Diagonal bracing is a lateral force-resisting technique using diagonal members, traditionally let-in wood boards or metal straps, installed at an angle within a wall’s framing to resist the racking, or sideways distortion, that wind or seismic forces can cause.
This traditional method predates the widespread use of structural sheathing panels, relying on the triangulated geometry of a diagonal member to resist lateral movement rather than a continuous panel surface.
While largely superseded by structural sheathing in most modern residential construction, diagonal bracing remains relevant for certain applications and is still found extensively in older existing buildings.
What Does Diagonal Bracing Involve?
- Diagonal wood boards let into the studs
- Metal straps installed at an angle across the framing
- Triangulated geometry providing lateral resistance
- Placement at strategic points within a wall or structure
Why Is Diagonal Bracing Important?
The triangular geometry created by a diagonal brace resists lateral movement effectively, since triangles maintain their shape under load in a way that a simple rectangular frame of studs and plates alone cannot. This principle remains fundamental to structural engineering even as the specific materials and methods used to achieve it have evolved considerably over time.
Homeowners renovating an older home should be aware that removing or cutting into existing diagonal bracing during a remodel, without providing equivalent lateral resistance elsewhere, can compromise the structure’s ability to resist wind and seismic forces even if it doesn’t affect the wall’s ability to carry vertical loads. Consulting a structural professional before altering existing bracing helps preserve a building’s lateral resistance. This caution helps preserve the building’s ability to withstand future events safely.
Diagonal Bracing vs. Shear Wall
Diagonal bracing uses angled members to create lateral resistance through triangulated geometry. A shear wall achieves similar lateral resistance using a continuous structural sheathing panel instead, the more common approach in modern construction.