Reuben and Tessa gang up on Bill, complaining about the shortcomings of story-and-a-half houses found throughout Minneapolis and Saint Paul. The discussion is focused on insulation, ventilation, heating, cooling, and ice dams. Reuben blogged about this topic back in 2011: My beef with 1.5-story houses
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.
Reuben Saltzman: First, let me hear, Bill. What do you like about a one-and-a-half storey house?
Tessa Murry: He said love. What do you love, Bill?
RS: No, there’s no way you can actually love them. What do you love about them?
Bill Oelrich: Well you walk into them and there’s always a built-in. It’s the most practical layout. You’ve get two bedrooms on the main floor, you’ve got a bathroom you’ve got a built-in buffet, you can easily open them up and make them look… Give them that open concept that everybody likes to have in their houses now. You go upstairs, you can have a complete master bedroom, bathroom suite attached. It’s awesome.
RS: And when people started finishing off those attics, those spaces that were never designed to be lived in, that’s where we started having problems.
TM: Probably the primary issue with these houses is that they are difficult to insulate, they’re difficult to air seal and it’s very difficult to have proper attic ventilation. And with all three of those issues, usually that leads to some problems with ice dams, water intrusion, frost in the attic, which can lead to rotting out the roof deck and other structural issues.
BO: Today guys, I wanted to talk about storey-and-a-half houses. I’m absolutely in love with these things. They’re all over the city, they’re beautiful, they’ve got tons of character, they have tons of charm, they’re manageable, they fit well into the world as we get smaller in houses. Right?
RS: Calm down, tiger. Calm down.
BO: Everybody wants a little smaller house. I just think they’re amazing. So I know the building scientist to my left here has serious reservations about them and I know the building inspector…
RS: Who used to own a one-and-a-half storey house.
BO: He lived in it. So tell me why I shouldn’t love them as much as I do. Give me something.
RS: Alright, you know what, I’m not gonna try to convince you. First, let me hear Bill, what do you like about a one-and-a-half storey house?
TM: He said love. What do you love, Bill?
RS: No, there’s no way you can actually love them. What do you love about them?
BO: When you walk into them, there’s always a built-in, it’s the most practical layout. You’ve got two bedrooms on the main floor, you’ve got a bathroom, you’ve got a built-in buffet, you can easily open them up and make them look… Give them that open concept that everybody likes to have in their houses now. You go upstairs, you can have a complete master bedroom, bathroom suite attached. It’s awesome.
RS: Alright, you know what, Bill? You’re right about all that. I do agree. I’ll admit, I had a one-and-a-half storey house. We bought it in 2004 and we lived there until 2011 and we did everything there. And we had what you’re describing. We had the master suite upstairs. We completely redid it. And for everything that you’re describing, yeah, there was a lot of stuff that we loved about the house, but there was a ton that I didn’t like, looking at it just as the home owner but as far as the building science perspective and home inspector perspective, there was a lot to complain about.
TM: Yeah, I had to bite my tongue while you were saying all that, because Bill, yes the aesthetics are amazing, yes, there’s all this character, people love character, the built-ins, blah, blah, blah. But as a building scientist, I look at those through a different lens and for about five years I worked for a home performance company and my primary task was to basically try to resolve the issues that people were having and they were usually in homes like those.
BO: So are these modern issues or? ‘Cause these houses have stood for 80, 90, 100 years. Why do we have issues now?
RS: Here’s a big part of it, they were never built for that area to be finished off. This was the attic and to make it really easy to get up to the attic they gave you a stairway, and it’s like, “Oh wow, you can get up and down really easy. You don’t need a ladder, but you can put all your storage up there. It’s wonderful”. And they worked fine for that purpose. But then, I’m no history buff, but I guess the way it worked was a lot of people would get back from the war, you’d have people living… More people living in a house than you used to have and all of a sudden they need more space. So they say “Alright, well, let’s finish this off”. And when people started finishing off those attics, those spaces that were never designed to be lived in, that’s where we started having problems.
BO: Okay, so what’s the tip of the iceberg? What is the first and most obvious concern that you run into on a regular basis?
TM: Well, that’s a great question, Bill. But just taking a step back, I’d say probably the primary issue with these houses is that they are difficult to insulate, they’re difficult to air seal and it’s very difficult to have proper attic ventilation. And with all three of those issues usually that leads to some problems with ice dams, water intrusion, frost in the attic which can lead to rotting out the roof deck and other structural issues with the framing in the attic spaces and also comfort issues. That’s huge. Right, Reuben?
RS: Yes, I was just dying to jump on that one.
RS: Yes, that’s a huge one.
BO: Well let’s talk about that, because… Yeah, attic insulation and air sealing, all that stuff sounds great but I think people are more concerned about how they feel inside of these spaces.
RS: You can’t get comfortable. No, it’s… But boy, it’s tough.
TM: It’s hard, yeah.
RS: I mean, what you need to do is have a lot of insulation on the walls, insulation on the roof and you need a good HVAC system to add heat when needed or remove heat when needed. Now, you notice the way I’m describing this, I’m not saying cool the space. I mean that’s what people are after. They say they want AC. But really, the way that air conditioning works is it removes heat and humidity from the air, and moisture from the air. It’s gonna remove that. So to do that, you need returns, and think about a one-and-a-half storey house. What do you usually have for return duct work? Nothing.
RS: You have a stairway which is your gigantic return, which is not directly connected to the duct work. If you’re lucky you may have one return duct. Unless somebody has done some major remodeling you’re not gonna have more than that. And that makes it extremely difficult to get that second level comfortable.
TM: And on top of that too, a lot of times like you were saying, Reuben, it’s impossible to get good insulation, good air sealing for that upper storey. So you’re already in the Winter time losing more heat and then the Summer time those spaces get so, so hot as well because of that, and there’s not enough supply registers and returns. The HVAC system wasn’t designed to handle that load on the upstairs.
RS: Yeah, you have such a load. On a normal bedroom, a normal room you’re gonna have maybe one outside wall, maybe two outside walls if you’re on a corner, and then depending on what it’s located you may have a roof above you, some heating coming down. So maybe up to three walls. On those one and a half stories, you’ve got it on everything above you and on all of your sides. So you only have one conditioned surface, and that’s the floor. That’s the only thing that might be conditioned and everything else, you’ve got the outside elements trying to change your temperature to whatever it is outside.
BO: Okay. So I get it. But this seems like a pretty simple problem to solve. I mean, we’ve got HVAC contractors who know how to build systems. It doesn’t seem like that big of a deal. So, why can’t they? I mean, you’ve got attic spaces, you’ve got plenty of room up there to work with. Just carve out some space and put a furnace in the knee wall.
TM: Again, if you take a step back, when you look at the house as a system, these houses have under-insulated upper levels. It’s really difficult to get adequate insulation in these spots and so you’re losing a ton of heat. So, if you look at it like, let’s just say, simple analogy, if you’ve got a car, you’re driving down the road and all the windows are down and it’s the middle of Winter, all of that heat is escaping through these open windows, right? This is like a storey-and-a-half house, they’re very leaky, they’re not insulated well. And so do you…
RS: Well, then just try and heat up the high.
TM: Thank you, Reuben.
RS: Won’t that fix it?
TM: Okay. So that’s what Bill is saying. Why don’t you just turn up the heat, add a second heater? Well, really, you should look at these houses and say, “How can we keep the heat in better? How can we insulate them better? How can we air-seal them better so we don’t need a bigger furnace to heat them?”
RS: Yeah. And if you are gonna redo it and you’re gonna put a furnace in there, I mean, just logistically thinking about where this is going to fit, that’s a lot of work. I mean, where are you gonna fit a furnace in a one-and-a-half-storey house? Are you gonna put it on its side in the knee wall attic? And then how are you gonna get that duct work to all the thinner spaces? I mean, I’m not saying it can’t be done. I’m just saying it’s a lot of work and it gets really expensive. Whatever your cost is to replace a furnace, $5,000, whatever it is, you got somebody in and out in half a day swapping on a piece of mechanical equipment. Now, consider how much work it’s gonna be to install all that duct work, go through thinner spaces, try to hide it, not have ducks going through the middle of the room. This adds up to a lot of money. I mean, I’m not saying it can’t be done. I’m just saying it costs a lot. So, you’ve got to really love that space.
BO: So, is this one of those things that just because you can doesn’t mean you should? Is there a better way to attack this as a system?
RS: Well, I think the first thing you should focus on is stopping the leak. Like Tessa said, focus on air sealing and insulation and then maybe some ventilation too. But you have a lot of challenges with one-and-a-half-storey homes.
TM: Yeah. They’re complicated systems because once you air-seal and you insulate those attic spaces you can create a whole host of other unintended consequences, which we’ll talk about in another podcast.
RS: Now, Tess. Just for anybody who doesn’t know what air-sealing is.
TM: Air-sealing. Air-sealing is when you go into an attic space and you physically find the holes and pathways between the conditioned living space and that unconditioned attic space. So an example of that would be like electrical wiring that goes through the ceiling or if you’ve got a knee wall access door, plumbing vents, wall-tops, framing. Lots of things can be attic bypasses, and so finding all of those little holes basically and physically sealing them up with spray foam or caulking will stop help prevent that warm air from leaking into that cold attic space.
RS: Yeah. And I’ll tell you, I mean, we’re recording this in the middle of summer, but if you wanna know where your air leaks are and you got a one-and-a-half-storey house.
TM: Good point.
RS: After it’s snow, just go look at where all your snow has melted.
RS: That’s where your biggest attic leaks are. It’s not an insulation issue. That’s air movement.
TM: Yes. And that’s a great point, Reuben, ’cause you can even go out after, like, frost and you can go look at these storey-and-a-half houses and see on the roofs all the places where you’re losing heat ’cause that frost will melt. And a lot of times too you can actually see thermal bridging, which is another kind of scientific terms for…
RS: You’re such a house geek.
TM: Yeah, I am such a house geek. I’m sorry. I apologize. But where the heat is being lost through the framing members in the slant areas. And Reuben tell me about your experience with trying to stop thermal bridging.
RS: Oh my Gosh. Alright. We’ll need to backup. So I’ll tell the whole stories. I had the one-and-a-half-storey home and we decided to finish that off. And I knew about all the issues, but I had an insulation person convince me, “Look, if we do it this way, that’s gonna be enough to make it comfortable up here to stop your ice dam issues.” And what we did was we gutted the upper level. It was finished but not finished well. We gutted it. We took everything out. Side note, while we had it gutted we had a big cold snap and there was some plumbing up there and one of the pipes froze.
TM: Oh, no.
RS: That was awesome, because it burst. It froze enough to pop the end off of a pipe, and my wife comes home from work and there’s water pouring, like pouring, pouring out of the living room ceiling and out of the light…
BO: You see houses clearly. How did that happen? How did you overlook that one, small detail?
RS: I didn’t think it was gonna get cold enough up there. Seriously.
RS: I mean, I thought there was so much heat leaking up through the floor there’s no way this is going to freeze and burst.
TM: Oh, man.
RS: And it wasn’t that cold. It was like just close to freezing, but… Yeah. So, that was an awesome flood and huge insurance claim. I gotta give learning messages out here. Know where your water shut-off valve is.
RS: I had never showed my wife where it was and so she calls me, I’m in the middle of a home inspection. She’s frantic, she can’t shut the water off and I had put something in front of it, so it was kind of hidden and she ended up calling my dad and she’s panicked and he had to talk her through where it probably is.
RS: So always know where your main water shut off valve is. So back to the one-and-a-half storey house, we gutted the upper level and we spray foamed it. We used closed cell spray foam up against the roof decking. It means it’s going in between each rafter and we filled it up with as much insulation as you could use and the high density foam. It’s like almost R7 per inch, that’s the insulating value. This is the best you can get.
BO: Okay, so we’re gonna break in. Tessa, explain closed cell versus open cell, why it makes a difference as quickly as you might be able to.
TM: Closed cell, it’s a higher R value per inch. Also, it can be used for a vapor barrier as well, a certain depth. So up to like two inches and then it provides a vapor barrier. So, it’s a vapor barrier, an air barrier and high insulation value. So that’s why you wanna use it in a space like what Reuben’s describing. An open cell, it’s not a vapor barrier and it has a lower R value per inch.
RS: So we filled up that space with this insulation and then we finished it off. And the beauty of this is that you don’t lose any headroom and then you can just put your insulation right up against the rafters. But what I didn’t even think about at the time was thermal bridging. It’s the insulating value of wood. It’s just about nothing. It’s R-1.
TM: R-1. [chuckle]
RS: R-1. It’s per inch. And so if you have a 2 x 4, it’s three and a half inches thick, you’re at R-3.5, which is not much. And just for reference, the current standard for a new home in Minnesota in the attic, you need R-49. That’s the minimum.
BO: What does the R stand for? It’s like resistance?
RS: That’s it.
TM: Yes, resistance to heat flow through a material.
BO: Okay, okay.
RS: What’s the formula for that Tess? No, just kidding.
TM: Don’t ask me to remember formulas from college.
RS: But yeah, I did all this and then not thinking through what happens with the wood and then every time it’d snow the snow would melt at each one of the rafters. So you could clearly see where every one of my rafters was from the outside, from the melted snow pattern.
TM: So how do you fix that then in the future? Well, there’s two options. One, add insulation to the roof deck and build the roof up from there, which means building a second roof deck on top of the existing one.
RS: So when you say add insulation to the roof deck. I mean back up, what does that mean?
TM: It means removing all the shingles, putting down rigid foam, putting on additional space for airflow if possible and then putting on a secondary roof deck, new plywood and new shingles. Not cheap and not easy. The second option, you could add more insulation on the inside, right? And this is the step you skipped, ’cause you wanted that headroom.
TM: But you could add more insulation to the inside, for down, and get some added R value there, but then you lose headroom, valuable headroom and a lot of times these storey-and-a-half houses are, the ceilings are already so low you don’t wanna do that.
BO: And the valuable part of that headroom is there’s equations to what’s legal space. And if it’s not legal space you can’t count it in your square foot finish formula. So you could be pouring money into a space that’s not technically finished space.
BO: Okay. There’s a project that the University of Minnesota did that speaks to your adding insulation at the roof deck. It’s called Project Overcoat. There was a long paper written about the whole entire project. We’ll link it up to our webpage, so people can actually understand what Tessa is talking about. It’s a complicated thing. Pictures will explain much better than what we can do quickly on a podcast like this. I’m not willing to spend all that money, so what can I do just to get beyond this problem of ice damming and other things like that? Where do I go from here?
RS: The really simple solution, yet, and this is what I tell people, I do inspections for a lot of people buying these one one-and-a-half-storey houses and I don’t try to talk them out of it. I just tell them what’s gonna happen. I’m gonna say, “It’s gonna be a little cooler in the Winter. It’s gonna be warmer in the Summer. You might wanna think about installing a window air conditioner in the summer to make it a little bit more comfortable and you might need to have a space heater. If you keep the door open to the upper level, you’re gonna have enough heat rising up there. It’s gonna make it tolerable during the winter. And then for ice dams look up and down your street after you get a big snowfall and you’re gonna see all your neighbors doing the same thing. They all get a roof rake and they pull all that snow off the roof. That’s how you stop ice dams. If you remove the fuel for an ice dam, you’re not gonna have it.
TM: So you’re saying those little… The pantyhose with the salt and the salt pucks and all those things don’t work?
RS: Oh man, we should do a whole episode just on ice dams. There’s so much to cover there. I’ve tried everything and yeah they kinda work but, boy, it’s a lot more effective to just remove the snow. And if you do that you really shouldn’t have a lot to worry about. But you gotta stay on top of it.
BO: Well, I like how you say the fuel for the ice dam. It just puts it in perspective. You take that away, it can’t happen.
BO: Ice dams don’t happen immediately. You can go out 12 hours after the snowfall or probably even two days after the snowfall and as long as you’re pulling it back, it’s… You’re not gonna have major problems. Just don’t wait three weeks and then you’ll have problems.
RS: I’d say it depends. We like to say that a lot, it depends on the year, I’d say most years, you’re not gonna have any issues with ice dams. People can be in these houses for five years and they’re like, “Yeah, my house is fine. I don’t have a problem.” And then year six, like we had last year, people get these ice dams like they never had before and then they get leaks and they get their ceilings destroyed like, “I don’t know what happened.” And the natural response is, “Who touched my house last. Oh, I had a roofer out to give an estimate last year, he did something.” We get those calls. I know this, ’cause people want us to come out and blame somebody.
RS: It’s like, “Hey look, this has always been this way. We just had different weather this year.” And sometimes you can go out there two days later and pull the snow off and you’re okay, other times you get a bad snow storm, it snows all day and you got the right temperature and you almost need to go out there a couple of times during that storm to remove snow to prevent ice from setting in.
BO: Okay, so don’t wait on it. Don’t take my advice and go have a cup of coffee and come back later. Get on it right away.
RS: It depends. The safest way to do it is to do it right away.
BO: Okay. Well, I don’t care what you guys say about these houses. I still love them.
RS: You still love them?
BO: And I would encourage my family members, who my brother owns one and he religiously goes out and scrapes off the snow off the roof and they haven’t had any problem.
TM: He doesn’t need a gym membership either in the winter and that’s wise.
TM: So the other issue about storey-and-a-half houses that we kinda breezed past but I think is potentially a big deal is moisture in these attic spaces, and frost, which a lot of times people can’t see, don’t know about until it’s too late and there’s a problem.
BO: Sure, and we’re gonna drill into that in another episode because that is something that when the Minneapolis Airport Commission started replacing windows and adding… When the MAC improvements happened to all the houses around the airport, suddenly there were all these moisture problems that had to be dealt with. Well, I don’t care what you guys say about these houses. I still love them and I’m not gonna stop loving them because they’re super cool. Thanks for tuning and everybody. Reuben, what are we gonna talk about next time?
RS: Oh, I can’t wait for our next one. On our next episode we’re gonna talk about how to fix ice dams. This is Tessa’s bread and butter. Tessa used to do this for a living. She would spec the work on how to fix ice dams on existing homes. So we’re gonna dig into one-and-a-half-storey homes, two-storey homes, single-storey and all the different challenges. Hot roofs, more ventilation, what does it take. This is gonna be a fun one.
BO: Thanks, Reuben, Tess. This was great. Clearly, it’s super important that you find a qualified home inspection expert to come out and do a thorough evaluation of the real estate you’re considering. Thanks for joining us. We’ll catch you next time.
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