The little things, like flashing and weather-lapping, keep the big stuff standing. Durability is becoming a lost art
That feel comes from sweat and dirt, just being in the field, doing things, trying things, and paying attention to it, not just going through the motions like there's nothing to be learned from this.
Welcome to ProTradeCraft's Career Toolbox. I'm Fernando Pages, and I'm here to help you turn your day job into a career.
When I looked up our guest's resume online, I found it states that Jay Crandell, a professional engineer, has over 19 years of experience in research, construction, and engineering. It should say, "well over 19 years," since I met Jay about 20 years ago and he was a hotshot building science and engineering wiz by then.
What's right in his bio is that Jay has extensive knowledge and experience in a variety of materials and methods, including many innovative technologies for the construction, which he's helped to pioneer.
Among them, shallow frost-protected foundations, something I worked with him on, hurricane codes, earthquake codes, steel framing codes, cost-effective wood framing, like the 24-inch on-center framing, and most recently extensive work on continuous exterior insulation.
In short, he knows it all and has focused his research and engineering on housing, which is very special for us in the home building and remodeling industry.
Construction materials and specs have a funny history
One of my favorite research projects that Jay undertook has to do with the history of wood construction in the USA. In this little book that he wrote, which you can find online, it revealed where we got our 16-inch on-center module for laying out studs in wood framing (hint, it has nothing to do with structure).
I'll ask him about it. I wanted to focus this interview on what folks in the trade should know about structure, as basic construction literacy. But Jay, he has another idea. He's more interested in talking about the reverse what engineers and designers should know and have experienced about hands-on building.
So, looking forward to learning something new, as I always do when I talk to Jay, I introduce you all to my old friend and counselor, Jay Crandell, professional engineer, and excellent human being. Jay, welcome to ProTradeCraft's Career Toolbox.
02:19 JC: Thank you, Fernando. I appreciate the invitation and look forward to our discussion today.
02:24 FP: You're a structural engineer that specializes in wood construction in residential construction. This is an odd specialty.
Most engineers of your caliber focus on high-rise buildings, and large infrastructure projects like bridges or nuclear power plants. What in blazes appeals to you about housing?
02:44 JC: Well, I think that there are several things, at many different levels. And indeed I didn't get in there... I didn't get into this type of work because I was seeking popularity.
And I do recognize, when you go into the field of engineering, people are thinking about nuclear power plants and bridges and high-rise buildings. And I have done some bridge design and some commercial building design, but I find my root in working with wood.
That's where I started in construction, with wood construction, more from an infrastructure standpoint. But I also had a lot of family connections in the home building realm.
I had relatives that did that; I had relatives that built my parent's home. And my grandfather, when he first started construction, became a carpenter in home building, built a lot of townhomes up in the Baltimore area. He stated that when he graduated from the sixth grade at the age of 12, and started in that track and was very gifted at it.
So, I learned a lot of sort of old-timey ways of doing things from him, and just got an appreciation for wood. And frankly, most buildings in the US are built from wood, and certainly, that stands true for homes.
Probably 98% are built from wood or at least parts of them from wood. I just had a very natural interest in learning more about wood construction, and that kind of led me down the path eventually to engineering.
04:12 FP: You wrote a history of wood construction in the United States. Do you remember the name of it? I often recommend it to folks that have some nerdy kind of interest in construction.
04:23 JC: Yeah. That was a fun project. It wasn't even a project; it was an offshoot of a project, where we were doing a very technical piece of work. We were trying to look at how safety, structural safety, and performance of housing, changed over the 20th century, 1900 to 2000.
And we have a very sophisticated way of looking at how buildings would perform, from an analytical standpoint, for wind, earthquakes, and those types of things. But how housing practices and materials, even open space design, how that affects the structural capacity of buildings over that century, because it was feeding into basically a study of what's the probability of a home becoming damaged or collapsing because of these changes.
05:13 JC: And it was a fascinating study at that level, but there was also a very practical level. We had to understand what had changed in the industry. So, having that need, for that data, for that purpose, generated the opportunity to write that document, which was a review of housing.
I forget the exact name of it, but housing, construction materials and methods from 1900 to 2000, I think, was close to the title of the document. But it is amazing how things have changed, and they have significant impacts that often are overlooked on how the building performs.
And so the industry, as it adapts to new materials and new design objectives for how people want to live in their homes, it has other effects that need to be considered from either a building code or a construction practice or a design practice standpoint.
06:10 FP: The unintended consequences.
06:12 JC: Exactly. And we don't like unintended consequences. Usually, somebody ends up paying for that, and we want to avoid those issues and make sure our codes are keeping up-to-date, and the building industry as well is aware of these things and keeping up-to-date.
Builders used to be skeptical of concrete footings
06:29 FP: One of the things I got a charge out of reading this history of wood construction in the United States was a little aside about concrete foundations and how the building industry notoriously is slow at adopting any new building materials or methods.
And one of the things I've had a difficult time getting into building practice was concrete foundations. And I read the quotes of the builder, saying, "I'd never put that under one of my houses," and I thought that was very funny.
07:03 JC: It is. The same thing goes on today. And so, at one point in time, concrete was a new material, and maybe they didn't... We didn't have concrete plans, all across the country, and consistency and standards for making sure you had the right mix, and proper guidance for how to install it. Hence, people were skeptical of it, and it was different than doing just a masonry foundation.
The whole idea of using a concrete footing was new at some point in time, and people were concerned about that. But you can see, over a century now, concrete footings are pretty much everywhere, although you still can use things like gravel footing.
And some construction technologies, like permanent wood foundations, actually still use the traditional more than 100-year-old wood sill, although it's treated now, on a gravel footing.
And the funny thing is, now, everybody is skeptical about that because it's not the mainstream practice, but it...
08:06 FP: But it was... Yeah.
08:07 JC: It's got the oldest history of anything.
08:09 FP: Where did 16 on-center framing module come from?
08:13 JC: Now, you're kind of pulling back into my cobwebs a little bit. I think it was... When you look at lath, and plaster, and some of the old finishes, even today, some of the building materials we have are all based on working with a 16-inch on-center framing.
And so, it was based on the practices that were done for finishes, at the time, and it just became the de facto standard when construction first came about. That 24-inch on-center framing, advanced framing, some of these things that aren't used commonly in the industry, they've been around for at least a century as well.
And the early 1900's Sears and Roebuck was providing, too, kit home offerings to the marketplace, back in the day when Sears and Roebucks were into housing. You could order your home on a railcar shipped from Sears, and they had two offerings. One, they would call standard built, that was 24-inch on-center framing construction. And the other was called quality build, 16-inch on-center framing construction.
So, that has stuck over time. And I think the 24-inch on-center framing, as good as it is when it's done right, still has this idea that "Well, that's just below quality home."
And so, there are pressures against doing anything but 16-inch on-center because people misunderstand the significance or what the real differences are between a 24-inch on-center framing and 16, for example.
09:52 FP: But it originally started as backing for lath and plaster. So, if you want to build with lath and plaster, use 16 on-center. But if you're going to use drywall, 24, it may work just fine.
10:04 JC: Right. And drywall didn't start to pick up until the middle of the 1900s. Lath and plaster were pretty standard up through even the 1950s, and then it went to plasterboard, and then it went to the full gypsum sheeting panels.
Professional wisdom comes from hands-on experience
10:19 FP: I wanted to focus our conversation on basic engineering literacy for builders, but you took it in another direction. You want to talk about the importance of having hands-on construction experience for the engineers, a feel for structure.
How did you come by this idea, that it's important for an engineer and a designer to have experience nailing studs and mixing plaster?
10:45 JC: Yeah. I think it starts... For me, it started at a young age, and not being afraid to work, that being an expectation, to work. I started working construction when I was in middle school, about the age of 14.
Of course, I had done construction work before then, but it was more like chores, not a job. And I worked in summers through college doing construction work, and in doing that, you just get a natural feel, not only for how things go together, how they work, stuff you can't see in a textbook. Stuff, when you create a temporary scaffolding, and you use X many nails to hold it up, you get a feel for what will support the load or not, what a piece of lumber looks like, or a portion of steel looks like that would support a given amount of load.
You start to get a feel for what works and doesn't work. And when I found later was brought together with a theoretical understanding of how things work, both things leverage each other.
Because the theory is not perfect either, it's not accurate. It might be safe, but it's not necessarily correct. And you can make errors on a calculator, just like you can make an error in driving a nail in construction.
So, the two together, more of a safeguard in preventing error, but that feeling comes from sweat and dirt, just being in the field, doing things, trying things, and paying attention to it, not just going through the motions like there's nothing to be learned from this.
There are things you can learn from everything you're doing, and that's particularly true of construction, because there's just so much variation in the way things are built, and different materials that can be used, even different nails that can be used.
Techniques, when you drive a nail this way, the lumber doesn't split, all of those things help you not only be a good builder, but I found that they probably were the most important thing to prepare me to become an engineer.
I had the good fortune of working at the NAHB Research Center, the National Association of Home Builders Research Center, and eventually became their structures and materials director. But in that role, the feel I developed even became more informed because we were testing assemblies, testing whole walls.
Even testing whole buildings to see how they stand up to earthquakes or hurricanes, and comparing that to what we analyzed and thought they would do. And when you have that kind of interaction going on, between theory and experience or feel, it creates a full picture of not only engineering but construction.
So, I was fortunate to have some of those experiences, but ultimately that all started right in the construction project.
Flashing is becoming a lost art
13:42 FP: That's why you're a particularly construction-friendly engineer to work with; you have a sense of empathy for the job site. I'd love to know from you, as a professional structural engineer, what are some of the basic concepts that we, as builders, should understand about structures if we pretend to construct safe homes and buildings?
14:04 JC: Yeah. There are probably several things that could be considered significant, and I think number one is, you brought up building science, energy efficiency, and that all relates to moisture control.
And we should be building structures to last. And to do that, particularly for wood framing and in typical housing construction, you need to protect it from moisture, whether that's coming from the interior, because of water vapor that humans give off and their activities give off, and controlling that correctly, to protecting it from the outside, the weather, with proper flashing and water-resistive barrier and cladding installation.
And these are small details that can make a big difference, whether flashing is lapped correctly, and often gets overlooked. But if those are wrong, then it will eventually impact the structure, causing it to degrade, either rot or mold or other things.
I think durability has been something that has been lost in the trades. And it's delicate little details. It's the guy out there installing the flashing tape or installing the wrap over the structure, it's imperative to get those things right, or everything that was invested in the structure would be open to harm from water.
Water is the enemy of wood construction. That's number one for me is protect the structure. Once you've done that, then the rest of it's pretty straightforward. Using good lumber, following the plan, following the building code, that's a relatively old traditional craft that hasn't changed a whole lot.
Not all structural loads are obvious
The only place it has changed, in particular, would be some of the materials you can use, like I-joist. But again, we're relying on the field, either a plan that's been designed or you look up in the code and make sure you get the right size joist.
Where it gets a little complicated is with hurricane and earthquake loads. A lot of people don't understand... They understand a gravity load, like a person standing on a floor, and the floor has to be able to support that person to take that load down through a beam or a column and then eventually to the footing and into the ground.
A lot of people can see that. But in an earthquake or a hurricane, you've got a sideways load on the entire building going on, and so the walls will want to rack in the plane of the wall. And it's those walls, the exterior walls in particular, that need to be braced so that they don't rack.
So, traditionally, years ago, a let-in brace at the corners of your building, an angled brace, and folks that have built those will understand, you don't have a let-in brace, you can push that building and make it sway. But you put a let-in brace in, and all of a sudden it's rigid, it doesn't sway.
And the next step up from that was then the use of board sheathing, and mainly if it's put in at an angle, and that was done through, again, the middle of the 1900s. And then after that, plywood came out. Now, plywood, a panel product, when you nail it around its perimeter to a wood frame wall, that panel becomes a rigid brace to that wall.
And so having a sufficient amount of bracing, based on the building size, the wind zone you're in, the earthquake zone you're in, is essential. Those are were all design decisions that all rely on following the code.
So, if you want to have a good structure, the code is your friend. Read it and use it. And if you don't understand it, seek to get answers from trusted sources.
And if you're entering into types of structures or conditions, like a lot of windows where you don't have much room for bracing, and you're beyond the code, then find a sound structural engineer to help you do something that meets the intent of the code.
The IRC provides engineering advice
18:24 FP: It's notable here since we were getting into the code, that I think we're maybe the only or one of the few countries in the world where we have a home building business that's separate and apart from the design side, architecture and engineering.
And because of that, we have a prescriptive code, which means it tells you what to do, versus a design code. A design code gives you formulas, right? But the prescriptive code tells you how many nails to put in that situation, what size board to use in that situation, tells you exactly how to do it. And that's our International Residential Code, a unique code that allows a builder to go out and build a home without the benefit of a structural engineer.
19:10 JC: Correct. And that tradition has carried forward, and I hope it never goes away. And, in fact, someone in the construction industry... Like myself, I was, at some point, you may think, "Why am I here? What am I going to get out of this?" That skill and trade that you develop will carry with you for your entire life, even if you move into some other vocation or career if you want to call it that.
In my case, that construction knowledge I gained, even though I moved into the field of engineering, I used that to build my second home. I was able to sell that and make a profit while I was still trying to get the engineering career going. And then I built my third home and sold that. And so that construction experience, I was using that for the benefit of my family and for other tradespeople that I was hired to work with me on those building projects, and I was also making money while I was pursuing another career.
20:12 JC: And I also always had that to fall back on. It's sort of a comforting feeling to know that, "Hey, if engineering goes bad or this doesn't look out for me, I've got a skill that's useful, it's always gonna be needed, and I can always go back and find good work in the construction field should I need to do that."
20:32 FP: Jay, it's always a pleasure to talk to you. Thank you so much for joining us today on the ProTradeCraft Career Toolbox, really appreciate your wise and very kind advice and your wonderful sense of humor.
20:45 JC: Thanks, Fernando. I enjoy this conversation, lots of fun.
Homework: Do your homework
20:55 FP: I appreciate Jay's take on engineering and life. Homework, what's the takeaway? What should you do next?
Well, if I were you, and I am, because I came up in the trades, I would do a little bit of study, I would do a little bit of reading. Jay recommends reading the building code. I do, too. It's not exactly a page-turner, but that knowledge is not only power, it also makes your work more interesting, when you know not only what you're doing but why you're doing it.
There's also a lot of excellent resources right here on ProTradeCraft. There are various videos about building science, and those videos are very good because they explore some of the physics of construction and some of the physics of durability and how things work. It's exciting stuff, and it's fun stuff.
There's also a series called Weatherization Nation, and it's terrific because it gets into the nuts and bolts of some of what Jay was talking about, like how to apply a flashing properly and why.
So, if you just make a habit of checking out some of the videos, some of the resources right here, even on this website, I think you're going to find that not only has your... Not only would you be more informed, but you'll also be more interested and engaged in what you're doing, and that's the key to a happy life, is a life that you're fully living, that you're fully engaged in.
—Career Toolbox is a production of SGC Horizon Media Network. I'm your host, Fernando Pages. And the show is produced by Dan Morrison.