Robotic systems and methods to treat vertical external surface of structure

A system to treat a substantially vertical external surface of a structure, comprising:

• a frame body to be positioned parallel to and proximate with the external surface and extend substantially horizontally from a first side to a second side;
• at least one connecting portion adapted to be attached to a cable to provide for vertical movement of the frame body;
• a wheeled carriage within a horizontal recess of the frame body, the wheeled carriage being able to roll within the recess to move horizontally along the frame body during treatment of the external surface;
• a robotic arm affixed to and extending from the wheeled carriage to an end proximate with the external surface;
• and
• a treating portion attached to the robotic arm near the end proximate with the external surface,
• wherein the robotic arm is adapted to rotate, vertically moving the treating portion during treatment of the external surface, and further wherein the treating portion is separately rotated to remain substantially parallel to and proximate with the external surface during rotation of the robotic arm.