Windows and doors: Design your home with windows and doors no taller than the standard 6-ft. 8-in. height. Larger openings may require additional strengthening measures. Be sure you select windows that meet the code specified “design pressure rating” (DP) for your wind zone (typically DP 30-50). Note that the DP rating varies with size, so a larger window will have a lower DP rating than smaller versions of the same window product.
In the 120-mph or greater wind zone, all glass must be protected from flying debris, yet it can be worthwhile in lesser wind zones as well. The primary purpose to prevent large openings that could allow wind pressures to build up inside and cause structural damage. Glass may be protected with “ready-to-install” removable plywood panels (according to code requirements) or commercial rated storm shutters, panels, fabrics or screens that meet impact-resistance standards.
Impact-resistant window and door units are also available; they offer continual protection from flying debris without pre-storm installation and additional safety and security benefits. The frame is extra strong, and the glass is made with special membrane that prevents an impact from creating a large hole even if the glass breaks. Look for a sticker or label in the corner of the glass or frame itself, indicating it meets one or more of the following standards: ASTM E 1996 (9lb), SSTD 12, Dade County PA201, or FBC TAS201. (Figure 1a, Firgure 1b, Impact Rated Storm Shutters)
In tornado areas, where there is not warning time to secure protective shutters, window protection systems should be passive (always in place without human intervention). In other words, impact-resistant windows and doors are recommended instead of storm shutters.
Garage doors, especially double-wide doors, are especially susceptible to wind damage. The loss of a garage door makes a very large hole that can allow wind pressure to build up enough inside a home to cause major structural damage. Install a pressure and impact rated door that meets the design pressure rating needed for your wind zone. Commercial wind retrofit kits are available to reinforce existing garage doors, but they don’t provide protection from flying debris.