What types of foundation investigation are there?
Foundation investigation covers all the techniques used to assess the condition and bearing capacity of a foundation. Depending on the question, this ranges from archive research to actually excavating a pile head.
Types of investigation
Various investigations can be used on a house, often in combination:
- Desk or archive research: studying construction drawings and foundation data to determine the original foundation type.
- Cone penetration test (CPT): a cone is pushed into the ground to map the soil structure and bearing capacity.
- Groundwater level measurement: monitoring wells are used to measure whether the groundwater level is low enough to leave wooden piles dry, which causes pile rot.
- Foundation inspection via trial trench: excavation exposes a wooden pile head for visual assessment.
- Timber sample analysis: samples are examined in a laboratory for fungal and bacterial decay.
- Joint and crack measurement: the course of masonry joints and cracks is measured to demonstrate settlement.
- Building survey: a general inspection of the structural condition of the property.
Application
The choice of investigation depends on the cause, such as cracking, a purchase, or planned work by a neighbour. Together, the investigations provide a reliable picture of foundation quality and determine whether foundation repair is needed.
Related terms
- Foundation investigation
- Cone penetration test
- Monitoring well
- Pile rot
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