Abstract: In a preferred embodiment, a motorized shed travels on a rail on two wheels thereof along a surface such as a roof while being adapted for spraying polyurethane foam from within a wind-diverter shed by a manual operator within, downwardly through a bottom port, and ventilation being through an upper open port having screen thereacross of a small mesh size which captures small droplets of polyurethane that might otherwise escape into exterior air and wind, from space within the shed. The walls of the shed are at an angle of preferably and typically about 55 degrees from a horizontal inclined inwardly as from a longer and wider base to a narrower top portion, and the shed has left and right sides of rectangular shape extending about 41/4 feet in length, a periphery along a lower edge of the shed being about 45 feet, and the shed has a height of preferably about 31/2 feet apart from the screen structure which may further increase the overall outer and inner height.