Residential subsidence case study
Challenge
Recurring clay shrinkage caused seasonal foundation movement, cracking the porch and garage while protected mature trees prevented conventional mitigation options.
Solution
Geobear stabilised vulnerable foundations using a non-invasive geopolymer solution, delivering long-term ground improvement with minimal disruption and no excavation.
Project duration
Ground stabilisation
Guarantee provided
The owners of a detached property near Saffron Walden began noticing cracking around their front porch where it joined the main house, together with movement affecting the attached garage. The damage first became apparent following an exceptionally hot, dry summer and worsened during subsequent periods of prolonged drought before stabilising during wetter seasons.
Site investigations confirmed that the property was founded on shrinkable clay soils susceptible to seasonal moisture changes. Mature protected oak trees located close to the property were also influencing ground moisture levels, contributing to recurring movement. Ground investigations identified stiff to very stiff clay soils beneath shallow strip foundations, consistent with clay shrinkage-related subsidence.
The homeowners wanted to permanently stop the seasonal movement rather than repeatedly repairing cracks that would simply reopen during future dry summers.
Traditional solutions were unsuitable. Removing the nearby protected oak trees was neither practical nor desirable, and doing so could have introduced the risk of clay heave. Conventional underpinning would also have involved significant excavation, disruption around the property and a much longer construction programme.
The solution needed to stabilise the foundations while preserving the surrounding landscape and allowing the homeowners to remain in the property throughout the works.
client quote
Sheena lashko
Following detailed site investigations and drainage assessments, Geobear designed a bespoke ground improvement solution focused on the affected porch and garage foundations. Preparatory works included CCTV drainage surveys to ensure the surrounding drainage network could be safely monitored before treatment commenced.
A specialist geopolymer material was injected through carefully positioned injection points around the affected foundations and treated to multiple vertical depths beneath the structure. Throughout the process, engineers continuously monitored the structure using precision laser equipment, ensuring controlled ground improvement and verifying stabilisation as the treatment progressed.
The installation itself was completed quickly, with only limited preparatory works required beforehand, avoiding the extensive excavation, spoil removal and heavy machinery associated with traditional underpinning.
The property was successfully stabilised with minimal disruption to the homeowners and without the need to excavate around the foundations or remove the nearby protected trees.
The homeowners remained in their property throughout the works, with the only preparatory activity involving drainage investigations and limited access beneath paving. Following completion, the property benefited from a long-term stabilisation solution backed by a 10-year transferable guarantee.
The customer particularly praised Geobear's professionalism, communication and attention to detail throughout the project, highlighting both the care taken during installation and the tidy condition in which the site was left.
Every home is unique. Our experts are ready to listen and provide answers tailored to your specific property and concerns.
