A machine and method are disclosed for deconstructing walls and other substantially vertical surfaces. The machine comprises a static, stand-alone support-frame. A carriage is movably mounted on the support-frame, which carriage is operable to be raised and lowered along the support-frame adjacent to a workface. To the carriage are mounted one or more nozzles, preferably the nozzles are mounted to the carriage by means of a nozzle carrier that is operable to move back and forth along the length of the carriage. The nozzles are connected to a high-pressure supply of an erosive material, preferably water. The erosive material, when forced through the nozzles, form jet streams that are directed against the surface of the workface, thereby eroding the surface. Optionally, the invention comprises means of yawing or means of rotating the nozzles in order to access the sidewalls of the opening in the workface produced by the invention. Optionally, the invention comprises means of adjusting the nozzles towards or away from the workface surface in order to maintain an optimal gap between the nozzle and the workface surface as the opening gets deeper. Optionally, the invention comprises a work platform mounted on the support-frame and operable to be raised and lowered along the support-frame, thereby providing access to the workface for workers cutting rebar and carrying out other ancillary tasks.