***CRITICAL*** Jamb Studs 1

[SBSUSA]

I have two scenarios here. First a description of the posts.

P1 - Single stud member with web at opening and capped with track. (1) 600S250-54 and (1) 600T200-54
P2 - Back to Back studs capped with track at opening. (2)600S250-54 and (1) 600T200-54

Height is 13'
Wind - 125 (gust 3)

Scenario 1 - The P1 jamb studs were installed with web side at opening and not capped. Sheathing has been put on and masonry veneer is nearing completion. Capping this is impossible without removing the sheathing (densglass and 1.6" HunterXci Plywood panels) and masonry. Are there means and methods for addressing this condition without removal of sheathing?

Proposed fix: Nest a 400S200-97 into 600S250-54 stud and cap the 4" member with track. See sketch attached.



Scenario 2 - Same parameters as above except P2 jambs have been installed as a box rather than an "I" and also without track.

Proposed Fix 1: Insert a 5x5x1/4" HSS column in between the boxed studs and secure this through the existing studs. Column to have no top or bottom plates.
Proposed Fix 2: Nest a 2x5x3/16" HSS column into the web of the stud closest to the window opening. This HSS would have an offset base-plate and anchored to the slab with 5/8" threaded rod with 6" epoxy embedment.

 

[jayrod12]

For number two, why could you just add a third stud back to back with the stud furthest away from the opening and then make sure all 3 are screwed together.

In fact same idea for number 1 but add a piece of flat plate to the stud at the opening to give them something to screw to.

 

[XR250]

Jayrod,

I think the issue with #2 is that the studs were installed toe to toe so they can not easily be screwed together.

I think P1 repair is fine (nesting the 4" stud)

For Scenario #2, how would you attach the window side stud to the tube steel if you used the 5x5? If you used the 5x2, I guess you could go thru the inboard flange.

 

[SBSUSA]

XR250,

Scenario 2 - I was thinking that fastening through the web of the window side stud into the 5x5 or 2x5. Fastening would occur with #14 Teks at the bottom and top crib studs and through the 2x6 WD blocking at the opening (would drill a pilot hole in the WD blocking to ensure a solid metal to metal connection). A big part of using a 2x5 vs a 5x5 is cost and the ability to anchor this to the slab. If using the 5x5 i would install a hold down (most likely a Simpson HDU10B at the slab and a stiffening angle at the top plate for a connection a the top of the frame.

Thank you for the responses thus far.

 

[jayrod12]

I would argue that the densglass on the outside and if you put a metal plate on the inside face of studs it would allow the pieces to work together.

I just don't see a need for HSS members in a steel stud wall that weren't required by the original design. It seems excessive.

 

[SBSUSA]

Are you saying that the dens glass on the exterior is acting as a connection for the toe to toe assembly?

 

[XR250]

I don't like counting on the Densglass to transfer load in that manner but in reality, it would probably be fine. I have seen numerous assemblies built without jamb to jamb connections and they seemed to hold up fine. Dunno if I would stick my neck out for it, however.

 

[jayrod12]

And in a perfect world I wouldn't either. But in a situation like this, you can build a good repeat client (if you want them) if you can avoid major re-working or cost.

Generally the steel stud inspection should happen long before the veneer has been started, but unfortunately that's not the case all the time. If you put an 18Ga plate on the inside of the studs and screwed them all together, where does the stud go adjacent to the opening? the densglass and plate would stop the compression flange from buckling for each wind direction, and then once you account for the veneer, densglass and plate, the three studs that are touching (but maybe not properly fastened together) are still going to move as a single unit.

 

[XR250]

I would probably be ok with it for one area but not for a bunch as the liability exposure would be too great for me. I would certainly make sure the Densglass is actually attached to each stud in the cluster. Suction is your biggest load so if it ain't attached, there will be no load transfer.

 

[jayrod12]

Agree. But if the densglass isn't attached properly, I would expect the issues to present themselves in the veneer anyway.

It's likely these studs are deflection governed as opposed to strength based on the height, depth and veneer type. In which case they don't necessarily need to be fastened significantly.