But over the years, maintenance procedures continued to change. As pieces of the limestone render came off, they were replaced with Portland cement, and other types of paint replaced the whitewash.
“They used Portland cement and house paint on masonry that was never designed for these types of materials,” said Mark Kutney, an architectural conservator at UVA Facilities Management.
The Portland cement is much harder and more moisture-impermeable, whereas the lime render allowed the columns to breathe. Paint-covered cement trapped moisture inside the columns, and the trapped water seeped into the bricks. In cold weather, the water would freeze, causing micro-fissures in the bricks. The moisture also allowed salt crystals to migrate from the cement and lodge in the micro-fissures.