Repairs At Dijon Church Reveal How Salt And Heat Can Damage Historic Stonework

Restoration work at Dijon's Church of Saint-Philibert in France is doing more than shoring up a troubled structure. Crews investigating persistent damage beneath the church’s stone floor uncovered multiple layers of burials, ranging from late medieval graves to stone sarcophagi dating back to Late Antiquity and the Merovingian period.

The discovery came as researchers looked into the church’s foundations after ongoing deterioration. The Cool Down reported that part of the damage traces to changes made long after the church was built, including a time when Saint-Philibert served as a salt storehouse in the 18th and 19th centuries. In the 1970s, a heated concrete slab was installed above ground, over material still contaminated with salt. Heating those deposits contributed to cracking and weakening in the surrounding stonework, according to the report.

In one excavation area in the transept, the team found a late medieval burial chamber holding adults and children laid in simple shrouds with a small number of items, including coins and rosaries. Researchers Clarisse Couderc and Carole Fossurier also identified slab graves dated to the 11th through 13th centuries, plus six sarcophagi from earlier eras. One stone coffin had a sculpted lid.

For mason contractors and restoration teams, the jobsite lesson is familiar: historic masonry failures rarely have one cause. Salts, heat, and past alterations can combine to accelerate cracking, movement, and surface breakdown. When floors or foundations are opened up in older structures, it also pays to plan for careful documentation and coordination with specialists, since structural stabilization and conservation work can intersect fast.

A public market notice outlines a major rehabilitation effort at Saint-Philibert, with the first phase focused on pillars and a second phase aimed at the bell tower and spire.

Read the full, original article from The Cool Down here.

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