There were a number of methods initially available for repairing sunken concrete. It included pushing steel and wood into the ground to recover sunken slabs and foundations back to their original position. Using such rudimentary methods, many would go on to claim themselves as experts, irrespective of whether they were trained or not. The only disadvantage here was that with time, such repairs only turned out to be futile.
Many of such methods also prevented the normal day-to-day functioning of businesses and even families for a residential building repair.
However, in most of such cases, it is usually desirable to have the slabs and concrete foundations corrected without having any appliances/furniture in the vicinity or depending on the nature of the real estate, families are moved and businesses disrupted.
These days a lot of changes have been observed in both the technology used and the level of expertise and experience of concrete contractors.
Two of the most commonly used methods for repairing concrete foundations and the surrounding areas are slab jacking and hydraulic jacking.
In slab jacking, grout is pumped beneath a concrete slab, which creates a lifting force that restores the sunken portion back to its original position. On the other hand, in hydraulic jacking, also known as piering, steel posts are sunk in through unstable soil after which, hydraulic jacks are used to stabilize concrete foundations, without causing any changes to the soil.
Choosing the Right Method for Repairing Concrete Foundations
Before zeroing down on the repair method, it is essential to determine what is causing such issues in the first place. This can be done by examining the brick veneer, moldings, mortar joints, trim boards and windows. The weather also needs to be taken into account as it can cause issues in the underlying soil.
Some of the commonly used methods for fixing issues in smaller slabs such as driveways, residential slabs, swimming pools and sidewalks happens to be slab jacking.
In slab jacking, cement grout is pumped in through small holes, which are located on the concrete slab. Once the grout is in place, it solidifies into a dense mass and provides the best bearing for concrete foundations.
If the grout used is of cement-soil-lime, stabilization of the base or sub-base will be effectuated by the lime in the slurry. This greatly aids in stabilizing the subsoil to prevent the problem from reoccurring.
In case the problems happen to be bigger ones, like the ones encountered in commercial and retail establishments, with issues of foundation shifting in areas like Queens, Manhattan, the Bronx, and the Staten Island, hydraulic jacking is used to stabilize the foundation and bring it back to its earlier levels.
In this process, mechanical jacks are strategically placed to lift the settled beam. The beam must be raised carefully to avoid further damage. Once the beam is raised, it is held in its place using footing and pier, which are specifically designed for this purpose.
Next, the footing is set deep so that variations in the soil moisture do not have any effect on it. Its design is such that it can have the load evenly distributed. The pier is tied to the footing using steel which provides support to the foundation beam.