What is a foundation survey?

A foundation survey is an investigation into the condition and load-bearing capacity of a building’s foundation. It is usually carried out to establish whether there are foundation problems such as pile rot or settlement.

How it works

A foundation survey often begins with a desk study, in which existing data on the year of construction, soil structure and earlier reports is examined. Fieldwork follows: using a trial pit or excavation, a pile head is exposed so that the wood can be assessed up close. A laboratory analysis of a wood sample reveals how far fungal or bacterial decay has progressed. In addition, the groundwater level is measured and crack and bed-joint measurements are taken to record whether the building is moving. Together these steps provide a complete picture of the condition.

Application

The result of a foundation survey gives a well-founded judgement on the foundation’s remaining service life and the need for repair. Owners use the report to decide whether and when foundation repair is required, and authorities and lenders base decisions on it. When buying a house in settlement-prone areas, such a survey is also often advisable.

Related terms

• Pile rot
• Cone penetration test
• Monitoring well
• Foundation repair

Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.