Stock photography, photos: Expanse of glass rooflights Stock photos of Wide area of industrial glass roof with many ridges, valleys and spans Photograph: © Alan Oliver Click for a larger image and more information Keywords associated with this stock photo: roof, glass, rooflight, skylight, glazing, large, area, concept, cleaning, industry, factory, glasgow, central, station, scotland, warehouse, ridges, peaks, valleys, ladders, sun, glint,