Vertical vs. Horizontal Sheathing – The TRUTH According to Code

Like, why is it that Awesome Framers keeps not staggering their studs? Number one. Number two—why do we keep running it vertically?

Two reasons. One is our houses are fully sheathed. They don't have to be fully sheathed to resist earthquakes or high winds. It all depends on where you're at. When the engineer does an analysis of that building, the engineer will tell us what we have to have to meet code. And remember—code has a safety factor.

But there are a whole lot of benefits if we just go ahead and fully sheathe the walls. One, the siding can attach to it. And there's an APA note on that. Like James Hardie fiber cement, LP SmartSide—we can nail right to the sheathing. We don't have to hit framing, even in high winds. So that's a benefit.

Full sheathing improves performance and efficiency

Fully sheathing means we don't have any difference in thicknesses of the wall plane—that’s easier. Fully sheathing our walls also tightens up the house, making it more energy efficient. Also, fully sheathing the house means that our engineers have a lot more flexibility when it comes to their design and calculations. And at $200 to $300 per hour, yes, we're paying for the extra sheathing and labor, but it significantly simplifies things for the engineer and ultimately us. And it leads to a more resilient building for the customer—hopefully multi-generations, right?

Here's West Fraser's website. Notice their wall sheathing—TallWall, QuakeZone, WindStorm. Basically, what they’ve done is manufacture in custom long lengths to be able to even get up past our plate-to-plate measurement and get up to, for example, the center of the rim.

What's the benefit of that? Well, if we go mudsill to the center of the rim, we can now start to eliminate hardware in high wind zones. That's pretty cool.

Tall panels reduce hardware and improve resilience

Something that Tor says in this paragraph that’s highlighted is that he feels that the framer’s time is better spent on taking extra care while nailing than staggering rows of blocking, as shown in Figure 91 to accommodate standard joints.

Now, if we scroll, this is what that would look like on the backside. We have a row of fire blocking, and then we've just added blocking above and below. So think about what he's saying there. I think this is pretty profound.

At a time when we're really trying to bring younger people into the trades and train them, the most important thing is to use the right panel, don’t overdrive your nails, and nail to the proper spacing. Because that’s what the engineer has looked up in the code table.

So when they spec 6" edge nailing and 12" field nailing, it's incumbent upon you and me to make sure that it's nailed at that spacing—with the nails not being overdriven. It’s far more important to get that detail right than staggering the sheathing.

If the engineer needs strength, they’ll tighten spacing

Additionally, if the engineer actually does need the extra strength, they can just have us tighten up the nailing—maybe go from six to four. That's almost no extra labor for us, and we get the same end result.

Something else I wanted to point out before the video ends is the Special Design Provisions for Wind and Seismic (SDPWS), page 46. Basically, this is the testing. There’s the American Wood Council—was that awc.com or awc.org? Just Google “American Wood Council,” you can get the NDS there.

A lot of the stuff that we just do as framers, we don't necessarily know where it came from. We could check the NDS. The Special Design Provisions for Wind and Seismic has all of this technical information in it. Here's an example of the 2021—I actually think I paid for this. Again, I'm kind of a nerd. I like to read this. It gets into a whole bunch of nerdy stuff.

But if you are somebody like me—we're framers and we kind of like this stuff—here's an example too. Lateral... anyway, case studies, right? So it turns out there is a thing called science, where in different universities and laboratories they do testing on this. And after major disasters, engineers go in and forensically look: how did this fail?

Orientation matters—but not as much as you think

Here we are—Washington Wood Construction, Wind and Seismic Code 2021. I just want to point out there's a whole bunch of stuff here. Again, link in the description below.

Here's a bunch of case studies on different diaphragm setups. You see how the sheathing is changed in orientation, staggering, etc. Then, if we get down here, we get into some of the code tables. But I just want to point out the footnote. Notice footnote number 6: diaphragm resistance depends on the direction of continuous adjoining panel edges with respect to the loading direction and direction of framing members and is independent of panel orientation.

Strength loss from unblocked horizontal joints

One thing I wanted to note as well is Tor covers this—blocking behind horizontal panel joints. You notice here that if you don't block and you just run your sheathing horizontally but no blocking at the panel seams, your wall has about 40–60% the strength of the wall that is solid-blocked and the panels are run either direction.

Just think about this for a second. For the criticism we get here on the channel for our tallest wall with no staggering of seams—but all of our panel edges are blocked—for those who insist on sheathing horizontally, most of them are not blocking the panel edges. So at the end of the day, our wall is significantly stronger than theirs.

One other note. And by the way, if you just look down Special Design Provisions for Wind and Seismic, he's linked right to that section. So we could actually go right to this document and find that section that supports that. I think actually I was just there—I just wanted to show you the whole thing.

Does horizontal sheathing really flatten walls?

Now, you might be thinking to yourself that horizontal sheathing helps to smooth out or flatten out our exterior walls. We've definitely heard that come up over the years.

But like my good buddy Aaron Jones from Big Dog Construction said—we got to go visit those guys in Canada, Grand Manan Island, last September—he made a comment to me when we were filming together: “In my opinion, the best thing you can do for a straight wall? Crown your studs.”

Yeah, the rest of it is kind of like... Now, I would argue—and I have a hard time believing—that 7/16" wood structural panels actually help to smooth anything out. I think if we were to look at a wall with like a WRB on it and we didn't know which direction the sheathing was oriented, we wouldn't really be able to make a value judgment on that.

So crown and cull your studs for the flattest wall.

Vertical wall sheathing saves labor and insulation

Now, the reason why we don’t necessarily want to go horizontal is because in our seismic zone, we would then have to block all of the panel edges. Remember, the tables show us what the resistance is in pounds per linear foot based on the nail spacing—and, of course, the sheathing itself.

If we add blocking, that is extra labor that is unnecessary. Second, when we add wood to the walls, that means we can't put as much insulation. So really—why would we do that?

Now, I do want to show you something. In the pursuit of trying to be intellectually honest—we all have biases. I have a bias. My bias is this: it's simply just easier to install vertically, because I can go plate to plate. And on really tall walls, I can order 8-, 9-, 10-foot sheets. I can maximize where the block lines land, minimize waste, etc.

What Thor Matteson’s book says about staggering

I highly recommend buying this. This is Thor Matteson, structural engineer—his book is called Wood-Framed Shear Wall Construction. I bought my version in the ICC (International Code Council) online store. I can't remember. You can also buy this off Amazon in printed form.

I just want to show you over here—this particular document, he calls out that staggering horizontal joints in tall shear walls... I've highlighted here that shear walls with staggered panel joints will deform about 25% less than if we just go ahead and line up the sheets as I show them.

25% less deflection ≠ stronger

Some of us read that and we say, “Oh, it's 25% stronger.” That's not what it says. It says it will deform 25% less. So let’s say the engineer calculates that in the big earthquake, my wall with all the panel edges lined up—not staggered—but all nailed with blocking on the edges, deflects 1/4 inch.

Which, by the way, is about all we need to be when we leave a job plum—right? Within a quarter, eighth to a quarter. So if my wall deflects 1/4 inch, and you take the time to stagger the sheathing as shown here—that means staggered rows of blocking—guess what? Your wall will have deformed 3/16 inch.

That’s just not enough, in my opinion, to justify all the extra labor.

Focus on what matters: results and resilience

This is what staggering your sheathing actually looks like. It's not just that my 8-foot sheets on the first row are offset by one stud bay on the second row. You notice that this example shows that the long edge is staggered—just like a floor.

So for those that say that you have to go horizontal and stagger—you’re just not getting enough value out of that to spend the time, in my opinion. Because remember, the engineer has a safety factor built into their calculations.

Don’t build by feelings—build with knowledge

One of the big things that we always do as framers is whine and whine about all the Simpson hardware and all the engineering. And everybody knows they’re all in cahoots. “This is just a way for Simpson to make a lot of money.” “This is a way for the engineers—they're just so dumb, they should have to work with me for a year before they go to engineering school.”

And then what happens? As framers, we look at that and we’re like, “I’m going to go ahead and put more nails in. I’m going to add more blocking.” And really, we don’t have any education to back that up—we just have feelings.

That’s up to you and your job site. For me, the whole point of this video is just to show why it is that our engineers allow this, that the code allows this, that our customers are not taking a penalty.

Our walls are going to be more thermally efficient. There’s going to be less nails, less wood, less labor involved. In the age of an attempt for resilient housing and affordability, this would be a step in the right direction.

In my opinion, the whole point of my channel is just to... I’m 47 years of age. I started framing—my first summer full-time was when I was 12, 1989. I am... I just am so thankful. I just—I just loved this stuff from day one.

As I was a teenager and started reading The Journal of Light Construction... and as you start to learn, you realize, “There’s so much I don’t know.” And now at 47, guess what? I realize there’s so much more that I don’t know.

So if you are an engineer, please comment below. What did I get wrong? We’ll have a pinned comment with an errata, because I’m sure I got some things wrong.

The whole point of this is: this information is out there. We have good reason to trust it. This isn’t just manufacturers saying, “Well our panel does this,” or “We’re TCO-tested” or “APA-stamped.” There’s an industry standard.

So it doesn’t matter if I pick LP sheathing, Zip sheathing, TCO, West Fraser, Weyerhaeuser. That’s why the engineer doesn’t really call out the specific manufacturer—they call out the panel thickness, nail sizing, and nail spacing.

Anyway, I hope you enjoy this kind of content. I should have made this a long time ago. We’ve been answering this question for so long. I actually wrote an article for JLC on basic shear walls.

Go buy Thor’s book. Go spend time at APAwood.org, the American Wood Council. If you’re interested at all in this stuff—why not just look to gain the knowledge? It’s there.

What do they say over at The Build Show? “Know better and build better.” I’m not a Build Show contributor, but I think I agree with that sentiment.

Anyway, hit that like and subscribe button. Share the video with somebody. And again—if you are an engineer, architect, designer, framer—I would love to hear your comments below.

And if you’re just somebody that’s kind of interested in this stuff, maybe as a potential homeowner, somebody that’s looking to get their house built—let me know in the comments below what kind of content you want to see. Do you have questions that we could maybe do our best to answer—or, even better, we can find somebody to answer them. Someone like Steve Basic Architect, or any of the others.

I love you all. We’ll see you in the next video. Thanks for hanging out.