Creating expansive great rooms or vaulted living spaces depends on the performance of a tall wall. But as wall heights extend beyond 10 feet—and in some cases reach nearly 20 feet—the structural demands become much more significant. Creating expansive great rooms or vaulted living spaces depends on the performance of a tall wall. But as wall heights extend beyond 10 feet—and in some cases reach nearly 20 feet—the structural demands become much more significant. Under the IRC conventional wood stud wall heights are restricted. There are exceptions that let you go taller than 10 feet without an engineered design, but they are limited. When load-bearing walls are greater than 10 feet they may require the assistance of a registered design professional.

In this edition of Pros Know, Greg Wells speaks with Dan Chaney, Boise Cascade’s director of engineering, about the challenges of tall-wall construction, and why choosing a dependable, high-performance product such as Versa-Stud® LVL can help support straighter walls, more predictable installation, and long-term performance. 

Q&A

Greg Wells: Hi. Welcome to Pros Know with Boise Cascade, I’m Greg Wells. Today we have Dan Cheney, our director of engineering, and he’s going to speak with us about Tall Walls.   

Dan Cheney: Thanks, Greg. Happy to be here.  

GW: In a lot of homes these days, you’re seeing taller walls. People like to have a little bit more space in the house. You know, kind of make them a little bit more visually appealing. Can you talk about that a little bit?  

DC: In some of these walls that we’re talking about, in the great rooms, can be up to 20 feet in height. I mean, we’re talking about two stories of unbraced height and those really need an engineer to take a look at them.   

GW: So why is that? What does the engineers stamp do?    

DC: So, an engineer, would he be looking for – he or she – would be how much deformation you’re going to get out of plane with the wind loading or seismic or what have you, and you just want to limit that out of plane deformation. And is a function of height. And so the taller you are, the more deformation you could have due to that wind loading coming from the outside of the structure.   

GW: So literally to say it’s like running into a wall. That wall is 20ft high. You’re going to have a lot of force for wind or seismic in an earthquake situation. That certainly makes sense. So, you don’t see a lot of 2x4s that are 20 feet tall. So how do people build tall walls today?  

DC: So a lot of times in traditional framing would be platform framing. The problem with that is if you, say, two 10 solid-sawn studs in a 20-foot wall…  

GW: So in that case they’re stacked on top of each other?  

DC: Correct. And so what you create there is what we call a hinge. And so certainly you can frame around that and frame for that. But much easier and much more predictable would be to use a solid piece from top to bottom plate.  

GW: So I imagine on the hinge, just like a book you keep opening, a book you can crack. Is that kind of issues any see with the hinge point?  

DC: Certainly. And you’re trying to transfer strength across a couple different nailed connections, which sometimes can be unreliable over time with deformation and shrinkage happening. And 1.8E, 20-feet long Versa-Lam stud is probably your product in that application.  

GW: Hey, Dan, just for clarification, we’re mentioning Versa-Lam® and Versa-Stud. It’s the same product, but versus stud is cut down to dimensions that fit standard wall framing.   

DC: That’s correct. So Versa-Stud is really Versa-Lam LVL cut down into traditional solid-sawn stud sizes 2×4, 2×6, 2×8 and the likes.   

GW: So you mentioned E value… you can you explain that a little bit.   

DC: Certainly. So E value is really just a measure of the stiffness. And so, the higher the E value, the stiffer the product. And as we talked about that out of plane deformation, you want as stiff of a product that you can, to limit that out of plane deformation. If you’re going to be framing around windows or hanging cabinets or installing tile, you really want to limit that deformation down to half an inch or less.  

GW: Okay. Let’s talk a little bit more about that. So we have the the Versa-Stud or Versa-Lam LVL used in wall framing. And you talk about having those come in long lengths. So that eliminates the hinge point. Talk about window and door framing. So does that have a lot of as you say, deformation characteristics in those as well?   

DC: It does. And so you have a rigid piece in your framing there. And what you want to watch for is cracking in outside finishes interior and exterior, where if you have too much deformation and movement back and forth in that horizontal plane, you’re going to get cracking and your homeowner is going not be happy and you’re going to get callbacks.  

GW: So with Versa-Lam, I think the other thing is it’s manufactured extremely straight. So there’s less shimming when they are installing the windows. Is that true or shimming when they’re installing cabinets.   

DC: Completely correct. So our LVL, Versa-Lam LVL is manufactured around 8% moisture content. Solid-sawn piece can be 18, 19, 20% moisture content. You will equalize at somewhere around 10 to 12% in the house. And so, with the solid-sawn piece having to lose moisture to equilibrate down to 12%, you’re going to get shrinkage, warpage some crook and twisting, where the LVL piece will actually gain moisture and stay dimensionally stable.   

GW: Okay. So, with Versa-Lam LVL you can get it in long lengths. It will work when you’re engineering a wall that’s over ten feet. It’s straight and stable. So it makes it easier to build those walls if used indoors and window frames it stays straight consistent without twisting, making the installation faster, and also helping the trades when they’re hanging cabinets, tile or doors.   

DC: Correct. And the all-important reduction in callbacks is really how it pays off for the builder and your customer.  

GW: So what happens if somebody has questions or gets stuck in designing a wall? What do they do?  

DC: We have a full team of engineers on our technical support team that can provide support. And then we also have BC calc, where you can design these walls yourself utilizing our software.  

GW: Thanks, Dan. That was some great information. I hope you learned something about tall walls. Be sure to check out our additional information at bc.com.