FOUNDATION SETTLEMENT

This farm is perched on the hillside and had a history of cracking and movement. It was discovered that it was founded on a 100mm thick layer of wet, very soft clay but with firm clay beneath. Deepening the foundations was considered justifiable on this occasion.

Settlement can lead to drains fracture which exacerbates further settlement. After repairing the drains, the crack widths and levels were monitored using a cheap and simple levelling system which recorded the levels to 0.1mm. As the rate of settlement is still continuing after 12 months, underpinning and movement joints have been recommended.

Surveys revealed that up to 50mm of settlement had taken place in the party wall. However this was only discovered when plaster was removed for damp-proofing. As current settlement appeared to be very minor, it was considered better to live with the problem than to underpin part of a terrace.

Note: less than 50% of cases of suspected foundation settlement are found to be directly attributable to movement in the foundations. A key element in any structural investigation is the defining of various contributions to any distress. Underpinning can be expensive and can lead to further problems especially when the property is not isolated.