The task at hand was to convert a turn-of-the-century department store into a combination of office and assembly spaces. Most notable among the assembly spaces is a rooftop bar and deck which includes a swimming pool.The existing masonry and wood floor structure with cast-iron columns is only moderately well suited to these uses. In order to provide lateral stability, we employed steel plate shear walls mated to hollow steel columns. The steel plates offered the right combination of structural rigidity, design flexibility, and constructibility.
On the first floor, our task was to maintain the historic storefront and also to tie the lateral loads from the stories above into a new steel-plate central core. Although originally designed as a cable horizontal “X” brace that was threaded through the floor joists, we worked with the contractor to come up with a more constructible solution employing segments of flat plates to create the “X” brace.
At the roof, our task was to add an assembly space that included a full-depth swimming pool on top of a masonry and cast-iron structure. Structurally we wanted to keep this as light as possible and manage the loads onto the cast-iron columns. Long span steel beams supporting a steel and wood deck kept the system light, but was also susceptible to vibrations. In order to minimize the vibrations, we added neoprene damping springs on top of the cast-iron columns. The springs limit the load on the existing cast-iron columns by having been added following the installation of all finishes including the water in the pool.
Check out a virtual tour of these innovative features below.