Stackable steel modules speed building core construction

Engineered as an alternative to traditional building core construction methods, such as cast-in-place concrete, precast concrete, and masonry, this patented, steel-and-concrete hybrid system can simplify and accelerate the construction of reinforced concrete stair and elevator core structures.

The CorTek Core System is supplied by Vulcraft, a fabricator of steel joist and deck components, in collaboration with its parent company, steel producer Nucor.

The newly launched system has been used on five projects to date, including the One Steamboat Place resort in Steamboat Springs, Colo., the Taxi II mixed-use residential building in Denver, and Limelight Lodge in Aspen, Colo.

The system is made up of modular, stackable cores that are factory-built and shipped ready to install. Modular construction minimizes site time and provides easy on-site installation. Stairs are pre-installed at the factory, and the stair rails are shipped inside the cores. This allows for safer, earlier, and more efficient trade access to floors. Workers can begin setting steel right away without having to wait on core curing.

Each CorTek system is custom-built to the requirements of the specific project. The architect and structural engineer are responsible for producing drawings and specifications that define the requirements for the core walls and stairs in the final constructed form. These drawings and specifications are given to the CorTek sub-contractor in order to begin shop drawings.

Once the all-steel cores are delivered on site, the CorTek installation process entails three steps: stack the cores; connect the steel, then continue erecting the structure; and pour concrete inside the core walls as erection continues.

The CorTek system is compatible with steel, concrete, and wood framing, and is structurally equivalent to cast-in-place concrete walls of various thicknesses, according to the makers. The modules go up with floor framing and do not require stripping. The interior surfaces can be left as is or finished with any standard wall
finish, such as paint, drywall, or laminate.