The second floor of our house has a fairly low ceiling, perhaps 6'8" or 6'10". The width of the structure is only about 16' with standard construction and the ceiling joists running parallel to to the gable walls.
I am planning to remodel the bathroom upstairs (complete gut job) and this gives me the opportunity to access the joists in this section of the structure. I would like to move the joists up 12" to create better head room (I'm 6'3" so the shower in the short ceiling bothers me).
I am thinking that if I move the joists one at a time by cutting them loose from the top plate and the roof rafters and then shortening them the appropriate length, they will move up nicely without affecting the structure at all.
There are no trusses, this is all an old stick-framed, farm house. I would even be willing to gusset the portion of the roof rafter that spans between the ceiling joist and the top plate if needed. The walls are balloon framed, but I don't think that makes a difference.
Edit:
Hmmm....I went up to get a picture, and I realized that there is no ridge board! The vertical piece exists between each ceiling joist and roof rafter pair. This makes me a little more hesitant.