, and the job of that is basically to contain all of the other components, it’s kind of like the foundation or the… I don’t know. It’s the home for everything else that contains the fire, is the actual chimney, but then within that, you’re gonna have the fire box and you’re gonna have special fire bricks and those are gonna help contain a lot of that heat. It’ll prevent a lot of that heat from reaching the actual chimney itself, and then you’re gonna have a throat, and that’s the part that transitions between the firebox and the flue, it tapers up, and then eventually you have the flue and that’s gonna be made out of… Typically, it’s gonna be made out of stacked clay tiles, and each tile is usually gonna be about 18 inches long, they stack them on top of each other, they fill mortar in all of the gaps in between each one, and then it vents out the top of the chimney.

RS: And hopefully, you’ll also have some type of rain cap on top that’s gonna prevent water from dumping into your chimney, and hopefully that rain cap is also gonna come with a spark arrestor, and that’s gonna be some screen that kinda goes around the top of it. And the original design of a spark arrestor was to prevent hot embers from rising up the flue, landing on a wood roof and starting the roof on fire, but really the more modern reason that we really like to see those as home inspectors is you’re gonna prevent things like raccoons and squirrels and birds, and Santa Claus from sneaking into your chimney and making a home out of your fire box. So that’s kind of the structure in a nutshell.

BO: Did you happen to note over the years that one particular part of this system seemed to break down sooner than others?

RS: Tessa, go ahead.

TM: Well, one thing that’s obvious that we can see as home inspectors is the exterior part of that masonry structure and viewing it from the roof, and I’d say one of the most common places we see issues is just degrading mortar in between bricks and then a cap or a crown that’s also degrading as well. And most, I’d say most chimneys around here have a mortar cap to them, and when the mortar is cracked and kind of falling off, then those are all locations where water can get in and start to expand and contract and break apart the top of the chimney.

RS: Yeah, for any of our listeners, I wanna define the difference between what you’re talking about, a mortar cap…

TM: Yes.

RS: And a concrete cap.

TM: Yes.

RS: Take it away Tess.

TM: That’s a good point. There’s a big difference, and so I’d say what, 95% of the chimneys we see have a mortar cap to them, which breaks down and degrades and needs to be maintained, versus the concrete crown, which is like the star of the show. If a chimney has that, we love to see that, it’s very rare, but the concrete, ideally, it overhangs the walls of the chimney a little bit, the bricks, so that it sheds water and water doesn’t just run right down the walls like they do with mortar. It’s a lot more durable, right? You’re not gonna have to see all the little cracks like you get in mortar, less frequently in, and… I don’t know, what’s the life span of a concrete crown, Ruben?

RS: A lifetime, I’d say. One of the chimney companies here in the Twin Cities that we still refer today is Jack Pixley Chimney Sweeps, and that name comes from the late Jack Pixley, and this guy would go around and he would teach at our ASHI seminars, and he’d teach at our monthly meetings, and he was just… I mean, this guy was all about raising professionalism in the chimney trades, and he would teach at the national level, this guy was well-known. And he had this nice diagram and he called it, a cap to last a lifetime, and I think it’s still what we use in our inspection reports, showing the concrete cap where it sticks out past the edges, and that’s what I’ve always called it. I’d say this really is designed to last a lifetime, these are great.

TM: And people might wonder, “Well, if they’re so great, why don’t we see them more? Why do people use the mortar instead?” Well, because of the cost, right? It’s a lot more work and a lot more money to have a concrete crown.

RS: Yeah. And if you wanna know which one you have, you just look at the top of the chimney, and if it looks like you’ve got mortar making a nice slope from the flue, the clay tile that’s sticking up out of the chimney and it just kinda tapers down and then ends right at the edge of the brick, that’s a mortar cap, that’s what Tessa’s talking about. You can just smear a bunch of mortar on there. Now, a concrete cap, like Tessa said, it sticks out past the edges, but to do that, someone needs to get up on the roof, you’d probably use scaffolding, build a wood form, have it stick out past the edges, pour the concrete, and then someday they’ll come back and they’ll take that wood form down and make it all look nice and pretty. So it’s way more involved than just smearing some mortar on there, and as such, of course, it costs a lot more money too. That’s kind of the big reason that it’s unusual to see these.

TM: But Bill, back to your question about which areas of these masonry chimneys have the most problems, I was just describing the exterior and kind of the common area that we as home inspectors identify as being problematic, and when you’ve got a mortar cap that’s got cracks and gaps in it, or you’re missing the spark arrestors, or you’re missing mortar on exterior walls, those are all locations for a potential water intrusion and issues, but I mean, there’s a whole bunch that we really can’t see that could be happening inside the flue of these chimneys, right Reuben?

RS: Oh my goodness, yes. And how often is there a problem where the strict standards of NFPA 211 would say that it’s not safe for use? I don’t know, I’m thinking of a number Tessa.

TM: I’m thinking 99.99% of the time. [chuckle]

RS: Something like that. That’s about what I had in mind. Yeah. None of them pass inspection.

TM: Yeah.

BO: So the cynical guy over here is thinking, after seeing a few of these, I’m not nearly as experienced as you guys are, but it always felt like what I saw was there from day one, it was built this way. Like when you see a gap in mortar at a flue that’s two flue sections above the throat, that didn’t get washed out by water, and if it looks exactly the same there as it did at the top, they just didn’t do a good job sealing it. Now, I was under the impression that at some point, the standards of building these things were raised quite significantly, and so… No? Ruben’s shaking his head no. Alright, no.

RS: No, they have changed, it’s not to say they haven’t changed. I took a trip down history lane on one of my blog posts many years ago, trying to figure out the hearth extension requirements, and I was able to get my hands on building code books going back to the ’50s. And so that then I do know they did change, but they didn’t change much, so…

TM: That sounds like a fun trip only you would enjoy. [laughter]

BO: Okay, okay, now you’re talking about codes, I’m talking about craftsmanship, and what I mean by that is, the code may have not changed but there is an inspector on this planet that was actually looking down, climbing up and looking down to make sure there were no gaps around those flue liners. They’re…

RS: They’re still not today Bill.

BO: Well, I understand that, but people like us come along with our fancy little cameras that we stick up and we say this thing needs to be sealed, there’s gaps. Do you see these gaps?

TM: Sorry to interrupt you Bill, but we should clarify how we inspect these chimneys at our company and then what we actually recommend to clients that are buying these houses with these wood-burning masonry structures ’cause there’s a difference.

BO: Okay, so we take a pole and it’s flexible, and it’s got a camera on it, and you jam it up. It’s a chimney enema. And you…


RS: Well, but that’s not included in the standard… The ASHI standards of practice and what we do on a typical home inspection, we’re not using that camera to scope the inside of the chimney, we, as home inspectors, we’re doing our best to inspect the exterior of it if we can remove a spark arrestor or a cap and look down with a flashlight we’ll do that, we’ll look at the inside of the fire box and stick our head up in the throat, use our flashlights to look at the flue tiles as best we can, but if someone wants to have the inside of that chimney flue, the clay tiles inspected, they need to hire, ideally someone who is CSA certified, Chimney Safety Institute of America certified to do a, what we call a level two chimney inspection. So that’s an additional fee in a separate inspection.

RS: Well put Tess.

BO: Gotcha. Okay, so I have a question about the throat.


TM: Yeah.

BO: So imagine the back of my throat is fairly smooth, humans are… They were delivered to this planet…

TM: This is a weird analogy already. [chuckle]

RS: Yeah pre-Covid.

BO: Yes, but we were all delivered in just about perfect form. I don’t think I’ve ever seen a throat in a chimney that was smooth like it’s supposed to be.

TM: Yes.

BO: And I don’t know how anybody would actually get in there and make it the way that we would like to see it. It feels like chasing your tail, the proverbial chasing your tail.

RS: Yeah, and I used to kinda think to myself, alright, this is what’s supposed to happen. I never see it done this way, what’s really the big deal? Does this even matter? All this little stuff like these little cracks and these little mortar joints, people have had this fireplace here for 20 years, they’ve been living here, they use it all the time, so what are we doing making a big deal about this stuff? Right? That’s what you’re after, right Bill?

BO: I’ll agree to that, yes, what are we doing making a big deal about this stuff?

RS: Alright, I have an answer to that. I have a blog reader, this was probably about seven years ago, and he said, “Reuben, you don’t know me, but I’ve been reading your blog for a while,” he lived out on the east side of town, and he said, “I’m having my siding replaced, and I’ve been in this house since it was built, and there is severe charing on the sheathing on the outside of my house going all up and down the chimney,” right at the area you’re describing Bill, right around the throat. And he’s like, “What in the heck is going on?” And he ended up calling out a couple of different fireplace inspectors, and he also got the building officials out from the city who had inspected this house when it was built. I believe it was a ’90s house, and they came out and everybody was on the same page, they all knew why this was happening. You know why it was happening, right Bill?

BO: It was built in the ’90s.


RS: There was no Parging in the throat. When you look up inside the throat, all you see is the rough edges of each brick, and throughout that entire throat, it needs to be parged. You need to have a smooth transition, and that’s gonna prevent hot gases from seeping in between those bricks. And it was never done, and this was near the point of starting this guy’s house on fire.

TM: Wow.

RS: So after I went out and saw that with my own eyes and I took pictures, and the pictures are on my blog, when I talk about chimney safety, I take it seriously now. The NFPA has come up with these standards based on people’s houses burning down, not based on, “Hey, this feels good, let’s do it.” This is real safety stuff.

TM: Reuben, can you explain what NFPA 211 is and why we recommend people follow their guidelines?

RS: Sure, yeah, NFPA is the National Fire Protection Agency. They’re the ones who write all of the fire codes such as the electrical code sprinkler codes, that’s the reason we have exit signs and all that other fun stuff. So they are the authority on fire safety throughout the US, and one of their books is called NFPA 211, and that’s where we get our standards for building fireplaces and inspecting them and maintaining them. It’s not law here in Minnesota, it’s not law anywhere to the best of my knowledge, but it is referenced repeatedly throughout the state building code. So some of those standards are kind of law in Minnesota, but the inspection standards are not incorporated, but it is the standard to go by when it comes to safety for a fireplace.

TM: But whenever someone’s buying a house that has this masonry wood-burning fireplace we recommend that they get it inspected per these standards. Correct?

RS: That’s right, and that’s what NFPA 211 says, is that any time you got the sale or transfer of a property, you need to have a level two inspection done. And so of course, it’s not law, nobody is forced to have this done, but it’s a very good recommendation and Tessa, why does it matter? Why have this done when you buy a house?

TM: Man, so that you know what you’re getting yourself into, because 99.99% of the time, these chimneys fail, these level two chimney inspections. And how much does it cost to make these chimneys per these standards safe to burn wood in? We’re talking thousands and thousands of dollars. Right?

BO: Yes, and that’s why… See you guys recommend a level two, I just recommend you put in a natural gas insert because the cost to do that is less than rebuilding this chimney. So I say that… Tongue in cheek, but it’s what I did in my own house, and I’m glad I’ve never looked back from my wood-burning box that smelled in my basement.

RS: Well, I can’t disagree with you, Bill. I mean, I’m totally on the same page. If I’m buying a house and it’s got a masonry chimney and a wood-burning fireplace, I would like the idea of using the wood-burning fireplace, and I would probably get that level two inspection done. The price is usually somewhere in the neighborhood of about 200 bucks, and I would wanna have that done so that if I wanna build a wood fire, I’ll go ahead and do it. But if anything comes up during that inspection, and it surely will, I’m gonna do what you suggested Bill, I’m gonna put in a gas insert, it’ll cost less money, you flip a switch and now you got a fire. And the beauty of these things is they add heat to your home versus a wood-burning fireplace, which actually removes heat from your house, so… Yeah, I’m with you.

BO: Yeah. And we should clarify… When you say a change of ownership, the reason why we’re talking about that is because the old owner might not use it the way the new owner’s going to use it.

RS: Yes, that’s another really good point that NFPA has, is that’s why they say when you have a change in ownership, because people are gonna use it differently, you may have had a family who was there for 20 years and they might use the fireplace every day and they use little logs and little kindling and they keep it going. And then you get the next owners who come in, you get some dumb teenagers, like I was… And the goal is, let’s see how hot we can get this… I remember we made that fireplace so hot growing up that the glass cracked on the door.

TM: What? Oh my gosh [chuckle]

RS: Yes, yes, we broke the glass, we got that thing so hot. So you get some dumb teenager like I was and they’re gonna see how hot they can get it and you keep it going for a long time, and this is a different use, you are stressing that thing like it has never been stressed before, and you can’t say, well, duh, the house burned down because they built the fire too hot, you should be able to build a really hot fire in there and not have your house burn down. That’s the level of safety we need.

BO: What did your parents say about that.


RS: I don’t remember anything having been said, it was just one of those things. They expected us to build hot fires, uh, it cracked, oh, What are you gonna do?

BO: It feels about what Neil would say. Anyway.

RS: Yeah, yeah. He’s pretty easy going.

BO: My dad, not so much. There would have been words and lots of them, usually four letters in a chain, but I digress. Okay, so other than the fact that I’m a proponent of gas, it doesn’t let me off the hook of having to maintain the exterior of my chimney, when the bricks are falling out, I still have to fix those, but it removes one variable from this equation that seems to be fairly expensive. And don’t forget, you have to remove bricks from the exterior to fix the interior, unless you do what? Which we all think is or know is the Cadillac of fixing a wood-burning chimney.

RS: Sorry… What do you mean? The liner?

BO: Oh my goodness, I stumped the two experts. Look at that.

RS: Well, I didn’t know where you’re going. I mean…

BO: Yes. It’s the stainless steel liner, it’s the super expensive liner that allows you to burn wood forever. So…

RS: Sure, sure. Yeah, yeah, those are nice. The challenge with those is that most of the time, there’s not enough room in there to just drop a corrugated stainless steel liner down there, now you’re reducing the flue size so much that the firebox opening doesn’t match it, so to get that to fit, usually they gotta break apart that clay liner, they take a big drill with a big rod and a ball on the end of it, and they bust it all apart and it all falls down to the bottom, and then they’re gonna have enough room to put that liner in… So it’s a big deal to put these liners in.

TM: Gosh. And you know what, a little factoid for you guys, the CPSC says there’s over 20,000 chimney fires per year, in these masonry chimneys…

RS: That’s crazy. That’s insane. The take away from that is that so often people say, Well, you know, this chimney company came out and they said it’s got a bad liner, just because they’re trying to sell a $10,000 liner. And we had Joe Schmoe’s chimney service, they came out and said, it’s perfectly fine. Well [chuckle], my challenge to you is, what certification does Joe Schmoe’s chimney service have, and what type of inspection did they do? And if they look back at you and they go, Huh, it means they’re not using any type of inspection standard, you got some hack with a flash light looking up inside the flue, and they’re going, Yep, looks good to me. Side note, you guys, I have to share this. I was on NextDoor the other day, this is in my neighborhood, and somebody had posted this question on there saying, “Hey, does anybody know of any good chimney people in the neighborhood, ’cause I’m looking… I wanna get it checked out.” And someone says, “Why do you wanna have it looked at?” And she said, “Well I just moved in, we’ve never used it before.” And the same person asking, he writes back, he says, “Just get a flash light and look up inside there, if it all looks clean, you’re good to go, if it doesn’t and it’s all dirty, just build a fire and all that soot will burn off and you’ll be good to go after that.” [chuckle] I could have died.

TM: Oh. Explain why that’s probably not a good option.

RS: What he’s describing, I mean this person has no idea what they’re talking about, but what he’s describing is you build a fire and then your soot, the creosote…

TM: Catches on fire.

RS: Catches on fire and you now have a chimney fire, this doesn’t just burn off, this is what will burn your house down. So this is really, really bad advice, so please don’t go to NextDoor for… No, I don’t care where you go, but there’s some hacks out there, that’s all. I just… I was reminded.

BO: Just make sure you verify the information you get off of these sorts of community sites.

RS: That’s good stuff.

TM: So you have been burning fires in your wood-burning fireplace, how often should you get that flue cleaned?

RS: I believe it’s somewhere around every 30 to 50 fires is a good number. Some people say, oh, get it cleaned annually. Well, if you build five fires a year, you sure don’t need that, it’s more about how often you use it, and one of the big variables there is what type of wood you’re burning, you’re burning clean dry wood, oak, stuff like that, you probably don’t need it done all that often, but if you’re burning some nasty stuff in there, like I surely did growing up. [chuckle] You’re gonna wanna get it cleaned a lot more frequently.

BO: Do we need an episode on which wood to burn inside a fireplace for optimal life expectancy and less creosote buildup? Yeah, it feels like way too much, too much info for me.

TM: Me too, and our audience, I’m sure.

BO: Going back to my childhood, there was more than one family interaction that was probably not ideal over green wood versus dry wood. My dad was very specific about what went inside the… We had a stove. [chuckle]

TM: Okay. Well, you know what, actually coming to think of it, my dad was a big advocate of those Duralogs, those things that you buy that clean the flue out. Are those complete trash or do they actually do what they say?

RS: I don’t know, I’m not really sure.

BO: You’re gonna have to do a before and after, Tessa. Go to your dad’s house, brings some Duralogs, burn ’em up…

TM: Well, we don’t… That was the house I lived in Wisconsin. Shout out to Plain, Wisconsin. Yeah, we sold that house 20 plus years ago.

BO: Plain, Wisconsin’s no ordinary place.

TM: [chuckle] It was very exciting, Plain.

RS: While we’re on that topic, though, about what you should burn in there, yeah, the chimney sweeping logs, I don’t know about all that, Tessa, but I remember I used to hear people get concerned with the fake logs ’cause they had the idea that these would produce a lot more soot, and that they’re actually bad for your fireplace, and I can tell you that that’s a myth. I did a blog post on that topic just recently, back in 2011, or wait, no, that was a while ago.

TM: Recently. Nine years ago.

RS: Yeah, I did a blog post on that. Artificial fire logs are actually cleaner, safer, easier and cheaper. Everything you can measure about these is actually better, except you don’t have real wood. And for me personally, I still prefer real wood. There’s something about the crackle.

BO: It’s the snapping, it’s the crackle, it’s the smell.

TM: Well, everyone can get on the same page that a real wood fire is really nice, right? But then, from a functional standpoint, and from a maintenance standpoint, and a safety standpoint, it doesn’t make sense at all. I’ve had this argument with Jay several times where he talked about, if we ever build our own house one day and he wants a wood-burning fireplace, I’m like, “No, we’re not doing that.” He’s like, “Well, why?” Well, the cost of a masonry wood-burning fireplace, number one, and then to maintain that, all the tuck pointing, the crown, all of that, and then you’ve got the issues with just the cracks and the gaps that happen over time in the clay flue liner, and potential issues with chimney fires, cleaning it out, and then the whole thing of you actually lose heat when you have a fire in a wood-burning fireplace. You lose heat from the house. It doesn’t warm the house up. Didn’t MythBusters do an episode on that, Reuben? Go check that out.

RS: They sure did, yup. Yup. It’ll warm up the room you’re in, but that’s it. The rest of the house gets colder.

TM: The radiant heat from it will warm up the space, but the rest of the house will actually lose heat. And so it makes so much more sense. It’s safer, it’s less maintenance to have a gas insert installed, and that’s more energy efficient.

BO: I think Jay was just messing with you, Tessa. I don’t think he actually thinks he wants a wood-burning fireplace.

TM: He does, he does to this day. And I wish he’ll listen to this podcast, so he understood why it’s not a smart idea. Well, especially if you’re building a newer house too. If that house is gonna be very air-tight and energy efficient, and you will not get that wood-burning fireplace to draft properly, unless you open up all the windows, which is not a good option either.

RS: Oh my goodness, we’re on that topic, Tessa. I’m in the middle of rewriting an old blog post on how to calculate make-up air for your home, and when you look at the calculations, the tables about what needs to be done in your home when you have a wood-burning fireplace, it’s just crazy.

TM: Yes, definitely. Well, I have seen some houses, some newer houses, high-end ones, we’re talking million dollar plus custom homes that have a wood-burning fireplace, ’cause obviously people like that, and then they have issues with not getting it a proper draft. And so what they’ll do is they install these… Basically these fans. What are they called?

RS: Draft assist fans.

TM: Draft assist fans, yeah, on the top of the flue of the roof that actually pulls the air out so that it can draft properly.

RS: Yeah, and there’s also a big area in Minneapolis, right around the airport, where all of the homes that have wood-burning fireplaces have those things installed. This was part of the MAC Program, the Metropolitan Airport Council. They had to go through and basically soundproof all of these homes, some type of settlement they had for everybody within a certain area, they had to soundproof them. So they go through and they insulate the heck out of these houses, they button them all up, so you don’t have this noise coming in, and they started ruining all of their homes because they weren’t taking into account building science. They would have combustion problems with their natural draft water heaters or fireplaces wouldn’t work right anymore. And so they went, “Oh, wait a minute. We gotta look at the whole house. This is a system.” So then they started having to replace water heaters with power vent water heaters, they’d replace furnaces with sealed combustion furnaces, and then they’d put those draft assist devices on fireplaces. So there’s a big area in Minneapolis where it seems like all the houses have those things.

BO: Well, I’m gonna have to jump in because you just teed up the next episode, which is unintended consequences. No, I’m kidding. We should probably actually talk about that.

TM: We should.

BO: Messing around with the piece of old houses, but…

RS: Didn’t we just do that podcast? I feel like Tessa waxed on that just a month ago.

TM: We talked about… I feel like we teed it up, but we didn’t get into the actual nitty-gritty and some examples of what we see.

RS: Okay.

BO: Alright. Well, Reuben just did, so look for that in a future episode, but I just have one closing thought. I just can’t think that some mechanical device attached to your chimney to help your fireplace actually work is a good idea. I feel like there’s a lot of room for failure in that equation, and… Maybe all of a sudden your chimney’s just not working really well, and your house is full of smoke. What happened? Oh, the fan broke. Tough luck. Now you get the disaster people to come and clean all that nasty of your house because fire stuff is terrible for you. So, icky, icky. Anyway…

TM: Yeah, it’s not a very durable system, is what you’re saying, Bill, to put a little fan on the top.

BO: Just doesn’t make me feel good, so…

TM: Right.

BO: Thanks, everybody. You’ve been listening to Structure Talk, a Structure Tech presentation. My name is Bill Oelrich, alongside Reuben and Tessa, and we will catch you next time. Thanks for listening.