The stability of a home’s structure is directly dependent on the stability of the soil beneath it. Sadly, the soil on which homes are built is not always stable. When the soil begins to shift, a home’s foundationlist can become compromised. Though there are many factors that can contribute to a shifting foundation, the most common of these factors are unstable soils (especially clay rich soil), poor drainage and plumbing leaks, poor grading or compaction, and tree roots.
Clay rich soils may be good for hot peppers and peanuts, but they are very damaging to foundations. Clay soils expand and contract when the moisture changes. Home owners may find that cracks in the home become more prominent before or after it rains or when the weather changes. This is because this type of soil expands and contracts as moisture is absorbed or evaporated. When the soil around a home becomes saturated with water, the clay expands and loses density. When the water evaporates, the clay becomes hard and dense again. Compounding the problem is the fact that soils don’t lose moisture evenly. If one area of the soil beneath a home’s foundation becomes oversaturated with water and another portion is less saturated, the water saturation beneath a home can evaporate unevenly. The oversaturated soil loses density and cannot support the pressure of a foundation. This unstable soil is the primary cause of foundation settlement.
Additionally, poor drainage conditions around a home can cause over-saturation of soil. Many homeowners have tried to address the problem of standing water around their homes. Such things as french drains and water run-off systems can be extremely helpful. However, sometimes these drainage systems are just not enough to prevent foundation damage. Once water problems have caused damage to your foundation, drainage systems will not be able to prevent further damage.
Another drainage issue is plumbing leaks beneath a home, which are often overlooked. These leaks don’t just happen in a crawlspace (where a plumber or air conditioning technician might find them); they also happen beneath the ground. Most commonly, these leaks are noticed by homeowners who spot random puddles of water around their home, especially during a dry weather period. These leaks don’t only cost money for plumbing repairs, they can also erode the soil around a foundation and cause long term problems.
As many coastal residents know, historically, coastal cities have been built on filled in land. Back-filled areas are not uncommon. However, when the filled in land has been improperly compacted, foundation issues can arise. Back-filled soils are not necessarily unstable. When compacted improperly, however, these soils can become loose and unstable. There are certainly instances when new homeowners are able to hold their builders responsible. And there are some insurance policies that cover foundation damage. However, foundation damage still needs to be addressed.
Last, interestingly, trees or shrubs with expanding roots can remove water from the soil around a home. They can also produce roots that will grow into a home’s foundation and cause damage. While some shrubs and trees can grow roots into the foundation, it is more commonly found that shallow roots are consuming water from the soil around a home. This adds to uneven water saturation in the ground surrounding your home.