Cross bracing

File:Detail of underside of canopy east side showing cross bracing, rafters, and decking - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, HABS TEX,50-KILL.V,1C-14.tif

Cross bracing between joists or rafters strengthens the members by preventing sideways deflection.

File:DETAIL VIEW OF TOWER SHOWING CROSS BRACING AND RIVETS - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA HAER CAL,38-SANFRA,141-14.tif

Cross bracing on a bridge tower

In construction, cross bracing, also known as herringbone strutting, blocking, bridging, and dwanging, are diagonal supports that intersect to reinforce structures.

Cross bracing is usually seen with two diagonal supports placed in an X-shaped manner. Under lateral force (such as wind or seismic activity) one brace will be under tension while the other is being compressed. In steel construction, steel cables may be used due to their great resistance to tension (although they cannot take any load in compression). The common uses for cross bracing include bridge (side) supports, along with structural foundations. This method of construction maximizes the weight of the load a structure is able to support. It is a usual application when constructing earthquake-safe buildings.

Cross bracing can be applied to any rectangular frame structure, such as chairs and bookshelves. Its rigidity for two-dimensional grid structures can be analyzed mathematically as an instance of the grid bracing problem.

Cross bracing may employ full diagonals, or corner bracing or knee bracing.

The idea of cross bracing is also applied to sport ram-air parachutes to improve their structural integrity.

Mining tunnels

To add rigidity to the construction of mining tunnels, the cross-beam connecting between arches is also a type of cross brace. They are often tubular and modified on the ends with clips or apertures for screw fastening. They serve as a stiffening element for the stability of a design. This brace could also be an ordinary cross-section wooden cross-beam, or even a board.

Cross bracing can be seen in situations like flooring, where cross braces are put between floor joists in order to prevent movement. It is also commonly used for ship making in order to stand against heavy winds or extreme weather.