St. Helen’s Chapel, Durham Cathedral - West Window

In late 2024, we assessed the West Window of St Helen’s Chapel, Durham Cathedral, and submitted a Glazing Conservation Specification for the treatment of the three clear diamond quarry lancets and six tracery panels dated between 1880-1920. Our proposal was approved and we began work in 2025, removing  the window with the assistance of Eden Stained Glass.

Rust from the support bars and ferramenta had left dark striped encrustations across the surface of the glass, and microbial growth was evident across the whole window, so the glass was thoroughly cleaned. Each panel underwent a thorough assessment to guide informed, case-by-case treatment decisions, and where fragility compromised long-term stability, the replacement of broken or weakened glass was often unavoidable. Mending leads were employed in areas where the glass allowed. We specified that the panels be re-leaded in order to stabilise and strengthen this window for the future, and to prevent further damage to the glass caused by deterioration of the lead. We releaded the panels with new leads close as possible to the original lead profile, and were able to divide one of the larger panels to match the corresponding panels in the other lights, which also made it more stable and safer to maneuver.

We retained and repainted the original interior support bars, and the two casement units were refurbished, their newly re-leaded panels reputtied into the frames. We also fitted new exterior lead cills to all three lancets, with internal upstands filled with washed gravel to aid in the expulsion and run off of moisture to the exterior of the building.