Jacking

In some cases where subsidence has occurred due to failure of the foundation but the ground floor structure / concrete slab is still structurally complete, it is possible to relevel the floor by jacking it back up again. An example of this might be a shallow slab foundation sat on poorly consolidated ground.  This is often a very cost effective method compared to demolition and rebuilding.

Before determining jacking as an option, Shire carefully assess the existing structure, ground conditions and site conditions.  Once confirmed as a viable option and designs completed, piles are placed at specific locations, to specific depths, then jacking heads are then placed on top of the piles. The toe of the jacking head is carefully placed underneath the slab.  The jacks are slowly lifted, one by one, whilst levels are monitored using laser equipment.

Once the floor / structure is jacked back up to level, the piles are permanently concreted in and the surrounding area is reinstated.  

Structures can be lifted by as much as 50mm. While this process is ideal for single storey structures, in some instances, it is possible to jack up a 2-storey building using the same process.  Shire have successfully used this method across the UK on a wide variety of structures.