Uneven floors mean the support underneath has moved.

Uneven Floors: diagnosed and explained.

An uneven floor means the support beneath it has moved: the slab, the crawl space framing, or the foundation itself. The signs show up in small ways first. A marble rolls across the kitchen. A gap opens under one end of a bookcase. Walking down the hallway feels faintly like walking downhill. What you are feeling is the floor structure following whatever is happening beneath it. On a slab home, the concrete itself has tilted or cracked because the soil under it compressed or shrank away. On a raised foundation, the joists and beams over the crawl space have sagged or the perimeter footing has settled, so the floor framing leans toward the low point. In Southern California, Arizona, and Nevada the usual engine is clay soil swelling through the wet months and shrinking through the long dry season, which cycles the foundation up and down unevenly year after year. A slight, stable slope in an older home may be history. A slope that is getting worse, or that arrives with cracking drywall and sticking doors, means the movement is still happening, and measuring floor elevations is how you find out which one you have.

For the repair side of this, the foundation repair solutions page lists every method Dalinghaus installs, including the ones that fix problems other than uneven floors.