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WOOD - Load bearing studs in a party wall

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I am checking the load bearing capacity of a wood framed wall that is
intended to be used in a party wall. This party wall consists of 2x4 studs @
16" mounted on 2x6 top and bottom plates. These studs exist on each side of
the wall. In other words, there are 2x4 studs @ 16" framed flush to one edge
of the sill plate and 2x4 studs @ 16" framed flush with the other edge of
the sill plate. These two "rows" of studs are offset so that there actually
exists 2x4 studs @ 8".

In a "normal" wall, these studs are laterally braced on both faces. For an
interior wall, there is gypsum wallboard on both sides. For exterior walls,
there is some kind of exterior sheathing (plywood or stucco) with gypsum
wallboard on the interior. Therefore, these studs are laterally braced
continuously about the minor axis. To determine the axial capacity based on
l/d ratios, I have used the distance between the sill plate and top plate
for my "l" and the depth of the stud for my "d".

In this party wall case, there is gypsum wallboard on only one face of the
studs. True, it is the compression face for the Code mandated 5 psf
partition load, but one edge is still laterally unsupported. My gut feeling
is that the capacity of the stud is somewhat less than if there was gypsum
wallboard on both faces but a lot more than if there was no gypsum wallboard
at all.

Since I realize that I'm not the first structural engineer to be asked to
use a party wall as a load bearing wall, I am curious what others have done
in the past to determine the capacity of studs laterally braced on one face
only.

Regards,
Bill Allen