Robin Jade Conde

PODCAST: Big and unusual home inspection finds

Today’s show talks about how home inspectors go beyond the call of duty and help homeowners more than expected.
Reuben explains wood foundations and moisture testing, polybutylene plumbing  and leaking. Tessa talks about health and safety issues such as drafting at combustion appliances, microbial growth in houses and elevated levels of moisture. Bill shares his experience with carbon monoxide during inspections. They also discuss aluminum wiring  as the worst and most expensive electrical problem that they may encounter during an inspection.
Bill asks about the quality of asphalt and organic shingles, and vermiculite insulation in attics. Reuben mentions that asbestos in this insulation causes health hazards. They also talk about balloon framing and molds in the attic.
Watch Reuben’s class on water intrusion here: Home inspector training: how to find water problems at walls – YouTube.



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: It’s quiet in the house today ’cause we don’t have a guest for this week’s episode, so we’re gonna go into what we call a garbage can conversation.


BO: Welcome, everyone. You’re listening to Structure Talk, a Structure Tech presentation. My name is Bill Oelrich alongside Tessa Murry and Reuben Saltzman. As always, your three-legged stool coming to you from the Northland, talking all things houses, home inspections, and anything else that’s rattling around in our brain. How you guys doing today? 

Tessa Murry: Doing good.

Reuben Saltzman: Fantastic, thank you.

BO: Very good, very good. What we’re gonna talk about today is we’re gonna talk about all those little scary boogeymen that live in houses, that if home inspectors aren’t looking out for, they can really get stuck by or get stung by, or whatever other painful affliction you wanna throw at. So…

RS: Burned. Get burned by.

BO: Burned, yeah.

RS: Yup.

BO: Biting seems more appropriate than burning, but whatever. I mean, you can play with fire if you want, Reuben. That’s fine.

RS: Yeah, alright. Sounds good.

BO: So why are we talking about this? Well, every now and then around the shop, something happens where you’re like, “That was a good find.” Or, you look at a picture and you realize, “I stared at this defect trying to figure it out and this other thing that was completely obvious, I didn’t see because I was looking so hard at this little detail,” right? And Reuben, I’m sure you’ve done this a thousand times where you’ve gone home and you’ve looked at some photos you took and you’re like, “Holy cow! I gotta report on that now too.” And that’s why we like taking so many photos when you’re out doing your work, right? 

RS: Yeah. Yes.

BO: Let’s line this up. So if you’re looking for boogey people who live in closets that are very scary, [chuckle] when it comes to home inspections…

RS: You’re trying to be very PC with that, Bill. You didn’t say boogeymen, you said boogey people.


BO: Yeah, well, I’m trying to do my part.

RS: Alright, very good.

BO: So let’s list them. What’s the big thing? And I’m the reason I’m asking it, I’m gonna just start, polybutylene plumbing, right? 

RS: Yeah.

BO: That’s a big deal. We can get into why it’s a big deal in a little bit, but aluminum wiring? 

RS: Huge.

TM: Yeah.

BO: Can’t miss that. Concealed water intrusion? 

RS: That’s… Oh, yeah, that’s a huge one for me. Oh, my goodness.

BO: You are kind of a water guy.

RS: That’s kinda my jam, like, if there’s one thing that I really like being able to find during a home inspection where I kinda think to myself, “Most people wouldn’t have found this,” it’s gonna be water intrusion. Finding that concealed area where the siding all looks good, but behind all that vinyl that looks great… I mean, and this is coming right off the heels of the show we just did with Mark Parlee, where you find those areas where it looks perfectly fine on the outside and then you peel back a layer and there’s nothing behind it. I feel good as a home inspector when I can find those defects.

TM: Well, and side note, when I was in training and I was actually shadowing Reuben, I remember thinking, “How the heck did he find that?” Like, on this huge house, he zeroes in on a spot and he starts poking, prodding around and finds this water damage behind this wood siding on this 1970s house underneath a window, and I’m like, “How the heck did he find that?” ‘Cause you couldn’t see it from the outside, you couldn’t see it from the inside, but if anybody listening to this podcast wants to know Reuben’s tricks about how to find exact locations of water intrusion…

RS: Preach.

TM: You have a class. [chuckle] We have a class available online. Do you wanna plug it? 

RS: Yeah.

TM: Yeah.

RS: We’ll put a link to it in the show notes. It’s a one-hour class that’s really intended for real estate agents, and I think we’ve got a two-hour version of it that we do for a home inspect… Maybe I’m confusing the two, whatever it is, [chuckle] it’s a long class and I made it free on YouTube and we’ll put that in the show notes.

TM: Yeah. Yeah, it’s a great class.

BO: So you have a nose for water, but water’s not the only thing that’s troublesome with houses. What else do we have going on? 

TM: There’s a lot of health and safety issue things that I look for too, and I know this goes above and beyond our standards of practice, if we’re following actually standards of practice. But looking for issues with backdrafting combustion appliances, problems with microbial growth in houses and elevated levels of moisture that can affect people’s health, things like vermiculite or friable asbestos that can get into the air people are breathing. Those are… I think, to me, those are all big deals too.

BO: The vermiculite conversation is one of those conversations where it goes anywhere from, “Egh, it’s in there,” to, “Oh, my god, I’m gonna die of cancer.” And it just depends on who’s involved in this conversation. I find that one to be fascinating, quite frankly. Well, what else have we got? I was thinking wood foundations. We see the occasional wood foundation up here in the Northland…

RS: That’s a huge one.


TM: Yeah, yeah.

RS: Yeah.

BO: It feels like a bad idea, but I remember back in the day when I worked at a lumberyard, the guy who owned the lumberyard built a bunch of spec houses, he’d lived in ’em and keep ’em for a year or so and then he’d sell it, and he built wood foundations all the time. I don’t know about this, and now I’m totally, no way, I have no interest in that.

TM: Yeah, it does seem like a bad idea, right? Let’s take some wood, bury it in the ground, wet soil, and see how long it lasts. But how many houses do you guys think are actually wood foundation out there? What percentage of the existing housing stock is wood foundation? 

RS: It’s gotta be less than 1%.

TM: Okay, that’s what I was thinking too, ’cause I feel like in the last five years that I’ve been inspecting that I’ve only run across a couple…

RS: Yeah.

TM: Maybe two.

RS: Yeah. They’re pretty few and far between. But boy, when you come across it, I mean, it’s just about never something where somebody knows that they’re buying a house with a permanent wood foundation, they just assumed it’s a traditional concrete block foundation, they don’t bring it up to you during the inspection. And there’s that disclosure form that the seller needs to fill out and there’s a box to check where it says the type of foundation. What if homeowners don’t even know that they have a wood foundation? So they just pencil with the form, they say concrete block or whatever, and you’re doing the inspection, and you’re not really even actively looking for this, because the instances are so few and far between. We see so few wood foundations, you’re not really even on the lookout for it.

TM: Yeah.

RS: But then you get all the way around the house and then you just… You kinda notice that all the areas that the foundation, the siding comes really close down to the ground and you’re like, “Wait, I haven’t even seen any of the foundation yet. This is odd.” [chuckle] And then you start actively looking for it and you realize, “I cannot find a bit of concrete. Everywhere where I should see concrete, I see plywood coming down into the ground, and people will do that with concrete. They’ll put some type of skirt over it, they’ll cover it, and you just kind of assume, “Well, yeah, they’re covering, but it’s down there.” But then you start digging into it and finally you realize, “Wait, this is a permanent wood foundation.” And it’s like this realization, and you think, “Oh my goodness, how many houses with a wood foundation have I already inspected… “


TM: Yeah.

RS: “And I didn’t even realize I was looking at a permanent wood foundation, and I just… I miscategorized it.” Anyhow, hopefully the answer is always zero, but…

BO: Yeah, for you it’s zero, there is no doubt.


RS: Oh, I don’t know, Bill. I’ve been surprised or I get almost all the way around the house before I realize, “Wait a minute, this is not a traditional foundation.”

BO: Inevitably, the drainage and grading is the worst you’ve ever seen.


RS: Yes, yes.

TM: Yeah. No gutters…

RS: You’re absolutely right.

TM: Ground slopes towards the foundation.

RS: And those are requirements. If you’re building a permanent wood foundation, you have to have really good grading, you have to have gutters, you have to have a good water management system, but somehow they’re always the worst.

TM: Yeah, yeah.

RS: I don’t know why that is. Please tell me.

TM: Well, actually, like you said, probably people that are living there don’t even realize what they have, or if they do, they don’t… Just oblivious…

BO: Perhaps a higher power just trying to accelerate the inevitable demise of this thing.


TM: Well, and how many of them, Reuben, have you inspected where they… You don’t find problems with them? 

RS: One.

TM: Out of how many? 


RS: Several dozen.


TM: Okay. [chuckle] Yeah. Yeah.

RS: I’ve looked at several dozen and I think there was one where I was concerned about an area and the basement wasn’t fully finished, and I was able to pull back the fiberglass insulation in kinda one of the worst areas, and there was just some very minor staining. It looked like it may have been wet once or twice, and they had a downspout dumping right to that corner. I was like, “Alright, fix your downspout. You’re probably gonna be just fine. I don’t have any big red flags.” That’s probably the best one I’ve found.

TM: Wow.

RS: Yeah.

TM: Yeah. Well, and they’re tough too, ’cause normally they’re fully finished on the inside, so…

RS: Yes.

TM: You really can’t inspect anything visually, it’s hard to at least.

RS: Yeah, yeah, and I don’t know if we’ve done a podcast on this, but we kinda came up with our own moisture testing protocol for permanent wood foundations, because we’d run into so many of them, and once we started doing moisture testing on stucco homes, and we bought a moisture testing company, we started having people ask about that, and so, we came up with a protocol for permanent wood foundations where we would remove the baseboard trim in a bunch of areas in the basement, and we’d stick moisture probes in the wall, or we’d cut back some drywall underneath the baseboard trim, and we’d actually look at the foundation walls in various areas, and then we’d bring a nailer with us and then we’d put the trim back in place. You’d have nail holes that somebody would need to patch. And of course, this is all done with a lengthy permission slip that the homeowner needs to sign off on.

BO: I say.


RS: Yeah, we detail exactly what we’re gonna do, a maximum of eight locations, and it’s not gonna be perfect, there’s a chance we could break the trim taking it off, like, you gotta be cool with this and we’ve done it on a lot of houses.

BO: It’s just one of those things that makes so much sense when you wanna finish your basement, and then it makes no sense when you think of 150 years from now. Okay, let’s get to the polybutylene pipes, because we had one of our newest team members, this happens on a regular basis. So you get out of training and you’re fired up and you’re ready to go, and you go, and this is a simple house, what could be possibly wrong with this? Well, it’s like the second one you go to on your own, [chuckle] and it’s got some odd ball thing.


TM: Yeah.

BO: And it’s polybutylene pipes. What’s the deal with these pipes and why are they a problem? 

RS: Leaks, basically, if we’re gonna say it in one word. The fittings tended to fail and they would fail with no warning. It’s not like it would slowly have a little pinhole leak. They would just rupture and you would have tons of water flooding a house. And there was a major class action lawsuit against PB or polybutylene piping and any of the stuff out there is a suspect. As far as I know, there is no recourse for somebody who has it today. I think any of the money that was available is gone. I suspect that the houses that have this piping where they haven’t leaked, my gut feeling is, they’re probably going to be okay, but there’s gonna be… For every time I say that, you’re gonna have five more plumbers going, “No, I’ve found this and I found a leak last week.” And you’re gonna have this anecdotal evidence to say, “No, it’s all problematic.” So, what I’m telling you on the podcast is probably not something that I would say to somebody who’s buying a house with this. I would tell them this stuff is known as a problematic material, and it’d be a good idea to get a plumber come out here and either put their blessing on it, have a plumber tell you it’s all good, or have it replaced. One of the two.

RS: And you know, the piping itself, it looks just like PEX. I mean, it’s almost indistinguishable from PEX, except you gotta think about the age of a house you’re looking at. I mean, if it’s an early ’90s house and it has PEX, it’s probably not PEX, it’s probably polybutylene. And the only way you’re gonna know the difference is by looking at the markings on it, and all the plumbing, it’s gonna have this little serial number or model number printed on it. It’ll say PB, and then it’s a four-digit number that I can’t remember off the top of my head, but it’ll be printed. It’ll have PB printed on there, and that’s how you know it’s PEX. It wasn’t the actual tubing that would fail, it was the fittings for it. So, that’s…

BO: Okay.

TM: Reuben, PB was around even in the ’70s, wasn’t it? ’70s, ’80s, ’90s? 

RS: I don’t remember the timeline. I don’t know.

TM: But up through the ’90s, though.

RS: Yeah, yeah, exactly.

TM: You don’t see PB after the ’90s.

RS: That’s right. Yeah.

BO: But it was the actual fittings at the joints that failed, not the cramp or the clamp or whatever they used to fasten it? Was it the fittings themselves that fail? 

RS: The fittings themselves, and I think the crimp rings would fail too.

BO: Okay.

RS: But my point is, it wasn’t the tubing itself.

BO: Okay, okay.

RS: Yeah. It’s wherever the piping would begin or end is where you’d have failure points.

BO: Okay, well, at least plumbing doesn’t run all around through your house and…

RS: Ha-ha, ha-ha.

BO: Enclosed inside of walls and floors and stuff.


RS: Oh, wait a minute. It does.


BO: What else do we have? Aluminum wiring is the one thing that pops out too. I remember early on when I was inspecting, I called Reuben ’cause I had a question, and this was… We were able to actually FaceTime or do some… Much earlier than Zoom, ability to communicate through video. I sent you a video or something like that, I don’t know, and I was looking at this electrical panel ’cause I had a question about double-tap, and I was looking so hard at this double-tap that I didn’t see the aluminum wiring, and he was very gracious to be like, you see the aluminum wiring, right? I was like yeah, I totally had that marked down, but what about this? 


TM: Bill, you know what, I’m embarrassed to say, I have a very similar story. Reuben, do you remember? It was like one of the… I think it was the first or second house I had out on my own after I got…

RS: Pretty sure it was the first one.

TM: I think it was. I think it was the very first house I did on my own, and I was super nervous about it and like you said Bill, it’s so easy to get caught up in the details, right? You’re nervous you’re gonna miss something, you’re looking at everything very closely, and I had sent Reuben a picture of the electrical panel, I had a question, I think it was about a double-tap, breaker or something like that, and he’s like… Or maybe it was… Maybe there was a little bit of melting on a wire or something, and he’s like, Reuben’s like, “Make sure you don’t miss the force through the trees.” I was like, “What is… Oh my gosh! This is aluminum wiring.” Like, I was mortified. I was like, oh my gosh! I almost missed the worst defect you can find in a house. But it’s crazy ’cause I hadn’t seen a single aluminum wired house the entire period I was in training, and then the first house I get on my own, boom, there it was.

RS: Yes.

TM: And it’s different to see it in real life than it is to see pictures of it or something. So, thank you for saving me on that one Reuben. [laughter] I never missed it again.


RS: I bet not.

TM: Oh, man.

RS: And you got a story to tell it.

BO: You know what’s interesting? In that moment, you’re feeling bad, you’re like whew, dude, we dodged a bullet. But then immediately that is removed and you have this overwhelming sense of remorse for the property owner, ’cause they are going to have a big turd to deal with today. And I just feel terrible for people, ’cause they probably don’t know what they have, ’cause maybe they didn’t get an inspection or maybe it wasn’t explained to them what this was or why it’s an issue.

RS: Or the last inspector glossed right over it.

TM: Right. Yeah. Didn’t see it. For people that are listening that don’t know why aluminum wiring is bad, Reuben do you wanna explain that? 

RS: I’d say it’s the exact same reason that PB plumbing is bad. It fails where it begins and it ends. There’s…

TM: Good analogy.

RS: The wiring does not start on fire in the middle, it’s all of the connections and it’s a matter of failed connections, where it’s a much more expansive material than copper, and when it gets hot, it expands and then it doesn’t contract to its original shape, and the fittings become loose, and over time, it leads to oxidation, resistance of electrical flow, which creates heat and it repeats the process, and eventually, you have a fire start and it’s the… What is it? The Franklin Research Institute found it’s 55 times more likely to reach fire hazard conditions. So, in a nutshell why it’s bad, the Consumer Product Safety Commission has a ton of information about aluminum wiring on their website, about what you can do if you have aluminum wiring and it’s either you redo every connection where it begins and ends, or you replace it. Those are kinda your two options. Either one is really expensive.

TM: Yeah. I would say this is probably one of the worst things we can find as home inspectors, wouldn’t you agree? I mean, the most expensive problem you can find.

RS: For electrical, yeah.

TM: Yeah. Yeah, yeah.

RS: Yeah, definitely.

TM: Yeah. And we forgot to mention too, which age house would you be looking for this? Mid ’60s to mid ’70s? 

RS: Yeah. Yeah. About 1965 to 1972 was the really bad stuff. After ’72, they started using a different alloy that wasn’t nearly as bad, but I don’t get into trying to identify which alloy was used and whether the connections are right or not. At that point, we punt to an electrician and we let them sort it out.

TM: Yeah. I think I’ve actually found aluminum wiring branched circuit wiring in a house that was 1977 before.

RS: Wow! 

TM: So, you know, they must have been… Whoever wired that house was using some left over aluminum wiring stuff. I mean, maybe it was the kind that doesn’t… That’s not as bad as the 1965 to ’72, but still again, that’s… We can’t determine that.

RS: Yup. Yup. Leave that up to an electrician.

BO: So virtually, every system in your house has got one big black eye over the history of the materials that was used.

RS: Yeah. I can’t think of much. I can’t think of much that didn’t have big problems.

BO: Okay. So on a rough, we had organic shingles, right? 


TM: Yeah. Yeah.

RS: Yeah.

BO: Who thought that was a good idea? 


RS: Yeah. Those aren’t around anymore.

BO: Do you think there’s any houses left with organic shingles on them? 

RS: There’s gotta be some, but…

TM: Yes. Yeah, one of our newer inspectors posted a picture of it not long ago.

RS: And I bet it was in horrible condition too, wasn’t it? 

TM: It was. Yes, and he posts that… I’m like, “That can’t be organic shingles because they’re all gone now.” And no, sure enough, it was. He had some good close-up photos and you could tell.

RS: Yeah, so if you look at your roof and it just looks absolutely nasty, to me, identifying whether it’s organic or not doesn’t really matter. It’s nasty. It’s time for a new roof.


BO: Was there a time when home inspectors were meant to identify an asphalt versus an organic when they were in good condition? 

RS: The standard of practice says you need to identify the type of roofing material, but the standards are vague. They’re not gonna tell you that you need to get down to that level of detail. If a home inspector says it’s a three-tab shingle, not… That’s all that we do. We identify three-tab shingle, architectural shingle, we don’t say the composition of the shingle. So I’d say no. Your standard of practice doesn’t require you to report on that.

BO: Okay, that’s good. So moving into the attic, we have vermiculite insulation that was used for a period of time and that’s all great. Who vacuums the insulation out when they drill a hole through a wall or run a wire, and when that stuff comes pouring out, the dust is really, really, really fine, so…

RS: It’s not necessarily limited to the attic space. You can have that in other areas too. We just… We had an inspector share a photo with us just recently where they had all the vermiculite fall down the wall and the whole bathtub area where you got the bathtub drain and the shut-off valves and all that. That whole area’s buried in vermiculite insulation. So it doesn’t need to be limited to your attic. Oh! And I’ve got a buddy of mine who had a house where it was falling down into the basement in the laundry room, and he said his wife was so freaked out, she was ready to move out of the house.

TM: Oh, wow.

RS: That was serious.

TM: Yeah, I’ve seen that in a few older houses I’ve inspected where it’s balloon frame walls, and they had it in the attic and it’s come down the exterior walls and showing up at the rim joist in the basement.

RS: Yeah.

BO: Balloon framing is not something you see very often.

RS: I don’t know how to identify balloon framing on a finished house.

TM: Well, I guess I’m assuming it’s balloon framing, ’cause how else would vermiculite get from the attic to the rim joist? And basically, age of the house, and when you’re in the attic on houses that are turn-of-the-century, sometimes you can look down at a gable wall in the attic, and you can see in between the rafters and you can look down if there’s no insulation. I don’t know if any of you have seen that before.

RS: Sure, you gotta be really skinny to get that far over to the edge, Tess.


BO: This doesn’t work in my world.

TM: Yeah, I was gonna say this is back in my insulation days.

RS: Yeah. And just in case anybody is wondering, balloon framing versus traditional platform framing. Balloon framing is where you’d have really long 2x4s, 16-foot 2x4s, and then you’d go all the way from the foundation up to the attic on a two-story house and you’d have no separation at the second floor, the second-floor floor, the first-floor ceiling, there would be no framing there. Today we stack stuff on top of 2x4s, but back in the day, you just attach it to the edges of 2x4s.

TM: Yeah. And then you would hang the floor system from the studs.

RS: Yeah, and you’d have a big passageway all the way from the attic to the basement.

BO: Is the vermiculite trust fund still open? 

RS: Sure is. We did a long podcast on that topic and… Yeah, if you have vermiculite… Oh, and we didn’t even talk about the problem with it, it contains asbestos.

TM: We didn’t. There we go.

RS: We are burying the lede here. Almost all of it will contain asbestos, and it’s one of the nastiest forms of asbestos where it’s really easy to have that stuff become airborne, and it can contaminate your house. Asbestos will cause asbestosis, mesothelioma. I can’t remember what else. Maybe lung cancer, don’t remember all the bad stuff it’ll do.

BO: None of it’s good.

RS: None of it’s good. Yeah, so you don’t want that.

BO: And even hard to clean out. How do you get all those fine particles out? And I’m sure there’s people who can do it and they probably use fancy techniques, but better not to find it than to find it.

TM: I was gonna say, when you hire someone who can remediate in vermiculite insulation, I’m pretty sure they de-pressurize the attic while they’re removing the insulation, right? 

RS: You know, we should get someone on the show and do a podcast about remediation.

TM: We should, yeah. I’m pretty sure they have to make sure that the attic is sealed off to the house, and then they use fans, I think, to de-pressurize it so none of the particles in the air from the attic can get back into the house while they’re vacuuming it out.

BO: Okay, so we’ve got wood foundations underground, we’ve got vermiculite up in the attic, we’ve got plumbing that runs all through the house, some bad shingles. Tessa, you were talking about some health and safety things. What were you thinking when you were talking about that? 

TM: Well, a couple of things that come to mind, just back drafting combustion appliances, and specifically, I would say the most common thing that we can find as home inspectors is natural draft or atmospherically vented natural gas water heaters, and especially in, I would say, houses that have been improved where people have… Let’s say they’ve replaced windows, they’ve air-sealed their attic, they’ve made the house tighter, they’ve added exhaust fans in bathrooms that they didn’t use to have exhaust fans, they’ve added an exhaust fan in the kitchen, maybe they’ve replaced the old furnace with a sealed combustion furnace. In theory, they’ve done all these things that improve the energy efficiency of their house, but people overlook this small detail that you still have this old water heater that relies on all of the air in the space for proper combustion, just the heat in the exhaust gases to rise up and out of the house. There’s no fan pushing it out or anything like that, it’s not sealed-combustion.

TM: And so, with that type of system, you really have to be careful and make sure that it’s drafting properly. And you can also run across problems with venting itself not being correct or not being sloped properly, or there being a block in the chimney or something, but I think this is becoming more and more of an issue today as we change out old furnaces with new furnaces and we leave these old water heaters in houses and we keep installing these atmospheric water heaters, ’cause they’re cheaper than a power-vent water heater. I know it goes above and beyond our standards that we’re required to do, but one thing that we do at Structure Tech is to do what we call a worst-case depressurization test, and we’ve probably talked about this on the podcast before. BPI, Building Performance Institute, is this credentialing organization, and they have this standard testing process to see if water heaters are drafting properly or not.

TM: So we try to follow that. I can’t say we do it to a T, but we definitely put the house in what we call worst-case situation, we make sure all the windows are closed, exterior doors are closed, we turn on all the exhaust appliances in the house to create a negative pressure, like the dryer, the bath fans, kitchen range, all of that. And we make sure that if you’ve got a furnace and water heater that draft together up the chimney, that the furnace isn’t running at the same time, ’cause that can actually warm up the chimney and help the water heater. So we make sure that that water heater’s been off, and then we turn on some hot water and make sure that we don’t feel any flue gases coming back out at the top, and that gap between the top, the water heater and the flue. And if it is spilling out, we call that, that water heater is back-drafting. And if it doesn’t correct itself within… Is that one or two minutes? What is the BPI current standard? I can’t remember.

RS: One minute.

TM: One minute? Okay, thank you. Then that water heater would fail back-draft test, and that’s an issue because you’ve got carbon monoxide, you’ve got moisture that’s coming back into the house and people are breathing that in. That’s a health and safety issue.

BO: I had one of those weird experiences when I walked into a house in the city. It was on top a hill, it was… There’s no reason this house should have had high moisture in it. And I walked in and it was soaking wet on the inside. It was a duplex, and tenant activity can be somewhat odd sometimes, and it was also an immigrant family, and there were several generations living under one roof and they were cooking a lot, and so there was a lot of boiling and a lot of stuff like that. But what I found quite by accident, because it was a super high house and I couldn’t get on the roof, is that the cap on the water heater had dropped down, and so this gas-burning water heater was not exhausting from the house, and so none of that moisture was leaving, it was just filling the house. And it wasn’t obvious at the time, but I got home and I saw a picture, I’m like, “That’s why.” I mean, windows were dripping.

TM: Wow.

BO: It was really interesting to see how much moisture was in that house, and there was no other explanation that I could find.

TM: Did you get a headache while you were inspecting that house? [chuckle]

BO: I pretty much probably had a headache all the time, so I don’t even know which days were headaches from carbon monoxide or just in general headache. But it’s weird, it’s… You guys have probably run into situations where your sixth sense is telling you something’s not right here.

TM: Yeah.

BO: And it’s only a matter of time before I open enough doors or pull off enough service panels that I’m gonna find the reason that this is happening.

TM: Similar to your experience, Bill, I had a house, and this has happened multiple times, and Reuben, I bet you’ve experienced this too, where it’s not the whole house that you feel the humidity, but you walk down into the basement and when you approach the utility room, it’s really warm and humid in the utility room.

RS: Yes.

TM: Have you felt that? 

RS: Yup.

TM: And usually it’ll smell a little bit weird too, and you’re like, “Okay, something’s back-drafting in here.”

RS: Yeah, it’s almost like a sweet smell.

TM: You know, a broiler…

RS: I don’t know how else to describe it.

TM: Yeah, it’s combustion gas. This is what we’re smelling. [laughter]

RS: Yes. Yeah.

BO: The sweet smell of combustion.


RS: I know that carbon monoxide is odorless, but the by-products of natural gas combustion, there’s something else in there where you can smell it. I mean, you know what you’re smelling.

TM: Yeah, so pay attention to that, but I think another big one is… And I’m gonna say the M-word, mold. Yeah, it’s mold, right? We’re all afraid to say mold, but mold is a big issue, and a lot of buyers we do inspections for, it can make or break the deal for them if there’s a house that has mold in it. And it’s not required to identify it, but I think it ties in with that what we’re doing is we’re inspecting this house and you have to be thinking about all these different issues and how they tie together, and who better to do that than a home inspector who’s looking at the roof system, looking at the siding, where the water goes on the outside, proper drainage and grading, the type of foundation that you have, the type of ventilation that the house has… You can kind of see occupant behavior too when you’re there, and if that’s impacted things. Are you seeing dark staining in the attic? Are you seeing condensation in the crawl space or mold in the crawl space? And keeping an eye out for all those things. Does the house have bath fans in the bathrooms? And all of that. I think that’s another really big one.

BO: How concerned are you with mold in the attic? 

TM: That is a good question. This is one that a lot of people have really strong opinions about. Me personally, I think it’s a sign of a bigger problem. You’ve got mold in an attic or dark stain in an attic, it means you’ve got a moisture problem. It doesn’t mean that you’ve got a ventilation issue. It means you’ve got moisture getting up there. And the first thing to do is to stop the moisture from getting into the attic, and you do that by air-sealing the attic so you don’t have warm moisture from the house rising getting up into the attic and condensing on the underside of the roof decking. And once you air-seal that attic from the house, you’ve got two completely separate spaces.

TM: And then in theory, that moldy air in the attic is never going to mix with the conditioned air in the house. It’s kind of like thinking, are you concerned about the mold that’s growing on your siding on the outside of your house? It’s outside your house, that once your attic is air-sealed, it’s outside your conditioned living space. So in that way, I wouldn’t be. But if you’ve got someone who’s deathly allergic to mold and you’ve got an attic that has a lot of bypasses connecting it to the house and you’ve got that air mixing and transferring, then it could be an issue.

RS: Yeah, and a lot of it is just perception. Good luck telling somebody that that mold in their attic isn’t gonna hurt them. Anybody’s gonna see it and they’re gonna… They’re gonna freak out. And that’s just what happens. So, a lot of this is just trying to manage perceptions and attitudes and unbiased fear and…

TM: Really… Yeah.

RS: We do what we can to manage that, but in the end, people are like, “Alright, thank you for explaining it. That really helps. Now, get it out.”


TM: Yes.

BO: Well, that falls in the whole situation where if you don’t own it yet, it’s not your problem to fix. But if I explain to you, “It’s not a big deal,” and you agree with me, and then you go to sell the house and it’s still there and the next person thinks it’s a big deal, now you’re holding this thing that’s not a big deal to you, and I guess you could always walk away from the person who thinks it’s a big deal, but… It’s just one of those things you just don’t wanna see it because you don’t wanna have to explain it later.

RS: Yeah, yeah, it’s a black eye on your house. And for that reason, a lot of people wanna deal with it when they’re buying, they don’t wanna deal with it when the next buyer comes in and freaks out on them, so… I get it.

BO: It’s sort of like chimneys where people are like, “Oh, I’m never gonna burn wood, so I don’t care to have a Level 2 chimney inspection done.” And it’s like, “That’s good. And I agree, but if the next person looks at your chimney and is like, ‘Oh, I wanna burn wood, it’s so beautiful, the smell, oh, the crackling.'” And then they find out the chimney needs a rebuild, now it’s… You’re negotiating. Okay, well, I think we’ve pretty much filled the garbage can full of one-off things. So, I think we should go ahead and put a wrap on this episode. Tessa, you’re the building scientist. Is there anything else you wanna bring up before you’re done with this? 

TM: [laughter] We could take a whole another episode just talking about building science stuff again because I love it so much, but I think we’re…

BO: Health and safety… Health and safety inside a house is a big deal? Is that what you’re saying? 

TM: It is, it really is. Yeah.

BO: Well, stay tuned for the Tessa Health and Safety review of all things structures. We’ll do that in a podcast and you can go really deep on all of these different things, so…

TM: Well, that’ll be fun. Different age houses, and all the different problems that each age house has, so people are freaked out to buy any age house… I’m just kidding. [laughter]

BO: You just can’t use the word “depends.” The whole episode.

TM: Oh, oh boy.


RS: Good luck.

BO: Alright, let’s do this. Let’s put a wrap on this episode. You’ve been listening to Structure Talk, a Structure Tech Presentation. My name is Bill Oelrich, alongside Tessa Murry and Reuben Saltzman. Thanks everybody for listening, we’ll catch you next time.