Floor panels, also known as floor decks, are a factory-built portion of a floor system with joists that are glued and fastened with sub floor sheathing at specified on-center spacing for the particular joist depth, material, and sheathing. Common joist materials include floor trusses, I-joists, and dimensional lumber such as 2x10 and 2x12. Floor panels offer a very quick method for setting a floor system in the field, typically using a crane. Occasionally floor panels will have a ceiling material applied to the underside of the panel in the factory, further speeding up the construction process in the field. Typical constructions principles still apply, floor trusses are required to be supported by and fastened to structural supports such as walls, columns, or beams.