Traditional Mass Concrete Underpinning: 3 Tips For Better Overall Stability

Posted on: 23 September 2016

If the foundation of a structure can no longer fully support the weight and capacity of the structure, further securing the foundation using one of the many different underpinning methods may be necessary. While there are many different techniques available, the most basic one is known as traditional mass concrete underpinning, and basically involves excavating underlying soil and replacing it with mass concrete. Here are 3 tips that will boost the overall stability of the resulting foundation.

Use Vibration-Compacted Concrete

Compact the foundation down as much as possible. A compacted concrete foundation will offer a lot more support and will be much more structurally sound because the aggregates within the mixture will be tightly bound to one another, so they won't have much room to move. There are many different ways that you can compact the concrete. Techniques involving mechanical compaction that rely on vibration tend to be most effective. The vibration causes air bubbles inside the concrete mixture to rise to the top.

Remove Plants, Shrubs, and Trees in Surrounding Area

The new foundation will be much more secure if there are no external conditions and factors constantly trying to jeopardize its structural integrity. With this in mind, you'll want to remove plants like shrubs and trees in the area designated for the traditional mass concrete underpinning. As these plants grow, their roots can easily extend towards the concrete base and may even eventually end up penetrating the concrete. This will cause the structural integrity of the slab to become compromised, and the concrete foundation may start to crack or crumble.

Ensure the Excavated Cavity is Filled Up

To ensure that you get great results with traditional mass concrete underpinning, you'll need to be careful when planning the entire operation. Make sure that the area of soil that you have excavated is wide enough and deep enough. After you pour the concrete mixture into the cavity, you'll want to use a rod bar or some other tool to ensure that the concrete has successfully filled in the entire cavity, and that there are no empty spaces present.


Traditional mass concrete foundation underpinning is perhaps one of the simplest techniques used to further stabilize a foundation. You can get great results if you are willing to put in the extra effort needed to stabilize the concrete base, and the foundation will easily support the structure it was intended for with ease.