Abstract: A ceiling grinding apparatus for use in surfacing concrete ceilings comprising a portable support assembly having independently suspended wheels; a central member vertically movable along the support assembly; a boom pivotally mounted on the central member; a grinding assembly coupled to one end of the boom including blade means rotatably supported in a housing; and a biasing mechanism for forcing the blade means against the ceiling during the grinding operation. An exhaust system is connected to the housing for removing the dust and concrete chips therefrom and transferring this material to a collection bag. A hydraulic motor is used to rotate the blade means and is driven by a hydraulic pump coupled to an electrical motor, with the hydraulic fluid being stored in the central member.