"Standard" Cold Formed Steel Box Beam?
"Standard" Cold Formed Steel Box Beam?
(OP)
Please take a look at the attached image from the Steel Stud Mfrs Assoc. - the question is: if a boxed header is chosen from the table, does it come "off the truck" pre-manufactured with NO seam welds/cap & screws required to be specified by the EOR? I'll withhold my thought briefly. Thanks






RE: "Standard" Cold Formed Steel Box Beam?
First; can you imagine there are two members attached each other, and no weld/bolt/bonding connection.
Second: these type of beams are from the material with high strength properties. So welding always is a problem, or difficult.
Third: You need to be careful for the load transfer on the faces of the member since the walls are not thick enough. The same apply at the ends of the beam. You need to think about how you will transfer the loads from the beam to the supporting members. Connection elements
such as punching with screw might be needed, and you will be concentration on the details of the connection.
The limitation in the deflection is mostly a code requirement for industrial/building application. The box member is better selection for the torsional applications in addition to other actions, but you still need to validate that your application is safe, at least meets the code requirements.
Corrosion protection is another issue with uncapped member that you need to take care.
RE: "Standard" Cold Formed Steel Box Beam?
RE: "Standard" Cold Formed Steel Box Beam?
RE: "Standard" Cold Formed Steel Box Beam?
The built up members come from the originating supplier (Dietrich etc) unassembled. Depending on the market and the specialty contractor:
1) Assembly may occur on site or in a fabrication shop.
2) Assembly details may be provided by the EOR.
3) Assembly details may be delegated to a specialty engineer working in behalf of the light gauge contractor.
That's my understanding at least.
Given the advantages that you mentioned did back to back, why do you usually go with box headers? Torsion/LTB? Connections?
Interesting. Oriented as track or strong axis?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: "Standard" Cold Formed Steel Box Beam?
Usually weak axis but this is more for non-load bearing jobs where i am only supporting wall DL. The other thing I do sometimes if the arch. conditions allow, is to use a single, light track for the head of the opening and then screw a "strongback" stud to the rear of the wall above the dropped ceiling that spans from jamb to jamb. The track then only has to carry out of plane loads. Boxed headers are labor intensive so anything to simplify the job is appreciated by my clients. I think Dietrich still makes a super deep leg track that can be used for a header that sits on top of the wall, legs down.
RE: "Standard" Cold Formed Steel Box Beam?
This is generally left up to the EOR to sort out. It can be delegated but it doesn't go away.
So far I've stayed away from all structural welding of light gage.
RE: "Standard" Cold Formed Steel Box Beam?
RE: "Standard" Cold Formed Steel Box Beam?