Curing subsidence in listed buildings using conventional piling and underpinning methods can actually disturb already fragile buildings, pushing them beyond repair.
Such is the situation at the 600 year old St Michael's Church in Market Stainton, Lincolnshire.
Restoration was put on hold after a ground investigation carried out by Ayling Associates revealed a small area of soft fill beneath the external south corner of the chancel arch. Over the years settlement has caused the arch to crack severely.
With very loose fill down to about 1.5m, stabilisation became essential before repairs could take place inside.
Traditional underpinning was rejected due to cost and concerns about the impact of vibration on the structure.
Instead Uretek's Deep Injection system was chosen, where resin is injected through small diameter holes to consolidate the ground and improve bearing capacity.
'The advantage of using Uretek is that we are stabilising the ground without having to excavate under a corner which was already in a poor condition, ' says consultant Brian Ayling.
Later this month, Uretek will inject at 1m intervals along the line of the foundations monitored by laser levels on the wall of the building. The work should be completed within a single day.
'The intervention on the historic fabric is absolutely minimal, ' says historic building consultant Lee Holmes, co-ordinating the work at St Michael's.
The church wall and rotted roof beams will be repaired next year.