Bracing Partition Walls to a Roof Structure when the walls aren't full height 1

[MJC6125]

I'm curious about how well kick bracing details work for the lateral support of interior partition walls in regards to allowing the roof structure to deflect without imparting a vertical load into the partition walls. I found the first two details shown below through a google search. Based on what I've seen in buildings, I think these types of details are relatively common. Are you concerned about how the brace detail in the one rigid brace doesn't technically allow the roof to slip up or down relative to the top of the wall?

I know there are alternative details when you have a nice smaller run of wall where you can kick near the corner of a wall in plan over to an adjacent perpendicular wall. But let's say you had a long run of wall where the top of wall is 12' and the roof structure above is 20'. Let's say its interior CFS wall studs and a bar joist and metal deck roof. Has anyone come up with a good solution for kicking/bracing the top of this type of wall? I came across this image from KootK from a previous thread for a CMU wall bracing detail. Would people do something like this for a metal stud wall.

 

[GC_Hopi]

If it's a vertical member hinged top and bottom, the assembly is unstable.

You should clarify this. Sounds like you are saying a simply supported element is unstable. I believe the intent is to not transmit the deflection of the roof to the partition.

Also the vertical member can be at an angle. I modified your sketch below.

 

[BAretired]

@GC Hopi,
To clarify, I am saying that the pinned link as shown below makes the assembly unstable, i.e. the applied horizontal force at the top of the partition cannot be transferred to the structure above.

I agree that the vertical member can be at an angle. Any rigid combination of members attached to the roof and the inverted bucket would be acceptable. The partition is contained laterally, but not vertically.

BA

 

[GC_Hopi]

Ok... I guess I was confused why you added that link between the wall and brace when my sketch did not have one.

 

[BAretired]

I was talking about your post dated 21 Sept 21 18:05, which showed nothing between the hinge and the top channel. In particular, I was responding to the following:

BA

 

[Yao1989]

So far I can only visualize BA's FBD with 2 rigid brace with vertical deflection track being stable.

Maybe you can also tie top of wall to the drop-ceiling, and the drop ceiling should be seismically braced as per local code. Alternatively I tend to agree with motorcity to maybe design as cantilever wall. I can't speak for california, but even in Washington State / Lower Mainland BC / Vancouver Island area, would we not still be looking at about 5psf for seismic as well for a 10psf wall?

 

[XR250]

Never seen a slip track used in these situations - only single diagonal braces to a standard track.
Deflection of the roof will cause the top of the wall to move sideways a bit - likely no big deal.
Also, take advantage of perpendicular light gage walls with a horizontally spanning top track or other girt.

 

[BAretired]

Single diagonal braces, as shown on the second sketch in the OP, create compression in the braces when the roof deflects. The detail may be acceptable for small deflections, but otherwise, the braces may buckle, or the partition may snake out of alignment.


BA

 

[XR250]

Single diagonal braces, as shown on the second sketch in the OP, create compression in the braces when the roof deflects. The detail may be acceptable for small deflections, but otherwise, the braces may buckle, or the partition may snake out of alignment.

Yes, basically what I said - And it is done like that all the time.

 

[BAretired]

As the OP pointed out, it is a common detail. It does not affect safety and may not be of serious concern.

BA