#10-16 screws shear capacity in dry wall 1

[sjtuchenyi]

I am doing a CFS steel stud project. it's an addition to existing building. At one location, the exterior steel studs (only take lateral wind/pressure, no axial) need to be installed under an existing ceiling (drywall). The contractor installed the top slip track with #10 screws to the underside of ceiling (drywall). So we are not sure if the screws penetrated to the existing ceiling framing (steel stud @ 16" oc) or just the drywall. I'll the screws are in drywall and try to find out the shear capacity of screws in drywall. any reference for the shear capacity of screws in the drywall. Thanks

 

[BAretired]

Can you remove a screw and measure its length?

BA

 

[Celt83]

"...the exterior steel studs (only take lateral wind/pressure, no axial) need to be installed under an existing ceiling (drywall)."

Exterior studs need to attach to something much more substantial than drywall ceiling. The drywall ceiling could be suspended from wire in which case the top of wall will have basically no lateral stability.

My Personal Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

Open Source Structural GitHub Group:

https://github.com/open-struct-engineer

 

[XR250]

The slip track resists a significant amount of torsion due to the stud gap eccentricity. This results in a force couple that needs to be resisted by tension/compression in the track web. Your screws have to be installed into something substantial enough to resist that load. Drywall ain't gonna cut it - neither will most light gage ceiling framing. The shear is also an issue.

 

[sandman21]

OSHPD Allowable tension and shear OSHPD Paper

 

[Tomfh]

A top track supporting external wall needs to mount to something solid, not just dry wall.

For an internal partition you might get away with it, but not external.

External wall junction is prone to wetting too, and dry wall turns to mush when wet. Screws will have effectively zero capacity.

 

[RPMG]

I had this problem with a coat rack once. It fell down.

 

[Ron]

A screw into drywall has a shear capacity of somewhere between 10 and maybe 50 lbf., with no safety factor. Don't do it.