I have a 50-yr old ranch-house, and most of the foundation is fine. The only problem is a sagging floor, next to the staircase to the basement. Here's why: The main construction consists of a center I-beam, with 2x10 floor-joists running from the center beam to the footers. The basement stairway runs next to, and parralel to the center-beam, so the joists on that side can't run all the way to the center-beam. There is a double joist at each end of the stairway (running from center-beam to footer), then another double-joist next to & parallel to the stairway (on the opposite side from the center-beam). The 6 floor-joists next to the stairway run from this double-joist to the footer. The problem is that the double-joist parallel to the stairs has pulled away from the one of the perpendicular dj's, 1/2" and sags 7/16". Also, about 3 of the floor-joists attached to the parallel dj have pulled away from the dj, and also sag slightly. (Above this parallel-dj is a kitchen wall, with cabinets & fridge against it. Kitchen floor has many squeaky spots.) I plan to add a 6x6 beam under the parallel dj, that will also support all the floor-joists that attach to that dj. I'll support the new beam with 2 lally columns. The beam only needs to be 8', but I want to extend one end (where the sagging has occured) an extra 4', so that the column is out of the way. I've read a lot about this, and have seen many warnings about going slow, etc. This doesn't sound too difficult, but I have several questions: - Do I really need to fill the columns with cement? If so, how is this done? (sounds tricky & messy) - I guess I need the 1/4" steel plates above and below the columns & jacks. Where do I get these? - How much footing do I need under the columns? I guess I'll use 4x6 or 6x6 pcs on the floor to spread the load. Is 1 or 2 feet adequate? Could I just use 2x6? (I'm not sure how thick the concrete floor is, but there are no cracks anywhere.) - I borrowed a floor-jack, which you adjust with a 1" threaded rod at one end. Is this adequate for jacking, or should I buy/borrow a bottle-jack? - If I need a bottle-jack, how big? (I don't want to buy more than I need, cuz I won't be doing much other work like this.) Thanks in advance for any input. -Joe P.