Monday, May 14th, 2012 by Cassi Sherman Henes
A lot of people believe houses just settle over time, is this true?
Yes, many times, home settle—this can be due to the compaction of fill soils, which is the most common reason. Other problems include settling due to hydro compactible soil, hillside creep, subsidence, and clay soil shrinkage. However, settling should not just be ignored as it places additional stress and friction on your home's foundation.
1. Compaction of Fill Soils
Fill soils, no matter how well compacted, will settle over time. This will usually cause some cracking and uneven sloping in your basement slab. When your slab behaves this way, it is a signal that your foundation is also moving. Don't be too alarmed, though, because slabs are made to crack and aren't terribly costly to replace. You do want to make sure that your foundation remains stable and functional with no cracking because your foundation is NOT made to crack.
2. Hydro-compactible Soils
You probably know this soil under the common term of "sand" or "loamy sand". It's the type of soil that collapses rapidly downward when it gets wet. Obviously, this is problematic if your home is resting on this soil because a heavy rain, broken pipe, or sprinkler mishap can cause rapid shifting, settling, and cracking of your foundation.
3. Hillside Creep
This movement can look very similar to settling, but it's actually where one portion of your home is sliding down a hill. This usually occurs with multi-level homes built into hillsides. The lowest level starts to shift down the hill and it looks and feels like that level is settling.
This movement is generally localized and abrupt. It's similar to a sinkhole type of situation. Subsidence can occur over mines, but many times it is simply that a pocket of hydro-compactible, or weak soil has dropped.
5. Clay Soil Shrinkage
Clay soil is most famous for heaving, however, it does contract if the clay dries out. This can cause problems for a foundation, especially if the clay was quite swollen and then dries it. It puts a great deal of stress on the foundation walls and footer.