Based on the provided content, there are eight primary causes of foundation failure and structural distress:

1. Poor Drainage and Water Accumulation: This occurs when water pools near the foundation due to improper grading, clogged gutters, or short downspout extensions, which can erode supporting soil.
2. Expansive Clay Soil Pressures: Common in Colorado, these soils swell when wet and shrink when dry, creating a cycle of vertical and lateral movement that stresses the foundation.
3. Inadequate Soil Compaction: If fill soil is not properly compressed during construction, it leaves voids that lead to differential settlement as the building’s weight compresses the loose ground.
4. Invasive Tree Roots: Roots can draw moisture out of the soil, causing it to shrink and create voids, or physically lift footings as the roots expand in diameter.
5. Hydrostatic Pressure Buildup: Saturated soil exerts intense inward force against foundation walls, which can cause horizontal cracking, bowing, or floor heaving.
6. Plumbing Leaks: Undetected leaks in supply or sewer lines saturate the soil, causing ground movement or washing away soil particles (erosion) under the slab.
7. Seasonal Drought: Prolonged dry spells cause clay-rich soils to contract and pull away from the foundation, resulting in a loss of support and settlement.
8. Substandard Construction Practices: This includes using under-strength concrete, omitting necessary rebar, or failing to account for specific soil conditions during site preparation.