Active Climate, Earth & Environment History, Languages & Philosophy

Understanding the performance and durability of paint systems for external traditional lime-based substrates

In plain English

AI plain-English summary

Historic buildings across the UK are suffering damp and decay because the paints and coatings meant to protect them often fail—or make things worse—and no one has systematically tested how these finishes actually perform on old lime-based walls. The problem is that modern paints are marketed as breathable and waterproof, but there is no solid evidence linking those claims to long-term preservation. Moisture trapped inside masonry accelerates deterioration, and with climate change bringing wetter winters and more intense storms, the damage is accelerating. This PhD project, run jointly between Historic England and the University of Bath, will fill that gap by testing how paints affect moisture movement, thermal performance, and the rate of substrate decay over time. If the research succeeds, it will produce the first robust, evidence-based guidance for choosing and applying paints on historic buildings. That will directly inform conservation policy and technical standards across the UK, helping owners, contractors, and local authorities avoid costly mistakes. The work could also reduce the carbon footprint of repairs by preventing premature repainting and unnecessary stripping of historic fabric—keeping more buildings warm, dry, and standing for longer.

View original technical description
Appropriate preservation of historic buildings is essential to ensure resistance to deterioration from the changing climate and pollution. Repair approaches must support net zero and carbon savings, in line with policy across local and national government, ensuring historic places retain a sustainable future. Understanding moisture movement is paramount as both vapour and liquid water may detrimentally affect the condition and durability of natural organic, metallic, stone, and lime (mortars and renders) to weathering. The exterior envelope protects the masonry and a range of traditional and modern finishes – paints and coatings – are marketed for conservation, all claiming to offer vapour permeability, aesthetic appeal, and waterproofing. Empirical evidence of early failure, or even increased deterioration of the fabric, suggest that these parameters may not identify what defines a coating that will preserve historic substrates effectively, and their performance is not well understood. The urgency for research is highlighted by the large number of historic buildings suffering from damp problems and associated deterioration, further exacerbated by inappropriate interventions, and changing climate patterns. We propose to address the substantial gap in knowledge through multidisciplinary PhD research between Historic England and University of Bath. The strong track record of collaboration spanning over 14 years, outstanding supervision, state-of-the-art laboratory facilities, and links to industry stakeholders, will ensure effective dissemination and high impact. Historic use of paints and coatings will be investigated to provide practical recommendations based on historical knowledge and robust experimental data. Through five interlinked work packages, including clear research questions, the student will investigate methods for assessing moisture transfer, establishing new methodologies for the study of durability and performance of paints and coatings on masonry and render, and their impact on the rate of building substrate deterioration. These will form the foundation on which to investigate how the paint impacts on moisture transfer or buffering, and this in turn affects thermal properties which are essential in keeping a building warm. Investigations will then be extended to the effect on the fabric of paint removal and repainting, layer compatibility and performance as a system, and paint application and drying processes which are commonly encountered by practitioners on site. The research will entail a close collaboration with built heritage professionals and craft practitioners, involving heritage sites with field tests; the outcomes will directly support Historic England policy and technical guidance on the topic, and benefit the wider conservation industry.

View the original record at the funder ↗

Researchers

Francesca Gherardi (Co-Investigator)Juliana Calabria-Holley (Co-Investigator)Richard Ball (Principal Investigator)Sophie Godfraind (Co-Investigator)

Related Research

Grants with similar aims, by meaning.

Salts and synthetic coatings on wall paintings: characterising their transformation, interaction and contribution to deterioration
Conserving ruined masonry: managing water regimes to enhance resilience in the face of changing environmental conditions
EPSRC DTP-Understanding Microplastic Release from Protective Paint
Climate change and the greening of masonry: implications for built heritage and new build
An assessment of binder leaching in traditional mortars for mass masonry structures

Original classification

Training Grant

Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.