This page will hopefully help guide you through a few different areas to help retro fit your existing home to be more hurricane resistant.
A major area that causes structural failure during a hurricane is the gable end truss. A gable end is the flat area of the house usually located on each side of the house and appears to form a triangle shape.
1. Gable End Bracing.
There are two methods that can be used to brace the gable end truss. Method #1 as shown in the illustration below is as follows:
Start by nailing a 2×4 8 foot long to the gable end up near the ridge of the roof. This brace will run perpendicular to the gable end and be nailed off to each of the next 3 to 4 trusses.
Now cut some 2 x4 blocking that will fit between each truss and nail them in place at the bottom cord near the ceiling line.
Last step is to nail another 2 x 4 8 foot long along the bottom of the trusses just above the blocking previously installed.
An alternative to the first method is to nail a 2 x 4 8 foot long on a diagonal, again as illustrated below.
This method is a much simpler installation, but probably not quite as effective as the first method. Which ever method you choose, you should start in the center of the gable end (highest point) and repeat this on either side of the center six (6) feet on center.
When employing the second method, the bracing should be reversed on the next brace that is installed after the center brace. That is, the second brace should be nailed at the bottom of the gable end and run upward. This way you have a good cross bracing on the gable end.
2. Window Protection
The Florida Building has addressed open protection requirements on all new homes as well as those that are substantially remodeled. Penning protection refers to a glazed opening such as windows, sliding glass doors or any other doors with glass in it. You can use the same techniques to protect the windows in your home, that are required in new homes.
One option is to simply replace all of your current windows with the new impact resistant windows. These windows are designed to withstand flying debris. This does not mean that they will not break, only that they will maintain the integrity of the structural envelope and not allow the wind and rain into the home. Once an opening is breached and the wind enters your home pressure will build until another structural component fails. These windows are designed as a complete system, that means that not only the glass is designed to particular standards, but also the frames and the method of attaching the windows to the opening.
Another method is the installation of an approved storm shutter, these come in different types. There are the roll down type shutters, however these are a permanent installation and should be done by a professional installer. A second form of shutter is the accordion style. These are used mainly for large openings such as large glass sliding doors. The final type is the individual panel/slats, be advised that with this type of shutter you will need a place to store them, and they are not permanently installed, as where the first two mentioned are. Should you select the storms shutter method to protect your window and door openings, verify that you are receiving a state approved system. These shutters should carry one of the following labels; ASTM E 1886 and ASTM E 1996 or Miami-Dade TAS 201, 202 and 203.
The final option (and cheapest) is the use of plywood to protect your windows. The Florida Building Code does not allow for anything less then 7/16 inch thick plywood, also it must be plywood, and not particle board. Even though the code allows for the use of 7/16 inch plywood the thicker the plywood the stronger it will be, but remember the thicker the heavier it will be also. It can be exterior grade, which is normally sold at a lower price. If you decide to use plywood, it needs to be attached to the structure, and not cut to fit within the opening, (see figure below).
There are many different types of anchoring devices that you can use. The Florida Building Code requires that the hardware be corrosion resistant and permanently attached to the building. It is suggested that you look into the different options available and pick the one that will work best for your application.
The next item that we need to look at is your garage door. The failure of the garage door can be catastrophic to the structure, much like the failure of a window. The new hurricane rated garage doors are reinforced with heavy metal bracing running horizontally, as well as heavy rollers and roller tracks and mounting hardware. There isn’t much you can do to your existing door if it is not one of the newer type doors.