Square brick panelling is stepped out above the sixth floor, providing a bearing surface for the heavy roof timbers and protection from fire. On the interior, heavy timber floor beams are spaced about four feet apart and held up by girders, forming fireproof layers between floors. References Industrial buildings and structures in Detroit Downtown Detroit Tobacco buildings in the United States Industrial buildings completed in 1888 Industrial buildings and structures on the National Register of Historic Places in Michigan National Register of Historic Places in Detroit Rock Ventures Romanesque Revival architecture in Michigan