I have a question regarding a sloping section of the 2nd story in my 1920 Dutch Colonial. There is an interior dividing wall between the bathroom and bedroom that has, I believe, pushed down on the floor joists creating a dramatic slope at the base of the wall. There is no interior wall directly underneath this on the first floor, and I believe it is the weight of this wall that has caused the floor to sag so dramatically. In the bedroom, there is a downhill slope in the floor towards this particular wall, and in the bathroom, it's the same situation although it appears much more dramatic as the bathroom has a width of only about 5 feet, and the floor appears to dive down about 4 or 5 inches in that small span of space.

I have heard advice to leave it alone and try to put down self-leveling agent on the subfloor in the bathroom, but have also received advice that it would be best to jack it up. Is it advisable to jack up the second floor from the first floor, and what would be the best way to go about doing it? Directly under this wall on the first floor is the center of my dining room, so a permanent lally column wouldn't work.