Q: I am rehabbing an old two-story balloon-framed house with a crumbling limestone foundation. I need to jack the walls slightly to repair the foundation. The floor joists rest on a 2-by leveling plate, and the 20-foot-tall studs are face-nailed to the sides of the joist ends (see illustration). With platform framing, I would ordinarily run a temporary beam under the joists as close to the foundation wall as possible and place my jacks under the beam. If I do that with this frame, I am concerned that the weight of the walls, which are carrying the second floor and roof, will shear the old face nails. Any suggestions?