A screening apparatus (10) comprising a frame, a motor assembly (16) for vibrating the frame, at least one screen (20, 30) mounted on the frame for separating materials by size and at least one feed device (35A, 35B, 35C, 35D) provided for delivering a liquid onto said at least one screen (20, 30), said at least one feed device (35A, 35B, 35C, 35D) being adapted to deliver said liquid onto the at least one screen (20, 30) to define a laminar flow of liquid and entrained or suspended solid material over the at least one screen (20, 30).