Underpinning, what is it?

What is Underpinning?

Have you ever asked yourself “what is underpinning”? Well, when building a new home, you might need underpinning, which is the process of strengthening the foundation or ground by digging deep and piling up concrete in order to provide more support for your structure. This article will give you a brief overview of what underpinning entails and how it impacts construction processes.

Underpinning is required when the structure of a property moves (subsidence) and the foundations need to be repaired. The soil beneath the existing foundation is excavated and replaced with new materials to repair the structure of the property.

In addition, when underpinning existing structures such as a house or garage, it is important that a qualified and experienced engineer evaluates the foundation before any work begins. They will evaluate how stable the foundation is and what repairs are needed in order to make sure that it can withstand additional weight without risking collapse. The engineer will either propose a plan to make sure that the structure is sufficiently stable or recommend demolition. If they approve of underpinning, it can provide stability and support for your foundation while also giving you more room for improvements such as adding on a garage or expanding the house.

What’s Involved In Underpinning?
Typically, there are four different techniques that can be implemented;

Soil Strengthening – an alternative to more costly and complex underpinning procedures, soil strengthening is carried out if the soils beneath a building’s foundations are weakened or removed. Also known as soil stabilisation, a specially formulated structural resin is injected into the ground, which effectively replaces the eroded soil.

Mass Concrete Method – during this procedure pits are dug beneath the existing foundations and filled with concrete, creating a secondary foundation layer beneath the primary foundations. It is best suited to structures with shallow foundations. Along with soil strengthening, the benefit of this type of procedure is that the building can still be used in the meantime.

Beam and Base Method – this is similar to the mass concrete method described above and involves reinforced concrete. A more advanced form of underpinning, a reinforced concrete beam is placed below the current footing, which then transfers the building’s load onto strategically positioned concrete bases.

Screw Piles and Brackets – a relatively quick and cost-effective form of underpinning, screw piles and brackets are employed when more traditional forms of underpinning are unsuitable, usually due to the need for extensive excavation work. In this procedure, a trench is dug around the affected area and screw piles are inserted deep into the ground, acting as anchor points. Support brackets are then attached to the screw piles and positioned underneath the foundations, enabling the structure to be lifted back into a level position.

If site is restricted, then the construction work will take a lot longer and it will be a more difficult job, which can make the work cost more, however All Ground Solutions are specialists in restricted area work and will endeavour to keep these costs as low as possible.,

Although underpinning is an expense, the cost of neglecting structural stability could be much higher, and putting your entire property at risk. In order to make your home structurally secure and safe to live in, the cost of underpinning is often worth it in the long run..

It’s a complicated process, and one that costs a lot of time and money. Before you try to fix the problem, be sure to seek professional guidance every step of the way to be certain you’re in good hands. For more information on underpinning contact us.