lateral brace within plane of wall

[structSU10]

Having an internal debate about laterals braces within the plane of a cold form partition wall - specifically using HSS chevron or X or single strut braces and the CF framing into that. Some think its asking for serviceability issues with the gyp board cracking and such, and requires joints along the attachments to the tubes- others don't really see it being any bigger issues than typical infill studs and potential for cracks in gyp and such due to general building motion since they are still clipped back to the building and have to move with the structure.

Thoughts?

 

[SteelPE]

These are items I am not sure I would really be concerned with. Depending on the size of your building the brace is likely moving very little. I might be more concerned in the brace were on the exterior of the building and you were transferring out of plane wind load into the bracing (which is the direction I thought you were going with the thread).

How much differential movement is expected in the brace (between the floor and the ceiling?

 

[JAE]

We do this all the time.
You have to design the brace not only for the in-plane brace lateral loads but also for the out-of-plane C&C wind forces on the brace, delivered to it by the studs that are attached to it.

This is all created by designers not wanting structural columns to be positioned inside the stud walls with little pilasters at each column.

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[structSU10]

Yes it is a mix of interior / exterior condition. The plan was to design the braces for bending from wind / seismic and axial loads.

The small movements I feel the same way about - and if a large EQ hits there is going to be repairs required to non-structural stuff no matter what. I know others in the office have done it, and haven't heard of any issues - figured I would see what others experience is. Architecture definitely leaves us not much other choice.

 

[KootK]

- I do this often too, as JAE has described.

- Were it a special concentrically braced frame, there might be concern for interfering with the brace hinging mechanisms but that's surely not the case here.

- From an in-plane, wall serviceability perspective, I'm not sure that I see the difference whether the brace is in the wall or somewhere else. The wall's got to deal with the same drift either way. Probably slightly less drift than a wall further down the line that's seeing drag strut elongation.

- In my heart of hearts, I would like to make this condition illegal and force everybody to put their columns behind their walls. I feel that's the natural solution and, often, the in wall condition causes me base plate connection grief.

 

[SteelPE]

I always try to get my columns behind the walls.... then again, I mostly work on warehouses. Columns behind the walls helps out with AB coverage. I have also been burned multiple times with misplaced anchors and have had to come up with a way to get post installed anchors to work with very little edge distance.

Putting the columns behind the wall doesn't win popularity contest though .

 

[structSU10]

From an in-plane, wall serviceability perspective, I'm not sure that I see the difference whether the brace is in the wall or somewhere else. The wall's got to deal with the same drift either way. Probably slightly less drift than a wall further down the line that's seeing drag strut elongation.

That was exactly my thoughts.

 

[JAE]

In my heart of hearts, I would like to make this condition illegal and force everybody to put their columns behind their walls.

Amen Brother!

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[KootK]

Amen indeed. I was in a restaurant last weekend that was exactly this kind of building. The "perimeter" row of columns were about 6' in from the exterior wall, just inside of the first row of booth seating. Roof cantilevered from that. I though it was so bizarre that I nearly took a picture (and now wish that I had). I should track down that architect and see if I can steal her business. My sell can be "I'm so bold that I only need my column twelve inches inboard of the walls!".

 

[Ceinostuv]

In my heart of hearts, I would like to make this condition illegal and force everybody to put their columns behind their walls.

Koot for President!

Putting the columns behind the wall doesn't win popularity contest though .

He'd win my vote, though.

Judgement-In-Training