Deflection of Gypsum Board (GWB) Shear Wall

[lutein]

We have a small one story wood structure, that we are using gypsum board as interior shear walls for wind resistance. We are trying to determine the shear wall deflection, which is a simple calculation for OSB or plywood sheathed shear walls (IBC Section 2305.3), but we could not find the Gt value for gypsum board shear walls. Do you know where we could find this value?
Gt = panel rigidity through the thickness (psi)

We were wondering if you could shed some light into this matter?

Any input is very much appreciated. Thank you in advance.

 

[TDIengineer]

Do you have walls with an aspect ratio greater than 1:1?

Usually deflection isn't checked, just that you don't exceed the very low allowable shear per foot value provided for the gypsum. But maybe I have been remiss.

 

[a2mfk]

I am also curious if serviceability is even a criteria in gypsum board shear walls? It would seem that any appreciable shear would cause enough forces at the screw heads to cause lots of visible distress such as screw/nail "pops", tape joint separations, cracks, etc. that would require some extensive repairs. In other words, it sort of is a one-time full-load system.