A house is no better than the foundation on which it is sitting, and in turn a foundation is no better than the soil that is under it. In preparation for the foundation sub-straight, all of the sod must be scalped, or in common language, removed, (a 6 inch minimum) and a mixture of clay and sand known as “select fill” must be bought in and compacted. Now that his has been completed, you are ready to build a foundation that will be properly supported.
Over the last couple of decades during the housing boom, many home builders were building houses in areas where the soil had a tendency to shift. Since most of the best ground in populated areas had already been taken, builders and developers found it necessary to sub-divide residential lots in areas with poor soil conditions for foundations; good to grow cornhaps, but not so good for building houses.
When many house foundations in a particular area fail, the excuse is that it's an act of God, and that there is nothing anyone can do about it. In reality, a builder is without excuse since there are geotechnical engineers available for testing and issuing an expert report with recommendations.
All engineers will recommend scalping at least 6 inches of top soil from the building site because it is considered “unstable sod”. Plant life does well in top soil because it will not compact, which allows the foliage to flourish. For excellent compaction and stabilization, a builder needs to bring in “select fill” which is a mixture of clay and sand.
If you should have a failed house foundation, you will need to hire a foundation repair company to place concrete piers around the perimeter of your house. Hydraulic jacks then lift and level the house with these new supports. Once you have determined that you have a failed foundation, act quickly because it will only get worse. If you should sell you home, by law you will be required to dispute any known problems, if you do not, the buyer will have future recourse against you.
The second biggest problem with stress on a foundation is cause by the plants and trees growing up and sucking the moisture away from one part of the slab and leaving the other part of it dry. This can also happen when a tree dies or is cut down thereby upsetting the moisture and structural balance. When you plant a tree, place it at least half of its mature height away from the house.