Single top track for gravity loads

[EngDM]

Hey all,

A detail I have seen quite often for non-structural steel stud framing is to have a single inverted track run across the opening as the header. However, these tracks have an insanely low Iy (weak axis) so I'm curious how it's justified to carry the gravity load from the wall above; even if it is just like 2 layers of drywall.

On a similar note, for load bearing steel stud walls I'd imagine if the point load occured midway between two studs the top track would fail in the weak axis before the studs do, yet I rarely see studs called up to align with joists/loading members above. If the wall is sheathed then maybe I could see it being able to spread the load out to the studs, but just drywall? I have a hard time accepting that.

 

[XR250]

It is common to do this. Ends up being a deep beam with sheetrock webs.

 

[EngDM]

It is common to do this. Ends up being a deep beam with sheetrock webs.

Do you know of a design example that goes through this thoroughly?

 

[XR250]

It is never designed. If you're worried about it, put a real header in there.

 

[EngDM]

It is never designed. If you're worried about it, put a real header in there.

Is there a rule of thumb width or height above the door that this sheetrock webbed beam works for?

 

[milkshakelake]

I don't see how this could generally work with a 4" track, but a 6" 12 gage track might work. But if it's 12 gage track, I wonder if you're actually saving any money.

I wouldn't consider it as a beam with sheetrock. I guess it could work if the design ratio is about 90%-95% and you consider the sheetrock to give a little additional push. I understand that it's a deep beam in reality. It's a matter of engineering comfort and liability, and I land on the side of supplying a header. What if the sheetrock is removed during renovation? Also, I don't think it's "common" to do this, from my own experience.

About tracks not being designed for a concentrated load between two tracks, I always specify studs to line up for this reason. And they actually do it on site. But remember that generally, you will also have a top track, bottom track, and rim joist. Those are all in bending. It's similar to the assembly for wood.

 

[XR250]

What if the sheetrock is removed during renovation? Also, I don't think it's "common" to do this, from my own experience.

It is a non-bearing wall (I assume interior) . If the sheetrock is removed, so is the load.
Never seen anything different here on non-bearing, interior walls.. Mainly 20-25 gage drywalls studs.
Most of these are not engineered. When I am asked to engineer it, I do put headers in.

 

[milkshakelake]

My goodness, I missed the part about it being non load bearing! Then I agree with you. Though that bottom track should be something more than low gage. But nobody designs non bearing walls anyway.

 

[dold]

Think about it this way. You can hang an entire sheet of drywall long side horizontal from the very end. It can support itself. So, is the track/header really doing anything at all? other than out of plane.

 

[EngDM]

My goodness, I missed the part about it being non load bearing! Then I agree with you. Though that bottom track should be something more than low gage. But nobody designs non bearing walls anyway.

Where I practice it is common for contractors to require sealed shop drawings for steel studs, interior or not. Just trying to math out the "typical" details/framing that is done for these walls, instead of just "that's how we do it".

@dold , you make a good point.

 

[lexpatrie]

Sorry I got lost at non-structural....

 

[dold]

Sorry I got lost at non-structural....

 

[EngDM]

Sorry I got lost at non-structural....

Lost you say? Let's get you back to your room Gramps.