The foundation is dependent upon the soil that surrounds it to hold the foundation in place.  In theory this relationship should stand the test of time, however, the one variable that cannot be controlled is that the soil beneath and around the foundation is constantly changing.   This is due to a variety of reasons.

UNSTABLE SOILS

Many clay-rich soils can be defined as “elastic” in nature.  In other words, they expand and contract with moisture content. As soils become saturated with water, the clay expands and loses strength. This condition allows the foundation to sink much the same as you would standing in wet mud. Conversely, clay soils contract when moisture is taken away. Unfortunately the soils do not always loose moisture evenly, which allows one area to contract faster than another. The soils contract, the foundation loses needed support and therefore settles.

POOR DRAINAGE

Improper drainage can cause soil instability by creating localized areas of saturated soils, which softens the soils and allows the foundation to settle. Poor drainage can be due to the localized topography of the area, “French” drains that have become clogged with roots and soil, gutter down spouts, etc.

POOR COMPACTION

Many homes are built on back-filled soils, which is a common and accepted building practice. However, care must be taken to properly compact the back fill before construction of the foundation. Improperly compacted back fill will slowly consolidate, sometimes over a period of years, which will allow foundation settlement.

PLUMBING LEAKS

Another potential reason for your foundation problem may be due plumbing leaks that allow water to saturate or erode the soil under or around your home. The water created from this problem is constant and will only continue to deteriorate the soil conditions around your home’s foundation.

TREE ROOTS

Many varieties of trees and large shrubs consume vast quantities of water. For example, some experts report that one large pine tree can remove as much as 30 gallons of water from the soil daily. If trees and large shrubs are located in close proximity to the foundation, excessive moisture loss can result. This will allow the soil to contract and the foundation to settle.