Foundation Repair

Soils experience most of their drying and shrinking from two common causes:

Drought: Prolonged dry periods cause soil to dry out. As we know, when clay dries out, it shrinks. Soil shrinkage beneath a foundation has the same effect as soil settling: It usually causes a section of the foundation to crack and settle into the void or hollow area where settlement has occurred.

Maturing Trees: The root system of a tree can be up to twice the size of the tree’s canopy. If a tree’s branches extend over your home, there’s a good chance that they extend under your house as well, drawing moisture up from the soil and causing it to shrink significantly.

The soils around your foundation experience wetting and softening primarily for these three reasons:

Heavy Rain & Flood Conditions: As clay soil gets wet, it holds on to water and becomes very soft. This soft soil can be weak, causing the home to shift (or “sink”) down into it.

Poor Drainage: If water is allowed to stand or “pond” next to your home, the soil will absorb the water. As it does, the soil can weaken and soften once again.

Plumbing Leaks & Broken Water Lines: When a home’s plumbing begins to leak under a slab foundation, the soils underneath can begin to become saturated, weakening their supporting capacity.

In order to level a site where a foundation will be built, builders sometimes bring in loose soil from another location to fill depressed or hollow areas.

This newly moved “fill” soil is much looser and lighter than the dense, hard-packed virgin soils at the site that haven’t been disturbed — possibly for centuries!

The fill soil brought in by the builder has to be compacted thoroughly before a foundation is built on top of it. If the soil is not compacted well, it may begin to compress underneath the weight of your new home, creating settlement problems that can damage your foundation.

Water passes through sandy soils rather than being absorbed. This fact makes sandy soils very stable. Instead of expanding as they absorb moisture and contracting as they dry out, sandy soils maintain a fairly consistent volume and density.

Because of their stability and good load-bearing qualities, sandy soils are less likely to shift and settle, so they rarely cause foundation problems. Unfortunately, sandy soils are less commonly found than other more problematic soil types.

Soils rich in clay and silt have the greatest potential to damage a foundation. Clay absorbs water easily, expanding in volume as it becomes more saturated. So-called “expansive clays” can cause foundations to crack, heave and shift.

When clay soils dry out, they shrink and crack, leaving gaps around a house where water from the next storm can penetrate easily and deeply to repeat the expansion cycle. Clay-rich soils usually cause more foundation damage by expanding than by contracting.

Loamy soils are usually a very stable soil that shows little change with the increase or decrease of moisture temperature.

The primary concern with foundations built on loamy soils is erosion. When soils underneath your foundation erode, they may begin to be inappropriate strata for sustaining the weight of a foundation and home structure.