As the 1980s loomed, the world was changing. The new smaller, high-lifting material handlers would not function properly on floors that were not flat. Modular partition systems increasingly used in high-rise office buildings required tight clearances between ceiling and floor. Enter Allen Face. The president of the Edward W. Face Co. had begun to develop a new method for measuring floor flatness in 1979. He introduced the concept in the November 1982 issue, although he didn't specifically use the term “F number.” In short order, Face's F-number system replaced the standard 10-foot straight-edge method, and by 1990 had been incorporated into ASTM and ACI standards. Face had proved that the world could be flat.
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