Err on the side of caution

Soils and their inherent properties are varied as much as they are unpredictable. For those who are unfamiliar with soil investigation and testing procedures, soil theories or the limitations of capacity equations should use the provided soil property information with caution. In addition to the following, it should be noted that exceptions to typical values of soil properties occur often.

• All foundations must have a factor of safety applied for design purposes (typically between 2 and 4).
• Foundations typically need to be taken down to a depth where seasonal changes and plant life will not affect the soil properties.
• Settlement is often the governing condition for designs and must be taken into account.