A common indicator of problems related to soil movement are stress features such as cracks, separations, tilting walls, and sloping floors. Sometimes, these stress features, particularly cracks, are normal, and don't indicate a problem related to a soils problem. How can someone tell if cracks and other stress features suggest a potential problem, or represent a "normal condition?" Here are a few basic things to consider:
1. Pavement, floor, or slab cracks that are off set may indicate movement related to the underlying soils. Offset cracks are those where one side is higher than the other. Offset cracks may indicate expansion or contraction of the underling soils.
2. Cracks in the wall plane of a stucco wall. Corner cracks that radiate from windows or doors are not uncommon, and may be related to minor settlement of poor installation of stucco. Cracks in the face of a stucco wall, particularly cracks that are across the entire plane of the wall, or don't radiate out from the corners, are not typical.
3. Cracks that increase in size and length over time. Hairline cracks in stucco might not indicate a problem. However, cracks that lengthen, widen, or offset over time are indicators of a progressive soil movement issue. Be particularly concerned about floor or slab cracks greater than a hairline, and be particularly concerned if the cracks get progressively longer, wider, or off set.
4. Interior drywall cracks. Always monitor interior building cracks. Once again, those that show a pattern of increasing over time should be professionally analyzed.
5. Finally, know if your home or building is constructed on fill soil. Cracks that appear on structures constructed on fill soil need to be particularly carefully monitored. Soil movement is a greater risk and concern on homes and buildings constructed on fill soil.