concrete-construction-resources

Wind Loads and Metal Building

Metal buildings are used all across the country for commercial and residential applictions. So considering the vast array of climates you encounter from county to county, let alone from state to state, it is so important to have your metal building designed with the proper wind loading for your area. The most important specification in determining wind loads for metal buildings is the wind speed. Most building departments across the country measure the wind speed at its highest level during a 3-second gust. This will give the maximum speed predicted for the design life of a prefacricated steel building. There are several factors that can influence the magnitude of the wind speed.

The first factor that influences wind speed would be the geographical location where you plan on erecting your steel barn. As an example, if you live in Florida, your steel building will have to be designed to withstand the forces of hurricane-strength winds. Also, the same goes if you live in any one of the states located in what they call “tornado alley”. Tornadoes are small and brief compared to hurricanes, but the wind speeds can be higher. And some hurricanes have been known to last an entire day, so even if the wind speed of a hurricane is lower than a short spurted tornado wind speed, they can do just as much damage by slowly wearing down a prefab steel building from the continuous stress and vibrations.

Since some parts of Florida are always being hit by hurricanes, the state always looks over and updates their building codes after major storms.
The physical location of residential or commercial steel buildings is the second factor that can influence the wind speed. Because winds can gust to higher speeds in exposed locations, for any given wind speed, the exposure in which a prefabricated steel building or any other structure is sited will be determined as falling into one of the following categories, exposure B (urban and suburban areas), exposure C (open terrain with few obstructions including shorelines in hurricane-prone regions), or exposure D (flat, unobstructed areas exposed to wind flowing over open water) and then engineering will design the steel building appropriately.

The third factor that influences wind speed would be the dimensions of the prefab steel buildings. The height of the structure is the most important because wind speeds have a tendency to increase as heights of steel frame buildings increase above ground level.

The last factor to affect the wind speed is the actual shape of the prefabricated building. The wind load isn’t just a one-sided frontal pressure that’s applied to the sheeting of a steel garage. The wind load is a product of a complicated distribution of pressure on every side because of the flow of air around the entire prefabricated steel building.