How Soil Affects Building

Central Missouri’s soil is mostly clay which is similar to a sponge, it shrinks when dry and swells when wet. Many homes are on multiple types of soil so that different parts of your home may be shifting at different rates.

Non-Cohesive Soils

• Organics—Black decaying or decayed vegetation
• Very low density and bearing capacity
• Suspends in water for a long time
• Silts—are very fine soil particles and are some of the least reliable for bearing. Changes capacity with moisture. Silts can only be compacted by dynamic compaction, they will rebound at a later date and cause structures to uplift. Normally consolidated silts will compress under a load when wetted.

Cohesive Soils

• Clay—Kaolinite, Illite, Smectite/Montmorillonite
• Water molecules attach to inner and outer layers of soil particles and push particles that expand the volume of the soil. As water molecules evaporate, clays consolidate and shrink.

Click here to download a printable copy of the Gibbs Company brochure.

For information on other educational items, please choose from the list below.
Warning Signs of Foundation Failure
Preventative Maintenance
Before You Build
Causes of Failure
What to Expect From a Foundation Contractor