Buildings everywhere face the risk of damage due to high winds, with each structure reacting differently according to its stiffness, strength and shape. Because of that, all buildings must be designed to safely respond to lateral wind loads. Wood’s elasticity and strength give buildings an advantage during high-wind events.
There are many ways wood can be used to help buildings resist high winds, which can occur along the length and width of the building, as well as through vertical uplift.
Photo: FEMA 488, Mitigation Assessment Team Report, Hurricane Charley in Florida. After Hurricane Charley, FEMA noted new wood-frame buildings built to the 2001 Florida Building Code standards generally performed well structurally.
In high-wind events, loads are typically applied in a series of short spurts. Wood is effective at resisting these loads because its elastic limit and ultimate strength are higher when tested for short periods of time.
Wood sheathing in the form of wood structural panels, fiberboard, particleboard and board sheathing can be used as diaphragms and shear walls that transfer loads delivered by wind events to the building’s foundation. Rigid, wood-frame construction, meanwhile, transfers lateral loads in the event of high winds. As with seismic performance, wood-frame construction’s numerous nailed connections give the load more paths to follow, reducing the chance of a structural collapse should some connections fail.
In a study by APA – The Engineered Wood Association, 8-foot-by-8-foot walls sheathed completely with plywood or oriented strand board exhibited three times the strength of walls sheathed with gypsum or constructed with let-in bracing.
—APA – The Engineered Wood Association APA – The Engineered Wood Association
Wind load requirements are covered under the national code standards but may vary by jurisdiction depending on wind zones.
- The International Building Code (IBC) General Design Requirements for Lateral-Force Resisting Systems (Section 2305) advise on code requirements for wind and lateral load resistance in buildings using wood shear walls and diaphragms.
- IBC Section 2308 offers guidance on wind and seismic loading for conventional light-frame construction.
- IBC Section 1609 must be considered for shear wall and diaphragm design when wind speeds exceed those allowed in IBC Section 2308. Section 1609 references wind loads established in American Society of Civil Engineers/Structural Engineering Institute Minimum Design Loads for Buildings and Other Structures (ASCE-7).
- ANSI/AF&PA Special Design Provisions for Wind and Seismic Standard with Commentary (Wind and Seismic) is a referenced standard covering material selection, design and construction of wood-frame assemblies. It largely follows the IBC, ASCE-7 and National Earthquakes Hazard Reduction Program.
To learn more about using wood for resilience during high-wind events, see the resources below.