Case Study
The Versatility of Steel Deck
Michael Jochim, structural engineer ICON Architectural Group
Mandan, North Dakota
Steel decking is a no-brainer for floors, ceilings, and roofs. Its ability to span significant distances is ideal for todays’ more open design aesthetic. And its durability often means a longer life for the buildings it’s part of. But, as structural engineer Michael Jochim recently reminded us in a conversation about how his firm, Icon Architectural Group, is using it in a project in North Dakota, steel decking is actually a much more versatile material.
Below are excerpts from that conversation.
As a structural engineer, what’s the appeal of steel deck?
“I really like using steel deck because of its flexibility, because of how far it can span, the loads that we get out of it, and the different uses that we have for it. … I like the ease of which it’s installed. You lay it out there, and you can either fasten it down with powder-actuated fasteners, or screw it down, or weld it down. And then I like that it comes in a variety of shapes and sizes.”
How well does steel deck match up with today’s design preferences?
“I work at an architectural firm as an engineer, so I’m always being pushed by the architects on what we can do with the structure to make it look nice. And so that’s another reason I really like steel deck. It comes in all different shapes. You’ve got your dovetails, your ends, your plateds, your acousticals. All help the architect provide the aesthetic that they’re looking for without having to add extra costs.
“Nowadays, architects are always pushing to make bigger spaces, more open spaces, cleaner spaces, and steel deck allows the spans to create those types of looks. On one particular project that we’re working on now, we wanted a nice, big front entry to this new high school, and we created this big curved entry roof. It’s actually the roof of the new media center inside the school, also. And so we utilized some curved deck that came out precurved to the radius that we wanted, and it’s finished on the bottom, too. So once they came and set it in place, the finished look was there and the architect got the nice, open curved look that they were looking for with a nice white ceiling on the inside right away.”
Are there applications where steel deck should be the preferred option?
“If you want a commercial building feel, I would consider steel deck and structural steel construction in general. Commercial buildings that are built out of wood tend to feel too residential. You end up with noise transfer between wood floors, and you may not be able to get the openness or the flexibility of the design if you’re stuck with a material like wood. … Steel deck is going to provide longevity to the building overall. During construction, it goes up quicker. It’s not susceptible to being left out in the snow and the rain. Whereas if you’ve got a wood building, you have to make sure that stuff stays protected during construction so you’re not ruining all those building materials by getting wet.”
Are there times where steel decking may not seem like the obvious material choice, but it actually works really well?
Back to the high school project I mentioned. They were looking at a proposed pool they wanted to add right away. Our first thought was precast double tees because of our concerns about the humid environment and the constant moisture in the air. Precast concrete feels like the better fit when you first consider your options. … But with today’s coatings, steel obviously could be an option here, and it ultimately was what we went with.
What about steel decking as a sustainable material and using it in projects where that’s a concern or priority?
“Using steel compared to other building materials, you’re going to get a longer building life out of it, for one. A properly constructed steel building with steel deck is going to last longer than something that’s wood framed.
“And then, because you can create more efficient designs with those longer spans, you’re using less material in general by creating these bigger open spaces. So, overall, you’re reducing how much material you’re using. And then from a recycling standpoint, they’re able to take old steel and recycle it and create the new steel deck, new steel shapes. You can’t really take old wood, take old concrete, recycle it and make new concrete, make new wood from it. I mean, sure you can recycle it for other uses, but the building materials themselves aren’t coming from recycled materials. So that’s one of the things I really like about steel is that it’s got the capability of being made from old steel at some point.”
Tell us more about how steel deck was used in the high school project you’ve mentioned.
“We ended up using nine different types of steel deck on that project. In a typical commercial building project, we’re usually only using one to three types. But because of the different conditions up there at the high school, we ended up using nine different types—from floor decks to roof decks, different shapes, different sizes, different thicknesses, spans. And that’s by far the highest number of decks I’ve ever used on a project in my 10 years.
“We had our typical building areas—classrooms, offices, that type of thing— where we had our standard inch and a half deck that we used. As we got to some of the larger open areas—the gymnasiums, the auditorium—we needed a bigger deck to span those bigger distances. And then we used a specialty deck in one area. It was a dovetail deck to give it a nice clean, finished look on the underside of the deck right away. And then we had a couple areas, I already mentioned.
“And then we had one area where we ran into an issue where we ran out of headroom due to a really large mechanical unit. In order to fit the mechanical unit in the room that we needed it to without having to pop up the roof and create roofing issues, we ended up pulling out all the steel joists and installing a six-inch deep deck that was able to span almost 20 feet over the mechanical unit and create an extra foot and a half of headroom over it to get the unit in there.
Any thoughts about switching materials in that instance?
“It was always going to be steel, and we were going to make it work. So the deck was the most obvious choice just because then we’re not having to deal with additional structure, we’re not dealing with extra joists, extra beams, that type of thing. So yeah, it was, ‘Yep, this is the problem that we have and we’re going to fix it using steel deck in some way, shape or form.’ ”