Ground investigation finds extension to be stable
Phil Howden inspected a property this week. The house has suffered from damage following deep excavation works near the property by a Statutory Undertakers’ Contractor, with heavy plant causing significant vibration. The Contractor had also needed to dewater due to high ground water levels.
The property is about 60 years old and was extended at the front about 30 years ago. A Consulting Engineer acting for the Statutory Undertaker inspected the property and reported that the front extension had suffered from foundation movement. They excavated trial pits and reported further that the extension was founded on a raft on Peat. They recommended that the extension was stabilised by underpinning.
When Phil inspected the property he discovered that, contrary to the previous Engineer’s report, damage indicated that the more historic original house had suffered foundation movement relative to the extension. A further ground investigation confirmed that the more recent extension was not founded on a raft, but on a pile and ground beam foundation. The investigation confirmed also that the original house was founded on a raft.
The second ground investigation confirmed the observations made by Phil that the extension was adequately founded and stable. It did not need underpinning.