Abstract: A movable support structure from which a window washer is suspended that utilizes the parapet wall of a building as a support or runway by directing the force applied by the weight of the washer downwardly into the parapet wall. An upright frame above the parapet wall extends upwardly in substantially the same vertical plane of the parapet wall. The upright frame is supported on the parapet wall by a first set of wheels that rest on the wall. The upright frame may be further maintained on the roof by a second set of wheels that rest on the roof. The wheels roll along the roof and wall to facilitate horizontal movement of the apparatus. The horizontal movement is guided by internal and external guide rollers that engage the respective surfaces of the parapet wall. In addition, a ladder depends over the edge of the wall such that a window washer may safely step over the parapet wall and into a position to begin cleaning.