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 can be raised and lowered along the support-frame. The carriage includes a carrier-bar, which may be straight or curved. One or more nozzles are mounted to the carrier-bar by means of a nozzle carrier that moves back and forth along the length of the carrier-bar. 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 and rotating the nozzles, and means of adjusting the nozzles towards or away from the workface. Optionally, the invention comprises a work platform mounted on the support-frame.