This innovative Nano Electro Application Technique (NEAT), which has received £200,000 from UKRI, enhances the penetration and long-term effectiveness of nanolime treatments.
Nanolime is a stone consolidant made of nanoscale calcium hydroxide particles suspended in an alcohol solvent, used by conservators to preserve and strengthen historic stonework.
Built heritage, from limestone monuments and buildings to archaeological sites, is vital to cultural identity, tourism, and the global economy. However, fine-grained limestone is difficult to consolidate using current methods, which often require costly, labour-intensive, and environmentally damaging interventions when stonework becomes severely degraded.
Researchers at Sheffield Hallam University have developed NEAT to directly tackle these limitations, enabling nanolime to reach deeper into deteriorated limestone without compromising the material’s visual or historic integrity. Laboratory tests confirm both superficial and in-depth consolidation are now achievable – a breakthrough with global potential for heritage protection.
Professor Fin O’Flaherty, principal investigator and professor of infrastructure engineering, said: "NEAT has been able to overcome one of the biggest challenges in limestone conservation - getting nanolime to penetrate deeply enough to make a lasting difference. This technique builds on years of research and responds directly to what conservators have been asking for: a reliable, science-based solution that preserves fragile limestone without harming its appearance or integrity. It’s incredibly rewarding to see a technology with the potential to protect heritage structures around the world in a way that’s both effective and sustainable."
Dr. Cyril Maucourant, project co-lead and postdoctoral researcher, said: “From a conservation standpoint, NEAT represents a real step forward. Beyond establishing the efficiency of this cutting-edge technology for built heritage applications, the Set in Stone project will also contribute to creating the spinout ‘NanoConservation’ from Sheffield Hallam University. This new venture will focus on developing greener, smarter, and more effective conservation treatments and will offer a wide range of services in the field of built heritage conservation”.
The Set in Stone project aims to demonstrate the technology’s effectiveness and deliver the first long-term examples of its performance as the technique and materials continue to evolve. The project also seeks to build user confidence and gather feedback to address practical challenges and guide future development.
For heritage conservation specialists, NEAT offers a safer, less labour-intensive, and more effective alternative to traditional stone consolidation approaches. For heritage owners and operators, it represents a practical solution to delay expensive remedial work – a timely intervention that could preserve historic fabric for generations.
Field trials will begin in coming months in the UK, Europe, USA and Canada, with Sheffield Hallam University collaborating closely with conservation partners to bring this technology from the lab to landmark sites around the world.
Find out more about the project here.
