Light Gage/Cold Formed Steel Wall - Continuous Bracing?
Light Gage/Cold Formed Steel Wall - Continuous Bracing?
(OP)
Forgive me if this is a very basic question - As I am new to light gage steel design....
When you are designing a light gage exterior wall - how do you establish 'continuous lateral bracing'? Is this assumed if sheathing is on the exterior (compression) flange? If yes - is there a minimum sheathing thickness or fastening requirement?
I have always been told that bracing is effective if it prevents twist of the cross section and/OR lateral movement of the compression flange. However, I'm not sure what constitutes "preventing lateral movement" (I have always assumed that metal deck on joist or steel beams acts as bracing - so I believe this would be similar)
I'm also desiging a CFS parapet wall and trying to determine if sheathing on both sides will act as continuous lateral bracing. I woudl think the only thing that would change is that you would now have two compression flanges due to wind loading from both sides.
If possible I would like to develop full moment capacity (Sx*Fy). Obviously this is only possible if the memeber can resist LTB. Otherwise you are stuck using the nominal flexural strength charts (KL vs Mn) which greatly reduce your capacity.
Does anyone have a reference they could suggest I review for this? I have reviewed the AISI manual/spec/commentary, but haven't found anything regarding this.
I greatly appreciate your help and again I apologize if this is an elementary question.
When you are designing a light gage exterior wall - how do you establish 'continuous lateral bracing'? Is this assumed if sheathing is on the exterior (compression) flange? If yes - is there a minimum sheathing thickness or fastening requirement?
I have always been told that bracing is effective if it prevents twist of the cross section and/OR lateral movement of the compression flange. However, I'm not sure what constitutes "preventing lateral movement" (I have always assumed that metal deck on joist or steel beams acts as bracing - so I believe this would be similar)
I'm also desiging a CFS parapet wall and trying to determine if sheathing on both sides will act as continuous lateral bracing. I woudl think the only thing that would change is that you would now have two compression flanges due to wind loading from both sides.
If possible I would like to develop full moment capacity (Sx*Fy). Obviously this is only possible if the memeber can resist LTB. Otherwise you are stuck using the nominal flexural strength charts (KL vs Mn) which greatly reduce your capacity.
Does anyone have a reference they could suggest I review for this? I have reviewed the AISI manual/spec/commentary, but haven't found anything regarding this.
I greatly appreciate your help and again I apologize if this is an elementary question.






RE: Light Gage/Cold Formed Steel Wall - Continuous Bracing?
RE: Light Gage/Cold Formed Steel Wall - Continuous Bracing?
thread507-226616: Wall Studs?
RE: Light Gage/Cold Formed Steel Wall - Continuous Bracing?
RE: Light Gage/Cold Formed Steel Wall - Continuous Bracing?
that should help you out.
RE: Light Gage/Cold Formed Steel Wall - Continuous Bracing?
DaveAtkins
RE: Light Gage/Cold Formed Steel Wall - Continuous Bracing?
Have others seen this regarding flexural bracing requirements:
"Bracing is effective if it prevents twist of the cross section and/OR lateral movement of the compression flange"
I don't think bridging restraints lateral movement of the compression flange - would you say it prevents twisting? Since its at the center of the section - I would think no.
I have read the post suggested above regarding braced walls. Posters seems to suggest that bridging is only effective for bracing in compression and that sheathing must be used for flexural bracing. Possibly the differnce in responses above has to do with the terminology - Compression vs Flexural bracing.
Your thoughts?
RE: Light Gage/Cold Formed Steel Wall - Continuous Bracing?
The book frv mentioned does have some design examples.
So does AISI framing design guide
RE: Light Gage/Cold Formed Steel Wall - Continuous Bracing?