High-Resolution Infrared Thermography for Structural Assessment of Historic Fibrous Plaster Ceilings at the Royal Albert Hall

The Royal Albert Hall (RAH) is one of the UK’s most iconic performance venues and a Grade I listed building. Among its most distinctive features are the fibrous plaster ceilings of the main auditorium, a lightweight composite system widely used in the late nineteenth century. Fibrous plaster presents major conservation challenges: its structural components, such as hessian wads and timber laths, are hidden from view and prone to ageing, moisture damage, and detachment. Failures can result in cracking, delamination, or collapse, but current inspection methods are invasive, labour-intensive, and constrained by safety or access limitations.

This project will test High-Resolution Infrared Thermography (HRIRT), accessed through the E-RIHS MOLAB platform, as a non-invasive method for assessing fibrous plaster. By detecting subsurface anomalies linked to cracks, voids, or moisture differences, HRIRT offers the potential to reveal concealed constructional features and early signs of deterioration without intrusive investigation. The RAH provides an ideal testbed, combining stringent conservation requirements with high international visibility.

The study will focus on a five-day acquisition campaign, supported by preparatory archival research, lab calibration, and a LiDAR survey to provide geometric context. Thermographic data will be processed using filtering and transient analysis, overlaid on the LiDAR model, and validated through selective visual inspections, historical records, and Portable Nuclear Magnetic Resonance Relaxometry (PNMRR). A supervised student researcher will generate annotated thermographic maps and a feasibility report, providing the first systematic assessment of HRIRT for fibrous plaster ceilings.

Outcomes include proof-of-concept for thermography as a diagnostic tool, initial datasets for benchmarking, and a draft protocol for rapid, repeatable surveys. Broader impact will be delivered through engagement with Historic England, specialist plaster companies, and professional bodies (FIS, IStructE, IHBC, CIOB, and ASCHB). Ultimately, the project aims to improve safety, resilience, and conservation across theatres and public buildings in the UK and Europe.