We were requested to survey a newly constructed extension that had subsidence issues near London. The extension had been constructed with insufficient foundations which had resulted in substantial building subsidence and structural cracking.
The building had been monitored after structural cracking had been noticed shortly after the building completion. Building monitoring is a way of identifying if a building is moving and by how much and in what direction. In this instance the building monitoring had recorded over 3mm subsidence in just a few months. The rapid rate of this movement will mean that if it is left, the extension would need to be demolished and rebuilt. Issue selling the property in the future will also be a hurdle that would be difficult to overcome because if a building surveyor identifies structural movement or building subsidence, insurance companies are reluctant to lend or if they do it is at inflated interest rates.
The reason this extension had suffered new extension subsidence and requires underpinning is because it had been constructed on a raft foundation that had been insufficiently designed for purpose. This is the reason that the building has suffered building subsidence and structural cracking and requires the extension to be underpinned and crack stitched.
The correct remedial solution for this building is traditional underpinning and crack stitching repairs. At Structural Repairs we are able to offer a full structural engineering solution in terms of having the foundations correctly designed and the remedial work undertaken.
The most common locations where we undertaken or remedial structural repairs are as follows, but if your area is not listed please contact us as we can probably help with your new extension subsidence issues.