Hurricanes are one of the most devastating storms that occur in nature. When they occur, they cause tornadoes, rip currents, and storm surge floods that can cause inland flooding. Hurricanes can also lead to the collapse of buildings most often by cutting through roof overhangs.
Roofs of buildings are usually provided with overhangs. The longer the overhangs, the more vulnerable are the roofs and the buildings to wind damage due to increased uplift loads. However, these overhangs are very important because they protect the building from moisture and also protect the wood used in the buildings from decay. In humid climatic zones associated with hurricanes or strong winds, this is an onerous situation that requires the designer to establish a trade-off between wind load and durability. To reduce roof vulnerability to strong winds, the following options should be considered for the building:
- Low-Storey Buildings: building vulnerability to wind increases with the number of storeys. Thus, One-story buildings are much less vulnerable to wind damage than two- or three-story buildings. Where multi-storey buildings are not expedient, don’t go for it.
- Roof Pattern: On average, hip roofs have demonstrated better performance against winds than gable-end roofs.
- Roof Slopes: Moderate roof slopes [i.e., 1:3 (33.3333%) to 1:2 (50%)] tend to optimize the trade-off between lateral loads and roof uplift loads (i.e., more aerodynamically efficient).
- Roof Sheathing Installation: Roof sheathing installation should be inspected for the proper type and spacing of fasteners, particularly at connections to gable-end framing.
- Installation of Metal Strapping: The installation of metal strapping or other tie-down hardware should be inspected as required to ensure the transfer of uplift loads.
- Adequate Fastening of Roof Shingle: If composition roof shingles are used, high-wind fastening requirements should be followed (i.e., 6 nails per shingle in lieu of the standard 4 nails). A similar concern exists for tile roofing, metal roofing, and other roofing materials.
- Glazed Opening Protection: Consider some practical means of glazed opening protection in the most severe hurricane-prone areas.
