Repairing Cracked Concrete Through Underpinning

24 February 2017
 Categories: , Blog


Concrete floors, walls, and foundations are subject to developing cracks if not installed expertly enough. Yet even the most competently installed concrete slab may end up succumbing to cracks as the result of a shifting sub-base, nearby construction, or other conditions that undermine its structural stability. When that happens, it is important that you take the appropriate steps to protect your home or business.

Repairing the crack itself is only the first step of this process. Unless your concrete is properly reinforced, it will likely suffer more such damage in the future. If you would like to learn about one of the most common methods of stabilizing a concrete foundation, read on. This article will discuss the technique known as underpinning.

The Basic Idea

The basic idea of underpinning is fairly simple: additional structural elements are introduced to help shore up the concrete's defenses. Such elements are generally installed beneath the concrete. As you can imagine, this makes underpinning a somewhat involved operation, one that often requires a good deal of excavation. The ultimate purpose of the introduced elements is to transfer the building's load to a deeper--and thus more stable--area of soil or bedrock.

Further Purposes

Underpinning is a versatile technique, and is capable of fulfilling a number of diverse purposes. As suggested above, it is used to prevent concrete cracks by eliminating unwanted settlement--in other words, by keeping the concrete as level as possible. It is often also implemented as a way to generate a greater foundation capacity, for instance when building new rooms or additions.

Underpinning is also utilized as a preservation tactic where older buildings are concerned. It allows modifications to be made to strengthen the existing foundation--or even to install a brand new foundation. It is also used to help support buildings that have begun to sink or tilt over, usually as the result of structural instability or what is known as ground subsidence--essentially, shifting soil.

The Underpinning Process

The oldest and most basic form of underpinning is often known as box underpinning. It is estimated that this technique has been in use for at least the last one hundred years. It involves the step-by-step excavation of the ground beneath the foundation. As each "box," or predetermined volume of soil, is removed, the resulting vacuum is filled in with fresh concrete. In this manner, the structure can be successfully reinforced by what amounts to a second foundation. To learn more, speak with a business like Burns Brothers Concrete Construction Corporation.