When the twenty-two year old built-up roofing system began to fail in 1991, the Navy decided to re-roof Building 680. Totaling 2,260 squares, Building 680 has one big roof! Constructed in 1993 to house an assembly line for submarines, the design was typical of industrial structures of this period; effective day lighting of the interior workspace was essential. In order to achieve that goal, the main horizontal plane of the roof was broken into 46 separate sub-roofs at five primary levels. Each vertical drop between levels provided an opportunity to install clerestory windows. The roof/clerestory arrangement used for this building is referred to an “aiken” roof.
Specific challenges Interactive Resources, Inc.’ design addressed included:
- Building Expansion Joints: a manufactured building expansion joint cover system (Expand-O-Flash) was selected to replace fabricated sheet metal components and to provide continuity between horizontal and vertical lengths of the expansion joint.
- Perimeter Flashing: the existing roofing system terminated at walls with membrane flashing only. These had failed, and water penetrated the building. Low parapet walls did not have copings. Our solution included installing surface-mounted reglets with sheet metal counterflashing at walls, and sheet metal copings at all parapet walls.
- Built-In Gutters: the original design included built-in gutters at the uppermost roof that ran the length of the building and were in questionable condition. These gutters were eliminated and replaced with conventional roof drains and overflow drains. Crickets were installed at either side to direct the water to the drain.
This project was awarded Second Place for a Large Roofing Project in the 1994 Document Competition sponsored by RCI (Roof Consultants Institute).