Cold Form Framing Attachment 1

[FootNMouth]

Are there any guidelines or code statements in reference to what are acceptable CFMF attachments to structure? I have a steel building that has exterior stud walls. In the shop drawing the studs are shown attaching to the bottom of wide flange beams for lateral support. We did not account for weak axis bending or torsion in the beam design and would prefer the studs attach to the composite deck.

Should we have stated these limitations in the construction documents?

 

[KootK]

Probably. This document is an excellent sampling of the kinds of connections that one can expect: Link. It shows connections to both steel beams and to composite decks. While none of them are representative of your particular torsion problem, I don't think that's off the table.

Certainly, I know of no prohibition against your supplier's detail. This kind of thing is often an issue with delegated design. If I feel that I might have strong preferences regarding the form that a detail takes, I'll show a "concept detail" to be fully fleshed out by the supplier when the time comes.

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.

 

[XR250]

The EOR should show a schematic of the stud attachment locations to his structure. As someone who does a lot of CFMF shop drawings, I can attest to the fact that this drives me insane.
That is why, in my opinion, the EOR should either do the CFMF design himself or sub it out directly and integrate the design into his work product.
Otherwise, this is what you end up with. Also, then the metal stud contractors are all bidding on the same design and are not guessing what their engineer will come up with.

 

[wannabeSE]

FootNMouth,
Have you looked at the architectural drawings to see if there is detail showing the cladding attached to the deck? On the structural edge of deck detail, I will typically include an optional kicker/brace to the bottom beam flange with a note saying the brace is required when the cladding is attached to the beam rather than the deck.

KootK,
Most of the cold formed connector manufacturers make a clip that attaches to the bottom of the beam.

http://www.steelnetwork.com/Product/VertiClipSLS

,

http://www.clarkdietrich.com/products/curtain-wall-bypass-connections/fast-strut-fs12-fs15

,

http://www.strongtie.com/products/CFS/SSB.asp#gallery

 

[jike]

I have two comments:

Before the design drawings are issued.....
Make sure that structural and architectural drawings are fully coordinated re: CFS including any braces that might be required for connections to beam bottom flanges, etc. If none are shown then make sure you have a feasible way of connecting the CFS to the structure without braces.

After the design drawings are issued for bids......
A change order might be required to execute the design with braces, if not fully thought out in the design phase.

Note that the Owner may not be happy accepting a change order because he was expecting a total design once the drawings were issued.