Framing Studs Steel Wood

Framing Studs: Steel vs Wood

The Great Debate: Steel Frame Versus Wood Framing – What Do You Choose and Why?


Foreword by Ian Thompson, Editor

The Great Debate: Steel Frame Versus Wood Framing – What Do You Choose and Why? 

For me, this is an interesting debate and, as usual, there is no clear winner. Why? Well, light gauge steel framing by its name is light, easy to handle and work with, it tends to be straighter than wood and, importantly, doesn’t suffer from the twisting effects that wood typically suffers from when drying out in your walls, trusses, and floors – especially in countries that use a lot of treated timber in their residential builds, like New Zealand. 

It’s no secret that I don’t like the excessive use of treated timber in any builds. It’s not sustainable, healthy for the installers, occupants, or the planet, and the reasons for use simply don’t stack up for me. Treating timber just adds another process to the supply chain that adds cost and plays into the hands of the bigger suppliers who add more margin than necessary because they know they can. And just because we use treated timber throughout our builds doesn’t mean we are safeguarding our buildings from rot and timber failure, after all, our leaky buildings resulted from bad design and poor workmanship.  Again, there is no point paying for high-performing products if they’re not installed properly, and this is one of the biggest issues in the building and construction industries today.

I’ve considered steel frames for residential builds before and there are many benefits, but the reason I haven’t used it yet is because many years ago, I visited a group home builder’s show home in Auckland that used a steel frame. The wind caught the front door and it slammed shut, the whole house literally reverberated, which put me off the system. Now, I have to add a caveat: this group home builder, like many, used the bare minimum insulation (only on external walls) and no sound insulative or vibration absorbing materials, so they literally screwed their gypsum board directly to the frame and It was no wonder the house sounded the way it did. 

Now, it’s important to note that I don’t build with light timber frames either, also known as ‘stick builds’, so I’m not a good source of reference here. But what I will say is that there are many merits to using steel frame systems, especially if you use it in conjunction with good sound-absorbing materials and insulation in your walls. For me, it is definitely worth considering as an alternative to stick builds. 

If you’re already a part of this industry or are just beginning your foray, you’ll understand the vital role that wood has played in shaping the landscape of house construction around the world. History, after all, is etched in timber in a lot of countries. But don’t be too quick to discard the merits of steel studs – the stalwart of commercial building. These unassuming, U-shaped components are the unsung heroes that reinforce your office space, your stores, your factories. 

The heart of this discussion lies in their divergent properties – wood, with its quirks, and steel, an exemplar of precision. Wood is a tried-and-true friend with a few idiosyncrasies, while steel is a reliable ally in the world of commercial construction, offering fireproof strength. 

In residential construction, wood has been our go-to material. Its familiarity and structural reliability have earned it a place in our hearts. And let’s not forget, wood is nature’s gift, a renewable resource we can cherish – if supplied by ethical growers and suppliers!

But why don’t we see more steel studs in homes? To answer that question, we need to look beyond the surface. Steel’s Achilles’ heel is its exceptional thermal conductivity. It’s like the proverbial ‘hot potato,’ ready to transfer heat at the speed of light. In a world where energy efficiency and environmental concerns are paramount, we need to reevaluate our choices. 

Join Matt as he dissects these materials and their applications. We’ll explore the fascinating world of insulation, fire resistance, and the impact of exterior mineral wool insulation. We’ve got some incredible products and solutions to share, like Pro Clima’s ThermalGrip MVA – the perfect fusion of innovation and practicality. 

I invite you to embark on this quest for knowledge with us, and as you’ll soon discover, there’s more to these studs than meets the eye. It’s not just about straightness, splinters, and the age-old wood-versus-steel debate. It’s about making informed choices, meeting code requirements, and building structures that stand the test of time.

Now, over to Matt.

Video Transcript

“All right, guys, today’s Build Show, we’re going to take a deep dive into wood studs versus steel studs. Now, if you’ve been in the business for any length of time, you realize that most residential job sites, most builds, are made from wood. We’ve been using wood in America for a long time, and wood has a lot of benefits. Of course, one downside is the wood’s not always perfectly straight. But steel studs, if you’re a commercial builder, this is your wall system. You almost never see wood on commercial jobs. You see these roll-formed, U-shaped, ready to accept the drywall. Very different properties, very different materials. Let’s take a bit of a deep dive on today’s Build Show and the differences and why you might use one versus the other. Today’s Build Show: Wood versus Steel Studs, sponsored by Proclima.

Okay, so let’s start with steel. You know, commercial jobs, as I said, they almost never have wood construction. It’s almost always steel construction, and there’s a lot to like when it comes to steel. Standard sizes, in other words, just like typical lumber, you can get what we call pre-cuts made for your standard wall heights. They’re always straight. There’s no rot issues, there’s no bowing and warping. You’re never pulling one off and sighting down it to see if it’s going to be nice and straight for you. But one of the big reasons it’s used in commercial construction is this, right here: fireproof. I can run this torch on this steel stud all day long, and it’s not going to catch fire. At some point, it may get hot enough to melt, but it’s not going to be a source of fire. And that’s one huge reason you see it in commercial construction all the time.

Now, wood, on the other hand, when we frame houses, we do need to be a little bit particular when we’re using our wood because wood has some downsides. Like it’s not always perfectly straight, it’s certainly heavy, you can get splinters. However, it is extremely easy to cut. It’s also really easy to find. There are lumber yards all over the US that you can get these. It is structural. It’s typically less expensive than steel studs. And, of course, one of the big reasons I like it is, it is God’s material right here. It is renewable. Those trees grow incredibly quickly. Every 20 years, a well-managed forest is cut, and we’re able to get these rapidly renewing wood studs. So, I’m a huge fan of wood, and one big reason why you see this in residential construction, besides, of course, the history, is that it’s structural. You can get structural steel, but most of the time when you see steel studs in commercial buildings, it’s in a nonstructural application where it’s only holding drywall on one side or the other.

But why are we not using steel studs more in residential construction? If you were to ask me, I think there’s one big reason, and it kind of goes back to one of the big benefits we talked about. So, check this out. Line it up, one, two, three, four, five, 5 seconds, and look how hot that steel gets. Of course, it’s going to get hot because we just heated it up. But look as I run my FLIR camera back all the way to the backside of the stud. Oh, I can feel that. That’s hot back there. Let’s see if I can actually show you a value on the backside of that. It looks like it’s gone up about… I don’t know, 15, maybe even 20 degrees in just 5 seconds of putting that on there. Now, of course, you know what’s going to happen to the wood if I do this, but let’s have some fun anyway. 5 seconds on the wood, one, two, three, four, five. Oh, interesting. It’s self-extinguished. I didn’t even have to use my little water bottle. So that’s good. So you can see where the fire was. It’s still hot here. But now you know what’s going to happen. I touched the backside of that and nothing. It’s totally fine back here. This one, I can still feel that heat on the backside of my hand. It’s still pretty hot. I can touch it. It’s under 100 degrees, but it’s not far off. It’s in the upper 90s here, whereas this wood stud at the face, it’s still hot, but back here where my hand is, I’m fine. I’m not feeling that heat at all.

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Here’s the deal. Steel studs are highly conductive. Steel, right? We make wires from steel. We make frying pans from steel. It’s meant to conduct heat. It conducts heat really well. Wood, on the other hand, does not conduct heat very well. We would never make a frying pan or try and run the electrical wiring in our house out of wood. In fact, wood has a pretty common rated R-value of roughly one per inch, R1 per inch. So this 2×4 stud inside your stud wall is giving about an R4 for insulation value. This steel stud, if I can touch it, is still pretty hot, almost zero, not quite zero, but almost zero because it’s very conductive. I found a really great example of this online on the website Building Enclosures Online, and Daniel Overbay has this great illustration here, which says, “Look, if we used an R19 bat insulation, it would be rated R19. But if we were to put that bat insulation inside a stud cavity with 2×6 metal studs on 16 inches on center, the actual effective R-value of that wall would only be R7.1, so way less than half the rated value.

Now, that same bat insulation, R19 rated, if we put it in a 2×6 wood stud cavity, we’re going to have an effective R-value of 16, which means that in residential construction, wood is a great choice. And if we’re going to use steel studs, we have to take a couple of other precautions. Let’s go back to the studio, and we’re going to break this down a little bit further. I’ll see you back there.

Okay, y’all, we did a mockup to try and break this down a little bit further for you. So, typical residential construction, 2×4, often in the South. In fact, I built my house with 2×4 construction, usually some type of wood sheathing. I’m a big fan of Zip System sheathing. Commercial construction, though, we talked about this earlier in the video. Most commercial construction around North America is this steel studing on the exterior of the building, and it’s not structural steel. Usually, that building is held up by some type of platform construction where you’ve got reinforced concrete decks being held by steel. And then, you’ll see often on the outside of that, the sheathing is a gypsum sheathing. It leads to a fire rating for a rated assembly. And then, a great option for adding both an air and a water barrier on top of that is this Pro Clima AR-Guard system. You’ve seen me do some videos on this on residential, but it’s all over the commercial world, and really, that’s where it came from. I’ve kind of encouraged residential builders to steal that detail because this acts like a rubberized kind of like a bedliner on the outside of that building. And you can see as it goes on, it forms a continuous membrane. So, we really like that. But back to the point we were making earlier that steel studs are highly conductive, so that even if I use my Rockwool bats in here, I’m still going to have a pretty big disadvantage for all that thermal transfer. They call that thermal bridging at each one of these studs, which is going to negate the high R-value of the cavity, such that the wall assembly’s overall rating is less than half what the assembly rating would be if it was just the bats.

Now, the Masonry Veneer Association has a really interesting article on this because apparently it was pretty common in the ’80s and ’90s to actually build residential houses with this type of construction. In fact, there was a study done by the Canadian Mortgage Housing Association, which my Northern friends probably know all about. American builders don’t know much about them, but they did a really interesting study, and I’ll link to that in the description below. The Masonry Advisory Council did a summary on this as they were talking about this type of construction. And they said this study was houses that were residential houses built with this type of construction, 2×6 depth rather than 2×4 depth like my mock-up shows. And they said the study was done over a 7-year period with this type of construction, and they monitored the inside of the wall cavities with thermocouples, relative humidity sensors, moisture sensors, and pressure taps. And then four years after they started the study, they opened up the wall to see how it was performing. And they said the results are startling. Building paper on the outside. Now, they weren’t using this Pro Clima AR-Guard; they were using building paper. Building paper and exterior gypsum board were very wet with significant amounts of mildew, minor corrosion of the building frame, and fiberglass bat insulation that was very wet. Now, here’s the deal. Here’s the reason. It’s not just an energy transfer that we’re worried about when we use this. We have a risk of condensation. And that’s what was happening on those Canadian houses that were built with this type of construction was real cold outside. That cold was transferring through, and the inside metal, just like you saw my hand earlier getting hot, the inside metal here was really cold, and a cold surface can be a condensation risk, especially in a cold climate in the winter. We have breathing, we have cooking, we have showering, we have humidity inside our houses. And if any of that air leaks into this wall cavity, it’s really easy to find a cold condensing surface if this was your construction type. The same can be true with wood construction, but because wood is an insulator and has an R-value, like I said earlier, of about R1 per inch, there’s a little bit less of a reduction in that risk, not totally, though. But that’s where this comes in that I wanted to talk about specifically here, and this is how we mitigate the risk of that condensation and all that BTU transfer by thinking about exterior insulation.

Now, if you’ve seen my house in my videos, I’ve made a lot, used a lot of this product. This is called Rockwool. Rockwool is a mineral wool insulation, and they make it for both cavities, like you see, that R15 bat that’s made for the interior of a 2×4 wall. But they make this product called Comfortboard. It’s an exterior insulation. It’d be akin to putting a sweater on in the winter time rather than stuffing insulation in between your ribs. You get more benefit from putting a sweater on the outside if it’s cold outside than you do trying to stuff insulation in between your ribs. And that’s what this Comfortboard is going to do to our wall assemblies, on both wood framing and especially in steel framing. And these days, with codes changing almost everywhere in North America, and when you see these steel studs on exterior commercial buildings, you’re going to see some type of exterior insulation. You’re also seeing a lot of Rockwool that’s getting high adoption rates in the States.

However, there is a bit of a trick to this because now when I fasten this to either my metal studs or my wood studs, I need to think about that process because I’m going to have to anchor whatever cladding is on the outside. You’ve seen me do a lot of rain screens where I’ve got some type of baton that I’m screwing on and screwing through into the studs. But it’s very typical in commercial buildings and certainly residential buildings to have masonry on the outside, to have brick, to have stone, rock, whatever masonry on the outside. And Pro Clima sells this really cool product. This is called the ThermalGrip MVA, Masonry Veneer Anchor. It’s going to come in two pieces to your job site. This piece right here is going to have a washer on it already, and you’ll see that this washer has some tongs, some grips on it so it’ll actually grip through into that insulation. And then, this is actually the masonry anchor that is going to go on this tie after it’s been screwed in, and this is going to go in the courses of masonry. So in between your brick layers where you’re mortaring it on, that’s going to go in there. And what’s cool about this is when we anchor this into a stud, whether it’s a steel stud or a wood stud, this can actually vary in its location of where it’s going to sit in that mortar joint.

Now, these come in various sizes, and they’re what’s commonly called a two-piece tie, where you’ve got this little piece right here, this little orange anchor that’s kind of arrow-shaped is particularly cool because when this anchors in and, by the way, you’re going to get them in all kinds of sizes, I just have four or five of their sizes here on the table. You’ll see that the shaft varies in length depending on the exterior insulation thickness. When this shaft penetrates into the gypsum sheathing on the outside, and especially when we’ve got this Pro Clima AR-Guard sheathing on here, you’re going to see the tip of that shaft actually penetrate into the gypsum sheathing a little bit before it stops. And that’s pushing against that fluid-applied weather barrier that we talked about, that kind of rubberized coating on the outside of the building, which is going to form a nice tight water and air gasket on the outside of this anchor.

What’s cool about these is this is an all-in-one solution. The mason just screws these into each of the studs, drops that on, and we’re done. One thing you do want to note, though, if you miss a stud, leave it in. That’s really a big problem. If you start screwing in holes and leaving those holes, now we’ve got a place where water or air can get into that cavity because we’ve made a hole in the gypsum. So if somehow you didn’t mark those correctly and you find that this driller tip right here is just spinning and didn’t actually purchase, don’t put another one in. Leave that one in and move on and put another one on. That’s a really good tip here, guys.

I think we’ve covered most of it. I do want to end with some assembly values for you, which I think are really interesting here. By the way, Rockwool has an effective R-value chart on their website that you can put in a bunch of assemblies. And, of course, I made a 2×4 mock-up, but let’s just say this is a 2×6 mock-up. Use your imagination. If this is a wood-framed 2×6 wall, 16 inches on center studs, and we added that inch and a half of exterior mineral wool insulation, now we go from that ComfortBat in the cavity, which would be R23 and roughly R6 on the outside for that exterior insulation to an overall wall value of 22.7. That’s huge. That’s a really, really good number. So that exterior blanket, that exterior sweater makes a big difference for the building.

Now, check it out. The same thing, but let’s say it’s a 2×6 metal frame, steel stud building. If we use ComfortBat inside the cavity, which is R24, but then we put an inch and a half of mineral wool on the outside, now the whole assembly R-value is 14.4. In effect, we’ve doubled the R-value from before when we only had cavity insulation. You saw that, I think it was 7.1 on that chart before. Now we’ve gone up to 14.4. So only an inch and a half of the exterior insulation, we’ve doubled the overall R-value of the assembly. And that’s a really big deal, guys.

Lots more information about these masonry anchors, in particular, on the Pro Clima website. Everything we talked about today with products, I’ll put a link in the description below. But if you’re a builder out there thinking about steel studs versus wood studs, think carefully about the assemblies, make sure that you’re choosing an assembly that’s going to be low-risk, and make sure you’re also meeting your codes for wherever you’re building locally because I suspect almost everywhere you’re building in North America, if you’re building with steel, you’re going to need some exterior insulation. And almost everywhere in the States these days too, except for maybe a few places in climate zones 1, 2, or 3, is requiring exterior insulation as well.

If you’re not currently a subscriber, guys, hit that subscribe button below. You know we’ve got new content here every Tuesday and every Friday. Follow me on Tik Tok or Instagram. Otherwise, we’ll see you next time on the Build Show.”

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