What is causing my home to sink?
How was your home built? What was the process? How did they lay or pour your foundation? Did you have to clear land or trees? Did they have to dig a hole for your basement? When your home is in the starting process of building, you have to find a place to put it, right? Regardless of where you put it, you need to have a flat area to work with. Large machines come in and move many layers around and a space is dug for your basement or crawlspace. By disturbing that natural soil layers, you have created new unstable layers around your home. When your foundation is finished it then gets backfilled with loose fill dirt. We like to call this the active zone.
The Active Zone
The 'active zone' refers to soil beneath the ground surface that is the most affected by changes in moisture as the season or climate changes. The active zone may vary from a few feet below grade to more that 30 feet below grade, depending on the area of the country in which you live. There are four common changes in soil that cause settlement of a home in many different areas.
Drying and shrinking of soil
When dry periods extend for months or years, clay soil dries out. And, as we know, when clay dries, it shrinks. As the amount of soil around your house shrinks in size, it creates an empty space for your home to settle into.
Did you know that the root system of a tree is often two times the size of the tree canopy? This means a tree with branched that extend over your home is likely to have roots that extend under your home, draying valuable moisture from the soil. So, what happens when the soil dries out around my home? More voids form and more settlement occurs.
Wetting and softening of soil
When you have heavy rains, clay soil gets wet and it hold on to the water making it become very soft. This soft soil can be weak, causing the home to sink down into it. In some ways, it is similar to stepping onto a muddy field, your foot 'squishes' into the soil and your home's footing does that same thing.
Poorly compacted fill soil
A common practice when developing neighborhoods involves removing soil from hilltops and placing it in valleys to create flat, buildable lots. When this fill soil is not compacted well, it will compress under the weight of the home which causes settlement.
"But maybe my home is done settling..."
The constant cycle of wet and dry periods is a major factor in settlement, and we know that Mother Nature never stops working. Remember, the layers of soil your home rests on are greatly affected by these changes in moisture. There is one way to be certain the problem won't keep getting worse and worse. By finding a solution that permanently ensures your home's stability is not dependent on those unstable soils, you'll no longer have to worry about these factors, which are not in your control.