Cats may have nine lives, but who has heard of a skyscraper having two lives? That is exactly the case in Ft. Worth, Texas. Chamberlin’s restoration team is hard at work in downtown Ft. Worth. Their task: to restore a landmark and give it new life through a complete metamorphosis.
The Bank One office tower at 500 Throckmorton and Fourth Street in Ft. Worth was damaged by a tornado that rocked downtown and destroyed several buildings in its wake in March of 2000. While the other buildings were rebuilt, the Bank One tower was left abandoned for almost three years.
Plans were made to demolish the skyscraper and use the land for parking, but the discovery of asbestos and the high costs of abatement and implosion made that plan impractical. In late 2003, principal architects, Corgan Associates, Inc., unveiled new plans to give the 37-story building a second chance at life, complete with a new use, a new name and a new design. The City of Ft. Worth and developer/owner TLC Green Property Associates I, L.P. agreed to abate, renovate and develop the building. This $65 million project would turn the Bank One tower of office spaces into The Tower, a high-rise condominium with over 300 residences and 30,000 square feet of retail stores, restaurants and offices.
To begin the project, CST Environmental removed hundreds of thousands of square feet of plaster containing asbestos from the vertical structural columns and other areas. Being that this is a very delicate process, Chamberlin was called in to seal the outer walls to create an airtight atmosphere inside the building. Chamberlin’s team installed a special string reinforced polyethylene material on the outside of the building sealing all window openings without glass using batten strips and fastening anchors as required.
After asbestos abatement, Turner Construction acquired the task of removing the entire interior and exterior skin of the building. Interior and exterior walls, air conditioning equipment, plumbing and wiring were extracted until only the skeletal concrete frame remained.
Chamberlin was responsible for the removal of all exterior glass, glazing, mullions, louver panels and temporary building wrap. In order to remove the exterior skin, eight swing stage scaffolds, one scaffold for each side of the building, were rigged. The swing stage work began at the 6th floor and worked its way up to the 38th floor at roof level.
Removing the remaining glass on the structure was no walk in the park, and safety was a big concern. While Chamberlin was working on the demolition of the upper levels of the building in the middle of downtown Ft. Worth, new construction was taking place below. Chamberlin had to develop a 100 percent safe and creative plan to prevent any and all debris from falling and seriously injuring someone.
Chamberlin waterproofing Project Manager, Bryan Payne, faced the challenge by coming up with a creative solution that was two-fold. First, the team put together the “swing stage diaper.” “In order to prevent falling debris,” Payne said, ”we attached a mesh netting directly to the building beneath the floor in which we were working. The debris net was attached using self-drilling screws and anchored into the existing curtain wall frame system.” The debris net hung under the swing stage and attached to the top of the back rail there by catching any debris that might fall.
Secondly, and most uniquely, all remaining glass was completely covered with an elastomeric sheet membrane. “This sheet membrane, which is actually designed for below grade waterproofing, bonds tenaciously to glass,” Payne said. The Chamberlin crew was then able to safely break the windowpanes to the inside of the building without the risk of losing shards of glass below. Once the glass was removed the glazing was cut and the mullions were detached and then demolished with pry bars.
After the demolition was complete, the process began to transform the building into The Tower. Chamberlin restored the concrete frame by utilizing high strength mortars to patch the spalling and damaged concrete beams and columns on the exterior of the building. An elastomeric coating was installed on all exterior exposed concrete surfaces after the completion of the entire exterior wall package to provide a new cosmetically appealing look and also to protect the concrete skin from future water infiltration damage. Chamberlin also constructed 372 new apartment balconies and installed a concrete topping on each to create positive drainage.
The building now has an entirely new exterior building envelope. The former tower, slick with reflective windows, now is encased in a cool, blue-green shell with inset balconies that create a sort of basket weave effect. The lower level is reconfigured from its familiar angled concrete columns into a box base skirt consisting of five floors and two below-grade levels that contain retail stores, restaurants and office space. The roof of the skirt features patio areas, a dog-walking path and a swimming pool for the condo owners. The Tower is scheduled to be finished and occupied in early 2005.
Payne reflects on the project with pride: “One thing that I consider the most unique about Chamberlin’s role in this project versus other projects is the degree in which we were able to impact the schedule. All finishes, dry wall, etc. could not take place until our work was complete and the new glass was installed.”
Chamberlin’s 20+ employees working on the exterior skin went the extra mile, sometimes working seven days a week in order to stay ahead of the curtain wall contractor’s work. Undoubtedly, it was the Chamberlin team’s commitment and creative problem solving that enabled them to both meet the project deadline and save the owner money. Chamberlin’s Superintendent, Paul Watson, applied his years of experience and lead crews to complete the demolition work 30 days ahead of schedule and under budget – a feat companies with less manpower and experience may have not been able to deliver.