Methods for manufacturing foam wall structures are described. The methods include placing a wall structure proximate to a robotic arm, orienting an imaging device so that the imaging device on the robotic arm faces a cavity in the wall structure, surveying the cavity using the imaging device, determining a spray foaming pattern to fill the cavity to a selected depth with a foam layer, orienting the spray nozzle so the spray nozzle faces the cavity, and spray-applying the foam-forming composition into the cavity to the selected depth by passing the foam-forming composition through the spray nozzle to form the foam layer. Foam wall structure manufacturing systems that are suitable for carrying out such methods are also described.