Typical domestic subsidence works are carried out under the insured peril ‘escape of water’ – the fundamental principle is that water escaping from the drainage has resulted in a washing away or softening of the soils beneath the foundation. This effect over time may result in subsidence or foundation movement. However, in some rare cases, no leaks can be located and the probability of an insurance claim are diminished.
This two-storey semi-detached property in North Cork was suffering from significant movement to the rear elevation. The drains were CCTV surveyed and hydrostatically tested as part of a process to demonstrate to the insurance company that such a peril has occurred. However, the drains were 100% watertight. We also tested the water supply but again, no leak was found. Unfortunately, this meant that the probability of an insurance claim for the homeowner was zero.
The homeowner still wanted to address the problem so a trial hole was opened to find that the area of distress was founded on made ground. This would suggest liability on the builder but the liability period had elapsed with several years. A scope of works was drawn up by the Consulting Engineer.
8 nr hollow bar raking micropiles were installed through the foundations and socketed into the underlying rock and pressure grouting was completed at 5 nr locations. On completion, the affected drainage was reinstated and put under test for the supervising engineer to witness and certify the works.