Updated: June 2015
Even though hurricanes and tornados are different beasts — separate classification schemes, different movement patterns, and often striking different parts of the country — they share one very important trait: extremely high wind speeds capable of tremendously destructive power.
For example, in 1969 Hurricane Camille exhibited winds in excess of 155 mph. The categorization system for tornados tops out at Category 5, which indicates a sustained wind speed of more than 155 mph.
If you live in an area susceptible to hurricanes or tornados, your damage prevention efforts are likely to be centered on shoring up your roof, window, and door protection.
Hurricane straps have a single purpose — protect your home during high wind events by securing all your home's connections: roof to wall, floor to floor, and wall to foundation. Typically made of galvanized metal, hurricane straps anchor roof-to-wall connections at every wall-to-rafter touchpoint. The idea may seem simple — "tie" the roof truss or rafters to the top of your walls — but hurricane straps can greatly improve your home's resistance to wind.
On multi-level homes, connecting upper floors to lower floors using straps continues the process of moving the load path down to the home's foundation. On multi-level homes, make sure wall-to-foundation connections use using anchor bolts.
Installing hurricane straps probably isn't a DIY project, so talk to a contractor, and remember that you may be able to install hurricane straps even if your home isn't due for a new roof.
Sheathing is the wood, plywood, or wafer board that's underneath your home's shingles and other roofing materials. Since sheathing isn't visible from your home's exterior, check it from the attic. Sheathing is typically attached to your rafters using nails, so look for and repair nails that have missed their mark. Also check for sheathing that's delaminating (plywood) or swollen (wafer board).
Gables are your roof's side walls. If not properly braced, gables may collapse more easily in a tornado or hurricane. The most common method of bracing entails placing 2x4" wood pieces in an X pattern from the top center of the end gable to the bottom of the brace of the fourth truss and from the bottom center of the end gable to the peak of the roof.
Consider purchasing impact-rated windows or installing wind shutters for windows or other glass surfaces, including sliding glass patio doors, skylights and French doors that are exposed to the elements.
Wind shutters (or hurricane shutters) are protective coverings designed to completely cover and protect window and door glass openings during high winds. While some homeowners build their own wind shutters (typically using 5/8"-thick exterior grade plywood), information about custom-built options is widely available online.
For any double door entrances, secure at least one door between the floor and frame with strong sliding bolts designed by the manufacturer or recommended by your hardware store. It is also possible to purchase and install impact-rated doors.
Try to install any door so that it opens out and away from the interior of the home, instead of the more typical "door opens into the room" installation. Doors opening outward provide added strength to the structure.
The Insurance Institute for Business & Home Safety website dedicates an entire section to reducing risks from a hurricane.
The Federal Emergency Management Agency (FEMA) encourages residents who live in tornado- or hurricane-prone areas to consider adding a safe room to their home.
For residential usage, a safe room often doubles as master bedroom, bathroom, or utility closet, with construction costs starting at approximately $6,500 to $8,500. If you're thinking about a safe room — especially a pre-fabricated model — be sure it meets FEMA safe room design and protection criteria.
When designed to FEMA specifications, a safe room offers "near absolute protection" — a very high probability that occupants will avoid injury or death during a tornado — to up to 16 people.
Visit FEMA's website for complete information about building a safe room for your home or small business.