Our 1994 2 story house has a slight dip in the kitchen floor. It is hard to measure, but it looks like a 1/4" dip over a 6 foot length by 3 foot width. In the basement, the I-beam sits in a cement-block wall, and the first metal support is about 8 feet from this wall. The dipped section sits about 2 feet away from the beam, and the long dimension of the dip follows the beam. Envision a line with an oval drawn under it (barely touching) and you'll get a good overhead view of the situation. The cement floor has a few cracks, but the cement wall has none. The floor joists show no indication of cracking or bending. Above the kitchen, there is no major weight loads, so I suspect the problem is below. I was considering renting a laser level and seeing if the beam is level. Would this be a good place to start? Anything else I should look for? Thanks.

Thanks for getting back to me so quickly. Iwill have to get a digital camera before I can send pictures. But this is a followup question. In another part of my basement, I moved the existing stairs from the wall about 1 and 1/2 inches. This is as far as I could go withoutout major structual problems. This movement was to accomodate some 2X2's. This wall was DRYLOKed and polyed. Then., I attached pressure treated 2X2,s directly to the wall covering the poly. My question is " What do you suggest prior to attaching the drywall a) leave empty space between the studs or b) fill in the space with stiff form board ? " Thanks, Raymond.