Harris Hall, reminiscent of a Christo installation, is wrapped with scaffolding. The scaffolding, erected by Jimmy Z Masonry, serves as a platform for workers to restore the building’s facade. Although Harris looks fairly good to the casual eye, close inspection reveals numerous problems. Although the facade has seen periodic and routine maintenance over the years, it has not had comprehensive attention for nearly 100 years. A description of some of what is being done follows.
The arrows in the photo above point to “spalling” of the limestone near the top of the building. Over time, as masonry joints have failed (an inevitable event), moisture entered the wall cavity and caused the mild steel supports to rust. As metal rusts, it expands and, when the steel is close to the face of the stone (~2” or closer), the resulting pressure causes the stone to “spall” or fracture. The next photo reveals a small piece of steel that caused the spall at the upper arrow in the photo above.
In such cases, either a portion or an entire stone will be replaced. This raises the obvious question, “won’t this simply happen again?” Eventually, it may, but meanwhile, we are addressing the source of the moisture, Water has been finding it’s way behind the stone facade principally because the grout between the stones has deteriorated over time. This has caused significant damage at the parapets (top of the wall). Repeated cycles of freezing and thawing destroyed the brick walls behind the stone. Eventually, the stone at the parapets would have failed dramatically. i.e. pieces of stone would literally fall of the building. Presently, the parapet is being dismantled, reflashed and re-built. See next two photos:
Above, large sections of stone lie on the roof, awaiting to be reinstalled.
Above: Worker cleans out stone joints in preparation for new grout.
Work in progress.
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