Underpinning Foundations: The Basics

Underpinning refers to the process of reinforcing the foundations of an existing structure. The support foundation upholding aged and failing structures may need underpinning as changes occur, particularly for buildings made prior to sound modern piling methods.

Underpinning saves the need to replace a foundation in its entirety. A failed structure that is not properly underpinned may break down and result in lost business opportunities, increased costs for a rebuild that could have been avoided, and other adverse consequences – most notably in terms of safety.

Failing foundations represent a liability. Without underpinning, there is a risk these structures will fail and become unsafe. In this article, the team at Piling Experts will explain how to recognise if your building needs underpinning and describe how the process works.


In What Situations Is Underpinning Necessary?

Underpinning becomes essential when the foundation has been damaged or aged to a point where it is no longer capable of safely and effectively supporting the structure in question, be it a house, apartment block, business or other premises.

Common causes include changing soil structures (due to moisture, water table changes, subsidence, plumbing issues, or tree roots). Sometimes the need to underpin may be caused by a suboptimal job by previous contractors, or even just the inevitable wear and tear that can occur over time.

The need to underpin may also arise due to changed usage and structure requirements, or due to excavation and building on neighbouring sites (which is particularly common in crowded urban areas). A business or operator will often need to underpin a structure that they plan to add a second storey to.

You may recognise that you need underpinning if you start spotting cracking in floor and walls, a floor that is no longer flat but at an angle, doorframes and windows that no longer align, or if you notice the building slowly sinking into the ground.


How Is Underpinning Achieved?

Underpinning can be achieved by a number of different methods and the correct solution will depend on the building in question, as well as its location and what surrounds it. Methods include concrete slabs and even resin injection, but the most effective solution in many cases is screw pile underpinning.

This involves sturdy metal pillars being used to underpin the building and restore it to its perfect position from an engineering perspective. In many instances screw pile underpinning will involve accessing and taking advantage of sturdier soils deeper down. One great feature of underpinning with an adaptable business is that your existing structure can stay standing.

This is the underpinning method we use here at Piling Experts, for many reasons. It’s cost-effective, minimally intrusive, can occur in short timeframes, and is the most reliable and dependable method of underpinning in our experience. It can stabilise and lift in residential, commercial and infrastructure settings, and help to ensure that the structure is more stable, strong and fixed in place over time.


The Sydney Piling Experts For Your Next Project

Here at Piling Experts, we have provided underpinning for a wide range of projects in Sydney and more broadly across the state of New South Wales. Our highly respected underpinning services have proven essential in supporting existing homes, warehouses, factories, stores and other infrastructure. This has empowered extensions and the ongoing existence of structures that were on the brink of failure.

We know how important it is to have not only the expertise, but the right equipment to get the job done in the many different settings our clients may require us to do the work. As such, we use screw piles and a 1 to 5 tonne piling rig, which allows us to access small areas frequently encountered in urban underpinning sites. This gear also allows our experienced team to enter into buildings to underpin from the centre when necessary.

Using this equipment, we can go down narrow paths and squeeze under low ceilings. We also will sometimes use bored pile with headstock detail, as this will allow us to support a neighbouring property or building prior to the excavation of your basement.

One of the main pieces of feedback we hear from our customers is that underpinning represents a significant cost-saving. The costs of demolition and rebuilding a structure can be extremely expensive and lead to the involvement of a significant number of contractors.

Underpinning can also be essential for preserving old-style houses and heritage buildings. Screw pile underpinning is also able to reduce disruption to a precinct by moving quickly and upkeeping aesthetics by maintaining buildings of a similar style.

If you have a building that is cracking or which is showing signs of its foundations giving, do not hesitate to contact Piling Experts on 0411 693 100 or info@pilingexperts.com.au. Our team would love to help on your project with our screw piling, bored piling, underpinning and other piling services.