Article describes various models of engine-powered vibrating screeds designed to save finishers time, labor and back strain. According to one screed manufacturer, an experienced finisher--with an experienced laborer spreading the concrete--can strike off 20,000 square feet in an eight-hour day when using a vibrating screed. Two men hand screeding with a 2x4--with two men spreading the concrete--would need 10 hours to finish the same area.
Each of the units is powered by a gasoline engine and offers vibration control, allowing for changes in frequency. The engine produces vibration in the screed attachment by rotating an eccentric (off-center) weight.