Hurricane Impact Windows
Many methods of protecting a home against hurricanes exist. None are fool-proof, but they include plywood, window film, shutters, and hurricane windows. The current gold-standard in testing is the Miami-Dade County hurricane impact test. Be clear that products that meet or exceed this test are appropriate for all areas that may be impacted by hurricanes, tornados or other high wind situations. Remember, it is your life and your property. Essentially all of Florida, and all the coastal regions of the United States should prepare for possible wind speeds of 110 mph or greater.
The impact tests do not guarantee the windows will survive a hurricane, but they do test specific conditions that they should survive. Impact survivability certainly helps home survivability. If you can maintain the structural shell of your house or business, you are significantly more likely to save the structure. Once wind enters a building, it becomes much more likely that the structure will be significantly damaged. Therefore it becomes imperative to protect all the openings in your building.
THE IMPACT TEST
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 products. There are two types of impact-resistant products: large-missile resistant and
small- missile resistant.
Large-missile resistantA product is tested as large-missile resistant after it has been exposed to various impacts with a piece of
lumber weighing approximately 9 pounds, measuring 2" x 4" x 6’ (no more than 8') in size, traveling at a speed of 50 feet per
second (34 mph). Then the product must pass positive and negative wind loads for 9,000 cycles, with impact
creating no hole larger than 1/16 x 5" in the interlayer of the glass. If you live in a building where doors and windows are located 30 feet or less above grade (e.g. above ground level) then the products must pass the large-missile test. If the doors and windows are more than 30 feet from the ground then they must be either large or small missile compliant.
Small-missile resistantA product is declared small-missile resistant after it has been exposed to various impacts with 10 ball bearings
traveling at a speed of 80 feet per second (50 mph). The product is then subjected to wind loads for 9,000 cycles.
From the Miami Dade office of Code Compliance. Search for products in the Miami-Dade system.
Hurricane impact resistant windows provide continuous protection from wind borne debris. The advantages are numerous: no shutters to put up, no plywood to cut and put up - in other words, continuous protection. Likewise, the windows are structurally part of the host so it is much more difficult for wind to get behind the windows and pull them off which can occur for shutters and plywood. While clear shutters do exist, they are less common so impact resistant hurricane windows provide the added advantage of letting light in.
In our experience, hurricane windows are somewhat more expensive than good according shutters. This is primarily due to the labor costs of removing and re-installing windows in your home.
Hurricane shutters (plywood, aluminum, or clear) provide significant protection from wind borne debris and must meet impact codes. The main problem with shutters is installation. Panel shutters are difficult to install. Accordion shutters are much easer to install, but even then they may require one to get up on a ladder. Companies used to make manually crankable accordion shutters (e.g. vertical accordion shutters that had a crank fixture inside to roll them down and up), but we have not been able to find a manufacturer for those in recent memory. Of the accordion hurricane shutters, the crank kind were the quickest and easiest to install while panels are the second most difficult after plywood. Plywood and panels have the very significant advantage of being much less expensive that hurricane impact windows and according shutters.
Window films make several claims, primarily impact resistance, solar and UV protection. While certainly better than no protection, films often provide the least protection of the options currently available. One advantage film offers is that glass is held together after an impact. Films main problem is that often window are not fastened properly in the house frame or the glass is not fastened securely into the frame of the window so that no matter how effective the film is, the glass comes out of the window frame or window itself comes out of the wall. Your hurricane impact protection is only as strong as the weakest link. Film has the advantage in price - it is generally the least expensive of the options. If you are sure that your windows and window glass are securely fastened and/or this is the only option you can afford, some protection is better than no protection.
Garage Door Impacts