back-to-back CFS studs

[Prestressed Guy]

I have a structural CFS project with the requirement for all studs to be 33-mil. Most areas this is not a problem but I have one location where the spacing would need to be 7” oc. I will be using 6” net spacing for this wall. I was planning to call for back-to-back studs at 12” to make the section symmetric. The contractor wants to use single studs at 6”. Are there any advantages one way or the other?

 

[a2mfk]

The only difference would be if you have no continuous sheathing/bracing on one of the compression faces, back-to-back studs screwed together would be better for lateral-torsion buckling. If this is a typical wall that is sheathed/gyp both sides, I can see no difference. Maybe someone else will catch something...

 

[MiketheEngineer]

Ditto -

It might make more sense at 6'' to make the stud to channel connections - in other words there will be more chance of more fasteners??

Might be easier to run electrical, pipe, ducts, etc?? Though I don't see it..

 

[Prestressed Guy]

The wall is fully sheathed both sides with 5/8 gyp. In either case all punch-outs will be aligned. The components are all make on a CNC rolling mill that cuts each stud to the requirements. It will even put in the openings for waste/vent pipe that follows slope for drainage. The program that lays out the wall can handle any spacing but doesn't understand back-to-back..

 

[a2mfk]

I see no difference, let the GC decide.

 

[Prestressed Guy]

Thanks.

 

[UcfSE]

If you're specifying bridging, it may make a difference on how the bridging connects if there are no available webs to fasten to (the back to back configuration). The difficulty making a web connection may come in to play at the stud ends also, not knowing all the specifics of your situation. Otherwise, the GC is looking at more screws to fasten studs together versus more screws to make sure the sheathing is connected to every stud. It may just be a personal preference he or she has.

 

[a2mfk]

Do you need to bridge usually on top of sheathing both sides?

 

[ishvaaag]

The closer separation will be better for the gypsum board, and wall itself, making it stronger and of more regular behaviour.