Image Credits: The Architect’s Diary

As time passes, the foundation of a building can easily fall into disrepair. The earth shifts, the ground changes, thus making places like basements and underground facilities easily compromised.

It’s not necessarily anything that any person has done incorrectly, but rather the natural effects of weather, earth changes, and settling. The good news is, there are methods and actions that can be taken to stabilize a foundation and keep it firm and reliable despite whatever may have caused it to start to show signs of failure.

In this guide, we are going to share with you some steps and tips for underpinning foundation, so you can know just what to do and what not to do should you need to use this process in your home or facility.

What Causes Foundation Issues?

There are a lot of causes to a weak foundation. Sometimes the cause is careless tactics or errors during the building stages, but most of the time the causes go a bit deeper, quite literally. Soil and subsoil are constantly changing. We see this shift in many things across the earth and it’s true in the foundation of buildings and underground facilities as well.

There is a process known as subsidence, which is the expansion and contraction of subsoil. Seasonal changes and unstable soil can make a significant impact on the foundation over time. The soil wears down or pulls away from the foundation and this results in a shifting foundation that requires more maintenance and TLC in order to keep it safe, secure, and stable.

This is where underpinning comes from.

How Do You Know Your Foundation Needs Help?

The foundation issue may not always be immediately obvious. There are some signs you can look for to determine if you might need to consider underpinning the foundation. This need is not just for homes, but could apply to other underground facilities as well as businesses with underground basements or storage facilities.

One of the most noticeable signs that could point to a foundation in need of care would be cracks in the surface materials and foundation. If you see cracks running up your basement walls, this is a sign that the sturdy foundation has been jeopardized.

Small cracks don’t necessarily have to be handled immediately but you will want to keep an eye on them. If these cracks grow to more than 1/4 of an inch, you will definitely want to consider underpinning as this could quickly become a dangerous situation. Diagonal cracks are another common indicator as well.

Additionally, some of the more obvious signs that may require immediate action include buckling or heaving walls and floors. Get these checked out right away.

What is Underpinning?

What is the solution to these issues? Underpinning is a solution that has been shown to be quite effective. This is a specific process that is used to reinforce the foundation and underground facilities like a basement.

Essentially, underpinning is a process used to strengthen and repair a foundation. This can be a complicated process. In order to prepare for underpinning, the area below the foundation must be dug out. This has to be done in various stages in order to prevent a total structure collapse.

Structural and geotechnical engineers review the structure and determine just how the process should work. They must first figure out how deep excavation needs to occur in order to complete the underpinning process.

The digging is completed in sections in order to promote the integrity of the structure during the process. Once that soil has been excavated, the crew will lay down a new material to create a brand new foundation for the structure. This material is typically concrete since it is commonly in an underground location.

Again, this part is still completed in sections in an effort to avoid a structural collapse. Eventually, this process will lead to a reinforced foundation that is stable and secure.

Underpinning Methods

There are 3 primary underpinning methods that can be used.

  • Beam and base
  • Mass pour
  • Mini Piled

Most underpinning crews use the mass pour method because it is more affordable to complete. This is also one of the more simple methods to put into place. It can typically be completed without having to stop and wait in between steps in the process.

Mini piled is perhaps the least used method. It’s a reliable method but it can take a lot of time, effort, and money in order to use this method and therefore it is not often turned to when underpinning needs to occur.


Regardless of the reason, underpinning is a method that can save a structure from collapse if it is used correctly. It must be completed carefully and precisely in order for it to be effective. If your structure is in need of underpinning, be sure to call in the experts to help with the process.