Shandy Heil, Attaway, Denise, Bankston, Jr., Joseph D., Baker, Eugene | 2/20/2009 9:53:26 PM
In a hurricane, a house becomes a pressure cooker if its outer envelope is pierced by high winds and wind-driven debris. When windows fail, high winds enter the house and can blow out an opposing wall or tear the roof off completely, leaving the home exposed to wind and water. Bob Vila, building expert.
Protecting the window openings of a house is probably one of the most important steps a person can take to protect their family and belongings. When a hurricane hits, high winds and pounding rains are the result. High winds can cause objects such as roof tiles, branches, garbage cans and so on to become projectiles. When this happens, the outer envelope – the separation between the interior and the exterior environments of a building is at risk.
As noted in the quote above, windows are key points of entry. If a projectile crashes through a window, damages can occur to the building structure and/or belongings stored inside. Because of their vulnerabilities, it is important to protect windows and window openings. Installing storm shutters or impact-resistant windows are two methods to use for protecting window openings.
Some of the most common shutter types are:
Two types of temporary shutters that can be used are manufactured panels and plywood panels. Manufactured panels are easy to install on lower levels of a house, have a low-to-medium cost, and must be installed and, then, taken down every time they are needed. Some materials these manufactured panels are made from, such as plastics, allow sunlight illumination.
Similar to manufactured panels, plywood panels are easy to install on lower levels of a house and must be installed and, then, taken down every time they are needed. These panels are inexpensive and block sunlight. Large panels can be heavy.
Storm shutters are required for all Louisiana homes in wind zones 120 mph and above and/or within 1 mile of the coast. Check with your local building code office for the storm shutter regulations in your area.
When installing any type of storm shutter:
The following are some tips to follow when installing temporary plywood shutters:
A range of types of fasteners can be used to attach a plywood shutter, including double-headed nails, wood screws, bolts, wood or masonry anchors, nuts and large washers.
If the shortest dimension of the window or door is 4 feet or less, space fasteners at 6 inches on center. If the shortest dimension exceeds 4 feet, space fasteners at 3 inches on center. Mount plywood and fasten into place. Mount the plywood with 2 fasteners first (one on each corner) then install the remainder of the fasteners -- this will reduce the strain on your helper and facilitate set-up.
Remember, even the best designed shutter will fail in strong winds if not installed properly. So, try to get as tight a fit as possible on the plywood. You don't want to allow wind to get under the shutter.
Another way to protect your home from damage in windstorms is by installing impact-resistant windows. Although these windows look no different than standard windows, they offer significantly more protection from wind-borne debris. In fact, these systems are capable of resisting impacts from large objects. For this reason, temporary shutters do not need to be installed before a storm strikes. In general, the frame and glazing work together to protect your home from both the elements and the significant internal pressure changes which lead to structural damage. While large wind-borne debris may crack the impact-resistant glass during the course of the storm, the window is designed to retain its integrity and not break apart. Should either the frame or glass be damaged, it can be repaired at your convenience after the storm has passed.
Impact-resistant windows are comprised of impact-resistant glass surrounded by a heavy duty frame securely fastened to the interior window header and frame. The construction and anchoring of these windows keep high winds and debris from damaging a home’s outer envelope.
Before you buy impact-resistant windows, be sure a Miami-Dade County impact test has been done on them. Miami-Dade County, Florida has the most stringent hurricane-related building codes and this test is considered to set the highest standards for impact-resistant windows. In Florida, residents building in hurricane zones must install impact-resistant windows or a permanent shutter system.
The impact tests do not guarantee the windows will survive a hurricane, but they do test specific conditions that they should survive. If the structural shell of a house or business can be maintained, the structure is more likely to be saved. Once wind enters a building, it becomes much more likely that the structure will be significantly damaged.
The Miami-Dade Building Code requires that every exterior opening - residential or commercial - be provided with protection against wind-borne debris caused by hurricanes. Such protection could either be shutters or impact-resistant windows. There are two types of impact-resistant products: large-missile resistant and small-missile resistant.
To find out if a window or other building product is certified for use in Miami-Dade County, go to the Miami-Dade County Building Code Compliance Office Web site.
Window Protection Misconceptions
People have been attempting to protect their windows against the elements for years. Some do it right, some don’t. Here are a few common misconceptions about hurricane protection products for window openings:
Understanding Impact-Resistant Windows
Miami-Dade County Building Code Compliance Office