The stone was cleaned to remove general soil, black gypsum crusts, biological deposits and copper stains. The mortar and sealants in the joints of the marble were replaced and the non-functional bird deterrent system was replaced.
General cleaning used low-pressure water and environmentally friendly cleaners to remove surface dirt. Copper stains were removed with a poultice that pulls the stains out of the stone, similar to a mud mask. The heavy soil and gypsum deposits at the carved stone and the east pediment sculpture were cleaned with laser technology. The laser removed the surface soil without impacting the deteriorated and fragile stone. The cornice level lion heads, east portico column/pilaster capitals and the sculpture also received a special conservation treatment, called consolidation, to slow the deterioration of the stone and loss of detail. Stone that had cracked was re-anchored and new stone was carved to replace elements that had deteriorated to the point of failure.
The bronze grilles and railings were cleaned of corrosion and refinished with a protective surface coating applied.
This project was completed in 2018.