What Is Underpinning And When Is It Needed?

Underpinning is a foundation repairs process used to fix failing foundations often caused by subsidence. If a foundation has settlement issues and needs extra support, it must increase its bearing capacity.

In this article, we will discuss what underpinning is, how to use it, and the different types of foundation and footing available to support your building project.

When is underpinning needed? 

Underpinning is required when a building’s foundation is damaged or needs extra support. It is used to reinforce the foundation. This process is also necessary when additional loads are placed on the structure, such as when adding an extra story.

Underpinning is needed when:

– The foundation is sitting on reactive soil

– Foundation’s backfill is not properly compacted

– Faulty drainage system in your house

– You notice cracks on walls and floors

– You’re having problem opening and closing doors and windows

– If you need to add an extra floor to your building

If most of these occur in your house, you need to contact local contractors for foundation repairs.

Types of building foundations and footings 

The various types of foundations and footings for buildings are –


This is the most commonly used foundation method. In this process, concrete slabs are placed directly on the ground to make a solid foundation. The soil beneath the slab must be compacted properly. Otherwise, the soil may settle with time and cause the foundation to fracture or collapse.

Continuous Footings 

Continuous footings are support structures that distribute the building’s load evenly. They are made of either strips or slabs. This method is used for the walls to support that is built on the sloppy ground.

Suspended Floors

Unlike a ground-based one, a suspended floor is not laid on the ground but above the ground. Stumps or piers are attached with it to the bottom.

Pad Footings 

The pad footing system distributes the foundation’s extra load evenly. They function by spreading the weight over a larger area, which prevents settling and helps to keep the structure stable.

House Stumps 

Stumps are made of timber, concrete, or steel and are used in houses to raise the foundation above the ground. 


Piles are metal or concrete supports that are driven into the ground to help bear a building’s weight. Piles are extremely helpful when the soil is too muddy to build anything else. They provide extra support and stability to build structures on top of it. Piles can be used with either a pad footing or a strip footing. Piles are commonly used with a pad footing or strip footing.

Board Piers 

Piers are thick posts made of steel or concrete to hold up the beam of the structure. Once the piers are set on the excavated holes, concrete is poured to secure the perimeter.

If you want to know whether you need an underpinning service, check our blog “does my home require underpinning?” 

Once you are sure that you need underpinning, you also might need to know the cost of underpinning. Please check this blog post to learn more in detail.