Concrete foundation repair can come about due to the slabs settling and moving as a result of what is below them. Clay and soil have to be carefully prepared before any building work can be undertaken upon the surface. So if this work was carried out badly, or not enough research was undertaken before building, the concrete can only fail.
Most ground foundations move slightly with time. They may be clay, or filled in with soil, and the builder will take this into account, when designing the structure, which is going to stand on it.
But even the best planned projects run into trouble, and concrete foundations can move or sink. Underpinning is the commonest method provided by engineering firms when it comes to repairing a foundation with problems.
At first this can be a traumatic time for anyone facing the problem of repairing a building with a failing foundation. As it strike at the heart of why the building was put there in the first place, and many contractors could be facing ruin.
The good news is, that modern technology has come so far, the solutions are not impossible.
The two commonest methods of tackling this problem, are Slabjacking and Piering.
Slabjacking is the process of pumping grout beneath the beam or slab, to produce a lifting force, restoring the desired levelling. This is often used when the concrete slab has simply sunk into the earth. But can be used, when engineers find a structure to be uneven. One of the commonest uses can be found in stabalizing, when cracks start to appear in a pavement or driveway.
Filling with pressure grout is one of the best methods of stabalizing a structure, when a void has been found beneath the site. These voids often occur due to water running beneath the surface. So cement slurry can be pumped in to fill the gap and divert away any unwanted water.
Piering is the method of driving steel pipe pilings into the ground to counter-act the results of a failing structure. A hydraulic ram will drive a section of Galvanised or epoxy-coated steel pipe into the soil. They can also be screwed into the ground with Helical Piers via a torque motor.
The idea of this is to find a stratum suitable enough to bear the weight above.