Residential ground improvement
Challenge
Clay shrinkage beneath shallow foundations caused seasonal movement and widening cracks, threatening a recently constructed home extension and boundary access.
Solution
Geobear delivered a fast, non-invasive clay shrinkage treatment, stabilising the extension foundations in less than one day with minimal disruption.
Project completed
Guarantee provided
Required
A homeowner in York experienced progressive movement affecting a recently constructed extension. Cracks had developed where the extension joined the original property and had become noticeably worse over successive summers before partially closing during winter.
The homeowner, a building professional, identified the movement as classic clay shrinkage affecting shallow foundations. Alternative repair methods including mini piling and mass concrete underpinning were considered before Geobear was selected to provide a faster, less disruptive solution.
The property remained fully occupied throughout the works. Site investigations confirmed shallow strip foundations bearing onto shrinkable clay influenced by nearby trees.
The extension had been constructed close to the neighbouring boundary, making traditional underpinning difficult and potentially disruptive due to restricted access.
The property exhibited seasonal movement, with cracks widening during dry weather and reducing during wetter months, indicating ongoing clay shrinkage beneath the foundations.
Conventional underpinning would have required significant excavation adjacent to both the property and the neighbouring boundary, increasing programme duration, cost and disruption.
The client wanted a permanent solution that could be completed quickly while avoiding unnecessary excavation and disturbance.
client quote
Tony Blaza
Following a detailed assessment, Geobear designed a bespoke ground improvement solution to mitigate the effects of clay shrinkage beneath the affected foundations.
Working externally around the extension, engineers injected a specialist geopolymer material at multiple depths beneath the shallow strip foundations through a series of small injection points. The treatment was designed to improve the bearing capacity of the underlying clay while reducing its seasonal shrink-swell behaviour.
The entire treatment was completed in less than one day, requiring only minor preparation works, including drainage checks and temporary access arrangements.
The non-invasive approach eliminated the need for excavation, allowing the property to remain fully usable throughout the repair process.
The extension foundations were successfully stabilised without excavation or traditional underpinning.
By improving the performance of the underlying clay soils, the treatment addressed the cause of seasonal movement while significantly reducing disruption compared with conventional repair methods.
The homeowner benefited from:
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