March 15, 2023

Featured in this photo, NOVA is performing special inspection services on a hotel construction project involving reinforcing steel of an external structure referred to as “diagrid” columns. Diagrid systems have a very unique appearance and are easily recognized. The term “diagrid” is a combination of the words “diagonal” and “grid” and refers to a structural system that is single‐thickness in nature and gains its structural integrity through the use of triangulation. Diagrid systems can be planar, crystalline, or take on multiple curvatures. Crystalline forms or curvatures are often used to increase their stiffness. Perimeter diagrids normally carry the lateral and gravity loads of the building and are used to support the floor edges.

The configuration and efficiency of a diagrid system reduce the number of structural elements required on the façade of buildings, therefore less obstruction to the outside view. The structural efficiency of the diagrid system also helps in avoiding interior and corner columns and therefore allows significant flexibility with the floor plan. Diagrid systems around the perimeter save the structural steel weight when compared to a conventional moment‐frame structure. The diagonal members in diagrid structural systems carry gravity loads as well as lateral forces due to their triangulated configuration. Diagrid can also save on the amount of structural steel utilized in a high‐rise building.

Photo credit: David Mendez, Kennesaw, GA CMT Special Inspector