Foundation is the most important feature of any house, building, or similar structure.  The whole building is set on a foundation, so it needs to be strong enough to support the entire house or building. However, there are times when the strength of the foundation doesn’t remain the same and is no longer able to support the structure or house built on it. In such cases, it is important to immediately look into this matter and start the process of reinforcing the structural foundation otherwise the house or building can collapse and result in serious damage.

What is Underpinning and why is it Required?

In common terms, underpinning a house is the process by which the foundation of a house is strengthened or reinforced so that it is strong enough to support the structure built on it. There are various reasons due to which a house or building would require underpinning, some of which may be:

Underpinning a House

  • An initial flaw in the foundation of the house
  • Addition of extra floors on the building
  • Subsidence is another reason, which means, a house is sinking into the ground
  • Sometimes major renovation also brings a change in the structure
  • Anny new nearby construction causing hollowness in soil that supports the existing foundation
  • Natural disasters such as earthquakes, floods, or droughts that make the structure unstable

It is always important to figure out the real cause of the damage that requires underpinning a house so that the issue is resolved from its very core.

What does Underpinning Involve? 

Underpinning is a constructional process that acts as a corrective way to rectify the faults in the foundation of the house in order to strengthen it. The main feature of underpinning a house is to solve one focused problem rather than building up a whole house from scratch because of a single problem. It uses extra concrete and any other required materials in order to make the original structure more stable and strong. Underpinning usually involves the advice of a structural engineer who knows all the proper techniques for completing the process efficiently and without much hassle.

This involves strengthening the old foundation or strengthening the soil structure by incorporating some fillers, or by expanding the foundation so that a load of building or house gets evenly distributed over a large surface area. This helps to reinforce the basic structure without changing or remodeling the entire building or house.

Types of Underpinning

There are broadly three methods used for underpinning a house:


  • Concrete Slab: It is a process in which the size of the foundation is enlarged and strengthened at the same time.
  • Screw Pile: This is a permanent solution that makes use of steel piers with concrete footings to strengthen the building and bring it back to original position. It closes all gaps and cracks.
  • Grout Injection: It is the latest method in which some kind of resin is injected in the ground to fill up the voids which later on expands and compresses the ground making it strong but it is not suitable for all grounds.

Sometimes two methods are combined to provide better underpinning solutions. For instance, screw pile underpinning is used to stabilize the ground and grout injection is used to fill the voids, providing the best solution.

Is Underpinning Important?

If there is a fracture in our body, the first step is to fix it with the help of surgery that attaches an external object to help straighten out the bone. Underpinning a house works in the exact same manner. When there is a crack in any particular area of a house, there has to be a thorough examination of the nature and extent of the damage, and then the plan of fixing it should be followed. If left unattended, these fractures could prove fatal for the house and cause long term damages. Therefore, it is always important to keep track of the damages that a house is susceptible to and follow through with underpinning when it is needed.