All structures settle to some degree over time, however, when a soil condition exists that allows one location to settle at a different rate and beyond the tolerances of the structural elements, you have a condition known as differential settlement. This condition can easily be identified by examining the structure of a building and attached components.
1) Look for obvious stair step cracks in the block walls. These will usually appear at corners or doors and windows.
2) The block "pulling" away from the top course or tie beam. In most cases the top portion of a block wall is poured solid. Oten this stronger structural element will span accross a failing portion of the foundation leavng a separation crack.
3) Windows or doors that stick or looked "racked". If your not familiar with the past repair work done on a house, look for doors that may have been "fitted" to an uneven opening.
4) Doors that open or close themselves. This is often a result of poor construction and does not alone indicate settlement.
5) Uneven Floors. Do you feel as if your walking downhill ?