The roof of the Smithsonian’s Arts and Industries Building covers more than 8,361.27 square meters (90,000 square feet). It includes 33 individual roofs over the building’s main spaces: the Rotunda, halls, courts, ranges, towers, vestibules between the towers, and pavilions. In addition, there are four transitional roofs between the Rotunda and the halls and courts; they were built to aid drainage at the intersection between the masonry drum of the Rotunda, the roof of the halls, and the roof of the courts. Light and airy exposed wrought iron trusses support the individual roofs of each of the 17 exhibit spaces; a small cupola with 16 small, circular clerestory windows rises at the center of the Rotunda roof.
Much of the original roof – specifically, the Rotunda, halls, courts, pavilions, towers, and vestibules between the towers – was covered in blue-black slate, with red and green slate accents. Many of these roof elements leaked and were replaced with metal roofs over the course of the last century. The towers and pavilions have retained their historic slate roofs with replacement slate. Today, the majority of the roofs have been replaced in stainless steel following the historic configuration. Decorative metal cornices run along all the roof edges; these cornices, as well as all metal decorations at the roof, are part of the original design. The original sculpture over the North entrance was restored as part of the revitalization. The statue is Columbia Protecting Science and Industry by the sculptor Caspar Buberl.
An Enduring Landmark
Despite repair and modification, the AIB roof has retained the same basic appearance since it was completed in May 1880 as part of the then-National Museum’s original construction. As such, the building is one of downtown Washington, D.C.’s most timeless and recognizable landmarks.