The Doff machine has always been the equipment to use when it comes to cleaning buildings. It cleans superbly, plus it poses no danger to the substrate. It’s the only cleaning equipment that’s approved by the English Heritage for the removal of contaminants from buildings. The machine consists of a water heating system, an adjustable nozzle and pressure and temperature controls. It heats the water while controlling the pressure at which steam jets out of the nozzle to keep it low. As a result, delicate surfaces don’t get damaged.