Foundation problems can occur when your house “settles” or “heaves.”
“Heaving” or “upheaval” happens when the concrete slab on which your house is built rises above the original foundation.
This usually happens when excess water gets under the foundation. The cause is often a sudden surge of moisture onto extremely dry clay soil. The water—from a monsoon rainstorm or a plumbing leak, for instance—causes the thirsty, shrunken soil to expand and push the foundation up.
“Settlement” happens when part of the foundation drops below the rest of it.
Soil under and around the perimeter of the house can become so dry during an Arizona drought that it causes cause the foundation to settle. Settlement is usually greatest near the perimeter of the foundation where the soil dries most quickly.
All houses “settle” a bit when they’re new. The products in the home will move a little bit until they stabilize. You may see tiny cracks in floor tiles or sheetrock. That’s normal and no cause for alarm.