Abstract: A method and apparatus for processing waste plasterboard consisting of sheets of paper or similar material adhered to a core of plaster of paris or the like, for recovering and separating the cover material from the gypsum of the core and for collecting each in a conveniently reusable form. A pair of rollers have parallel axes of rotation and are held to a variably close spacing under pressure while being counterrotated to grasp and crush pieces of plasterboard, delivering the paper and crushed gypsum core material to a vibrating screen which separates the two for separate collection and subsequent reuse as raw materials or for other purposes. A second crusher and screen may be used for additional separation of the materials.