Johnston says he has overseen entire projects that cost less than the façade restoration at Cook County Hospital, which was approximately $25 million. The entire building’s exterior comprises about 135,000 square feet, and approximately 100,000 square feet of the façade was restored. “The façade is the reason why that building was saved. Just the details and really how beautiful that façade is saved the building from being demolished,” Johnston says.
Wiss, Janney, Elstner (WJE) Associates Inc., which served as exterior envelope restoration consultant, first became involved with the Cook County Hospital project in 2013 when the county asked the firm to complete a façade inspection. Based on WJE’s experience with the building, it again was hired to complete due-diligence assessments for the development team. During construction, WJE was charged with designing and providing construction administration support for the façade restoration, which included terra cotta, brick and stone, window replacement and restoration, and roofing replacement.
“The building was in really rough shape before the exterior repairs because of weathering and lack of maintenance,” explains Rachel Will, an associate principal with WJE, who served as project manager for Cook County Hospital’s exterior envelope rehabilitation. “The building had been abandoned long enough that it was a stabilization effort at that point. Nobody was really maintaining it from a water-infiltration standpoint and that likely was not happening much before the building had closed, knowing that it
was a municipal building. Funding is always a challenge and funding for maintenance for exterior work is even more scarce.”
Stainless-steel strapping and netting had been previously installed as temporary stabilization measures to hold the terra cotta in place on the building. WJE’s team began their inspections in June 2018. Will says the month-long inspections were very detailed, especially for the terra cotta. “We did a full investigation of a drop location, documenting it so we could share what we found with the entire team,” she says. “We use Bluebeam with survey sheets, photos and annotations to share information with the general contractor and the masonry contractors almost immediately, so everybody understands the existing condition of the façade.”
There were more than 4,000 pieces of terra cotta replaced, and then another 10,000 pieces were removed, repaired and re-installed. WJE also oversaw 10,000 square feet of brickwork replacement/reconstruction. Will explains every retrofit job has concealed conditions, some of which can be anticipated based on experience with these historic masonry-clad buildings, but there also are many conditions you can’t foresee. “What was interesting about this building is some of the detailing that would have been typical of the original construction time period—things that we know from history of working on other buildings—wasn’t always what was expected at a specific location,” she explains. “The best way to describe it is early value engineering. We’d find issues where the steel support terra-cotta units and brickwork were not connected to the structural steel frame. Additionally, significant amounts of deterioration were caused by unrestricted water infiltration for years.”
Late in the process, some original drawings of the façade were found but no original details or terra-cotta shop drawings existed. “We were hopeful we might find terra-cotta shop drawings, just because the original was from the Northwestern Terra Cotta Co., which had been located in the city of Chicago historical- ly,” Will says. “They have archives in the National Building Museum in Washington, D.C., but there was nothing. You don’t ever expect that you’re going to find drawings of these older buildings, but it’s definitely a nice reward when you do.”
Today, there are only two terra-cotta manufacturers operating in the U.S. The team selected Gladding, McBean, which is located in California, to manufacture terra-cotta replacement units. The process of making new terra-cotta pieces has not changed much over the years. “The process of terra-cotta restoration is pretty involved, and it really starts with the onsite survey,” Will explains. “Following the survey, types of units designated for replacement are removed as samples and those samples get shipped to the manufacturer where they develop a series of shop drawings for each unit being replaced that then were reviewed by WJE and the masonry contractors.”
Gladding, McBean developed shop drawings to create the models and molds required to fabricate the terra cotta. Will says the shop drawings are developed utilizing conversions for the dimensions to account for the shrinkage of the clay. “They can’t just take a negative of the piece and make it from that because it would be too small,” she explains. “From those drawings, they fabricate the pieces with different fabrication methods, including hand pressing, extrusion, slip casting and ram pressing. The majority of these fabrication techniques were utilized to create replacement units for the Cook County Hospital restoration.”
“The whole process takes forever,” Johnston adds. “Some of the pieces can be extruded, which is more like the Play-Doh factory, if you will, where they make the profile and then they’re able to push the pieces out. But the bulk of the pieces are just hand-packed clay into molds. Then they get fired in a kiln and glazed. From the time we started pulling pieces, it was about a calendar year by the time the new pieces showed up.”
Johnston visited Gladding, McBean several times throughout the project to view samples and ensure the process was moving forward smoothly. He explains: “I went into those first meetings as a construction- minded person, asking, ‘How many pieces a day? How many pieces can you get on a truck? How long is the cooking time?’ Once I saw the process, I realized it’s more like artwork. Not many things are touched by human hands anymore, like terra cotta is. Each artist stamps his or her pieces with their symbol and number, and they’re very proud of the pieces they make.”
PHOTOS: Walsh Construction
Be the first to comment on "Chicago’s Historic Cook County Hospital Is Redeveloped into a Hotel and Food Hall"