To properly restore the Olmsted Terrace, a six-phased project is underway by the Architect of the Capitol (AOC) to repair the masonry at the terrace walls.
During the last 120 years, there has been little maintenance performed on the stone and conditions of the terrace have deteriorated. A materials condition survey found that the marble and granite is stained and damaged and requires maintenance and repairs. Repairs include deconstructing and rebuilding some of the walls, repointing, patching holes, cleaning the stone, and trimming and removing trees and bushes along the terrace walls. Work also includes the assembly of scaffolding, and cranes will be present at times to remove heavy stones. During each phase, the walls, pedestal, steps and curb will be dismantled, repaired and reinstalled by AOC masons.
The stone cleaning at the west central terrace's mid-level was completed fall 2016. This work was performed in preparation of the Presidential Inauguration, as it served as a backdrop to the event. The work included removing copper stains from the wall area up through the balustrade using a poultice.
Poultice is a combination of a very absorbent medium (it must be more absorbent than the stone) mixed with a chemical, which is selected in accordance with the type of stain to be removed, in this case copper. The concept is to re-absorb the stain out of the stone.