CELLULAR-METAL-FLOOR-RACEWAY WIRINGCELLULAR-METAL-FLOOR-RACEWAY WIRING282. Cellular-metal-floor raceways are formed by employing for the floor construction of the building structural members made of corrugated sheet steel. Seven types of cellular steel floor, as made by the H. H. Robertson Co. of Pittsburgh, are shown in Fig. 9.196. Cross-sectional views of completed floors and their adaptation for the installation of the electric wiring system are given in Figs. 9.197 and 9.198.