Oshin,
I am not arguing that the shear wall needs to be laterally braced for the shear loads. If it were allowed to move out-of-plane, than the shear wall could pull away from the truss and then what good would it be. I am saying that we typically considered the truss bracing (purlins or sheetrock) to be acceptable out of plane bracing for both the 5 psf partition load as well as the stability for lateral loads. As far as a method, maybe this is a rule of thumb, but wouldn’t the bracing force about 2% - 5% of the lateral load on the shear wall? Similar to bracing forces for beams and trusses? We have usually used this same rule to brace shear wall elements. In the case of wood framing, this would result in a lower force than the 5 psf partition load. That is why I posted the 5 psf load for lateral bracing the wall. Is this the wrong approach here? Will the sheetrock and or purlins provide acceptable bracing for short (10’-0” in this case) wood framed shear walls?
Jeff