In a more unusual challenge, ground engineering experts Mainmark UK supported award-winning Claim and Risk Solutions provider GHG Solutions Ltd in successfully strengthening the ground beneath a Watford junior school, damaged by a badger sett.
With the void below the classroom block being dark and the warm, under the school became the perfect home for a family of badgers. But the resulting tunnels caused damage to the drainage network, undermining the school’s foundations.
Mindful of not disturbing protected wildlife, GHG Solutions Ltd worked closely with Natural England, the Government’s adviser for the natural environment in England. An artificial sett was built and the badgers relocated within the school grounds. Once the badgers were moved, it had to be confirmed by Natural England that there was no badger movement or activity at the old sett for 14 consecutive days. Only after this period could any groundwork commence.
GHG Solutions Ltd were instructed to support the school by its Insurer, bringing Mainmark on board and instructing the team in the early stages. The project was completed in just nine days during a half-term week with Mainmark safely improving the ground, filling the voids and strengthening the 96 concrete pad foundations beneath the classroom block.
The large badger sett had compromised the ground, which already had a slight gradient beneath the building, causing significant soil disturbance, raising concerns over the long-term stability of the foundations and structure above.
GHG Head of Technical, Steve Wright, said: "The challenge was to produce a scheme to remove the live badger sett beneath a block of six school classrooms. We quickly established that no temporary classrooms were economically available, so we had to design a remedial scheme with the classroom block in situ and in full use. The project was originally designed to be completed over two discrete phases, although Mainmark UK’s flexible and collaborative approach, together with effective leadership of the site team, enabled the project to be delivered in one phase, significantly ahead of the programme.”
The Mainmark team conducted 15 tests to assess the soil’s strength, and the external pad foundations were treated with Mainmark’s Teretek® resin technology. To facilitate this, core holes were carefully drilled through the classroom floors, creating access points for the keyhole injection of the Teretek® solution. The minimally invasive method enabled targeted injections beneath each foundation pad to fill voids and strengthen the ground without major disturbance to the building structure or school activities.
Early collaboration with the school, loss adjuster and ecological consultants ensured all stakeholders had the opportunity to contribute to the planning process.
Mainmark UK Residential Lead, Freya Chapman, said: “With nearly half a million badgers across England and Wales, it comes as no surprise that badger setts are becoming more common in urban environments. We carefully aligned with school holiday periods, minimising disruption to staff and pupils while fully complying with the licensing conditions set out by Natural England. Thanks to the collaboration between GHG and Mainmark, the school saved nearly £250,000 in potential temporary relocation costs.”
Mainmark Ground Engineering (UK) Ltd is a subsidiary of the Mainmark group of companies, established in 2016. The company has over three decades of experience and has established itself as a pioneering force in the industry, leading the way in developing and delivering cutting-edge solutions. Mainmark has earned international recognition as an award-winning ground engineering organisation.













