The building began the climb from a 185' concrete base, located on the northwest corner of the World Trade Center site, where in November 2006 400 cubic yards of concrete were poured on the building’s foundation. In May 2008, the concrete core rose to street level and has continued to ascend at a rate of approximately one floor per week. When construction is complete, more than 200,000 cubic yards of concrete (more than three times the concrete used for the Empire State Building) will have been poured at 1 WTC and concrete contractor Renzo Collavino of the Collavino Group is responsible for all of it.

Among the many preparations for such a massive undertaking, The Collavino Group sought a product solution that would standardize the above-grade core wall to slab connections in order to meet the high-profile project’s aggressive construction schedule. Working closely with Dayton Superior’s National Sales Manager Don Van Gerve and Barker Steel, The Collavino Group selected Dayton Superior’s D55 MetalStrip for the task. In addition, the Collavino Group utilized a number of Dayton Superior products including bar supports, rock anchors, coil rod, nuts, plates, grout and form release, making Dayton Superior a significant provider of product solutions for the 1 WTC structure.