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POST-HURRICANE OPPORTUNITIES 24
www.homeenergy.org
MARCH/APRIL 2005
HOME ENERGY
W
hen Florida was
slammed by a record
four hurricanes in
the late summer of 2004, many
homes were seriously damaged.
Following the storms, the
demand for repairsincluding
reroofingfar exceeded the
supply of contractors who
could provide such services.
Meanwhile, many Floridians
experienced power outages that
left them without air condi-
tioning, and suffered accord-
ingly. Further, many homes
sustained floor water damage
particularly in carpeted or
wood floor areas.
Although coping with the
aftermath of hurricanes is dif-
cult, Florida Solar Energy Cen-
ter (FSEC) looked to provide
help by offering practical advice and
applying research ndings to those who
were tackling repairs after a hurricane.
Most homes can be made more energy
efcient and comfortable, which is par-
ticularly advantageous in the event of
power outages, and more resilient when
facing future storms.
Cool Roofs
One major repair that must often be
made after a hurricane is reroong. By
choosing the right roong materials,
you can make your entire home cooler,
which will result in reduced energy use
when your air conditioner is on, and
more comfortable living conditions
when power is not available.
Over the last decade, FSEC research
has clearly shown that a white reective
tile or a white metal roof can reduce
space-cooling loads by 20% or more.
More recent testing has shown that
unnished Galvalume roofswhich
look like brushed aluminumcan pro-
vide about half the cooling benet of
white roofs (see Improving Attic Ther-
mal Performance, HE Nov/Dec 04,
p.12). Light-colored tile roofs can pro-
vide similar improvements in perfor-
mance. FSEC tests show that attics
covered by dark shingle roofs can reach
temperatures as high as 140�F on sum-
mer days. Meanwhile, a white metal or
white tile roof never gets much hotter
than the outside temperature. Light-col-
ored tile or metal roofs register some-
where between dark shingle roofs and
white tile or metal roofs.
Though metal roofs can cost twice as
much as shingle roofs, and tile roofs cost
3 times as much, they last at least 2 to 3
times as long and keep the home much
cooler. That means average savings of
about $120 per year in reduced air con-
ditioning as well as a much cooler home
when the power goes out and takes the
air conditioning with it.
If you must choose shingles for struc-
tural reasons (many roofs cannot support
POST-HURRICANE
OPPORTUNITIES
Although coping with hurricanes is difficult, it does offer
the opportunity to make homes more energy efficient
and comfortable.
BY DANNY PARKER
D
ANNY P
ARKER Rehab
HOME ENERGY
MARCH/APRIL 2005
www.homeenergy.org
25
the weight of tiles without physical
strengthening), it is best to select the light-
est-colored shingles available.You should
also consider installing a foil radiant bar-
rier on the underside of the roof decking.
Testing performed for the Florida Power
and Light Company showed that simply
choosing white shingles would reduce
space cooling by 4% , and choosing light-
colored shingles with a radiant barrier
should cut cooling costs by twice that or
more. All these options will provide
slightly better comfort on the interior
when air conditioning is not available.
A standard, 2,500 ft
2
roof will cost
$5,000$6,000 to replace with shingles,
$8,000$12,000 to replace with metal,
and about $15,000 to replace with con-
crete barrel tile. Many homes cannot
support the weight of a tile roof with-
out extensive work beforehand, making
metal roofs, such as factory-painted
white or Galvalume, the more practical
choice for many households.
A Stronger, More
Forgiving Roof
When a house is exposed to hurricane
forces, the roof is the building component
most susceptible to damage, followed by
the walls and openings, and then the
foundation. Data collected by HUD stud-
ies after major hurricanes bear this out.
These studies found that water penetra-
tion was also a major problem whenever
roong material was removed by wind
action. For steep roof systems, many roof-
ing failures occurred at the ridge or gable
ends, where wind-induced forces were
the highest. In a number of forensic eval-
uations, it was consistently found that the
presence of gable ends increased the
chances of roof failure after hurricanes.
Roofs that are likeliest to fail during
hurricanes are poorly attached tile roofs
or older lower-cost shingle roofspar-
ticularly those applied with staples, which
are now forbidden by current Florida
building codes (the allowed fastener sys-
tem is nails). Properly attached tile and
metal roofs tend to do better in such
storms, as evidenced in numerous post-
storm studies conducted by HUD after
Hurricanes Andrew, Hugo, and Iniki in
the 1990s.
However, construction quality mat-
ters with all roong systems. Properly
installed hurricane straps, nails, and
screws are a must.Tile roofs should be
stoutly installed with screws rather than
with mortar set, which is more prone to
failure. Even with proper attachment for
tile roofs, particular attention should be
given to strong fasteners at the eaves,
corners, and ridges where failure is
more common. A properly attached
shingle roof with high-quality architec-
tural-grade shingles should do well.
In any case, homeowners seeking
repairs should obtain multiple bids and
deal only with licensed, reputable con-
tractors. However, this is exceedingly dif-
cult after a storm. Many homeowners
with leaking roofs are looking for imme-
In the past fteen years, research has
shown that the leading cause of building
failure during high-wind events is the fail-
ure of one or more windows or doors
which often fail due to ying debris, not
because of the wind by itself. To minimize
the possibility of window and door failure,
impact-resistant glass products have been
developed to withstand debris and wind,
which in turn lowers structural vulnerabil-
ities during a storm.
Impact-resistant windows use either
laminated glass or shatter-resistant lm.
Shatter-resistant lm is less expensive
than laminated glass, and is often used
in retrotting operations. The lm is
placed on the interior of existing window
glass, and upon impact, the lm is
designed to hold the shards of broken
glass to the lm, reducing injury to resi-
dents and home alike.
Laminated glass was developed for use
in the automotive industry in the 1930s.
Car windshields use laminated glass that
has a
3
/
100
-of-an-inch plastic interlayer
(usually polyvinyl butyral) in the middle
of two regular pieces of glass. Researchers
have found that by increasing this plastic
interlayer to
9
/
100
-of-an-inch, laminated
windows can provide better protection for
homes during high-wind events. Even
though the glass may break with a high
velocity impact, the shattered glass
adheres to the plastic interlayer, virtually
eliminating glass hazards. When
laminated glass windows are installed in a
residence, they can usually withstand
winds up to 130 miles per hour, including
impacts by ying debris.
At a cost comparable to that of most
high-quality windows, impact-resistant
windows offer benets including higher
security, improved noise abatement,
99% protection from ultraviolet light,
and increased energy efciency.
Window companies are making even
more improvements to laminated glass.
For example, Hurd Millwork Company pro-
duces FeelSafe windows, which are
Energy Star rated and also provide storm
resistance that exceeds building code
requirements for all coastal regions from
Maine to Texas. Another company,
CertainTeed, has released a new impact-
resistant option for vinyl windows. These
high-impact-resistant windows meet
wind-borne debris testing standards of
the International Building Code. The win-
dows differ from other brands of
laminated windows because they dont
require special installation procedures.
Whether deciding on laminated win-
dows or impact-resistant lm, employ-
ing these technologies in homes will
help to reduce damage during high
winds. By providing impact resistant
windows in new construction and retro-
ts, especially in tornado- and
hurricane-prone climate areas, builders
can add value to their product, which
may set them apart from the
competition. Whether you are a builder
or a homeowner, using these window
technologies will provide peace of mind
before, during, and after the storm.
Elka Karl is an associate editor at
Home Energy magazine.
Better Glass for Coastal Homes Rehab
26
www.homeenergy.org
MARCH/APRIL 2005
HOME ENERGY
diate solutions, and that often means
improvised xessuch as tarpaulins.
And the fact that older shingle roofs
often fail when exposed to severe winds
leaves many homeowners whose homes
have shingle roofs looking for roong
contractors at the same time as they are
recovering from the storm.
In spite of the energy and longevity
benets of the light-colored tile or metal
roofs, many homeowners still choose
shingles, partly because they are cheaper
to install. Many homeowners choose
dark-colored shingles for aesthetic rea-
sons.Wind-resistant shingles are available,
although they are more expensive. It is
generally best to use three-tab self-seal-
ing shingles with a six-nail application
pattern, but yo