Building on Solid Ground
Why is building on solid ground so important? Foundation problems can occur for a variety of reasons, the number one reason being the type of soil. The entire country has different types of soil, some are more sandy, others are more wet and muddy. To know and understand what kind of soil your home is built on, or your future home will be built on, you must know the different kinds of soil to build on solid ground.
Expansive Soil
These soils contain minerals such as smectite clays and they are good at absorbing water. When soil absorbs water, it increases in volume. Expansion of up to 10 percent or more is common in this type of soil. Swelling soils causes cracked foundation, or cracks in floors or basement walls. Expansive soils also shrink when the moisture evaporates. This will cause the removal of the support from buildings and fissures can develop. Fissures are long opening cracks. The presence of fissures will allow the cycle of shrinking and swelling of the soil to continue and cause stress on the structure. This type of soil can cause greater damage to a home than floods, earthquakes or hurricanes combined. Piering foundation repair is often used in this situation to transfer the weight of the home onto steel rods.
Subsidence
This occurs when large amounts of water withdraw from certain types of rocks, such as fine grain sediments. When the water is not there anymore, the rock consolidates and falls in on itself. Subsidence is a big problem due to increased use of groundwater and development of land and water resources. It is especially a problem in more humid areas like the southwest with soluble rocks like limestone and gypsum. Clearly, any structure that was built on top of these types of rocks can have major foundation problems. Signs to look for are vertical or diagonal cracking that is both inside and outside of the home. Cracks that can open and close depending on the season. Piering a house can have a significant impact on this type of damage.
Hydro-Compactable
Also called collapsible soil, this type is low density and loses a substantial amount of volume due to wetting and/or increased load. This type of soil can lose up to 20 percent of its original volume. This usually occurs in arid temperatures and where intense flooding occurs. The cycle of dry and wet causes the soil to have an unstable structure. Signs that the soil around you is hydro-compactable are:
- Lawns that absorb water quickly, but is not green.
- A handful of soil will be dry and blow away easily.
- Soil forms a crust when dry.
- Curving cracks occur in concrete surfaces.
All of these types of soils can have a huge impact on the strength of your foundation. When the soil is constantly shrinking and expanding, or there is a substantial amount of stress on the soil, it will cause the foundation to crack. The most important thing to do in these cases, no matter where you live, is to install a pier foundation. This will allow the home’s weight to be placed on steel rods rather than the unstable soil. For more information, contact a team member at MAGNUM® Piering.