University Lofts was a project located in downtown Binghamton, NY. Originally, a department store was on the site, and the facade was left in place. There had been a serious fire inside of the building, so the entire inside had to be torn out and replaced. To rebuild it, it was decided to use cold formed steel construction. The system used was custom rolled sections using the Howick Machine. The steel supplier was Vanguard Light Gauge Steel Buildings in Winchester, VA. We were contracted by Vanguard to provide the structural engineering services.
With this system, the light gauge steel is purchased in rolls of flat steel. The building wall and floor system is input into the system to develop sections and panels that are custom rolled and cut by the machine. There is very little wastage, and there is a lot of control over the fabrication. It eliminates most of the cutting of the light gauge steel on site, and also most of the attachments are done in the shop.
The walls were assembled as panels, and floor trusses were assembled in Winchester and hauled up to Binghamton, where they were erected by the contractor. In addition to rebuilding the interior of one building, we structurally designed a 3 story addition to the building behind the one that had been gutted. The addition was hot-rolled structural steel framing with cold formed steel and composite concrete metal decking for the floors, and cold formed steel walls.
By prefabricating sections of the building in a shop environment, the schedule can be compressed significantly. Weather is not so much of a concern, and doesn’t slow the project as much as it does when everything is assembled on site.
With cold formed steel construction of this type, there are some things that are critical:
- Drawing accuracy is critical. It is important to have a good survey of the site before proceeding. The foundations have to be laid out with extreme accuracy, and prior to fabrication, it is important to recheck the layout of the foundations. Any errors will cause serious problems with erection.
- Quality control is important. It’s important to verify the connections of the joints are done properly. While highly skilled labor isn’t needed, it is important the the person assembling the sections can handle driving the screws and understands how they are to be placed (not bunched together).
- Truss design can be an issue. The engineer should design the trusses first, not the person working with the software for the machine. It saves a lot of effort if the trusses are standardized, and quality control is better too.
- Prior to fabrication, the engineer must check the shop drawings. Don’t run ahead of the engineer, otherwise changes may be needed after you fabricate.