Cracking in walls is the most common sign of foundation movement and may form within or between components. Despite the width of any crack, a key aspect of any subsidence investigation is to determine if movement is ongoing or not.
When an extension begins to move away from a building, a vertical crack will usually form at the interface of the building and extension. This crack will be wider at the top as the extension rotates away from the original structure. The corner of the extension will normally act as the pivot point.
In terms of diagnosing progressive movement, there can be simple signs to suggest that the building is still moving e.g. cracks which have been repaired and re-opened can strongly suggest that movement is not historic. This crack in Blarney St was repaired at some point yet has continued to open and is now in the order of nearly 8mm!!!!!!
The building showed other signs of movement internally in the form of cracked floor tiles and ceiling cracking between the function of both buildings.
The remediation scope was a series of small diameter displacement piles known as Grundomat supporting RC ground beams beneath the foundation.