I suspect you are seeing the results of normal shrinkage of
framing lumber, it is just compounded by the 2x6 framing. Rather
than re tape and bed the corner, I would wipe the corner in with
painter's latex caulk at the next paint job. Lumber shrinks
across the grain exponentially as compared to with the grain.
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"donald girod" wrote in message
...
Over the seven years we have been in the house, all of the
exterior vertical corners in my house have opened up about 1/16"
or more in the middle part of the corner (starting about 18" up
from the floor and extending to about 18" short of the ceiling).
The framing is 2x6, of course. Because of the layout of the
house, there are three such corners in the house; there are two
corners in the attached garage, which is 2x4 construction, and
these corners have not cracked to any significant degree. None
of the interior partition corners, nor corners where partitions
meet the exterior walls, have opened up. Two possibilities
occur to me: the nature of an exterior corner post assembly is
different from other corners, and 2x6 lumber moves 60% farther
under moisture changes than does 2x4 lumber.

So, what is likely going on with these corners, and what might I
have done with the drywall to prevent this? By now, probably
not much can be done to fix it, since the corners open and close
with the seasons to some extent (it will be less noticeable when
summer humidity and heat return). I am going to clean out and
fill the three corners with flexible white caulk, but I expect
there will still be some cracking, at least of the paint layer.