Foundations — Part 2
Do you really need to have a basement? Fine — then we had better talk about the right way to build one
Phil and I have returned to continue our discussion on foundations. In Part One, we covered slabs and frost walls, and in this part we cover basements and crawl spaces.
Do you really need a basement? If there's no programmatic need for a basement (like the need for a workshop), then perhaps you can do without one.
Insulation: Inside or outside? There are many reasons to insulate on either side. We weigh the pros and cons.
ICFs. Insulated Concrete Forms are sometimes but not always cost-effective. After discussing the cost-effectiveness of ICFs, I share a neat thermal break detail for the bottom of ICF walls.
CapillaryForces that lift water or pull it through porous materials, such as concrete. The tendency of a material to wick water due to the surface tension of the water molecules. breaks. Your concrete is like a sponge soaking up moisture — moisture out of the ground, and moisture originating as rain. You want to isolate your framing from this moisture. Also, I share the history of the termite shield.
Sill seals. We talk about a couple of our favorites, and, as promised, we provide links. We've recently been using a couple of Protecto Wrap products, the Triple Guard Energy Sealer and the Premium Energy Sill Sealer. Phil's office has been using gaskets from Conservation Technology
Thermomass. We have a discussion about this "inverted ICF" product. (Concrete on the outside, insulation in the middle.)
Crawl spaces. Just don't do them. If you do do them, treat them like mini-basements.
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As always, Phil treats us to a song that we should all have on the studio playlist. This time it's the song “Content to Reform” by Diane Cluck.
Thanks for tuning in. Have a great summer everyone. Cheers!
Chris: Hey, we’re back. How are you doing, Phil?
Phil: I’m doing great, Chris.
Chris: Great, great. Nice drinks!
Phil: Let’s pretend they’re not all done. We might need another to get us through the rest of the “foundations” topic. Foundations can be pretty dry stuff – if you do it right!
Chris: Nice one. We did slabs in Part One. So, Part Two: here we go! Let’s talk about full-on basements. Phil, where does the insulation go: inside or outside?
Phil: That’s a really great question! And you know what? We still do it both ways.
Chris: Do you? Yeah, we do it too. If you’re doing out-sulation (you know, when you’re wrapping the building in foam), because your wall has projected out in front of that foundation, it’s very convenient and easy to keep that foam insulation going (or the rock wool or mineral wool types of insulation).
Phil: Right. So, these are reasons why you’d choose insulation to the outside of your foundation wall.
Chris: Right. Maybe you want to make that thermal massHeavy, high-heat-capacity material that can absorb and store a significant amount of heat; used in passive solar heating to keep the house warm at night. work for you, you know? If it’s on the inside, it’s a warmer thing.
Phil: Right. And sometimes that works. But you also have to heat up that whole mass.
Chris: Exactly. Good point! Yes.
Phil: Right. It’s a good question. The way it would work well is if you wanted to dampen the effect of the temperature swings. That would slow things down, so that’s one reason to do it.
Chris: Martin wrote a great article on this. In fact, we’ll make sure that there’s a nice link off to the left of the page in the “Related Content” box.
Phil: He goes through a few other things which I think are always on our minds. Another reason to insulate to the exterior is that it gives you more room in your basement.
Chris: Oh, yeah.
Phil: You don’t have to fill the studs in. You just stick it to the outside. You don’t subtract your square footage.
Chris: That’s right.
Phil: Duh, that’s a pretty good one. You also run into problems with stairs, if you have a stair on the outside wall. That whole thing goes away if you put exterior insulation on.
Chris: You know, I think twice in my career, I’ve been brutally burned by that.
Chris: Twice! And that’s why it sticks with me.
Phil: Shame on you, Chris.
Chris: Shame on me. Kid… intern… nice job… oh, yeah! And, what I’m talking about, people, is when your wall is not that thick – which, of course, shame on you there. (But this was years ago, Phil, years ago!) And you’re planning your stairs, and the first floor looked great, and you say, “Make sure the stair is down.” But then your foundation bumps in. And now your 3-foot-wide stair is 2-foot-6, and… Oops!
Phil: And you try to insulate it – there’s no way!
Chris: Oh, yeah. And now you’re done. Stupid architect!
Phil: That’s how I learned!
Chris: Yeah? Failure’s a great thing. It teaches you.
Phil: Why else, Chris? Why else do we put it on the outside? One is: you could argue that it’s harder to insulate the rim joist – and air-seal the rim joist – on the inside. So, if you’ve got the insulation on the outside, that whole thing is gone. Sometimes we do that anyway, because you get a little extra insulation.
Chris: Yeah, but… it’s going to be easier for me to argue why not to. For example: sure, you can run that insulation up and insulate the rim joist. But now, I’ve got to protect that insulation – I have to see that insulation from the outside – so, something’s going over it, whether it’s a stucco or it’s a metal. I’ve been doing this a lot; I don’t know if you have…
Chris: But if you’ve just got that 8-inch gap between your siding and the ground, with this level-ish building…
Phil: What do you do with that? What a drag!
Chris: I’ll tell you what I’d do: I’d get some coil stock.
Phil: That’s it! That’s the best way to do it.
Chris: Yeah. I’d get some coil stock metal with a matte finish (prefinished, whatever…) and you just run that around the perimeter of the building. It’s protected, and basically, it vanishes. And Bob’s your uncle. Done!
Phil: Martin and his article has a whole list of strategies to handle that – metal flashings, fiberglass panels. (People are making fiberglass panels for that.) Another is EIFS. But to me, EIFS is kind of a crappy solution. It can get beat up; you can get your weed-whacker up against it.
Chris: Oh, yeah. Or a kid with a baseball bat. Yeah. It’s tough stuff. But hey, it’s a solution.
Phil: Cement board – I’ve seen that happen a few times. (It is an issue. You have to deal with that.)
Chris: Right. And one way to deal with it: insulate on the interior, especially if you can spare that square footage on your building. Insulate on the interior. Basically, what you’re doing, thermally, is you’re removing the foundation wall from your whole assembly.
Phil: That’s right. If you insulate on the exterior, it’s essentially a thermal bridge all the way through, unless you insulate underneath the footing.
Chris: Exactly. And that’s where I was going with that. Underneath the footing – I’d say 98 times out of 100 – there’s no insulation under that footing. And that can be done, people. That can be done. We do it in commercial buildings – you can get higher-density foams. But that takes some know-how. Twenty-five hundred PSI is your presumptive soil pressure that you use and design your concrete for. I can get foam insulation that can take that amount of pressure. So, you can substitute that and put foam in underneath. But that’s another big step and another labor step and…
Phil: We’ll throw you a detail. I would say, “Be bold!” Look into it. Take a simple job and try it.
Chris: We’ll get into ICFs in a little bit – like the Passivhaus that I did in Saco – Roger Normand’s Passivhaus (Edgewaterhaus: I’ll give it a little plug!). I came up with this detail (and I was surprised that I seemed to be original about it).
Phil: I’m not surprised. You’re smarter than you look.
Chris: Well, thank you (Wait!). Where the ICF meets the footing – you pour a footing, business as usual – you put high-density foam right there along the bottom (it’s almost wedged in at the bottom of the ICF), and you pour the ICF wall on that. So, basically, the wall is this thermal mass inside this insulated thing.
Phil: Essentially, it’s sort of a chunk of EPSExpanded polystyrene. Type of rigid foam insulation that, unlike extruded polystyrene (XPS), does not contain ozone-depleting HCFCs. EPS frequently has a high recycled content. Its vapor permeability is higher and its R-value lower than XPS insulation. EPS insulation is classified by type: Type I is lowest in density and strength and Type X is highest. that sits right in the bottom of the ICFs – just in that middle piece of cavity.
Chris: Exactly. And I ask my engineer, “Why can’t I do this?” and he says, “Well…”
Phil: “Well, I’m an engineer, so I’m going to say ‘No’ before I...”
Chris: No, no. My engineer’s great. Joe Leasure. He’s a great guy; great guy. Give him a little shout-out: L&L Engineering. He’ll handle the creative stuff.
He said, “Well, structures bear on the most rigid thing. So, what will happen is: it will compress (especially as it’s curing) but then, all of your little rebar that’s sticking out – that’s tying the footing to the wall – is going to take all the load.”
Chris: Exactly. And I said, “So…?” and he said, “So, you’re probably fine because there’s no way you’re going to crush that one-inch piece of steel, especially if it’s every three feet. But – here’s the thing – that steel is now open to moisture so it could (there’s not a lot of oxygen in there…) hypothetically spall. So I’m going to call for epoxy-coated rebar.” And I said, “are we done; we got it?” and he said, “yeah” and I said, “alright. We’re doing it!”
Phil: That’s cool! Post that, Chris. That’s good.
Chris: Yeah. It’ll be one of the details. ICF details. So, we were back to insulating on the inside… right?
Phil: Right. Other reasons to do it.
Chris: What’s Martin say? What were his reasons?
Phil: One thing he says is it integrates more smoothly with the construction schedule. It happens after the building’s dried in, rather than when the excavation contractor wants to backfill. (Then you’ve added this extra variable to him. He does not like that!)
Like we’ve just referenced, it’s easier to provide an uninterrupted connection between the below-slab insulation and the insulation to the interior. So then, your only connection is through your rim joist and up into the insulation. So, you don’t have to worry about that thermal break through the footing and the foundation wall.
Chris: And people, you can always take that rim joist – by the way – and even build a normal 2x6 dumb house, you know? Just 2x6 and regular pink insulation. (I won’t name names of what kind it is, but you know what I mean: with fiberglass batts.). And you can take that rim joist and just move it in 2 inches – an inch and a half – and put a band of insulation around that. Boom! You’ve just created a thermal break for a good chunk of your house that ordinarily wouldn’t be there – that was cheap and easy. Sure, you’ve got to think a little, but only a little. Only a little, Phil.
Phil: Only a little. It’s not so hard.
Chris: So, we’ll post some details of insulating to the interior – which is, in my mind, easier to do.
Phil: And then you don’t have to deal with that little chunk of foam of 8 inches on the exterior. You save money there. One of the other things, though, is: even though you put foam on the inside, you’ve got to cover it up by code. You can’t leave it exposed. So you have to put sheet rock over top of it, which means you have a stud wall again, with a chunk, or you go with Thermax… I don’t know if you’ve used that before…?
Chris: I have, yeah.
Phil: So, it’s a polyisoPolyisocyanurate foam is usually sold with aluminum foil facings. With an R-value of 6 to 6.5 per inch, it is the best insulator and most expensive of the three types of rigid foam. Foil-faced polyisocyanurate is almost impermeable to water vapor; a 1-in.-thick foil-faced board has a permeance of 0.05 perm. While polyisocyanurate was formerly manufactured using HCFCs as blowing agents, U.S. manufacturers have now switched to pentane. Pentane does not damage the earth’s ozone layer, although it may contribute to smog. with a covering…
Chris: A coating on the outside. Then you can get either foil or they’ve got a myriad – I used the word “myriad,” Phil…
Phil: Really? I like “plethora,” but myriad’s good.
Chris: They have a plethora of coating options.
Phil: Thermax is expensive, but it’s still kind of a quick problem-solver, I think.
Chris: If you’re not going for aesthetics or anything like that. I mean, maybe we’ll hear from them saying, “Hey, it’s not that bad looking. It looks good.” But basically, there are flame-spread ratings for Thermax.
I think ICF people run into this all the time, where people are thinking, “Well, I will do an ICF foundation; maybe I’ll do sheetrock later or a gypsum wall board,” and so they leave it that way. And then the code-enforcement officer says, “Hey, hey, hey. You can’t leave it like this,” per whatever – I don’t have the citation number of that code, but because it doesn't meet the flame-spread rating. So little Johnny can walk over with his lighter and start a fire just by holding it to your wall. You can’t have that in a building material.
Phil: That’s right. One of the other things that we should talk about: what kind of insulation do you put on the outside of your house when you use it?
Chris: Well, I’ll tell you what I like. I like using the Roxul mineral wool.
Phil: The drain board.
Chris: The drain board.
Phil: It's more rigid than the batts. It’s a different sort of thing.
Chris: Oh, yeah. Yeah. People, get the drain board. It’s almost a board product. In fact, that’s what they call it so that you know it’s not batts. It’s hydrophobic, so…
Phil: Water doesn’t stick to it.
Chris: It sheds, it drains.
Phil: Unlike polyiso, which likes to suck it up.
Chris: Right. And what happens when you bring that in? You’re reducing your effective R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. of that material, because it’s now saturated and cold… conductive water. Polyiso is not a good subterranean insulation, generally speaking.
Phil: No. XPSExtruded polystyrene. Highly insulating, water-resistant rigid foam insulation that is widely used above and below grade, such as on exterior walls and underneath concrete floor slabs. In North America, XPS is made with ozone-depleting HCFC-142b. XPS has higher density and R-value and lower vapor permeability than EPS rigid insulation. or EPS [are better].
Chris: Those command that subterranean market, and are laced with fire-retardants and things like that. And that’s the reason why we’re trying not to use those.
Phil: And one of the reasons we’re not using Roxul to the interior is that we’ve got some concerns with formaldehydeChemical found in many building products; most binders used for manufactured wood products are formaldehyde compounds. Reclassified by the United Nations International Agency for Research on Cancer (IARC) in 2004 as a “known human carcinogen.".
Chris: Yeah. Formaldehyde and heavy metals, too. I don’t think it’s that bad anymore, because basically, a lot of it’s made from slag from steel manufacturing. It’s not as bad for you, but it is this waste product that can have all kinds of other contaminants to it, depending on how it’s separated from the manufacturing process of another product.
Phil: So, if we shook our next drink, say, with a little bit of Roxul drain board… would we drink it?
Chris: I would.
[The guys laugh.]
Phil: The answer is, “Wait! What’s the drink?”
Chris: Yeah. Exactly. What is that drink? One of these! Gosh, these are good! I’m loving this cocktail, this episode. I’m going to give it five stars. Five stars.
Phil: Oh, excellent! I’m glad to hear it. I don’t very often get to host the cocktail.
Chris: Oh, but every time you do, it’s always a special one. And it’s always really good.
Phil: Thanks for saying so, Chris.
Chris: Well done. So, yeah. What were we doing? We were insulating to the inside. You’ve got to protect that rim joist. It’s good if you protect it both inside and outside. Be careful of the vapor sandwich that you could make.
Let’s talk about capillary breaks, Phil. I remember, I don’t know… twelve years ago? A long time ago… Kid. Chris Briley’s in an architectural office, recommends to his superiors (or his upper management or whatever), “We should put a capillary break underneath the sill.” And they said, “A what??!”
Chris: I think it was the era. It was the early nineties. “What do you mean, capillary break? We’ve got sill seal.” Well, it’s different. It’s different than that little pink piece of foam.
Phil: Or blue.
Chris: It could be blue. But, what you’re trying to do is – Oh! Oh! I get to tell the termite shield story!
Chris: And this may have come from Joe Lstiburek when he visited our college and spoke, but I’m not sure…
But anyway. Back when… picture the thirties. Door-to-door salesmen, that sort of thing. Just like they’re convincing people to put lightning rods in their barns, they were also convincing builders and people to “protect your house from termites. Put a termite shield between your foundation and your sill plate.” And basically, that was just a bent piece of metal. It was just metal. It was metal flashing. But the theory was that this metal would project out and bend down. And the termites would crawl up your foundation and hit this metal that would bend down and go, “Oh, oh. We can’t climb around it.” And they’d fall. [The guys laugh.] And entomologists were outraged! They said, “That is ridiculous! They negotiate that in nature all the time. Leaf edges – all the time. That does not stop termites.” So they debunked the whole termite shield industry. And then, what should happen, but not maybe a decade later? All these houses that were in termite zones that did not have the termite shield were infested with termites. And those that had the termite shield were fine.
Phil: How about that!
Chris: How about that! And they said, “See! It protects you from termites. You entomologists are stupid.” And it takes another layer of science for them to go, “Well, actually, termites like – what kind of wood? – dying, dead, decaying wood. Just get in there. Moist wood.” So, basically, that metal – what it was doing – was not keeping the termite out, it was keeping the wood dry. So, ta-da! Capillary break; that’s what that is. So, the termite shield came back, and occasionally, you’ll still see it labeled as “termite shield.” Of course, it actually is a termite shield for the termite country because you’re desperate to keep that sill plate dry and clean and free of termites.
Phil: So, what do you use? We use this little gasket by a company called Conservation Resources that we typically spec.
Chris: Oh really? I don’t know if I knew that gasket. What did we just use…? I want to say it was Tremco. No, it wasn’t Tremco. Oh crap! I’m going to send a link; I even have a photo of it. I’m spacing out. Maybe I’ll edit in right here. [It was Protecto Wrap Triple Guard Energy sill seal.]
Phil: Okay, we’ll both follow up.
Chris: We’ll follow up and we’ll put in our products. It was a T-shaped product, so it capped the wall and then it ran down the wall and then you could put on your sill plate and you could peel off another piece of stickiness and put it back on. So, you just capped off everything and sealed it and…
Phil: Alright. I want to see yours. I’ll show you mine if you show me yours.
Chris: You’ve got it, buddy. That’s what this podcast is all about. He says with a wink.
Phil: I’m glad this is not video.
Chris: Yeah, me too. Thank God it’s radio.
Phil: So, Joe Lstiburek had a six-digit idea.
Chris: A six-digit idea? Did he use those words?
Phil: He didn’t, but our friend Martin Holladay used those words in referencing one of Joe’s ideas.
Chris: Well, he’s welcome to it. So, what did Joe say?
Phil: He suggested that it was time for manufacturers of fiber-cement siding to create siding which is bumpy on the backside. Isn’t that a cool idea?
Phil: One of the questions I have is: would we gain anything if we had exterior insulation on the outside that was bumpy as well?
Phil: It would be akin to that dimple-mat.
Chris: It would, but if you’re inviting air in behind the insulation – I mean, that could be cold air, so – it could be defeating your insulation.
Phil: So, we’d have to seal that on the outside.
Phil: Maybe it’s not such a great idea. Joe was smarter than I was in this case; I was trying to interpolate.
Chris: Well, nice try.
Phil: I tried.
Chris: But, I’m happy to shoot it down, Phil. Lob another one up and I’ll blast it away.
Phil: I’ll let you know if I come up with anything.
Chris: But, no. I love that idea. Why wouldn’t they make it so there are little gaps there?
Phil: Yeah. There’s our rainscreenConstruction detail appropriate for all but the driest climates to prevent moisture entry and to extend the life of siding and sheathing materials; most commonly produced by installing thin strapping to hold the siding away from the sheathing by a quarter-inch to three-quarters of an inch. . We’re doing it all the time.
Chris: Yeah. I’m shocked when I find out someone’s not doing a rainscreen. But, anyway, we’re talking about foundations. What about crawl spaces? Are we going to go to the evil, evil crawl spaces? Or do you want to talk about ICFs?
Phil: Let’s talk about ICFs for a second. I know that ICFs are something that you guys are using.
Chris: Yeah. Have you used ICFs?
Phil: We’ve only managed to get it into a project once or twice. We used to start with it a lot more often, but it always gets value-engineered out. Builders say, “I can do that. Why can’t I just make my own?”
Chris: You see, it’s interesting – because the projects that I’ve done, the builders do it themselves. They don’t hire the form-work guys. They are carpenters and they do the wall. They are happy to learn ICFs, and do the ICFs, and so they’ve adopted that as their trade. So, the concrete guy comes and delivers the concrete and vibrates it there and they do that.
Phil: But, at the same time, proprietary ICF package is more expensive than just going out and buying your own XPS or whatever.
Chris: Oh, without a doubt! You’re going to pay more for the product, but you’ll pay less for the labor. If your builder is not into that labor anyway – if that is not labor money that he is trying to carve out – then he’s not into that product. I think it’s one of those things where – and it doesn’t go off without a hitch. Heck! Just read Roger Normand’s Edgewaterhause blog. (You know, the Passivhaus idea.) Whooo! That was a tough ICF job. They were tall walls, and it was their first time doing it. Man. They had some blowouts and it’s really spooky to see an 8- to 10-foot tall wall full of concrete…
Phil: Blow out?
Chris: Well, not just blow out, but… You watch them true it up. They can shake it, wobble it… and you just think to yourself, “My God, that is heavy. That is a lot of weight that they’re just kind of moving with these braces and all that jazz.” So, it’s not easy. Everyone says it’s like Lego blocks and you fill ‘em – done! Awesome! And it actually takes a little more work than that. You’ve got to wire them up and get the rebar and someone’s got to do some engineering to it. But, we’ve done it successfully many times and it’s been, I think, a really great product.
Phil: Well, I’d love to hear some comments from listeners, even if it’s just anecdotal. Are more people starting to use ICF, or is it going in the other direction?
Chris: I tend to feel like it’s going in the other direction, but that’s personally. I think it’s going that way in our office. It’s been a while since we’ve done ICFs.
Phil: I’ve had an issue in the past with some of the ICF guys – some of the sales folk – who say things like, “It’s equivalent to an R-40.”
Chris: Yeah. In Arizona, punk!
Phil: “It’s an effective R-40.”
Chris: Yeah. “Effective!”
Phil: And I’m counting it, saying, “Wait a second. You’ve got… 2 inches to the outside?!”
Chris: And 2 inches to the inside! Yeah, here’s my pet peeve: that’s not science, buddy.
Phil: That’s R-20!
Chris: I think it was Oak Ridge National Laboratories – they did the whole ICF study – they actually did walls in different climates and tested this so-called "effective R-value" that these guys peddle. And, okay, here’s the thing: R-value is not even a real number; it’s a value.
Phil: I thought ‘R’ stood for real!
Chris: [He laughs] It’s supposed to be resistance, but ‘U’ is resistance and ‘U’ is a factor – because you are actually using that in an equation – and ‘R’ is a value so the consumer can understand it. ‘R’ is resistance. There are three ways to transfer heat (you know that): radiation, convection and conductionMovement of heat through a material as kinetic energy is transferred from molecule to molecule; the handle of an iron skillet on the stove gets hot due to heat conduction. R-value is a measure of resistance to conductive heat flow.. And ‘R’ deals with conduction. So when they say, “an effective R-value” – Shut up! An R-value is resistance. By having concrete in there, you’re not increasing the R-value – you’re doing thermal mass – you’re increasing thermal mass. That’s a whole different metric and a whole different ball game. And so, I cannot plug R-40 or R-50 into my energy model. Thank you very much, moron.
Phil: [He laughs] I’m with you. And I asked him, and he said, “A typical wall has thermal bridgingHeat flow that occurs across more conductive components in an otherwise well-insulated material, resulting in disproportionately significant heat loss. For example, steel studs in an insulated wall dramatically reduce the overall energy performance of the wall, because of thermal bridging through the steel. everywhere – and we don’t have it – so, we’ve bumped up our numbers to…”
Phil: Come on, really??! Eyes wide open.
Chris: Eyes wide open, people. Here’s the thing: if you’re insulating your foundation – the thing is, you can screw sheet rock right to it – have your builder run the numbers in terms of whether it’s cost-effective. And for you, and for that builder, it might get written off and deleted and then you go with something else. And I’m fine with that.
Phil: Bottom line is that it’s not a bad product.
Chris: Not a bad product.
Phil: It’s a good idea. And maybe it’ll come down in price.
Chris: But it’s not the only way to do this.
Phil: It’s not. Have you ever used the Thermomass product, Chris? It’s like the inverse of ICF. You’ve got concrete on the outside and a chunk of insulation on the inside.
Chris: I’m actually using that on a slab. We’re going to do the frost wall with that. I should say what it is, first. You can Google ‘Thermomass’ and you’ll see that it’s the opposite of ICF. They have a little insulated insert in the middle.
Phil: Give us numbers, Chris. Do you know the thickness of the insulation? I remember it being – what is it – 4-2-4 or something like that?
Chris: Yeah. 2-4-8-10… you can keep going. But, here’s the trick: there’s some engineering involved. You have to use proprietary insulation in the middle – it looks like just Dow blue board; it looks like XPS, but – it has this coating on each side of it that they say is important. You have to have this coating.
Phil: It’s a thin layer of magic, and for that, you pay.
Chris: Right. You can’t use some other product. So, you buy this sheet-good – it already has these pre-determined places where the little fiberglass thing goes through and it locks (so it sits in the form nicely and all that jazz). So it’s a great idea, a great product, but I always feel it’s overpriced. We almost did it on a project in New Hampshire, but we ended up just insulating to the interior because it just got cost-engineered out. Value-engineered out. But, we’re about to do it for this little frost wall.
Paul: The cost is coming in okay?
Chris: Yeah, it’s coming in okay. The builder is really fine with it. It’s a little early – it might fall out of the project – we’ll see.
Paul: And you’re doing it because you just want to try it? It seems like a cool idea…?
Chris: I’m doing it because the builder said that’s his preferred method of doing this, and have I ever heard of Thermomass? And I said, “Let’s talk, buddy!” So right now, I’ve got a builder who’s saying he likes the stuff, he’s used it before, he’s very comfortable with it, and he thinks it’s great. I think that it’s one of those things where, optimism is worth – I don’t know – ten to a hundred grand, depending on the size of the project. Attitude is worth something; it’s worth real cash money.
Phil: I like the fact that you just quantified optimism in dollars. That’s awesome!
Chris: Yeah, if only I could get paid for my optimism… I’d be rich!
Phil: That’s really interesting about the Thermomass. I’m a little suspect. I remember walking the floor of a building energy conference a couple of years ago with my friend who’s an engineer and he looked at those concrete walls that were thinner – I think that the concrete was four inches – and he said, “I don’t like that. It feels funny to me. I don’t trust it.”
Chris: Here’s the thing: they have their own engineering staff that will help you out and will stamp it. On this project in New Hampshire, we went through the engineering. Those fiberglass links? That’s what’s important about them. He said, “You don’t have a 10-inch wall anymore. You have two 4-inch walls.” Really we’re only bearing on one, so yikes! Engineering is a big piece of that.
Phil: Alright. What else have we got? We’re pretty good!
Chris: Well, except for crawl spaces.
Phil: Alright. Do you want to talk a little bit about crawl spaces, Chris?
Chris: Yeah. Don’t have them! Done!
Phil: A crawl space is the same thing as basements, right? It’s a short, little basement. And if you’re really going to do it right, you’re going to do it the same way you did the basement.
Chris: Exactly. With a slab and a vapor barrier, because… come on! The reason why we hate them and are calling them evil is because, a lot of times, they are open right to the ground. Right? So we have moisture coming up from the ground – and it’s lingering in the space – and then we have people saying, “Oh, then you need to vent the crawl space.” And then you have people saying, “No! For God's sake, don’t vent the crawl space – now it’s a frigid crawl space with condensing water everywhere and now you’ve got bugs and all that.” They are evil, evil, evil things. Please don’t do them if you can help it. But they’re out there. And that’s the other thing. What about the existing foundation? I don’t know if we have time to get into the existing foundation.
Phil: I don’t think so. I think that would be a deep-energy retrofit. A DER. Have we done a DER podcast?
Chris: I feel like we have, actually. We’ve talked about it while drinking before, Phil.
Phil: That’s right. It could have been that.
Chris: And again, I should just bring something with me all the time when we’re together – with beverages talking about architecture – because I always come away from these conversations saying, “Wow! We should do a podcast on whatever it was we just talked about.”
Phil: That’s alright. That’s why we got inspired to do this!
Chris: Yeah, exactly. We would actually go to a forum or a seminar, meet with that person who did the seminar, and you and I would be talking (or it’s just you and me in a group of people), and we say – “My God, this is way more interesting than what we just sat and listened to.” The stuff that we’re learning here, and the experiences that we’re all sharing…
Phil: Maybe not quite as polished as the guy.
Chris: Oh, nowhere near as polished. But that’s another attractive feature to it.
Phil: Here it is; case in point.
Chris: Alright. Do you want to wrap it up?
Chris: That’s “Foundations and Slabs and Stuff,” from the Green Architects’ Lounge.
Phil: That was fun, Chris. Good to see you again.
Chris: Good to see you again. Let’s do this real soon.
Phil: Let’s do it. Cheers!
Phil: Cheers! Thanks, all!
[The episode closes with a song by Diane Cluck: “Content to Reform.”]
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