The Wind Resistance Capabilities of Concrete Roof Tile Robin Anderson, Technical and Strategy Development Manager, Westlake Royal Roofing Solutions
Many regions of the United States, including Florida and the Southeast, are subject to high-wind conditions that can damage homes and buildings. The roof is highly susceptible to the wind damage due to its location on top of a home or building. Therefore, it is imperative when choosing roofing materials to select ones that can withstand severe wind events. Concrete roof tile is an option that provides substantial defense against the powerful forces of wind and helps prevent weather-related property damage. Wind can be complex. It is affected by temperature and pressure differences in the Earth’s atmosphere, as well as by variations in terrain and topography. However, when wind meets a home or building structure, it will typically perform in predictable ways. For example, wind meeting the side of the structure will travel up and over the roof edge causing varying degrees of uplift pressure.
Wind Uplift
As an integral part of the U.S. building codes, ASCE 7-16, or Minimum Design Loads and Associated Criteria for Buildings and Other Structures, outlines key wind uplift pressure considerations including: ■ The uplift pressures that affect a roof are highest at the corners of the roof (i.e., eave/rake corner, peak of the ridge at the rake edge) 24
FLORIDA ROOFING | April 2022
■ The edges: rake and eave, are a close second in uplift pressures ■ As wind moves across a roof’s surface, negative pressure (suction) is created.
Factors Affecting Wind’s Impacts to a Roof
There are many factors that influence how wind may affect a roof, such as its speed and direction when it encounters the structure. Factors include: ■ The design of the roof. Steep slope gable roofs are more susceptible to wind uplift than low slope hipped roofs ■ Fastening methods. The number, style and frequency of fasteners such as nails, screws or foam adhesives can significantly change the overall wind resistance of the tile’s installation. ■ Local weather. The High Velocity Hurricane Zone region receives higher frequency of high winds.