Responsibility for building cladding and infill

[joeHSE]

Let's say that I've designed a steel framed structure that the Architect has chosen to clad with aluminum panels backed up by cold-formed studs. The structural steel is clearly my responibilty but what about the studs for the cladding? Who's responsibility is it to design the cold-formed stuff for C&C loading?

 

[BAretired]

It depends on your agreement with the architect. If you specify it then it's your baby.

BA

 

[OHIOMatt]

It would depend on your contract with the architect.

I would typically include the studs in the scope of my proposal unless specifically instructed that another design professional was taking responsibility.

If the architect is taking resposibility, I would show the studs, and lable them "See architectural" or something of that nature.

 

[joeHSE]

Well, I guess I've looked at studs that are strictly infill as non-structural components and so they do not fall under our typical scope of work with the Arch. I also read the Code of Standard Practice that way as well, i.e. I don't have to call out stuff that may connect to "my" steel if it is not directly related to the structural steel of the building. That said, I wonder how far it would go in a courtroom if all the cladding and infill blew off a building and all I can say is that, "Hey, its not structural. The building is still standing."

 

[JedClampett]

If I had the room in my budget, I'd do it myself. It just seems to be in your self interest to make sure that's done right.

 

[steellion]

The exterior CFS studs ARE structural and need to be designed by an engineer. Whether that engineer is you or another engineer (often a consultant of the CFS contractor) depends on the contract and the specs. It's worth asking the question.

 

[JAE]

I also read the Code of Standard Practice that way as well

The AISC code of SP doesn't deal with light gage metal studs at all - not a source to verify whether you are required to design them.

I agree with the others - depends on your contract. Maybe it needs to be clarified in your next project agreement.

 

[joeHSE]

Steellion: Indeed, they should be designed by an engineer...just not me necessarily.

JAE: You got me on the CoSP. Its the first place I thought to look since the building is steel framed.

The responsibilty for the design CF studs should be clearly defined in the project agreement (and the contract documents if necessary).

Thanks to all.

 

[TTUengr51]

Agreed, specify the CF stud infill in a performance specification to have the CF framing subcontractor hire a specialty engineer. Treat it similarly to pre-engineered trusses by specifying loads, deflection criteria, etc.

My firm works with a couple of CF framing subs that hire us to perform this type of work. This is especially helpful if the sub likes to panelize the systems, as they may have proprietary systems which they like to utilize.




Nick Deal, P.E.
Michael Brady Inc.

http://www.michaelbradyinc.com

 

[rscassar]

My opinion, the external wall framing needs to be designed and inspected by an engineer. In my locality, it is common for the wall framing supplier to design and certify the installation of their product. As the engineer who oversee's the project, I request that the wall framing contractor submits shop drawings 7 days prior to fabrication for review. This is not to critique their design, it is to ensure that nothing is missed between the overlap of my 'structural design' and the wall framing contractors design.

If it is a non-loadbearing situation and none of the stud infill forms part of the bracing system, I would just specify on the drawings that the metal stud walls are by the wall framing subcontractor. If I wanted some movement between the stud walls and the steelwork, I would say that the top track is to allow +/-0.5" vertical movement.

 

[Ron]

I agree with steellion in the respect that it is a structural component. It is accepting and transferring loads to the structure.

The design, as others have noted, can be by you or others, but it is a structural function, delegated or not, and in my opinion, you have the responsibility to check the submittal of the delegate engineer to determine compliance with YOUR structural design concept.

Put enough in your contract to at least do the submittal check if not the full design.

 

[paddingtongreen]

To start things off, send a letter to the Architect reminding her that the infill system studs/girts must be designed and the drawings sealed by a PE and remind her of the applicable code and the version to be used.

Some cities take their own sweet time to incorporate model code revisions into their own codes, particularly if the director of code enforcement doesn't like something. I got into trouble for using the latest revision for a job in a major city. I had to go back and check that it met the older version; it didn't, I had to make changes.

Michael.
Timing has a lot to do with the outcome of a rain dance.