Underpinning Foundation Structures


Underpinning foundation

What is underpinning?  Foundation underpinning is the process of strengthening and stabilizing a settling foundation of an existing structure.  In order to achieve this with the underpinning method, galvanized steel shafts, also know as helical piers or screw piles, are inserted into the ground until they hit supportive soil stratum.  These piers allow the foundation load to be transferred to stable soil.   As a result, this deep foundation system helps to level the structure.  AB Chance Helical Pile Foundation Systems are an alternative to micropiles as a common method in underpinning.

Underpinning contractors for commercial or residential foundation repair

Underpinning Foundation Solutions Brochure

Underpinning structures with helical piers for sinking house or settling buildings.

Here are some of the reasons you may want to consider underpinning:

  • The original foundation is simply not strong or stable enough.
  • The usage of the structure has changed.
  • The soil surrounding the foundation may have changed over time.
  • The construction of nearby structures may require the excavation of soil supporting the existing foundation.
  • It is more economical to fix the  present structure's foundation than to build a new one.


Underpinning foundation refers to the process of strengthening or stabilizing an existing foundation that has become weakened or unstable due to various factors such as soil settlement, water damage, or structural damage. This process involves providing additional support to the existing foundation to prevent it from sinking or shifting further.

Underpinning may involve excavation work to access the foundation and install additional support structures such as piles or piers. This can be a complex and costly process, and it is typically carried out by professional contractors or engineers who specialize in foundation repair.

Please fill out our form to contact one of our helical pile installation specialists to give you more details on structural underpinning for sinking foundations.