What causes foundation settlement?

Is this foundation problem? Do I need to concern about it?

• I bought a house 3 yrs ago, slab foundation, around lake area (have you guys heard "shifting soil", Yazoo Clay in Mississippi, the house is around that area.) http://cedb.asce.org/cgi/WWWdisplay.cgi?0001128 When I bought the house, the inspection person said the foundation has NO problem, despite little cracks on the corner ceiling, he said it caused by the settlement... Anyway, I got a foundation repair company to test the level of the house, because I see a crack on the hall way wall and the hall way ceiling surround the attic letter entrance (the crack appeared after I bought the house, seems like the previous seller did some touch up work, and the touch up work couldn't disguise the problem anymore, so the cracks showed finally). The reference is in the middle of the living room, then 3 bed rooms on one side of the house are not leveled, 1 bed room is 4 lower, 1 bed room is 2 lower, another is 1 to 2 lower. The other side of the house is kitchen, it's 1 to 2 higher (I had water pipe burst last yr this time, the pipe was fixed after 1 month or so). Of course the foundation repair company wants to convince me to fix it, but since I am on the lake with Yazoo clay, I want to know is this necessary to be fixed, is the unlevel degree in a acceptable range? If not, will the problem worsen? I am planing to stay this house for at least 5 more yrs, am I taking risk by not fix the "foundation problem"? Thanks ALOT!

• Answer:

  I think you should fix it. If you just bought it, you should get a lawyer and try to sue the previous owner for non-disclosure. If you do not fix if, you will have to disclose the problem when you put if up for sale. Good luck!