At 226 Jackson, MILBURN performed a total interior demolition of all ceilings, MEPs, flooring, and finishes back to the exterior walls on all 14 stories of the former Chicago & Northwestern Railway Company building located in the heart of Chicago. On top of the interior demolition, MILBURN was responsible for removing the existing roof to make room for an additional floor and roof deck installation. The demolition totaled over 5400 tons of material including over 900 tons of existing steel, 800 tons of miscellaneous construction debris, and recycling 95% of concrete and aggregates.
We funneled demolished material from each level to our dumpsters using skip hoists combined with rollers and skid steers, ensuring that we handled the material with machinery as often as possible. With the project located in a busy part of Chicago, we coordinated flaggers to ensure that we removed dumpsters smoothly and kept traffic flowing.
Our Biggest Challenge
The biggest challenge we faced was implementing a structural bracing plan for an unforeseen wall type. To maintain an existing parapet, we consulted with a structural engineer to figure out how we could remove the existing finishes back to the exterior walls without undermining the parapet. Through a lot of engineering and coordination, we developed a bracing plan that kept us safe and on track.
The sequencing plan began by reinforcing the exterior walls using an engineered bracing system. From here, we removed a portion of the existing red clay tile underneath the parapet. Then, we braced the parapet from underneath, while still accommodating for the installation of new beams. With the bracing in place, the concrete subcontractor installed new concrete beams in between the reinforcement. We then removed one section of bracing, demolished a portion of the roof, and removed the final bracing to leave the parapet intact.
We repeated this sequence in alternating column bays until we demolished the entire roof.
The End Result
We completed this project on budget, on time, and with a happy client. The project started in December of 2019 and finished on schedule in August of 2020. This project offered a unique and complex set of challenges, but it’s a perfect fit for the type of jobs we love taking on. Our foreman Juan Ocha and Brokk operator Jesus Magana were critical parts of this project’s success. Juan’s coordination of our crews with other trades and Jesus’s careful Brokk operating kept us incident-free and on schedule.