A helical pier is a foundation pier or pile made of steel that contains helices just like the thread of a screw. It is driven into the soil, to depths of the foundation by use of a hydraulic motor. Helical piers are used to support structures especially where soil conditions are challenging. Minimum excavation of soil and foliage is required.
With existing foundations that have problems such as interior or exterior cracks (most of time these look like stairstep cracks on the external walls of the home) or where soils are weak. This happens a lot when homes or businesses are built on soil that has not been compacted well. They transfer the weight of the structure to soils deep into the earth that bear the load.