This video from Face® Construction Technologies (Dipstick.com) was produced in 1993 to instruct contractors in the use of the highway straightedge in concrete floor construction -- specifically in association with placement, strike-off and finishing practices that result in flatter and more level concrete floors. The modifications that were made to traditional highway straightedges... and the techniques demonstrated in the use of the tool on concrete floors... were largely the invention of Face Companies Chairman and MIT graduate engineer Sam Face (1923-2001). His hands-on consulting with contractors and their finishing crews in more than 20 countries in the 1970s, 80s and 90s made him a legend in the industry. He was named a fellow of the American Concrete Institute. "The Sam" Golden Trowel® Award, given annually to an individual who has made outstanding contributions to the industry, is named in honor of Sam Face. The Face Companies developed the F-Number System; the Face Floor Profileograph; the Face Dipstick® Profiler; and many of the superflat floor finishing techniques used around the world today. This has led to the evolution of improved equipment, products and procedures designed to produce flatter and more level floors. Visit The Flat Floor Library™ at Dipstick.com for more information on F-Numbers, other concrete floor tolerances and helpful documents on flat concrete floors and concrete floor measurement. The F-Number System, developed by The Face Companies in the 1970s and 80s, is recognized as one of the most important developments in the concrete industry of the last 50 years. Face introduced the Face Floor Profileograph in 1977 and the Dipstick Floor Profiler in 1982 to measure the flatness and levelness of concrete floor slabs. The F-Number System (and its associated instrumentation and installation procedures) was the first of two Face Companies technologies that won NOVA Awards, the highest international honor for construction innovation.