quality control procedures to ensure that welds are done properly and do not deteriorate over
Given the difficulty in providing lateral load resistance for the large open spans associated with
hangar bay structures, it often appears desirable to incorporate the roof deck into the lateral load
system as a flexible diaphragm. However, these same large spans involved in hangar structures
often require large deflections in the frame before the deck produces the desired resisting forces.
Designers should therefore avoid relying on a steel deck as a diaphragm in the hangar bay and
provide a dedicated secondary horizontal lateral load system unless careful analysis is conducted
on the deck's stiffness and load response. The deck may, however, be assumed to provide local
support to elements, such as top chord/flange support to joists/beams.
The designer should consider whether it is permissible to support suspended loads directly from
the underside of the steel deck. The contract drawings should clearly indicate when this is
allowed and the means by which the connection is to be accomplished.
Walls and partitions of the hangar bay should be non-load bearing. The walls of the O1/O2
portion of the facility may be designed as load bearing if structurally isolated from the hangar
structure. This is particularly useful as that load bearing wall structures are typically more rigid
than the steel frame of the hangar bay. The O1/O2 structure may or may not be built as an
integral part of the hangar structure. In either case, the weight of the O1 and O2 structure may
be used to help provide stability in those cases where additional dead load is desirable.
Side walls of the OH space should be insulated hollow concrete masonry units (CMU) sized in
accordance with American Society for Testing and Materials (ASTM) C 90, Loadbearing
Concrete Masonry Units or reinforced concrete (RC) walls to a height of 3.05 meters (10 feet)
above the hangar deck. Above this height, use preformed (corrugated), protected-metal panels or
similar materials. Alternatively, an interior wainscot wall of CMU or RC may protect an exterior
wall of architectural facia which extends to the ground elevation.
The exterior walls of the O1 area, typically composed of shop spaces and other light industrial
function, should be constructed of materials similar to that of the lower OH area. The material
selection for walls of the O2 area, typically office space not expected to be exposed to the
durability challenges of the O2, may be expanded to include light gage framing or similar
Other miscellaneous or structurally independent buildings which may be part of the project, such
as mechanical equipment enclosures and storage rooms, should be constructed with requirements
similar to the O2 area.