Steel column 1-hr inside wood stud wall

[Yikes]

We are designing a Type V-A apartment building where we need a steel column (supporting > 2 floors and roof) inside a wood stud wall. the column thus needs individual protection. the structural engineer also want positive attachment to the wood shear panel, which means the column will have nailers on 2 sides and plywood shear panel on the 3rd side:

How do we provide 1 hour encasement on the shear wall side? This was going to have exterior plaster. If we have to bump out with more drywall, we will (it will look odd), but even then, it appears the plywood shear panels create a fire path through the one hour encasement.

 

[Mark K]

Tubular columns are regularly located in wood stud walls. I did it all the time and had no pushback from Architects so I assume you will find there is a relative simple solution.

I understand the nailers on the side of the tube, if the tube is used to resist some uplift, but the additional plywood seems unnecessary. Replace the added plywood with drywall.

 

[e hilton]

can you put the shear wall ply on the inside, where a bump won’t be noticible?

 

[Robert]

What is the interior finish? If it is type X won't that give you the one hour (assuming stucco exterior)?

 

[mark handler]

2019 CBC 704.2 Column Protection
Where columns are required to have protection to achieve a fire-resistance rating, the entire column shall be provided individual encasement protection by protecting it on all sides for the full column height, including connections to other structural members, with materials having the required fire-resistance rating. Where the column extends through a ceiling, the encasement protection shall be continuous from the top of the foundation or floor/ceiling assembly below through the ceiling space to the top of the column.

Exception: Columns that meet the limitations of Section 704.4.1.
704.4.1 Light-Frame Construction
Studs, columns and boundary elements that are integral elements in walls of light-frame construction and are located entirely between the top and bottom plates or tracks shall be permitted to have required fire-resistance ratings provided by the membrane protection provided for the wall.

 

[Yikes]

Mark, thanks for the link. The inclusion of "columns" in CBC 704.4.1 (exception) is new to the 2019 code. This developer had us rush in the initial plan check set in December, just before the code change. The 2016 code section describes columns as part of the primary frame.