Specifiers today are becoming more and more exacting as to the flatness of concrete floors. To help meet their increasingly stringent demands, a new surface leveling beam has been developed that follows and supplements the vibrating screed but does not substitute for it except on thin toppings and overlays, or on relatively thin slabs such as those used in residential work. They key to its operation is that it oscillates horizontally and does not move vertically at all, as vibrating screeds do. Because of the vertical component of their motion, vibrating screeds tend to pump concrete up behind them. The resulting vibrated surface may not be entirely flat and is sometimes too high.
The surface leveler is made of a single light alloy beam that vibrates in the longitudinal direction of the beam. The vibration is produced by an external vibrator fixed at one end of the beam with a special suspension attachment which gives the leveler the directional movement. It saws off the high spots left by the surface vibrator. The top surface only is vibrated, so the beam is easily pulled and leaves an even surface flush with the bottom of the beam.