The Pros and Cons of Concrete Underpinning

The Pros and Cons of Concrete Underpinning

Concrete underpinning is an economical solution to repair strip footings that have experienced foundation movement. The procedure entails driving steel foundation piers through existing footings in order to reach load-bearing soil beneath shifting top layers.

Underpinning is an effective method to increase living space without moving home, but it is important to carefully consider its advantages and disadvantages before deciding if this technique is a good match for your property.


Underpinning is one way of strengthening and supporting your building’s foundation. This process adds additional footings beneath its existing foundation to allow it to rest on deeper soil strata that has a higher load-bearing capacity, helping prevent movement in your structure while upholding its structural integrity. Underpinning can be costly; so before undertaking such work it is essential to determine its costs first.

Underpinning costs vary widely based on project type and location. Furthermore, how long it takes to complete underpinning can have a significant effect on its final price. While underpinning requires an upfront financial commitment from you as the homeowner or developer, its long-term benefits could make the initial expense worth your while.

Underpinning is essential, and should only be undertaken by professionals with experience and appropriate credentials. Improper underpinning can cause major structural damage that requires costly repairs; additionally, improper underpinning leaves buildings vulnerable to further deterioration or collapse.

Underpinning is a method in which builders dig holes beneath an existing foundation and fill them with concrete, before installing steel piers to transfer its load onto new soil. This approach may be necessary when foundation damage has occurred due to tree roots or other causes.

This method is also widely employed when adding an extra storey or changing the use of an existing building, as it eliminates excavation costs while decreasing concrete needs. It can be an economical choice.

Helical piers offer another viable option for foundation installation and are installed using hydraulic press to connect with brackets that hold them to foundations. They feature an inner core that has multiple helixes extending throughout the soil for increased stability compared to traditional concrete foundations.

Mass concrete underpinning is the most widely utilized approach to underpinning. This technique involves excavating holes beneath a foundation and pouring concrete to support existing structures, with this often being the most cost-effective option available; however it may not suit every building due to shallow foundations; for these buildings alternative methods of underpinning may be required.


Underpinning jobs vary in time depending on their complexity and soil type; most often this process will take two to three days; in certain instances though it may require deeper excavation and replacement of more of the existing foundation to ensure structural integrity of a building. It’s essential to hire a company experienced with undertaking such works due to potential hazards associated with such work requiring special consideration and care from workers on-site.

Concrete underpinning is the go-to approach when it comes to underpinning homes or buildings, and one of the more popular methods involves digging holes underneath the building and pouring concrete to create a new foundation beneath its existing one. Although this option works well for most structures built on reactive clay soils that move quickly, this solution could cause differential movements between the underpinned section of a structure and its main body of support.

Underpinning is typically used when an existing foundation is too weak to support the structure. It may also be employed when adding extra floors or changing usage – for instance converting an unused basement or cellar into living space requires underpinning to secure its foundation for this new use.

Underpinning can add value to a property. A well-underpinned house may feature higher ceiling height and more windows to let in natural light, creating the sense that space feels bigger and more welcoming while improving the aesthetic value of a home. Underpinning can increase property values.

There are a few underpinning methods, including mass concrete underpinning and screw pile underpinning, that are both effective but require different skills and materials to use successfully. Mass concrete underpinning is a traditional solution that involves excavating soil beneath existing foundations before replacing it stepwise with concrete poured over stages; making this option a good option for older buildings with shallow foundations.

Screw pile underpinning is another popular method for underpinning projects, although not suitable for all situations. Without adequate training or experience in its application, screw pile underpinning may become dangerous to workers who may not know how best to conduct it. Screw pile underpinning should only be considered when mass concrete underpinning cannot be completed due to ground conditions or other reasons.


Underpinning is a construction technique which involves increasing the depth of foundations under existing structures in order to give them additional load-bearing capacities and provide more load bearing capacities. Such foundational solutions can be utilized in many situations, including when an existing foundation needs repair or reinforcement and/or when new additions require extra load-bearing capacity. No matter if it involves mass concrete underpinning, beam and base underpinning or mini pile underpinning – work must be carried out gradually and carefully planned so as to ensure the existing structure can support its new foundations. Underpinning involves excavating and replacing soil beneath foundations with concrete, without harming existing foundations or interfering with drains and sewers. Any work undertaken must be carefully planned so as to minimize disruptions caused by this work and preserve existing infrastructure such as drains and sewers.

Traditional concrete underpinning is the most prevalent method for underpinning houses on reactive clay soils and can help reduce differential movements caused by changing moisture content of soil (slab heave). It involves digging holes 2m-3m apart around the house and pouring concrete into them under its foundations. It usually works best as part of an effective underpinning strategy against differential movements caused by changes in soil moisture content or differential movement due to differential settlement or differential movement caused by changes.

Beam and base underpinning is an advanced form of underpinning used when existing footings have reached their load-bearing capacity. It can be done quickly as part of renovation or extension projects; less invasive than underpinning but still requiring careful consideration to the existing structure is the objective here.

Resin injection underpinning is another approach sometimes utilized. While not as efficient, resin injection may only be an option if nothing else is available. As it does not provide permanent support, resin injection can damage soil permanently.

Underpinning with screw piles and brackets is a more durable alternative for underpinning, suitable in cases when mass concrete underpinning cannot be utilized. Furthermore, it can help combat differential settlement on reactive soils.


Underpinning is the practice of increasing the depth of a foundation so as to strengthen it and create more solid footing for buildings or additional stories. There are various techniques used for underpinning, including concrete slab underpinning, helical underpinning and screw pile underpinning. Underpinning should only be undertaken when original foundations cannot adequately support buildings or their loads; or when new additions cannot alter existing depth. Typically underpinning occurs when current foundations cannot support increased loads without modification – for instance when adding another story is being constructed without changing depth of existing foundations or when adding another story cannot modify existing depth due to restrictions in depth of existing foundations being inflexible enough.

Underpinning can usually be completed without much disturbance to the environment; however, it’s important to remember that such work can generate dust and debris which is spread across an urban environment with numerous buildings nearby, which is one of the major disadvantages of underpinning.

Underpinning is an effective and cost-efficient solution to expanding the livable space in your home at an affordable cost. Furthermore, this form of underpinning can also repair foundation damage that has occurred within your property, and even help prevent water leaking into the basement from outside sources.

Underpinning is typically performed by excavating and extracting soil from your basement or crawlspace before pouring a fresh layer of concrete to replace it. While this process is tedious and unpleasant, it must be carried out to protect the foundation of your home and ensure its continued stability.

Underpinning can also protect your home from soil erosion that could lead to shifty footings, leading to cracks in walls, ripped-up drywall and jammed doors or windows above-ground structures. Furthermore, foundation settlement can make installing new mechanical aspects difficult.

Underpinning your basement can also make it easier to access mechanical aspects of your home, such as plumbing and wiring. This makes updating outdated plumbing, insulation or saving on energy costs more accessible as well as adding lighting fixtures in your basement more readily.


Howard Coleman