Understanding traditional underpinning methods
Facing foundation problems is daunting, but having a clear choice of solutions brings control. When a property needs its foundations strengthened, several types of underpinning methods are available. The right method depends on critical factors like the building type, soil conditions, and the severity of the movement.
This overview breaks down the common methods—including the non-invasive Geobear solution—to help you understand the options. Remember, the best first step is to seek expert guidance to remove the guesswork.
| Method | How it works | Best for | Key Considerations |
|---|---|---|---|
| Mass (Concrete) Underpinning | Small sections, or 'pits', are excavated under the foundations and filled with fresh concrete to create deeper, stable footings. | Older buildings or small areas of localised movement, where stable soil exists at a shallow, deeper level. | Proven, and cost-effective for small areas, but very time-consuming and labour-intensive. |
| Beam and Base Underpinning | A reinforced concrete beam is constructed under or alongside the original foundations, supported by concrete bases at strategic points. | Larger properties or situations where the structure’s load needs to be widely and evenly redistributed for higher load-bearing capacity. | Strong and long-lasting, but requires an engineered design and is highly disruptive. |
| Mini-Piled Underpinning | Concrete or steel piles (100–300mm in diameter) are drilled deep into the stable ground (3–20+ metres), then connected to the existing foundations. | Deep foundations, poor surface soil quality, or sites where access is very restricted (e.g., properties with limited side access). | Minimal excavation and low vibration, but can be costly and requires specialist equipment. |
| Cantilever Needle Beam Underpinning | Beams, acting like needles, are inserted under the foundations and supported by piles or mass concrete at one or both ends. | When access immediately beneath the wall is limited, but deep foundations are required. | Effective for restricted access, but requires highly skilled engineers and is very time-consuming due to careful excavation. |
The modern, low-disruption alternative: The Geobear Solution
Instead of heavy excavation and concrete, the modern Geobear solution uses precise, non-invasive technology to quickly stabilise the ground beneath your home.
Resin Injection Underpinning (The Geobear Solution)
Also called: Chemical underpinning or Geobear treatment
How it works
We inject our specialist, two-part resin into the ground through small diameter tubes. This material expands as it travels through the soil and voids, compacting and stabilising the ground beneath your home. This action is precisely monitored using laser levels and can gently lift the structure to restore it towards its original level.
Best for
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Solving movement in smaller or lightweight buildings.
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Remedying minor subsidence issues, especially those caused by voids or leaking drains.
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Areas where minimal disruption is absolutely essential.
| Pros (What's in it for you?) | Cons (What to be aware of) |
|---|---|
| Quick – Most jobs are completed within a day, allowing you to get your life back to normal fast. | Not ideal for very heavy commercial or large infrastructure loads. |
| Non-Disruptive – No heavy excavation, shoring, or mess on your property, and you typically don't have to move out. | Not the right solution for cases of major, severe subsidence that require extremely deep-piled support. |
| Proven & Engineered – Our solutions are based on decades of engineering expertise, ensuring a custom-designed treatment unique to your home. | Its effectiveness can be reduced if the soil contains significant organic matter (over 10%). |
| Safe & Sustainable – Our technology has a carbon footprint up to 70% lower than traditional concrete methods. | Soil type needs to be correctly identified to ensure the correct resin is used. |
Root barriers: A complementary solution
While not a true underpinning method, a root barrier is a critical supporting method used when trees are the cause of ground movement.
How it works:
Physical barriers or trenches are installed to prevent tree roots from drawing excessive moisture out of reactive clay soil.
Best for:
Subsidence that has been directly diagnosed as a result of tree root activity (desiccation).
How to choose the right underpinning method
It is perfectly normal to feel confused by the different methods. The complexity of the ground means one size does not fit all. We crush that complexity by offering you a clear path forward.
Your eventual choice of ground solution will depend on:
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The original cause of the ground movement (e.g., tree roots, leaking drains, poor soil).
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The stability and depth of the load-bearing soil.
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The size, age, and load-bearing requirements of your property.
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Your specific budget, and constraints regarding time and access.
The most important step is getting expert knowledge. If you are in any doubt, consult a structural engineer for further advice. Geobear can help with this by conducting a professional assessment and providing a full report with our specific findings and recommendations for the steps moving forward, ensuring you have the confidence and knowledge you need.
