Protecting Your Home from the Winds of a Hurricane
Protecting Windows and Doors
You can shutter now. Or you can shudder later.
Chances are that's what will happen when a hurricane heads towards your area
and you realize you haven't made any plans to secure your home. Take the
necessary steps ahead of the hurricane's arrival to protect your home and its
contents.
Plywood Storm Shutters
Installing plywood shutters over all exposed windows and other glass surfaces
is the least expensive and more effective ways to protect your home. Plywood
shutters that you make yourself, if installed properly, can offer a high level
of protection from flying debris during a hurricane. Plywood shutters can be
installed on all types of homes. You should cover all windows, french doors,
sliding glass doors and skylights. Before installing plywood shutters, check
with your local building official to find out if a building permit is required.
It is important that you have your shutters ready before hurricane season and
that you mark and store them so they can be easily installed during a
hurricane.
Measure each window and each door that has glass, and add 8 inches to both the
height and width to provide a 4 inch overlap on each side of the opening.
Sheets of plywood are generally 4X8 feet and you should use a minimum thickness
of 5/8 inch, exterior grade. Thicker plywood will offer slightly better
protection. Tell your local building supply retailer the size and number of
openings you need to cover to determine how many sheets will be needed.
To install plywood shutters you will need bolts, wood or masonry anchors, large
washers, a drill with the proper size and type of bit, a circular saw, hammer,
and wrenches to fit the bolts. Be sure to wear eye protection and work gloves.
For windows 3 feet by 4 feet or smaller installed on a wood frame house, use
1/4 inch lag bolts and plastic coated anchors. The lag bolts should penetrate
the wall and frame surrounding the window at least 1 3/4 inches to anchor into
the 2X4 wall stud. For larger window, use 3/8 inch lag bolts that penetrate the
wall and frame surrounding the window at least 2 inches.
For windows 3 feet by 4 feet or smaller installed on a masonry house, use 1/4
inch expansion bolts and galvanized permanent expansion anchors. The expansion
bolt should penetrate the wall at least 1 inches. For larger windows, use 3/8
inch expansion bolts that penetrate the wall at least 1 inches.
Cut the plywood to the measurements for each opening. Drill holes 2 inches from
the outside edge of the plywood at each corner and at 12 inch intervals. Drill
four holes in the center area of the plywood to relieve pressure during a
hurricane. Place the plywood over the opening and mark each hole position on
the outside wall. Drill holes with the appropriate size and type of bit for the
anchors. Install the anchors, the plywood, and the bolts to ensure a proper
fit. On wood-frame houses, make sure that the anchors are secured into the
solid wood that frames the door or window and not just into the siding or trim.
Mark each shutter so you will know where it is to be installed and store them
and the bolts together in an accessible place.
If the opening is larger than one sheet of plywood, you will need to make
shutters with 2X4 bracing. This bracing can be two 2X4's at the middle and
bottom of the two sheet of plywood, evenly spaced, with the 2 inch side
attached to the inside of the storm shutter. Attach the 2X4's to the outside of
the storm shutter with 2 inch, 10 gauge wood screws before installing the
shutter.
Commercial Hurricane Shutters
Another way to protect the openings in your home is to install commercial
hurricane shutters. Hurricane shutters are available in various types and price
ranges. You should thoroughly review each type of hurricane shutter before
purchasing to determine which type best suits your need and price range.
Another consideration should be impact testing and product certification from
an approved testing laboratory. Southern Building Code Congress International
(SBCCI) certification and the Dade County Building Code product certification
are the only impact certifications that are currently accepted by the South
Florida Building Code, one of the strongest building codes for wind in the
nation.
What is impact testing?
To simulate the effects of a hurricane, several tests are now performed to
determine a products effectiveness again those wind forces. These test are
"Impact" test and "Design Pressure" test, both performed by a Certified
Independent Engineering Laboratory.
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The "large missile" test is performed by shooting a six foot long, nine pound 2
X 4 from an air cannon at 34 mph. This simulates 150 mph wind carrying large
debris. This is used for openings below three stories and elevations of 30 feet
or less.
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The "small missile" test is performed using small steel balls, or gravel to
simulate the effects of air borne gravel and rocks. This is used for buildings
over 3 stories or greater that 30 feet in height.
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Positive and negative pressure tests are performed to test the ability of the
shutter system to withstand "static" (constant), "cyclic" (gusts), "negative
static" (constant vacuum), and "negative cyclic" (vacuum gusts), wind
pressures. Static testing is performed to determine the strength of the system
when sub jected to constant wind forces, both negative and positive. Cyclic
testing is performed using wind bursts, 1 - 3 seconds in duration, which are
gradually increased until the shutter fails. Ratings are then given to specify
the test load. For example, a 41.2 per square foot (PSF) rating is equivalent
to approximately 120 mph winds.
Types of Hurricane Shutters
Hurricane Panels
Hurricane panels can be used anywhere on the ground level or
that you can safely reach with a ladder. They are installed when needed and
stored when not needed. They can be installed using the direct mount method,
using wing nuts to attach to permanent fasteners in the wall, or installed in a
track system that can be permanently mounted or removable.
Hurricane panels are primarily used to reduce the overall cost of protecting
your home, without compromising strength. Entry doors, sliding glass doors, or
ground level windows are the best place to use hurricane panels. Installing
hurricane panels above the first floor can be difficult and dangerous, although
it can be done with the proper ladders and at least two people.
Accordion Shutters
Accordion shutters, one of the strongest shutter systems
manufactured, are becoming a very popular system in this area because of the
performance and price. This system is permanently installed, slides easily and
quickly from side to side, and stack out of view from inside the home when
open. The operation is manual and the shutters can be closed from inside or
outside most homes. Accordion shutters are very effective, especially when
covering large areas of glass such as sliding glass door, window walls, patios,
and openings above the first floor.
Accordion shutter systems also provide security for extended absences from your
home since they can be easily closed and locked.
Bahama Awning Hurricane Shutters
Bahama awning shutters offer wind protection as well as energy
savings. They shade the window from heat gain due to direct sunlight and are
very popular in South Florida. For hurricane protection, this system
incorporates either a lexan sheet or solid sheet of aluminum to reinforce them
for impact resistance. These shutters can be operated from inside only on
single or double-hung windows.
Colonial Hinged Hurricane Shutters
Colonial hinged hurricane shutters look like a standard
decorative shutter but have a much stronger attachment system. They too,
incorporate either a lexan sheet or solid aluminum sheet to reinforce them for
hurricane protection. These are fully functional and can also be used to
provide energy savings when closed.
Roll Down Hurricane Shutters
Roll down shutters are probably the most recognized in the
industry and offer combined good wind protection with ease of operation. These
shutters are operated from inside the home, either manually or by electric
motors which also allows them to be used for security and energy efficiency.
There are many options available with this type of system but the obvious
advantage is for use above the ground floor level.
Typically, roll down shutters are the most expensive of all the shutters
systems but are also the easiest and quickest to operate.
Other Hurricane Protection Systems
Impact Resistant Glass Systems
Impact resistant glass has been used for many years in commercial applications
such as bullet proofing, security and protection from high winds on
skyscrapers. Residential applications are now becoming popular and window
systems are now available that meet the Dade County and SBCCI impact
certifications. One great advantage of impact resistant glass systems in that
the protection is always there, 24 hours a day, 365 days a year, without having
to install or close a shutter. These systems are typically expensive but should
be considered if building a new home or replacing existing windows.
Consideration should be given to the possibility of having to replace the
window (or windows) if it is impacted hard enough to break the glass.
Impact Glass Film Systems
Window film systems have become very popular in recent years, especially for
security. There are many manufacturers of window film as well as many different
types of protection that is offered. If you are considering window film for
hurricane protection, you should ask the vendor for all impact testing
certifications and information. Because you will be installing a window film on
an existing window, a film system that "anchors" to the window frame will
usually provide you with the best protection. Once again, consideration should
be given to the possibility of having to replace the window and film if it is
impacted hard enough to break the glass.