Cover: Satellite image with the tracks of Hurricanes Ivan, Frances, Jeanne, and 
Charley superimposed over the Gulf of Mexico shorelines of Georgia, Florida, 
Alabama, and Mississippi.

Summary Report on
Building Performance
2004 Hurricane Season
FEMA 490 / March 2005


Title Page:

Summary Report on
Building Performance
2004 Hurricane Season
FEMA 490 / March 2005


Table of Contents
Executive Summary 
Chapter 1 Purpose and Background 
Chapter 2 Description of Hazard Events 
2.1 Charley
2.2 Frances 
2.3 Ivan 
2.4 Jeanne 
2.5 Cumulative Hurricane Damages 
Chapter 3 Building Performance
3.1 Wind Hazard Observations
Key Observations
Structural Performance 
Accessory Structures 
Building Envelope 
3.2 Flood Hazard Observations 
Key Observations 
Foundations and Structures 
Accessory Structures and Construction Features
Beneath Elevated Structures 
3.3 Implications of Poor Building Performance 
Residential Buildings 
Commercial/Industrial Buildings 
Critical and Essential Facilities 
Chapter 4 Conclusions and Recommendations 
4.1 Wind-Related Conclusions and Recommendations 
General
Hurricane Classification 
Structural
Accessory Structures 
Building Envelope 
4.2 Flood-Related Conclusions and Recommendations
General
Structures and Foundations
Accessory Structures and Construction Features
Beneath Elevated Structures 
4.3 Critical and Essential Facilities/Shelters, 
Conclusions and Recommendations
4.4 Design Guidance and Public Education 
Recommendations
Design and Construction Guidance 
Public Education and Outreach 
Matrix #1. Design and Construction Recommendations 
Matrix #2. Building Code and Regulations 
Recommendations 
Matrix #3. Public Outreach Recommendations 
Matrix #4. Recommendations Specific to Critical and 
Essential Facilities 
Acronyms
Glossary
References and Resources 
[END TABLE OF CONTENTS]


Executive Summary

The nation will remember 2004 as a record-setting year in terms of presidential 
disaster declarations and administered disaster aid. In 2004, President Bush 
issued 68 disaster declarations of which 27 were due to hurricanes. Time and 
again the U.S. was impacted by hurricane force winds and waves that damaged 
cities and small towns in 15 states, Puerto Rico, and the U.S. Virgin Islands.

Of all the regions that endured the hurricane season, the State of Florida bore 
the brunt of the record-setting storms as Hurricanes Charley, Frances, Ivan and 
Jeanne tested the federal and state fortitude in disaster response and recovery.   
Communities were devastated as wind and water damage from the four storms 
battered residential, commercial, industrial, and public facilities. Disaster 
assistance totaling more than $4.4 billion was approved for Floridians, and to 
date, 1.24 million storm victims have applied for federal and state assistance 
(FEMA 2005b).  The financial impact of the season will likely exceed $20 
billion, according to preliminary loss estimates from the Insurance Services 
Office's Property Claim Services (PCS).

The four hurricanes that struck Florida in 2004 were all significant events; 
however, the hurricanes were each distinctive in terms of their wind and water 
action and resulting damages.  The first of these, Charley (designated a 
Category 4), was the first design level wind event to strike the U.S. mainland 
since Hurricane Andrew (1992) and caused more wind damage than flood damage. 
Frances (Category 2) and Jeanne (Category 3), while not as strong as Charley, 
were still very damaging hurricanes resulting in additional wind damage.  
Hurricane Ivan delivered not only strong winds (Category 3), but also caused 
significant flood damage to buildings and other structures, even those built 
above the 100-year flood elevation.

The impact of the four hurricanes was intensified by their back-to-back 
occurrence; three of the hurricanes followed similar paths or had overlapping 
damage swaths (refer to Figure 1 Storm Track Map). Frances an Jeanne followed 
almost identical paths across Florida from the east coast (around Port St. 
Lucie) to the west coast (north of Tampa area).  


Figure 1 - Graphic Image: Depicts the storm tracks of the four hurricanes and 
the paths they took across the State of Florida.


These two very wide storms crossed the path of Charley (which traveled west to 
east) in central Florida creating an overlap of impacted areas in Orange, 
Osceola, Polk, and Hardee counties. As a result of these overlapping impact 
swaths, damage resulting from the later hurricanes (Frances and Jeanne) was 
difficult to distinguish from earlier damage caused by Charley. For instance, 
roofs that failed during Frances or Jeanne may have been weakened or damaged by 
Charley and more prone to failure. For this reason, most of the recommendations 
and conclusions contained in this report are based on observations made after 
Hurricanes Charley and Ivan and are supported by observations made after 
Hurricanes Frances and Jeanne.

Following Hurricanes Charley and Ivan, the FEMA Mitigation Assessment Teams 
(MATs) performed field observations to determine how well buildings in Florida 
and Alabama performed under stresses caused by the storms' wind and water 
impacts. A Rapid Response Data Collection Team performed field observations 
after Hurricane Frances that focused on critical and essential facilities; 
however an assessment was not performed after Jeanne, because Jeanne and Frances 
impacted a similar region. Overall, the MAT observed building performance 
success in structural systems designed and built after Hurricane Andrew. This 
Summary Report focuses on the ongoing need for improvement in building 
performance.

Primary Observations

Wind
Most of the wind damage was preventable. The winds primarily damaged building 
envelope systems which, upon failure, allowed wind-driven rain to enter building 
interiors causing not only loss of function, but millions of dollars of damage 
to building contents due to the rain and subsequent mold growth. Based on 
observations of wind damage after Hurricanes Charley, Ivan, and Frances, the 
most consistent failures were: 

Roof covering failures allowed water to penetrate throughout building interiors 
and in some cases led to structural failures. 

Mechanical and electrical equipment failure left holes in roofs (allowing wind-
driven rain into building interiors) and significantly impacted the function of 
the buildings (i.e., communications equipment needed for 911 response was blown 
off roof).

Soffits, which are architectural elements at roof overhangs, frequently failed 
and allowed significant amounts of wind-driven rain to enter otherwise undamaged 
buildings. 

Window and door failure exposed buildings to the damaging effects of wind-driven 
rain. Broken windows and doors allowed internal building pressures to increase 
rapidly which sometimes led to structural roof and wall failures.

Where design level winds were experienced, current building code provisions 
appeared to adequately address the design of the structural building systems, as 
there was overall little wind damage to these systems except to older buildings 
which were not constructed to current code.

Many critical and essential facilities, including shelters, did not perform as 
well as intended. Significant loss of function occurred due to largely 
preventable failures in building envelope performance from high winds during 
Charley, Frances, and Ivan. For example, in Charlotte County, over a half-dozen 
fire stations, three hospitals, numerous police stations, and the County 
Emergency Operations 
Center (EOC) were badly damaged. Some of these facilities were unable to provide 
essential functions in the days, weeks, and sometimes months following Hurricane 
Charley. Hurricanes Frances and Ivan, both of which had wind speeds below the 
design-event, caused significant damage to building envelopes of critical and 
essential facilities. Many of these failures were a result of the age of the 
facilities (not built to current standards) and lack of proper maintenance.

Lack of a continuous load path in the structural systems of older buildings led 
to structural failures. Un-reinforced masonry (URM) load bearing wall buildings 
performed poorly, as did older wood frame buildings, because neither building 
type had adequate connections between structural members to transfer wind loads 
from the roof system to the foundation.

Flood
Flooding associated with Hurricane Ivan significantly damaged structures 
including those built above the regulatory 100-year flood elevation, especially 
in back bay areas. 

Damage caused by significant wave action, which is typically anticipated and 
experienced in V Zones, also occurred in Coastal A Zones. 

Multi-family residential structures located in areas outside the 100-year 
floodplain (as designated on the FIRMs in Zones B, C, and X and which are not 
required to have deep foundations) were severely impacted by erosion, causing 
the shallow foundations to fail, resulting in total collapse of the buildings.

Flooding and wave action significantly damaged utilities, enclosures, stairs, 
and accessory structures located under the first floor of elevated buildings.

Walkway sections and piles from docks and marine structures, along with other 
damaged materials, added to the debris in high flood levels causing severe 
damage throughout the inland bays.

Buildings with first floor elevations lower than required by current minimum 
standards were observed to sustain more damage from wave action, debris impact, 
and flood waters than buildings built 
beyond the standards.

Sidebar: DESCRIPTION OF FLOOD ZONES

Zones X, B, and C. These zones identify areas outside of the Special Flood 
Hazard Area (SFHA). Zone B and shaded Zone X identify areas subject to 
inundation by the flood that has a 0.2-percent probability of being equaled or 
exceeded during any given year. This flood is often referred to as the 500-year 
flood. Zone C and unshaded Zone X identify areas above the level of the 500-year 
flood.

V Zone. The portion of the SFHA that extends from offshore to the inland limit 
of a primary frontal dune along an open coast, and any other area subject to 
high-velocity wave action from storms or seismic sources. The Flood Insurance 
Rate Maps (FIRMs) use Zones VE, V1-30 to designate these Coastal High Hazard 
Areas. The SFHA are subjected to inundation to the flood that has a 1 percent 
chance of being equaled or exceeded during any given year. This flood is 
referred to as the 100-year flood. 

Coastal A Zone. The portion of the SFHA landward of a V Zone in which the 
principal source of flooding is storm surge, not riverine sources. Coastal A 
Zones may therefore be subject to wave effects, velocity flows, erosion, scour, 
or combinations of these forces. The forces in Coastal A Zones are not as severe 
as those in V Zones but are still capable of damaging or destroying buildings or 
inadequate foundations. A Zone areas are subject to breaking waves with heights 
less than 3 feet and wave run-up with depths less than 3 feet. It is important 
to note that FIRMs use Zones AE, A1-30, AO, and A to designate both coastal 
and non-coastal SFHAs. The SFHA are subjected to inundation to the flood that 
has a 1 percent chance of being equaled or exceeded during any given year. 
This flood is referred to as the 100-year flood.

For NFIP flood zone definitions, refer to 44 CFR 64.3.

[END OF SIDEBAR]


Primary Recommendations

Wind

1.  The performance of building envelope systems in high wind events requires 
attention. Design guidance and code changes are needed as described in this 
report.

2.  The performance of critical and essential facilities/shelters in high-wind 
events must be improved. The MATs proposed stricter design requirements, as 
outlined in this document. Communities and states need to develop and implement 
mitigation retrofit programs and take advantage of FEMAs mitigation programs: 
the Pre-Disaster Mitigation and the Hazard Mitigation Grant Program. 


3.  Emphasize best practices for schools and shelters as described in FEMA 424, 
Design Guide for Improving School Safety in Earthquakes, Floods, and High Winds, 
FEMA 361, Design and Construction Guidance for Community Shelters, and in the 
latest codes and standards governing wind resistant designs.


Flood 

The primary recommendations based on damages observed after Ivan are:

1.  Re-evaluate the hazard identification/mapping approaches in Coastal A/V 
Zones.

2.  Re-evaluate the storm surge modeling methodology.

3.  Require V Zone foundations for new construction in Coastal A Zones subject 
to erosion and/or wave heights greater than 1.5 feet. Require deep pile or 
column foundations in coastal areas mapped as Zone B, C, or X, where erosion is 
possible.

4.  Elevate the bottom of the lowest horizontal structural member above the Base 
Flood Elevation (BFE) in Coastal A Zones, as is currently required in V Zones.

5.  Emphasize best practices as described in FEMA 55, Coastal Construction 
Manual and in the latest codes and standards governing flood resistant design.

6.  Use Hurricane Ivan tide levels, inundation limits, and areas subject to wave 
effects as proxies for reconstruction guidance.


7.  Use flood and corrosion resistant materials below the BFE as recommended by 
American Society of Civil Engineers (ASCE) 24-05 and the Coastal Construction 
Manual (FEMA 55).


Chapter 1

Purpose and Background

The purpose of this document is to summarize the observations, conclusions, and 
recommendations that were obtained during post-disaster assessments sponsored by 
the FEMA Mitigation Division in response to Florida's 2004 hurricane season. 
More than ten rapid response teams and two Mitigation Assessment Teams (MATs) 
were deployed to document observations and provide recommendations.

The rapid response data collection teams focused on coastal high water marks, 
inland wind effects, residential and commercial building performance, critical 
and essential facility performance, and mitigation program effectiveness. The 
MATs assessed damage to the built environment and relied on the perishable data, 
such as high water marks, collected by the rapid response teams to quantify 
flood and wind effects of the hurricanes.

The MATs are composed of national experts in hazards (wind and flood), coastal 
processes, and building codes.  The experts are engineers, architects, policy 
makers, code specialists, and building officials.  MATs are sent out after 
disaster events for which the damage summaries and subsequent conclusions and 
recommendations are likely to have national implications. Assessment an 
documentation of the performance of buildings constructed to the Florida 
Building Code (FBC) has national significance because the State of Florida 
enacts some of the most stringent coastal construction codes an regulations for 
wind and flood.  Therefore, if buildings built in accordance with Florida's 
codes and regulations perform well, then the FBC stands as a good model for 
other coastal communities. However, if new building envelopes are damaged by a 
wind or flood event that is below the design level event in the FBC, then this 
indicates a significant problem for many coastal communities because even the 
most restrictive code in use is inadequate.

Building codes and standards, and floodplain regulations are adopted and 
enforced to regulate construction in at-risk areas. In Florida, the Standard 
Building Code (SBC), and the South Florida Building Codeboth with local 
amendmentswere used to regulate construction in Florida until early 2002 at 
which time the Florida Building Code (FBC) 2001 Edition was adopted statewide. 
The FBC is administered by the Florida Building Commission and governs the 
design and construction of residential and non-residential (commercial, 
industrial, essential/critical facilities) structures. The FBC 2001 is based on 
SBC; however, Florida has completed updates to the 2001 Edition and will 
release a 2004 Edition of the code for adoption in July 2005. The 2004 edition 
is based on the International Building and Residential Codes (IBC and IRC).

In Alabama, which adopts building codes on a statewide basis only for state-
owned buildings; jurisdictions have traditionally adopted editions of the SBC, 
however, the City of Orange Beach adopted the 2003 IBC in the summer of 2004 and 
the City of Gulf Shores adopted it as an emergency measure after Hurricane Ivan. 
Other affected communities, such as those in unincorporated Baldwin County, 
still enforce the SBC.

For flood hazards, FEMA establishes by regulation the minimum floodplain 
management requirements that communities must adopt and enforce in order to 
participate in the NFIP (44 CFR Section 64.3). These requirements are the basis 
for the other codes and standards that are used to regulate floodplain 
construction. FEMA studies the impacts of hurricanes and tropical storms on 
coastal buildings to determine if its minimum requirements are effective in 
reducing flood damages. If problems are identified through a MAT or other 
evaluation, they can be addressed through regulatory changes to the NFIP, 
proposing changes in building code requirements, or through technical guidance 
and training.

MATs were deployed after Hurricanes Charley and Ivan for the following reasons:

Hurricane Charley MAT (FEMA 488). A MAT was deployed in Florida to observe the 
first major design level wind event to strike the U.S. mainland since Hurricane 
Andrew. The MAT assessments illustrate the progress made in building performance 
and highlight needed improvements. 

Hurricane Ivan MAT (FEMA 489). A MAT was deployed in Florida and Alabama in 
response to a code level flood event with near code level winds. This storm 
allowed for evaluation of both the building code and flood ordinances and 
regulations governing coastal construction. When significant flood events occur
such as those associated with Hurricane Ivan where flood levels exceeded the 
100-year flood elevationsit is important to assess and evaluate the accuracy of 
the models used to analyze and prepare the flood maps as well as the accuracy of 
the existing maps (if conditions have changed since the maps were developed). 

Hurricane Frances Hazard Mitigation Technical Assistance Program Report. 
Following Hurricane Frances, a team of structural and building envelope experts 
was deployed to assess damage to critical and essential facilities to help 
determine the extent of damage, the mode of failure, and what types of eligible 
mitigation projects could minimize damage to these buildings in the future. 

Hurricane Jeanne High Water Level Report. To document the severity of riverine 
flooding after Hurricane Jeanne, a field study was conducted to collect and 
survey riverine and coastal high water marks in affected Florida counties.

This summary document consolidates and presents the findings of the MATs and the 
supporting tasks and provides guidance to state and local governments to improve 
the reconstruction process and advise policymakers during their upcoming 
Legislative and State Building Code update cycles. This Summary Report describes 
building performance for hurricane winds (Charley, Frances, and Ivan) and 
hurricane-related flooding (Ivan) in Florida and Alabama only, even though other 
states were impacted by the hurricanes. The conclusions presented in this report 
are based on the MATs observations, evaluations of relevant codes, standards, 
and regulations, and meetings with state and local officials, building 
associations, contractors, and other interested parties. These conclusions are 
intended to assist the States of Florida and Alabama, communities, businesses, 
and individuals in the reconstruction process and to help reduce future wind and 
water damages promoting the economic well being of the nation.


Chapter 2

Description of Hazard Events

To determine how well buildings performed, it is first important to understand 
the characteristics of the hurricanes, specifically their wind and water 
components at landfall.

2.1  Charley

Hurricane Charley made landfall on the Gulf Coast of Florida on August 13 as a 
very compact storm (refer to Figure 1, Storm Track Map). The hurricane eye had 
an estimated radius of maximum winds of 6 miles with hurricane force winds 
extending outward up to 25 miles from the center, and tropical storm force winds 
extended outward up to 85 miles (Figure 2, Hurricane Charley Wind Swath Map).  
The maximum recorded wind speed obtained for the storm at landfall from National 
Weather Service (NWS) weather station (Station PGD) before it failed was 112 
miles per hour (mph), 3-second gust wind speed.


Figure 2 - Graphic Image: Hurricane Charley Wind Swath Map. This map depicts the 
track that Hurricane Charley made across Florida and the various wind gust 
speeds.


According to report from the NWS, the center of Charley crossed the barrier 
islands of Cayo Costa and Gasparilla as a Category 4 hurricane o the Saffir-
Simpson scale with maximum sustained winds of 149 mph.  After crossing the 
Florida barrier islands, Charley moved up Charlotte Harbor before making 
landfall at Mangrove Point, just southwest of Punta Gorda, Florida. Communities 
around Charlotte Harbor including Punta Gorda and Port Charlotte were impacted 
with sustained winds estimated at 125-130 mph (1-minute) and gust winds upward 
of 155 mph (3-second) in built-up areas.  Hurricane force winds (with 3-second 
gust winds as high as 105 mph) in built-up areas of Orlando continued to cause 
damage across the peninsula of Florida until Hurricane Charley exited into the 
Atlantic Ocean near Daytona Beach, still categorized as a hurricane.

The storm surge from the hurricane was significantly smaller than originally 
predicted due to the storms compact size and the northeastward turn it made 
just prior to landfall. Although the storm was reported to have some Category 4 
winds, the hurricane did not generate water levels typical of a Category 4 
hurricane, which are often in the range of 10 to 14 feet. Instead, high water 
elevations along the open coast from Naples north to Ft. Myers Beach and Sanibel 
Island were 5 to 8 feet. Inland bays, including areas near Port Charlotte and 
Punta Gorda, measured up to 1.5 feet. 


2.2 Frances

Hurricane Frances was the second of four deadly hurricanes that swept through 
the State of Florida during the 2004 season, just weeks after Hurricane Charley 
left its catastrophic mark. Frances struck a wide stretch of Floridas east 
coast early September 5 as a Category 2 hurricane on the Saffir-Simpson scale 
according to the National Hurricane Center (NHC) (refer to Figure 1, Storm Track 
Map).


Figure 3 - Graphic Image: Hurricane Frances Wind Swath Map. This map depicts the 
track that hurricane Frances took across Florida and the various wind speed 
gusts.


Hurricane Frances hit Florida with reported maximum sustained winds of over 105 
mph and storm surges over 5 feet. The highest 3-second gust winds measured by 
the Florida Coastal Monitoring Program during Hurricane Frances were 112 mph at 
an open-exposure site south of Fort Pierce. Hurricane-force winds extended 
outward up to 75 miles from the center, and tropical storm-force winds extended 
outward up to 205 miles (Figure 3, Hurricane Frances Wind Swath Map). Frances 
made landfall near Sewalls Point, Florida, on September 5 as a Category 2 
storm, and moved west across the central Florida peninsula while weakening to a 
tropical storm. Hurricane Frances unusually long duration, a result of its slow 
forward speed, significantly impacted the functions of critical facilities 
because of building fatigue. 


2.3 Ivan

Hurricane Ivan made landfall on September 16 as a Category 3 hurricane, 
according to the NHC, with estimated maximum sustained winds of over 100 mph and 
with wind gusts of up to 120 mph, torrential rains and coastal storm surge, and 
large battering waves of up to 16 feet in inland bays, and up to 19 feet along 
the open coast and inland bays (Figure 4, Hurricane Ivan Wind Swath Map). The 
hurricanes strongest winds were located east-northeast of the storm center. 
This aspect, coupled with the higher, on-shore directed winds, associated storm 
surge and accompanying breaking waves, resulted in much of Ivans destructive 
impact on the Florida Panhandle coast and Gulf Shores, Alabama. 


Figure 4 - Graphic Image: Hurricane Ivan Wind Swath Map. This map depicts the 
track that hurricane Ivan took across Florida and the various wind speed gusts.


Many of the barrier islands exposed to Hurricane Ivans strongest winds and 
storm surge are low lying and were washed over by storm surge. Coastal storm 
surge flooding crossed the barrier islands, undermined buildings and roads, and 
opened new island breaches.  

In addition to the storm surge, breaking waves eroded dunes and battered 
structures. The storms arrival was concurrent with high tide, which exacerbated 
storm surge flooding.

2.4 Jeanne

Hurricane Jeanne made landfall as a Category 3 hurricane on September 25 at 
Hutchinson Island, just east of Stuart, Florida. The storms landfall location 
was only about 2 miles north (3 km) from Sewalls Point, where Hurricane Frances 
struck Florida just 3 weeks earlier. According to the NHC, Jeannes eye diameter 
at the time of landfall was approximately 60 miles, its maximum winds were 120 
mph over a very small area north of the center of circulation, and movement was 
west-northwest at approximately 9 mph (Figure 5, Hurricane Jeanne Wind Swath 
Map). Storm surge of 3.8 feet above normal tide levels was measured near Port 
Canaveral, Florida, about an hour after Jeanne made landfall. The maximum storm 
surge was estimated to be 6 feet above normal tide levels.


Figure 5 - Graphic Image: Hurricane Jeanne Wind Swath Map. This map depicts the 
track that hurricane Jeanne took across Florida and the various wind speed 
gusts.


2.5 Cumulative Hurricane Damages

Alabama and Florida residents braced for impact and endured the aftermath 
of four hurricanes in August and September 2004, large events separated by a 
brief pause of just days. Intensifying the rapid-fire hurricane strikes was the 
track similarity shared by Frances and Jeanne, and the overlapping zone of 
effects among Frances, Jeanne, and Charley. Though Hurricane Ivan tracked 
through the Gulf of Mexico and hit Alabama, the storm brought severe wind and 
water effects to Florida as well as Alabama. Though varied in degree, the 
hurricanes each resulted in wind and water damage to commercial, residential, 
and public facilities, as well as vegetation, agricultural crops, and 
infrastructure such as utilities and roadways. Though the wind swaths, flood 
levels, and tracks of the hurricanes are easily mapped, the boundary of damages 
associated with each event is not so easily drawn. Field observations were 
difficult to perform before the next hurricane struck. As such, the overlapping 
hurricane events and track similarities led to a succession of damages that is 
almost easier to consider cumulatively than separately. 

The outlay of resources to disaster communities can put into perspective the 
degree of sustained damages (FEMA, 2005b): 

More than 548,000 citizens were assisted in FEMA Disaster Recovery Centers 
throughout Florida.

Approved aid for Public Assistance (public facilities) disaster damages 
surpassed $604 million (FEMA, 2005c).

Approved aid for Individual Assistance disaster damages surpassed $1.16 million 
(FEMA, 2005b).

Nearly 1.24 million victims applied for federal and state assistance.

Almost 877,000 housing inspections were completed.

FEMA provided more than 15,600 temporary housing units to hurricane victims.

An estimated 53 million cubic yards of debris was cleared.

More than 33,000 NFIP claims were received.


Chapter 3

Building Performance

Building performance observations were made based on estimated wind speeds and 
flood water levels to determine whether  buildings performed as designed and to 
identify appropriate mitigation measures. Building age, function, and 
construction are considered when observing building hurricane damage to generate 
an overall summary of building damage and performance.

3.1  Wind Hazard Observations

The majority of wind-related damages observed during the 2004 hurricane season 
were observed and documented for Hurricanes Charley and Ivan.  Wind-related 
damage associated with Frances and Jeanne, though significant and widespread, 
was difficult to document because of overlapping damage paths. Wind-related 
damage to critical and essential facilities is documented for Hurricane Frances.  
In general, the type of wind damage observed was similar across the paths of all 
four hurricanes.

Key Observations

Building structural capacities appeared to have improved since Hurricane Andrew 
(1992) because of stronger building codes and better enforcement, resulting in 
less structural damage overall even from intense hurricane such as Hurricane 
Charley. Buildings designed to codes and standards that were revised after 
Hurricane Andrew in 1992 performed better than the older building stock.  It is 
important to note that only Hurricane Charley produced winds that were at or 
above the current design requirements of the FBC and the International Building 
Code/International Residential Code (IBC/IRC) used in Alabama. Except for 
Hurricane Charleys landfall area, the wind damage was caused by wind speeds 
that in many cases were 2040 mph lower than the current design level wind 
speeds specified in the applicable codes. 

Winds primarily damaged building envelope components and accessory structures. 
Building envelope failure (specifically roof coverings, roof mounted equipment, 
soffits, wall coverings, and unprotected glazing) led to widespread damage to 
building interiors throughout the paths of the hurricanes. During Hurricane 
Frances, which had wind speeds well below design levels, the long duration of 
the winds caused fatigue and subsequent damage to some building envelope 
systems. 

In general, many critical and essential facilities did not perform as well as 
intended. Although most damage was to facilities built before current code 
standards, the structural and envelope systems of some newer critical and 
essential facilities also failed.

The majority of building damage was caused by: (1) insufficient wind resistance 
of building envelope systems which allowed wind-driven water infiltration into 
buildings, resulting in contents damage and loss of function; and (2) impact of 
windborne debris (primarily related to Hurricane Charley). The performance of 
buildings observed by the MAT varied depending on their location in the wind 
field, the age of construction, and implemented hazard mitigation efforts (if 
any). 

Wind induced damage and failures to building structures and components occurred 
where there was a break or discontinuity in the load path. Although significant 
design improvements ensure a continuous load path in the structural systems of 
buildings, the observed damage indicates that the requirements and guidance 
relative to load path for non-structural components and cladding elements still 
needs improvement.

Sidebar: SUCCESS STORY: 
SANIBEL SCHOOL ON SANIBEL ISLAND
The Sanibel School was designed and constructed to the 2001 FBC and as such, 
sustained only minor damage from Hurricane Charley (loss of gutters and some 
wind-driven rain issues). Dedicated on August 10th, just a week prior to the 
landfall of the storm, Sanibel School likely experienced wind speeds around 
the level of Category 2 winds. Although these winds were below the 130 mph (3-
second gust) design wind speed for the site, the building performed very well 
and opened on time with no loss of function.

[END OF SIDEBAR]


Structural Performance

The MAT observed limited structural damage to residential structures, including 
site-built structures and post-1994 U.S. Department Housing and Urban 
Development (HUD) code-manufactured homes, as well as commercial structures 
throughout the wind field of all four hurricanes. Worth noting is the limited 
damage observed throughout the path of Charley, especially in the areas where 
code level winds occurred. A larger portion of structural failures occurred to 
the older buildings and to pre-1994 HUD code-manufactured housing. No structural 
failures were observed to structures designed and constructed to the wind design 
requirements of the 1997 Southern Building Code (SBC), the 2001 FBC, the 2000 
IBC/IRC (in Alabama) or ASCE 7 (national design standard). There were isolated 
instances where newer structures sustained structural damage; partial failures 
occurred where design or construction was not code compliant. The following are 
overall observations of the structural performance grouped by structure type.

Wood frame. New wood frame houses built in accordance with FBC 2001 and the 2000 
IRC performed well structurally, including those located in areas that 
experienced winds of up to 150 mph (3-second gust) in Charley. For each 
structure, load path was accounted for throughout the structure, including the 
connection of the roof deck to supporting trusses and rafters. Loss of roof 
decking on newer homes was rare. 

Manufactured housing. Manufactured housing performance was a function of unit 
age and of the regulations under which they were constructed and installed. In 
high wind areas, pre-HUD standard homes were mostly destroyed beyond repair. 
Pre-1994 HUD standard homes performed variably, but the vast majority of these 
homes located in the path of Charley were damaged significantly even though the 
wind was less than the current design wind speeds. While post-1994 HUD standard 
homes performed well structurally, these units sustained damages related to 
building envelope and accessory structure failures. Improved performance of 
post-1994 manufactured housing was observed, however the MAT also found 
widespread damage caused by the failures of improperly designed and constructed 
attached accessory structures, such as carports and screen rooms. When these 
attached structures failed, they often tore away siding, roof covering, roof 
decking, and the exterior walls of the units to which they were connected.


Photograph: Manufactured housing that had structural damage resulting from 
accessory structure failure.


Concrete/Masonry. Reinforced concrete and reinforced masonry structures 
performed well. Failures occurred when roof structural systems were inadequately 
connected to the top of the concrete walls or frames and in URM structures. URM 
buildings, especially older ones, fared poorly (including designated critical 
and essential facilities).

Steel-framed. No structural failures were observed for steel-framed buildings.

Pre-engineered metal. Pre-engineered buildings, usually designed to satisfy the 
minimum standards, often performed poorly. Poor performance was observed mostly 
in older buildings where corrosion of structural elements and exterior panels 
had occurred. Very few pre-engineered metal buildings designed to resist high 
winds were observed during the assessment. Of the small sample observed, all 
survived with minimal cladding damage and without structural failure with the 
exception of the public shelter in Arcadia. 

Accessory Structures 

Significant damage to accessory structures occurred throughout the paths of the 
hurricanes. Most of the accessory structures observed were associated with 
residential dwellings and many were attached to the primary residence. 
Generally, these structures were aluminum screen enclosures (typically observed 
as pool enclosures) and aluminum porches or carport structures. Not only did the 
accessory structures themselves fail, but in many cases the failure of the 
accessory structure led to damage to the primary residence at the point of 
attachment. In several instances, pieces of the failed accessory structures 
became windborne debris, damaging the primary residence with which it was 
associated as well as neighboring residences. 

Building Envelope 

As building structural capacities have improved because of stricter building 
codes and better enforcement, the performance of the building envelope is 
becoming increasingly important. The building envelope includes exterior doors, 
non-load bearing walls, wall coverings, soffits, roof coverings, windows, 
shutters, skylights and exterior-mounted mechanical and electrical equipment. 

Based on building performance observed during the 2004 hurricane season, the 
five building envelope components that, in many cases, continue to perform 
poorly are: roof systems (of greatest concern is mortar-set tile roof systems), 
exterior mechanical and electrical equipment, soffits, windows, and doors 
(unprotected glazing), and wall cladding (especially exterior insulation 
finishing systems  EIFS). The failure of, or damage to, one or more of these 
systems allowed rainfall to enter buildings, which resulted in significant 
damage to building interiors and contents. Building envelope failure and rain 
water intrusion were also key reasons for widespread loss of building function, 
most notably in critical and essential facilities.

Building envelope failure allows an increase in the internal air pressure of a 
building and allows wind-driven rain to enter the building. Increased internal 
pressure can also lead to structural damage. Infiltration of water weakens 
gypsum board ceilings, causing them to collapse, and destroys building contents. 
Mold bloom can quickly occur in hot humid climates if a building is not dried 
out immediately. 

Roof Coverings 

The performance of roof coverings during the 2004 hurricane season continued to 
raise concerns. While improved performance was observed, damage to roof overings 
continues to be the leading cause of building performance problems during 
hurricanes. 

Variation in roof system performance was primarily related to installation and 
attachment methods, with the failure of mortar-set tile roof systems observed 
most frequently. Failure of roofing components (i.e., edge flashings, copings 
and gutters/downspouts) frequently contributed to roof covering failures.

Tiles. Tile roof damage (both clay and concrete) occurred during Charley, Ivan, 
and Frances, but was most prevalent along the path of Hurricane Charley due in 
part to the large percentage of homes and buildings with tile roof coverings in 
Charlotte, Lee, and De Soto Counties. Tile damage from Hurricanes Frances and 
Ivan was also observed, both of which had much lower recorded wind speeds than 
Charley. Damage ranged from blow-off of hip and ridge tiles (which was very 
common even in areas with only moderate wind speeds) to large areas of blown off 
tiles (which was less common). The tile underlayments generally remained intact 
so even buildings with significant blow-off areas typically experienced little 
or no water infiltration from the roof (except in cases where the roof deck 
failed). Tiles located on ridges, hips, and edges of the roof were frequently a 
point of failure, especially when they lacked mechanical anchors.


Photograph: Roof missing/dislodged tiles. In addition to the damage shown in 
this photo, this  one-story roof lost virtually all of the hip and ridge tiles 
during Hurricane Charley. (Punta Gorda Isles)


Tiles or tile fragments were frequently the source of windborne debris and 
damaged nearby houses. In several cases, a neighbors house sustained 
significant contents damage (by wind-driven rain entering through windows broken 
by flying roof tiles) even though their roof system did not fail. Additionally, 
tile roof systems themselves are prone to damage by windborne debris.

In general, the size of the blow-off area of tile roofs attached using mortar-
set systems was much greater than for tile roofs attached using foam-set and 
mechanically attached systems. Failure on mortar-set roofs occurred from 
debonding from the mortar patties, debonding from the underlayment, and 
underlayment failure.

Hurricane Charley was the first hurricane to deliver near-design wind speeds to 
test the new foam-set attachment method for tiles (developed after Hurricane 
Andrew in 1992). Although large areas of blow-off were unusual for foam set roof 
systems, there were a large number of partially damaged foam-set roof systems 
with damages typically resulting from improperly sized and/or located foam 
paddies.

Asphalt Shingles. Although damage was observed on several new roofs, asphalt 
shingles installed within the past few years generally appeared to perform 
better than shingles installed prior to the mid-1990s. This was likely due to 
product improvements (adhesives) and less degradation of physical properties due 
to decreased weathering. On roofs with damaged shingles, almost all the shingle 
fasteners were located too high on the shingle. Additionally, where new roofs 
were installed on top of old roofs (without removing the underlying layer), 
large numbers of the overlay shingles were blown away, most probably due to the 
reduced fastener penetration into the roof deck.

Metal Panel Roofs. Although not as common as asphalt and tile roofs, numerous 
building types with metal panel roofs were observed. Systems where the panels 
acted as the deck and the roof coverings appeared to fail the most. 5-V Crimp 
panel systems typically performed very well. 


Photograph: Aggregate from the Indian River Memorial Hospitals roof (Vero 
Beach) broke several of the patient room windows (which were covered with 
plywood after Hurricane Frances).


Low-Slope Membrane Systems. Some failures of low slope roof systems (built-up 
roofs, modified bitumen, and single ply) were observed. However, the largest 
observed problem was lifting of gutters, edge flashings, and copings, which 
resulted in progressive failure of the membrane. Another common failure mode was 
membrane puncture caused by windborne debris. In several instances, roofing 
aggregate became windborne missiles and broke adjacent windows, thereby 
allowing wind-driven rain infiltration into buildings. 

Exterior Mechanical and Electrical 
Equipment Damage 

The hurricanes resulted in many instances of damage to mechanical and electrical 
devices mounted on the exterior of buildings. Failure of this equipment resulted 
in rain water intrusion to building interiors and facility loss of function. Of 
most concern were the many failures and resulting loss of function associated 
with critical and essential facilities along the paths of the hurricanes. 

Damaged equipment on commercial and critical/essential facilities included 
heating, ventilating, and air conditioning (HVAC) units, exhaust fans, relief 
air hoods, rooftop duct work, communications equipment and lightning protection 
systems (LPS). Equipment attached to these buildings was often essential to the 
operation of the facility. Equipment failed as a result of non-existent or 
inadequate anchoring. Displaced equipment frequently left large openings through 
the roof or punctured the roof membrane allowing rain water to infiltrate the 
building. 


Sidebar: SUCCESS STORY:
THE HOLMES REGIONAL MEDICAL 
CENTER (ROCKLEDGE)
Staff removed loose aggregate from the built-up roofs just prior to Frances 
landfall, likely minimizing window breakage and thereby preserving the 
availability of patient rooms. Additionally, the aggregate surface of a portion 
of the upper roof had been previously re-roofed in a manner that encapsulated 
the aggregate, preventing aggregate blow-off.

[END OF SIDEBAR]


Photograph: A large HVAC package unit was blown off this curb during Hurricane 
Charley. Note the loose LPS conductors this side of the curb. This school had 
significant damage from several pieces of rooftop equipment that blew off the 
building roof. (Port Charlotte Middle School)


Soffits 

Widespread soffit damage was observed throughout the areas impacted by 
hurricanes, resulting in unnecessary rain water intrusion into building 
interiors. Soffits are architectural non-structural covering and cladding that 
enclose overhangs at the edges of roofs. Soffits failed by both downward and 
upward pressure. Where soffits were lost, rain water was driven over exterior 
walls sections, into wall cavities and attic spaces, and ultimately into the 
main portion of the building. 


Photograph: Soffit damage on the third story of a multi-family building. 
(Captiva Island)


Soffit failure led to many instances of significant damage to building 
interiors.

Doors 
Normal width swinging doors performed well with only small numbers of failures 
observed. Failures of large doors, such as rolling or sectional garage doors, 
and apparatus bay doors at fire stations, were more common. Failure of an 
exterior door has two important effects. First, failure can cause an increase in 
internal pressure, which may lead to exterior wall, roof, interior partition, 
ceiling or structural damage. Second, wind can drive rain water through the 
opening, damaging interior contents and leading to mold development. Interior 
building damage resulting from door failures is generally preventable if doors 
and tracks that connect roll up doors to walls are strengthened and reinforced.
New wind- and debris-impact resistant doors typically performed much better than 
the older doors. Improved performance follows the application of minimum 
criteria for debris resistance as specified in the FBC.


Photograph: Failure of three of six new doors on a fire station in Charlotte 
County resulted in the loss of the entire roof structure over the apparatus bay 
during Hurricane Charley.


Windows and Shutters 
Preventable damage to building contents occurred in buildings located in 
windborne debris areas, (as identified in the 2001 FBC and ASCE 7), where 
glazing was not impact resistant or protected by shutters. Glazing failure 
resulted in damage to building interiors and, in some cases, resulted in 
structural failure in older buildings. 


Sidebar: SUCCESS STORY:
CHARLOTTE COUNTY SOUTH ANNEX BUILDING
In anticipation of Hurricane Charley, the Annex building was retrofitted with 
new galvanized metal shutters at a cost of $10,000. With the shutters in place, 
the Annex sustained only minimal damage as Charley blew in winds of 125 mph. The 
$10,000 investment is minor when compared with a taxpayer savings of over half a 
million dollars, which would have been the cost to replace the broken windows of 
the building, had the shutters not been installed. Employees and the community 
also avoided losses in time-off from work and interruption of services, which 
would have accompanied lengthy hurricane damage repairs. Just two days after 
Charley, with minor repairs still in progress, the South Annex was open for 
business.

[END OF SIDEBAR]


Significant window damage was observed in manufactured housing parks after 
Hurricane Charley. This is likely due first, to the lack of manufactured housing 
regulations that require window protection in windborne debris regions (even 
though this is required of all other one- and two-family site-built dwellings) 
and second, because of the presence of many non-engineered and poorly 
constructed accessory structures that failed and became sources of windborne 
debris (even in areas outside of defined windborne debris regions). 
Significant window damage was also observed on many commercial buildings and 
critical/essential facilities throughout the area impacted by the hurricanes, 
especially in buildings with many windows (such as hotels, offices, and 
hospitals). The Charley and Ivan MATs and the Frances rapid response assessment 
teams all documented instances at hospitals where broken windows resulted in 
loss of function. Most shutters and laminated glazing systems observed on 
buildings performed well. Damage and failures occurred when non-rated shutter 
systems were used; when they were not properly installed; or when they did not 
have the strength to withstand high winds or the impact 
of large windborne debris.

Wall Coverings
Wall covering damage was observed throughout the hurricane-impacted area. In 
residential and light commercial applications, the most common damage was to the 
vinyl siding systems; some instances of brick veneer failures were also observed 
after Hurricane Ivan. Failure of vinyl siding was most commonly observed in 
manufactured home parks; upon failure, the underlayment (either asphalt-
saturated felt or housewrap) was also often blown away and wind-driven rain 
entered the wall cavity and initiated mold growth. Significant failures were 
observed on buildings with EIFS and stucco. Much of the failed vinyl siding 
became windborne debris damaging nearby structures.

Photograph: Example of wall cladding failure. The building had synthetic stucco 
installed over molded, expanded polystyrene insulation and gypsum board. The 
gypsum board blew off during Hurricane Ivan.


3.2 Flood Hazard Observations

Key Observations

The majority of flood-related damages observed during the 2004 hurricane 
season were associated with Hurricane Ivan. The storms arrival was concurrent 
with high tide, a condition that maximized storm surge flooding which was 
estimated at 10 to 16 feet above normal high tide levels. Extreme storm surge 
conditions occurred along 90 miles of the Alabama-Florida Gulf shoreline, 
extending 5 miles west and 85 miles east of the hurricanes track. Flood levels 
in many bays and sounds exceeded the mapped BFEs on published FIRMs by several 
feet. Damage to buildings in mapped Coastal A Zone areas from flood-borne debris 
and wave action was extensive and in some cases was characteristic of damages 
that would be expected in mapped V Zones. Additionally, many buildings in mapped 
C Zones sustained significant flood-related structural damage as a result of 
erosion and scour, which is anticipated in V Zones. The current maps that show C 
Zones are not based on existing conditions along the coast.

Foundations and Structures
Flood-related structural damage was observed along the Gulf coast from Gulf 
Shores, Alabama, to Pensacola Beach, Florida, along the intra-coastal waterway, 
and along the shorelines of Escambia Bay. Structural damage occurred to 
residential structures (single and multi-family) 
and commercial structures from a combination of significant storm surge 
elevations, wave action, and debris impacts. The most extreme cases were 
building failures due to erosion of supporting soil under buildings with shallow 
foundations. 

Shallow Foundations 
Several multi-family buildings constructed on shallow foundations in areas along 
the Gulf coast were severely damaged due to erosion and scour. Many of these 
buildings were originally constructed in Zones B, C, or X, which did not require 
deep foundations, but now would require deep foundations if the flood zone was 
determined from the current methodologies and coastal conditions.


Photograph: A multi-family condominium collapsed after Hurricane Ivan due to 
erosion of supporting soil under the shallow foundation.


Pile Foundations
In coastal areas, structures built on pile foundation systems along the inland 
bays and the open coast of the Gulf performed well except for shallow-embedded 
pile systems on barrier islands that sustained significant erosion. Relatively 
few pile failures were observed of newer, post Hurricane Opal (1995) homes. Two 
condominium buildings along the Gulf Coast were reconstructed with deep-pile 
foundation systems after Hurricane Georges (1998); both buildings experienced 
beach erosion during Ivan similar to that of Hurricane Georges, but the building 
damage from Ivan was not catastrophic. Losses to the condominiums were generally 
limited to lower level damage from the erosion of sand and from storm surge 
elevations that exceeded lowest floor elevations. Pile foundation performance 
along inland bays and sounds varied depending on how well they were constructed 
(i.e., fasteners/straps). 


Photograph: Several structures were completely torn off their pile foundations 
during Hurricane Ivan as a result of significant flood depths, waterborne debris 
impacts, and lack of connections.


Slab-on-Grade Foundations
Residential slab-on-grade foundations in Coastal A Zones experienced substantial 
damage or complete destruction when flood elevation levels exceeded the 
elevation of the top of the slab. Many slab-on-grade houses that sustained 
significant flood damage were older homes constructed prior to FIRM publication 
located outside the designated floodplain.

Stem Wall Foundations 
In general, stem wall foundations performed well against storm surge and wave 
and debris impacts. However, some buildings were significantly damaged due to 
the elevation of the finished floor being lower than the flood levels.


Photograph: Flood water from Hurricane Ivan exceeded the required elevation of 
the top of the lowest floor supported by the stem wall foundation for this house 
leading to severe damage caused by waves and debris impact.


Pier Foundations 
Pier foundations typically performed poorly. These foundation systems were 
typically unreinforced and associated with pre-FIRM structures. Some reinforced 
piers failed due to lack of structural capacity to withstand wave and debris 
loads on the buildings.


Photograph: High flood levels during Hurricane Ivan and lack of structural 
capacity to withstand waves and debris loads caused this reinforced pier 
foundation to fail.
 

Accessory Structures and Construction 
Features Beneath Elevated Structures

Extensive damage to enclosures, utilities, and accessory structures located 
beneath elevated buildings occurred due to storm surge, wave, and debris 
impacts. Not only were these systems totally destroyed, but the resulting debris 
damaged other materials and systems attached above the flood levels (i.e., 
siding). Damage to docks and piers was extensive, which also led to a 
significant source of flood debris that threatened to damage landward 
structures.


3.3 Implications of Poor Building Performance

When a building performs poorly as a result of natural disasters, the impacts 
transcend the cost of repair to include the human cost associated with damaged 
homes and businesses and their oftentimes sentimental contents. Community safety 
can be jeopardized if critical/essential facilities, such as fire stations or 
emergency shelters, cannot function due to disaster damages. The following 
summarizes the impacts of poor building performance on a community level.


Photograph: At the Martin Memorial Hospital (Stuart, Florida) wall panels blew 
off the elevator penthouse during Hurricane Frances. Rain water entered the 
elevator equipment room damaging much of the equipment. The falling panels 
punctured the main roof and at least one of the lower roofs. Because of rain 
water infiltration and lack of elevator service, floors 2 through 6, which 
contained 75 percent of the hospitals beds, were inoperative. Many patients 
were relocated to other hospitals until the penthouse walls were re-sheathed and 
new elevator equipment was installed.


Residential Buildings
The primary impacts of residential building performance failures are economic 
damages, displacement, and human suffering. Economic costs include repairing or 
replacing damaged homes and their contents. Loss of personal possessions and 
relocation during reconstruction are common outcomes of residential damage. 

Commercial/Industrial Buildings 
Damage to commercial and industrial buildings typically results not only in the 
need for reconstruction and repair but also in loss of function. The loss of 
function can impact an entire community if the building houses a large company, 
multiple offices, or a vital business (i.e., bank or supermarket). Additionally, 
if businesses are unable to operate, large segments of a community may be 
without work and income for significant periods of time.


Critical and Essential Facilities
Critical and essential facilities are needed to lead and manage response and 
recovery operations after an event. These facilities include EOCs, police and 
fire stations, hospitals, schools, and shelters. In general, buildings that 
function as critical and essential facilities did not perform to the level 
expected. Critical and essential facilities throughout the area impacted by the 
four hurricanes sustained significant loss of function. The most common loss of 
function was caused by failure of building envelope components, allowing wind-
driven rain to damage the interior. The poor performance of the buildings 
hampered the ability of the responders to provide assistance to communities. In 
many cases, service functions were returned within a few weeks of the hurricane 
through repair of equipment, and through dispatching and operations support 
provided from other facilities. Long term impacts are being experienced and 
cannot be remedied until severely damaged facilities are repaired or replaced. 
Many of the hospitals impacted by the hurricanes sustained some loss of function 
due to building envelope damage.


Photograph: An emergency roof (shown) was installed after Hurricane Charley blew 
the mechanically attached PVC membrane roof covering off the concrete deck of 
the Fawcett Memorial Hospital.


Photograph: The Charlotte County Sheriffs Office/County EOC, located in a pre-
engineered metal building, was significantly damaged and completely taken 
offline. Despite having openings protected with shutters, the building failed by 
loss of roof panels (failure of roof clips) and loss of metal wall panels. These 
failures allowed damaging amounts of rain and debris to enter the facility 
resulting in closure of the building. The county was aware of the weakness of 
this facility, and prior to Charley, had begun the design process for a new 
county EOC facility that would meet statewide Enhanced Hurricane Protections 
Areas (EHPA) requirements and guidelines not used in the design of the existing 
structure.


Numerous fire and police stations were heavily damaged by Hurricane Charley. 
Many of them could not respond immediately after the hurricane.

Primary causes of damage to hospitals were rain water intrusion due to roof 
covering (typically initiated by metal edge flashing failure) and roof top 
equipment failure and window damage from roof aggregate. This damage to building 
envelopes led to extensive internal damage in key hospital areas such as 
emergency rooms, intensive-care units, and general use areas.

All the observed shelters prevented loss of life, which is their primary role. 
However, many of the shelters sustained damage and loss of function. 

A new shelter experienced a partial building collapse during Hurricane Charley 
when design and construction requirements for EHPA were apparently not properly 
followed and implemented.

Many schools sustained significant interior water damage.


Photograph: This school building experienced several building envelope problems, 
which allowed water intrusion, but it did not disrupt operations. Damage and 
disruptions may have been worse if design wind speed conditions had been 
experienced.


Chapter 4
Conclusions and Recommendations

The following conclusions and recommendations are based on the most significant 
damages observed by the MATs and Rapid Assessment Teams deployed after 
Hurricanes Charley, Frances, and Ivan. Additional conclusions and 
recommendations are included in the individual reports for these hurricanes.  
The following sections outline the most significant conclusions and 
recommendations. Detailed recommendations are included in four matrices 
presented at the end of this Summary Report.

4.1 Wind-Related Conclusions and Recommendations

Houses built in accordance with the FBC 2001 or the IBC 2000/2003 generally 
avoid most wind related structural issues. At this time, improvements must focus 
on preventing rain water intrusion and protecting the building envelope.  
Protection of the building envelope is important in minimizing losses to 
building contents.

General

NOAA/NWS Monitoring System


None of the Automated Surface Observing System (ASOS) and other systems that 
were impacted by the strongest winds of Hurricane Charley (as far inland as 
Orlando) continued to report wind information throughout the storm. Assessment 
of structure and infrastructure performance is keyed to wind speed estimates 
experienced throughout the area of impact. Based on performance during Hurricane 
Charley, National Oceanic and Atmospheric Association (NOAA)/NWS surface wind 
and weather monitoring systems in areas of the U.S. threatened by hurricanes 
must be hardened and provided with backup power and better data storage.

Hurricane Classification
Building performance across the paths of the hurricanes varied significantly 
by location in the wind swath area. The categorization of a storm by a single 
hurricane classification has limited use in post storm assessment. Wind field 
estimates and wind speed swath maps (refer to Figures 25 for examples) are 
critical to properly assess storm events and their implications for building 
design, construction, and code development.

Structural
To minimize damage or prevent failure of older buildings (both residential 
and commercial), mitigation actions that create a continuous load path from the 
roof deck to the foundation must be undertaken. Specific recommendations are 
included in Matrix #2, Building Code and Regulations Recommendations.

Accessory Structures 
Historically and typically, aluminum structures have had little rigorous 
engineering applied to them because they have been regarded as auxiliary and 
even expendable structures. As such, the widespread failure of these structures 
observed after the 2004 hurricane season was anticipated. 

Connection detail failures and inadequate bracing were frequently the 
initiation points for the ultimate failure of accessory structures indicating 
that, in general, designers, installers, and building department personnel may 
not be sufficiently knowledgeable about the design and construction of wind 
resistant aluminum structures. Attention is generally given to the size and 
spacing of members, but not to connection details. Revised guidance associated 
with Table 2002.4 (FBC 2001), prepared by the Aluminum Association of Florida 
(AAF) should be used until the adoption of the 2004 version of the FBC. Specific 
recommendations relating to accessory structures and attachment are cited in 
Matrix #1, Design and Construction Recommendations.

Building Envelope 

Poor building envelope performance resulted in extensive property damage and 
substantial loss of function. Poor performance was a function of both inadequate 
wind resistance and damage from debris impact. 

Inadequate resistance to large wind pressures on building envelopes 
(particularly roof systems and soffits) and rooftop equipment was responsible 
for much of the damage incurred by the hurricanes. 

Windborne debris, especially during Hurricane Charley where wind speeds in some 
areas were 120 mph 3-second gust and greater, caused significant envelope 
damage. 

Recommendations to improve building envelope performance include: modifications 
to building codes, Florida statutes, and regulatory requirements (refer to 
Matrix #2); specific recommendations by building envelope element (Matrix #1); 
and additional/new guidance materials and public education (Matrix #3, Public 
Outreach Recommendations).

Building Codes, Florida Statutes, and Regulatory Requirements 

Buildings built in accordance with older codes are typically vulnerable to 
envelope and equipment damage because older codes had inadequate criteria or no 
criteria at all. Where buildings were designed and constructed to newer codes 
(FBC or IBC/IRC), some of the observed failures were due to failure to comply 
with code provisions in the design and/or construction phases. Other failures 
were the result of installing materials and systems that cannot perform under 
high-wind loads (i.e., the use of inadequately secured soffit panels). Because 
these elements are not considered structural elements, their design and 
construction is often overlooked during design, construction, and code 
enforcement. Therefore, improvements are needed in the design requirements of 
codes themselves and with code enforcement. Specific code change recommendations 
are included in Matrix #2.

Building Envelope Systems

Certain building envelope components reported on in previous MAT reports 
continue to be initiation points for substantial interior damage and/or 
progressive failure. The following elements require additional guidance and 
design; specific recommendations by element type are included in Matrix #1.

Roof systems. Many roof coverings of all types continue to fail at unacceptable 
rates during hurricane events, even when wind speeds are below design levels. 
Failure is due to the age of the coverings (coverings that were never considered 
for their ability to resist what is now understood as design level wind loads), 
debris impact, and design and construction related issues. Inadequate attention 
has typically been given to edge flashing, coping, and gutter/downspout design 
and installation despite their roof area locations, which are subject to the 
highest wind pressures. 

Exterior Mechanical and Electrical Equipment Damage. 
Displacement or damage to these units resulted in loss of function associated 
with the damaged units and, in many cases, loss of function of the occupied 
space serviced by the equipment. Rooftop and ground level equipment is not 
receiving the design, installation, or code compliance needed. 

Soffits. In numerous buildings, wind-driven rain intruded into areas where 
soffits were displaced or lost. Widespread loss of soffits was observed in 
residential construction.

Wall Covering. Wall coverings continue to be an initiation point for progressive 
failures leading to interior contents damage or pressurization of the building.

Doors. As building performance has improved and resolved many of the large 
structural issues, increased attention can be focused on doors and wind-driven 
rain infiltration. Weather stripping and vestibules are recommended to minimize 
interior damage from wind-driven rain.

Windows and Shutters. The required protection of windows and glazed doors in 
areas within the ASCE 7 windborne debris region appeared justified based on the 
amount of observed windborne debris from Hurricanes Charley, Frances and Ivan. 
The FBC windborne debris provisions in the panhandle should be changed to match 
those in ASCE 7. Most shutters observed on buildings performed well. Many homes 
and businesses that experienced only contents damage could have prevented these 
losses if their building envelope openings were protected. 

4.2 Flood-Related Conclusions and Recommendations

The most severe flood-related damages experienced during the 2004 hurricane 
season were associated with Hurricane Ivan. Several general conclusions were 
drawn based on damage observations by the MAT. 

General 

Flood levels several feet higher than the mapped BFEs on the FIRMs were 
recorded. Several reasons could account for this: Ivan may have been a storm 
with a higher return period than the 100-year event shown on the FIRMs; there 
may have been changes in the topography over the 20 to 25 years since the storm 
surge modeling was initially performed; or older storm surge modeling 
methodologies may have failed to produce accurate estimates. Recommendations 
based on these observations are:

Re-evaluate the hazard identification/mapping approaches in Coastal A/V Zones. 
Re-evaluate the methodology to determine flood zones and flood elevations in 
coastal high hazard areas to address the inconsistencies of observed damages 
versus anticipated damages based on mapped flood zones. Flood hazard mapping 
procedures and methodologies in coastal areas (especially on barrier islands and 
on mainland, open coast shorelines) may need revision to capture anticipated 
future coastal conditions (for instance, the possible effects of multiple storm 
events and long-
term erosion).
 
Re-evaluate the storm surge modeling. Re-analyze the storm surge modeling, which 
provides the storm surge elevations for the mapping analysis, because of 
significant changes in the barrier islands since the modeling was first 
performed.

Reconstruction Guidance. Use Hurricane Ivan tide levels, inundation limits, and 
areas subject to wave effects as proxies for reconstruction guidance until such 
time as new, up-to-date regulatory studies and maps can be prepared and adopted.

Structures and Foundations

Pile Foundations. Although pile foundations generally performed well, their 
performance varied depending on the level of detail followed during building 
construction. Additionally, flood-borne debris contributed significantly to the 
structural damages that were observed by creating unanticipated loads on pile 
foundations. Recommendations to address these issues are presented in Matrix #1.

Shallow Foundations. In areas subject to coastal erosion and scour, shallow 
foundation damage was extensive and the structural failures dramatic. The most 
extreme cases were building failures due to erosion of supporting soil under 
shallow foundations. Shallow foundations are not appropriate for supporting 
structures in coastal areas subject to scour and/or erosion and should not be 
permitted. Specific foundation design measures related to barrier island 
construction and bay/sound shoreline area construction are provided in the 
Matrix #1. 

General recommendations on the foundations are:

Elevate the bottom of the lowest structural member above the BFE for Coastal A 
Zones. Damages to lowest floor elevations were widespread in the flood damaged 
areas. All new construction (including substantially improved structures and 
replacement of substantially damaged structures) in Coastal A Zones should be 
elevated with the bottom of the lowest horizontal structural member at the base 
flood level.

Freeboard. Require freeboard for all structures in all flood hazard zones with 
the amount varying with building importance and anticipated exposure to wave 
effects. Recommendation is based on ASCE 24-05, which addresses freeboard and 
elevation requirements for flood resistant materials and equipment. Specific 
recommendations are provided in Matrix #2. 

V Zone standards. Require V Zone foundations for new construction in Coastal A 
Zones subject to erosion, scour, and/or wave heights greater than 1.5 feet. 
Require deep pile or column foundations in areas mapped as Zone B, C. or X, 
where erosion and/or scour are possible.

FEMA 55 Coastal Construction Manual. Emphasize best practices contained in 
FEMAs Coastal Construction Manual and in the latest flood resistant codes and 
standards.

Accessory Structures and Construction 
Features Beneath Elevated Structures

Accessory structures such as stairs and enclosures built beneath elevated 
buildings were totally destroyed. Most of this damage is preventable by limiting 
the construction of these enclosures and other systems built beneath elevated 
buildings. Not only are the enclosures, stairs, utilities, and other systems 
severely damaged, but they become a significant source of flood-borne debris, as 
were docks and piers. Once dislodged by storm surge, wave action, or wind, these 
features can act as obstructions and create unanticipated loads on the 
foundations and increase the potential for structural failure. Refer to Matrix 
#1 for specific recommendations related to these structures. 

To discourage construction that results in this type of damage, flood insurance 
claims payments for stairs and building access structures should be limited to a 
reasonable fraction of the policy limit and claim procedures should be modified 
to ensure flood insurance policy ratings are correct, particularly with regard 
to enclosures and obstructions.


4.3 Critical and Essential Facilities/Shelters, 
Conclusions and Recommendations 

Poor performance of numerous critical/essential facilities and shelters 
occurred in the fall of 2004 during Hurricanes Charley, Frances, Ivan, and 
Jeanne. The building damage these facilities sustained during the hurricanes led 
to significant, yet avoidable, loss of function. 

Many essential and critical facilities (excluding shelters) were housed in older 
buildings and most apparently were not mitigated to resist known hurricane wind 
risks. If these critical and essential operations were housed in buildings 
constructed to current code (which provides levels of protection from wind and 
in some cases to windborne debris), some of these buildings could have then 
remained operational. Alternatively, many of these facilities could have 
remained operational if key areas of the buildings had been mitigated or 
retrofitted for wind and windborne debris design requirements for their 
locations as specified in the current code. Code improvements are also needed. 
The current practices for designing, constructing, retrofitting/mitigating, 
and maintaining critical/essential facilities can be improved.

In addition, the continuity of critical facilities needs to be ensured. In 
some cases this means designing beyond the existing code minimums (e.g., remove 
or replace roof-top aggregate). A vulnerability assessment should be performed 
to assess the building performance and utilities that service critical 
facilities. This would provide the building owner a better understanding how the 
building will be impacted during a storm and how the operations will be impacted 
by limited utility services. As an example, electrical service may provide power 
to lift stations for sewage; if the building were used as a shelter and 
electrical service is disrupted during a storm, backup systems would likely be 
required, but certain portions of the building may not need to be 
operational. 

The performance of buildings used as hurricane shelters also varied widely. 
Performance varied from numerous successes to an instance of a partial building 
collapse. Although only minor injuries were reported, large numbers of people 
within shelters were traumatized because of poor building performance or 
perceived poor performance when comfort issues were compromised. In Charlotte 
and Lee Counties in Florida, shelters used during Hurricane Charley were located 
within the storm surge inundation zone for a Category 3 hurricane; luckily, 
due to the compact size of the hurricane, typical storm surge was not generated 
and the shelters were not flooded; however, if typical surge had occurred, this 
shelter would have been flooded.

To achieve building performance during hurricanes that will preserve the 
facility function, the following are recommended in addition to the specific 
recommendations provided in Matrix #2 and Matrix #4, Critical and Essential 
Facility Recommendations.

Expand the use of the critical/essential facility designation. Buildings other 
than those defined by ASCE 7 Table 1 may be vital in the response or recovery 
after a hurricane, or they may house functions that need to remain operational 
during or after an event. For example, damage to a medical office building, 
though not necessarily a Category III or IV building, could adversely affect the 
hospital functions. Additionally, skilled nursing homes, Alzheimers units, and 
perhaps independent living or assisted living facilities could benefit from this 
designation.

Prioritize the critical and essential facilities. Although all critical and 
essential facilities are important, some are more critical than others. 
Buildings sheltering large numbers of people (e.g., greater than 1,000) and 
buildings that have regional importance (e.g., a county EOC or regional 
hospital) should be designed, constructed, and maintained more conservatively 
than normal critical and essential facilities. Existing critical and essential 
facilities should also receive the highest priority for mitigation (retrofit). 
Designers should also remember that codes and standards recommend the minimum 
design requirements for facilities (even critical and essential facilities). 
Designers should implement known best practices for high-wind design above the 
minimums required.


4.4 Design Guidance and Public Education 
Recommendations

Design and Construction Guidance

Many building component failures observed during the 2004 hurricane season were 
the result of the failure to implement well-established basic construction 
practices. Designers and contractors need additional guidance to understand 
wind-resistance issues and to provide methodologies and best practices when code 
guidance is vague or unclear or does not exist. Based on the MATs observations, 
specific design, testing and construction guidance is needed for the several 
areas listed below. 

Detailed recommendations are included in Matrix #3:

Design Guidance

Roof coverings, gutters, and downspouts

Rolling and sectional doors

Soffits

Rooftop equipment

Other exterior devices and equipment such as pool equipment, 
swing sets, and storage sheds

Electrical and communications equipment

Testing Guidance

Test methods: Most of the methods used to test envelope assemblies are static 
tests, which are inadequate for some assemblies. The development and application 
of dynamic tests are recommended.

Construction Guidance
Manufacturers instructions: There were numerous instances of significant 
deviation from manufacturers installation instructions. Manufacturers need to 
ensure adequate instruction (bilingual instructions would be advantageous) and 
training.

Public Education and Outreach

Much has been learned in the past three decades regarding practices that need to 
be implemented to achieve good building performance during strong hurricanes. 
Although improvements are still needed with respect to design guides, test 
methods, building codes, and construction/inspection practices, many designers, 
manufacturers, building officials, and contractors did not fully implement the 
current state of knowledge (e.g., FEMA 55, FEMA 361, FEMA 424, ASCE 24-05) with 
respect to buildings located in hurricane-prone regions. A renewed, 
comprehensive educational effort is needed to avoid the hurricane building 
damage cycle, wherein buildings are constructed, damaged, repaired, or rebuilt
to a condition often no better than the initial damageand then damaged again in 
a future weather event. Specific recommendations for the following audiences are 
included on Matrix #3. 

Building owners and homeowners 
Architects/engineers/consultants 
Building officials 
Contractors 
Manufacturers 
Associations 

The greatest educational challenge is to get those in need to take advantage of 
educational materials that are available. To the extent possible, materials and 
seminars should be free or of minimal cost. To achieve this goal, governmental 
funding or private sponsorship may be necessary. However, the ultimate incentive 
likely lies with building owners and homeowners, and the decisions they make in 
selecting design and construction teams that will produce the best product for 
their dollar.

Matrix #1.
Design and Construction Recommendations

(As related to Wind Hazard)

The following pertain to Accessory Structures:

Building Component - Attached and Detached
Recommendation - Add additional anchors at corner post connections to concrete.   
Action Required by:  Designer, Contractor.

Building Component - Attached and Detached
Recommendation - Use AAF Guide to Aluminum Construction in High Wind Areas until 
FBC 2004 is adopted.  
Action Required by:  Designer.

Building Component - Attached and Detached
Recommendation - Increase wind resistance of accessory structure walls parallel 
to primary building (e.g., tension cable, solid K bracing).
Action Required by:  Designer.

Building Component - Attached and Detached
Recommendation - Provide lateral bracing in roof planes using rigid diagonal 
structural members.
Action Required by:  Designer, Contractor.

Building Component - Attached
Recommendation - Ensure attached building and primary building can withstand 
equal wind pressures. 
Action Required by:  Designer, Contractor.

Building Component - Attached
Recommendation - Determine implications to primary building if attached 
structure collapses.
Action Required by:  Designer, Contractor.

Building Component - Detached
Recommendation - Determine ability to withstand windstorm events to reduce 
windborne debris.
Action Required by:  Designer, Contractor.


The following pertain to Building Envelope:

Building Component - Roof Systems
Recommendation - Testing: Roof assemblies susceptible to dynamic loading should 
be dynamically tested to obtain realistic measure of their wind resistance. 
Higher safety factors should be used for those assemblies requiring dynamic 
testing, but for which dynamic test methods are not available.
Action Required by:  Designer, Contractor, Government Official.

Building Component - Re-roofing
Recommendation - Tear off old roof (do not re-cover) in areas where basic wind 
speed is 110 mph or greater.
Action Required by:  Designer, Contractor.

Building Component - Re-roofing
Recommendation - Install additional sheathing fasteners if existing sheathing 
attachment is not in compliance with current building code.
Action Required by:  Designer, Contractor.

Building Component - Asphalt shingles
Recommendation - Ensure manufacturers installation instructions are followed 
(i.e., starter strips and nail locations) and use Recovery Advisory Nos. 1 and 
2.
Action Required by:  Designer, Contractor.

Building Component - Asphalt shingles
Recommendation - Re-evaluate attachment of factory-laminated tabs.
Action Required by:  Manufacturer

Building Component - Metal panel roof system
Recommendation - Ensure that chalk-line clip locations for panels with concealed 
clips are not excessively spaced.
Action Required by:  Contractor.

Building Component - Metal panel roof system
Recommendation - Base uplift resistance on ASTM E 1592.
Action Required by:  Manufacturer, Designer.

Building Component - Metal panel roof system
Recommendation - Specify close spacing of fasteners at eaves, and hip, and ridge 
flashings.
Action Required by:  Designer.

Building Component - Tile roof system
Recommendation - Use Recovery Advisory No. 3.
Action Required by:  Designer, Contractor.

Building Component - Tile roof system
Recommendation - Develop tiles with improved ductility via internal or backside 
reinforcement or bonding film in hurricane-prone regions (e.g., develop tile 
similar to laminated glass).
Action Required by:  Manufacturer.

Building Component - Tile roof (foam-set) system
Recommendation - For foam set tile, simplify number of installation options and 
clarify requirements.
Action Required by:  Manufacturer.

Building Component - Tile roof (foam-set) system
Recommendation - Modify training and certification programs to ensure that foam-
set roof installers are adequately trained.
Action Required by:  Manufacturer, Contractor.

Building Component - Tile roof (foam-set) system
Recommendation - Use a higher safety factor (e.g., 4) to account for application 
and testing issues.
Action Required by:  Manufacturer, Designer.

Building Component - Mechanically attached roof systems, Recommendation - 
FRSA/TRI re-evaluate use of safety factor of 2.  
Either develop dynamic test method or use existing test method with higher 
safety factor (e.g., 3).
Action Required by:  Manufacturer, Designer.

Building Component - Built-up roofs, Recommendation - Develop and codify 
technically-based criteria for aggregate surfacing  
on built-up and sprayed polyurethane foam roofs.
Action Required by:  Manufacturer, Government Official.

Building Component - Edge flashings & copings, Recommendation - Comply with 
ANSI/SPRI ES-1 (2003). Use safety factor of 2 -  3.
Action Required by:  Designer.

Building Component - Edge flashings & copings, Recommendation - Install edge 
flashings on top of membrane to clamp it down.
Action Required by:  Designer, Contractor.

Building Component - Edge flashings & copings, Recommendation - Place a bar over 
roof membrane near edge of flashing and  
coping to provide secondary protection.
Action Required by:  Designer, Contractor.

Building Component - Gutters & downspouts, Recommendation - Use professional 
judgment to specify and detail gutter uplift  
resistance.
Action Required by:  Designer.

Building Component - Gutters & downspouts, Recommendation - Design Guidance: 
Develop design guide, test method, and 
code  criteria for gutters, including attachment of downspouts.
Action Required by:  Manufacturer, Contractor.

Building Component - Rooftop walkway pads, Recommendation - Research wind 
resistance of roof walkway pads.
Action Required by:  Manufacturer, Government Official.

Building Component - Soffits, Recommendation - Design Guidance: Develop design 
guidance for attaching soffits, 
including design of baffles or filter media to prevent wind-driven rain from 
entering attics.
Action Required by:  Manufacturer, Government Official.


The following pertain to Exterior Equipment:

Building Component - General, Recommendation - For all exterior equipment, 
recommend safety factor of 3 due to 
uncertainties pertaining to wind load. 
Action Required by:  Designer.

Building Component - General, Recommendation - Design Guidance: Develop guidance 
and code criteria for attaching 
condensers and rooftop mechanical equipment (including ductwork).
Action Required by:  Designer, Government Official.

Building Component - General, Recommendation - Evaluate the need to better 
secure exterior devices, such as pool 
equipment and roof-mounted solar heaters.
Action Required by:  Designer, Contractor, Building Owner.

Building Component - Cowlings, Recommendation - Anchor cowlings on exhaust fans 
to curbs using cables. 
Action Required by:  Manufacturer, Designer, Contractor.

Building Component - Access panels, Recommendation - Modify access panels 
attached by manufacturer to ensure secure  
attachment (see FEMA 424). 
Action Required by:  Manufacturer, Designer, Contractor.

Building Component - Lightning protection systems, Recommendation -  Attach 
lightning protection systems, per FEMA 424.
Action Required by:  Manufacturer, Designer, Contractor.

Building Component - Lightning protection systems, Recommendation - Design 
Guidance: Develop guidance and 
code criteria for attaching lightning protection systems. Anchor communication 
towers and satellite dishes.
Action Required by:  Designer, Contractor, Manufacturer, Government Official.

Building Component - Vinyl siding
Recommendation - Design Guidance: Develop design guidance for attachment.
Action Required by:  Manufacturer, Government Official.

Building Component - EIFS
Recommendation - Design Guidance: Develop design guidance for attachment and re-
evaluate existing test method.  
Action Required by:  Manufacturer, Government Official.


The following pertain to Doors:

Building Component - Exterior doors
Recommendation -  Specify wind-driven rain resistant weather-stripping at 
exterior doors (see FEMA 424).
Action Required by:  Designer.

Building Component - Entrance vestibules
Recommendation - Design entrance vestibules in areas where basic wind speed is 
greater than 120 mph.
Action Required by:  Designer.

Building Component - Rolling & sectional doors
Recommendation - Consider type, size, and spacing of door, frame, and frame 
fasteners to withstand wind loads. If frame is attached to wood blocking, then 
consider blocking attachment. 
Action Required by:  Designer, Contractor.

Building Component - Rolling & sectional doors
Recommendation - Maintain adequate edge distances for frame fasteners. 
Action Required by:  Contractor.


The following pertain to Window and Shutters:

Building Component - General
Recommendation - The window industry should re-evaluate current test procedures 
to better represent dynamic wind loading produced by hurricane and tropical 
storm winds. 
Action Required by:  Designer, Contractor, Manufacturer, Government Official.

Building Component - General
Recommendation - Develop window assemblies that are more wind-driven rain water-
resistant.
Action Required by:  Manufacturer.



Matrix #1. (continued)
Design and Construction Recommendations

(As related to Flood Hazard)

The following data pertains to: FOUNDATIONS AND STRUCTURES

Building Component - General
Recommendation - Design foundations and structures to withstand loads from 
flood-borne debris during a base flood event (100-year).
Action Required by:  Designer.

Building Component - Foundations on barrier islands
Recommendation - Require V Zone foundations for new construction in Coastal A 
Zones subject to erosion, scour, and/or subject to wave heights of 1.5 feet or 
higher during a base flood event. 
Action Required by:  Government Official.

Building Component - Foundations on barrier islands
Recommendation - Use pile or column pier foundations for A Zone areas not 
subject to erosion and not subject to 1.5 foot (or higher) wave heights to 
minimize flood-borne debris damage. Stem wall foundations may be appropriate for 
areas subject to shallow flooding, but foundation walls are not recommended. 
Action Required by:  Designer, Contractor.

Building Component - Foundations on barrier islands
Recommendation - Require deep pile or column foundations in areas presently 
mapped as Zones B, C, or X, where erosion and/or scour is possible. 
Action Required by:  Government Official.

Building Component - Foundations on barrier islands
Recommendation - Require use of self-supporting lowest floor system that will 
not collapse if undermined for high-rise construction in areas outside the V 
Zone. 
Action Required by:  Government Official.

Building Component - General
Recommendation -  Use flood and corrosion resistant materials below the BFE as 
recommended by American Society of Civil Engineers (ASCE) 24-05 and the Coastal 
Construction Manual (FEMA 55).
Action Required by:  Designer, Contractor.

Building Component - Foundations in bay and sound shoreline areas
Recommendation - Require V Zone foundations for new construction subject to 
erosion and/or scour in bay areas outside mapped V Zones. 
Action Required by:  Government Official.

Building Component - Foundations in bay and sound shoreline areas
Recommendation - Require V Zone foundations for new construction subject to wave 
heights of 1.5 feet or higher in bay areas outside mapped V Zones.
Action Required by:  Government Official.

Building Component - Foundations in bay and sound shoreline areas
Recommendation - Use pile, column, or pier foundations for A Zone areas that are 
not subject to erosion, scour, or 1.5-foot (or higher) wave heights to minimize 
flood-borne debris damage. Stem wall foundations may be appropriate for areas 
subject to shallow flooding, but foundation walls are not recommended. 
Action Required by:  Designer, Contractor.

Building Component - First floor elevation
Recommendation - Elevate all new construction (including substantially improved 
structures and replacement of substantially damaged structures) in A Zones with 
the bottom of the lowest horizontal supporting member above the base flood 
level. Freeboard for all structures in all flood hazard zones is desirable; the 
amount will vary with building importance and anticipated exposure to wave 
effects.
Action Required by:  Designer, Contractor.


The following data pertains to:  ACCESSORY STRUCTURES AND CONSTRUCTION BENEATH 
ELEVATED STRUCTURES

Building Component - Dock and Piers
Recommendation -  Implement design requirements for docks and piers that 
minimize damage to other structures.
Action Required by:  Designer.



Matrix #2.

Building Code and Regulations Recommendations

(As related to Wind Hazard)

The following data pertains to Building Envelope:

Building Component - Edge flashing and coping 
Recommendation - FBC Section 1503 (Weather Protection) should require compliance 
with ANSI/SPRI ES-1 for 
edge flashings and copings. 

Building Component - Gutters
Recommendation - FBC Section 1503 (Weather Protection) and IBC/IRC: Develop and 
add criteria regarding uplift resistance of gutters. 

Building Component - Metal panel roof system
Recommendation -  FBC Section 1504 (Performance Requirements): Require 
compliance with ASTM E 1592 for testing the uplift resistance of metal panel 
roof systems.

Building Component - Roof system
Recommendation - FBC Section 1510.3 (Recovering vs. Replacement) and IBC/IRC: 
Require removal of existing roof covering down to the deck and replacement of 
deteriorated sheathing in areas where basic wind speed is 110 mph or greater. If 
existing sheathing attachment does not comply with loads derived from Chapter 
16, then require installation of additional fasteners to meet loads.

Building Component - Asphalt shingles
Recommendation - FBC Section 1507.2 (Roof Covering Application) and IBC/IRC: 
Require compliance with UL 2390. Also require six nails per shingle and require 
use of asphalt roof cement at eaves, rakes, hips, and ridges where basic wind 
speed is 110 mph or greater (refer to Recovery Advisory No. 2). 

Building Component - Mortar-set tile roof system
Recommendation - FBC Section 1507.4 (Clay and Concrete Tile) and IBC/IRC: 
Provide an alternative to the use of mortar to attach field tiles and hip/ridge 
tiles.
 
Building Component - Built-up roof 
Recommendation - FBC Section 1508 (Roof Coverings with Slopes Less Than 2:12): 
Add technically-based criteria regarding blow-off resistance of aggregate on 
built-up and sprayed polyurethane foam roofs.

Building Component - Ridge vents
Recommendation - FBC Section 1503 (Weather Protection) and IBC/IRC: Add criteria 
regarding wind and wind-driven rain resistance of ridge vents. Attachment 
criteria require development, but TAS 110 could be referenced for rain 
resistance. 

Building Component - Soffit
Recommendation - FBC/IBC/IRC: Criteria regarding wind resistance of soffits 
should be added, and wind-load criteria for soffits require development. Wind-
driven rain resistance of ventilated soffit panels should also be added. TAS 110 
may be a suitable test method, modified as necessary. 



The following information pertains to WINDOWS AND SHUTTERS:

Building Component - Shutters
Recommendation - FBC Section 1606.1.4 (Protection of Openings): Add requirement 
to label shutters (other than wood) because without labels, building owner does 
not know if shutters are suitable. 

Building Component - Windborne debris region
Recommendation - FBC: Revise the Florida panhandle criteria to match ASCE 7.  

Building Component - Shutters
Recommendation -  Revise Chapter 15C of the Rules and Regulations of Florida to 
provide window protection systems (and a strengthened structure around openings) 
on Zone II and Zone III units being installed in the windborne regions defined 
by Chapter 16 of the FBC.


The following data pertains to EXTERIOR EQUIPMENT:

Building Component - General
Recommendation - FBC Section 1522.2 (Rooftop Mounted Equipment): Make applicable 
throughout the State of Florida for all wind speeds. Develop and add criteria 
that pertain to attaching lightning protection systems. Provisions also included 
in mechanical and electrical codes. 


The following data pertains to CRITICAL AND ESSENTIAL FACILITIES:

Building Component - General
Recommendation - For hurricane shelters and EHPA, adopt wind speed recommended 
by Florida Department of Community Affairs (FL DCA) in the SESP and the ASCE 7-
02/2001 FBC wind speed map design wind speed plus 40 mph using Performance 
Criteria 3. Currently this is a recommended best practice in the FL DCA shelter 
design guidance and in FBC Section 423, Part 24; change to a requirement. This 
criterion should be required by the SESP and should be used until the 
International Code Councils High Wind Shelter Standard is completed in 
2006/2007 and available for adoption. 

Building Component - General
Recommendation - Minimum debris impact protection should be per ASTM E 1996 
Category E for a 9 -pound 2x4 (nominal) missile traveling at 50 mph. This 
criterion should be required by the SESP and should be used until the 
International Code Councils High Wind Shelter Standard is completed in 
2006/2007 and available for adoption.  

Building Component - General
Recommendation - As an alternative to designing shelters to the SESP or ASCE 
criteria, design or retrofit buildings to be used as shelters to the design 
guidance provided in FEMA 361, Design and Construction Guidance for Community 
Shelters.  


Matrix # 2 Building Code and Regulations Recommendations (continued)

(As related to Flood Hazard)

The following data pertains to FOUNDATIONS AND STRUCTURES:

Building Component - General
Recommendation - Adopt ASCE 24-05 for elevation requirements and flood resistant 
materials, equipment.

Building Component - General
Recommendation - Re-evaluate the hazard identification/mapping approaches in 
Coastal A/V Zones (refer to glossary for definitions). 

Building Component - General
Recommendation - Re-evaluate the storm surge modeling methodology.



Matrix #3.

Public Outreach Recommendations (related to Wind Hazard)

The following pertain to: BUILDING OWNERS AND HOMEOWNERS

EDUCATION TOPICS 
- Plan and budget construction projects that incorporate natural hazard 
mitigation measures.
- Select design and construction teams knowledgeable in effective construction 
methods in hurricane-prone areas.
- Prepare and protect building prior to hurricane landfall.
- What to do after hurricane passes (building inspection for damage, emergency 
repairs, and drying out building interiors).
- Rebuild damaged structure in manner that protects against future damage. 
- Inspect exterior connections and fasteners for wear, corrosion, and other 
deterioration.
- Educate building owners on how wind-driven rain water enters buildings, the 
resulting implications (loss of electricity, mold), 
and prevention methods.

OUTREACH METHODS 
- Tailor informational pamphlets to homeowners and building owners.
- Develop strategy to distribute information (e.g., standardized information 
sheets during sale of building). 
- Enlist assistance of real-estate companies and organizations such as the 
Building Owners and Managers Association.
- Provide public service notices at start of each hurricane season.
- Develop informational materials on how wind-driven rain water enters 
buildings, the resulting damage, and prevention methods.


The following pertain to: ARCHITECTS, ENGINEERS, and CONSULTANTS

EDUCATION TOPICS 
- Improve the technical proficiency of building envelope design.
- Provide adequate level of design details for connecting rooftop equipment, 
including mechanical, electrical, and lightning protection. 
- Share post-disaster building performance information to maximize the value of 
lessons learned.

OUTREACH METHODS
- Prepare monographs for trade-wide distribution.
- Prepare web-based tutorials and seminars.
- Encourage colleges and universities to augment existing curriculum with 
hurricane-resistant design instruction.


The following pertain to: BUILDING OFFICIALS

EDUCATION TOPICS 
- Share post-disaster building performance information to maximize the value of 
lessons learned. 
- Train building officials to identify structural weaknesses that may cause 
structure or building component failure 
during a hurricane (e.g., unbraced gable ends, missing truss bracing, truss 
anchorage, window/door anchorage).
- Implement effective enforcement techniques to maintain a high construction 
quality.

OUTREACH METHODS
- Conduct annual seminars for building officials and plan reviewers in coastal 
areas to share lessons learned.
- Implement hurricane disaster building inspection training program and train 
the trainer program.


The following pertain to: CONTRACTORS

EDUCATION TOPICS
- Educate contractors who construct building envelopes and install rooftop 
equipment on hurricane resistant fastening 
and anchoring systems.
EDUCATION TOPIC - Educate contractors on how wind-driven water enters buildings, 
the resulting implications 
(loss of electricity, mold), and prevention methods.

OUTREACH METHODS
- Develop and distribute visual tools such as instructional videos or DVDs.
- Conduct on-the-job training to highlight failures that occur when simple 
anchoring techniques are not applied.
- Encourage trade schools in hurricane-prone areas to augment their curriculum 
with courses on state-of-the-art 
hurricane-resistant construction.


The following pertain to: MANUFACTURERS

EDUCATION TOPICS 
- Educate manufacturers of building envelope materials and rooftop equipment on 
the performance of their products during hurricanes.
- Encourage manufacturers to provide special guidance for use of their products 
in hurricane-prone areas. 
- Develop improved products and systems for hurricane-prone areas. 
- Manufacturers should educate designers and contractors on their product

OUTREACH METHOD - Develop and distribute informational notices to manufacturers.


The following pertain to: ASSOCIATIONS, INSTITUTES, AND SOCIETIES

EDUCATION TOPIC - Advocate hurricane-resistant design and construction to their 
membership.
OUTREACH METHOD - Develop educational materials for distribution to their 
members and industry.


Matrix #3.
(Continued) 

Public Outreach Recommendations (related to Flood Hazard)

The following pertain to: BUILDING OWNERS AND HOMEOWNERS

EDUCATION TOPICS 
- Educate building and homeowners in the risks of natural hazards and best 
practices for mitigating damages.
- Educate homeowners on the risk of constructing enclosures and accessory 
structures beneath the first floor and 
emphasize the significant damage that will result during a severe coastal flood 
event.

OUTREACH METHOD - Tailor informational pamphlets to homeowners and building 
owners.


The following pertain to: ARCHITECTS, ENGINEERS, CONSULTANTS, BUILDING 
OFFICIALS, and CONTRACTORS

EDUCATION TOPICS 
- Share post-disaster building performance information to maximize the value of 
lessons learned.
- Emphasize best practices such as Coastal Construction Manual (FEMA 55). 
EDUCATION TOPIC - Emphasize importance of strong structure-to-beam connections 
to prevent structure detachment 
from the foundations while piles and beams are still intact. 

OUTREACH METHODS 
- Prepare monographs for trade-wide distribution.
- Prepare web-based tutorials and seminars.
- Encourage colleges, universities, and trade schools to augment existing 
curriculum with hurricane-resistant design and 
construction instruction.



Matrix #4.
Recommendations Specific to Critical and Essential Facilities (refer also to 
other matrices)
These recommendations are related to Wind Hazard.

The following data is General.

Building Component - Detailing and notations on the building plans 
Recommendation - Facility plans should delineate the facility area designed to 
function as a shelter or hardened area. 
Details of the shelter or hardened area and the envelope elements should be 
provided to ensure that the construction 
requirements are clearly understood by the builder and building official. 
Provide facility design criteria and maximum design 
pressures for the main wind force resisting system  (MWFRS) and for components 
and cladding.
Action Required by:  Designer, Contractor, Critical Facility Manager/Owner.

Building Component - Material selection
Recommendation - Reinforced concrete roof deck and reinforced concrete and/or 
reinforced and fully-grouted concrete masonry 
unit (CMU) exterior walls are recommended. - FEMA 424, Design Guide for 
Improving School Safety in Earthquakes, Floods, 
and High Winds, and FEMA 361, Design and Construction Guidance for Community 
Shelters, provide detailed guidance on 
material selection for structural and building envelope systems. 
Action Required by:  Designer, Contractor, Critical Facility Manager/Owner.

Building Component - General
Recommendation - Develop additional criteria to help insure continuity of 
function. See FEMA 424 and FEMA 361.
Action Required by:  Critical Facility Manager/Owner.

Building Component - General
Recommendation - Emphasize best practices for schools and shelters described in 
FEMA 424 and FEMA 361 respectively, 
and in the latest codes and standards for wind resistance (ASCE 7).
Action Required by:  Critical Facility Manager/Owner.

Building Component - Design guidance
Recommendation - Develop a comprehensive design guide to complement FEMA 424 for 
mitigating existing facilities.
Action Required by:  Designer, Government Official.

Building Component - Perform vulnerability assessment 
Recommendation - Perform vulnerability assessment to ensure continuity of 
operations. The assessment should evaluate 
the building performance and utilities that service  critical/essential 
facilities so that the building owner understands 
impacts to the facility during a storm and operational  impacts due to limited 
utility services.
Action Required by:  Critical Facility Manager/Owner.


The following data pertain to STRUCTURAL:

Building Component - General
Recommendation - Implement mitigation measures or structurally retrofit 
critical/essential facilities to design levels other 
than minimum code requirements for general use buildings. Do not house critical 
facilities  in lightly engineered buildings 
such as pre-engineered metal buildings.
Action Required by:  Critical Facility Manager/Owner, Designer.

Building Component - General
Recommendation - Educate designers: buildings designed to minimum EHPA 
requirements does not guarantee that building 
used as shelter will be properly designed and constructed to resist extreme wind 
events.  Emphasize best practices for shelters 
described in FEMA 361.
Action Required by:  Designer, Contractor.

Building Component - General
Recommendation - Educate designers: American Red Cross 4496 provides a baseline 
for a shelters integrity and performance, 
but meeting this criterion does not guarantee that the building will resist wind 
and windborne  debris associated with hurricanes. 
Emphasize best practices for shelters described in FEMA 361.
Action Required by:  Designer, Contractor.

Building Component - General
Recommendation - Conduct special inspections for key structural items and 
connections to ensure performance of critical facilities.
Action Required by:  Critical Facility Manager/Owner, Contractor.

Building Component - General
Recommendation - Design critical and essential facilities with wind loads using 
an importance factor of 1.15 in accordance with 
ASCE 7. For some facilities, design using the 40-mph increase with importance 
factor of 1  (recommended for shelter EHPA 
design in FBC Section 423, Part 24). 
Action Required by:  Designer.

Building Component - General
Recommendation - Incorporate hazard mitigation peer review into design approval 
process to ensure that critical and 
essential facilities are adequately designed to resist extreme winds.
Action Required by:  Designer.

The following data pertain to ACCESSORY STRUCTURES:

Building Component - Detached
Recommendation - Strengthen the anchorage of structures and portable classroom 
buildings at schools.
Action Required by:  Designer, Contractor, Government Official, Critical 
Facility Manager/Owner.


The following data pertain to BUILDING ENVELOPE:

Building Component - General
Recommendation - Contract drawings and specifications for new construction and 
remedial work on existing building 
envelopes and rooftop equipment should undergo rigorous peer review, submittal 
review, field  observation (inspection), 
and testing prior to construction.
Action Required by: Designer, Contractor, Government Official.

Building Component - General
Recommendation - Implement mitigation measures in buildings not built to current 
building codes to protect roof coverings, 
wall coverings, window and door systems, and rooftop equipment.
Action Required by:  Designer, Critical Facility Manager/Owner.

Building Component - General
Recommendation - Conduct special inspections for key building envelope 
components to ensure performance of critical/essential 
facilities. Inspect roof top equipment twice a year. Inspect doors, windows, and 
wall  coverings at 5-year intervals. Conduct 
special inspections of the entire facility (both structural and building 
envelope systems) after storms with wind speeds in excess 
of 90 mph 3-second gust winds. 
Action Required by: Critical Facility Manager/Owner.

Building Component - Roof structure
Recommendation - Install hurricane clips or straps on inadequately connected 
roof beams  and joists in those buildings that 
will be occupied during a hurricane.
Action Required by: Contractor, Critical Facility Manager/Owner.

Building Component - Roof decks
Recommendation - Strengthen inadequately attached roof decks.
Action Required by: Critical Facility Manager/Owner.

Building Component - Roofing
Recommendation - Replace aggregate-surfaced roof systems with non-aggregate 
systems.
Action Required by: Designer, Contractor, Critical Facility Manager/Owner.

Building Component - Roof system
Recommendation - Design roof system that will prevent water infiltration if roof 
is hit by windborne debris.
Action Required by: Designer.

Building Component - Edge flashings and copings
Recommendation - Install exposed fasteners to weak metal edge flashings and  
copings.
Action Required by: Designer, Contractor, Critical Facility Manager/Owner.

Building Component - Gutters and downspouts
Recommendation - Install tie-down straps on gutters to avoid membrane blow-off.
Action Required by: Designer, Contractor, Critical Facility Manager/Owner.

Building Component - Rooftop equipment
Recommendation - Anchor all rooftop equipment.
Action Required by: Designer, Contractor, Critical Facility Manager/Owner.


The following data relate to Doors:

Building Component - Door
Recommendation - Design or mitigate to the 2001 FBC for the 120 mph (3-second 
gust) design wind speed.
Action Required by: Designer.

Building Component - Rolling and sectional doors
Recommendation - Purchase and install high wind-rated, sectional/rolling  doors 
to protect against high wind.
Action Required by: Designer, Critical Facility Manager/Owner.

Building Component - Rolling and sectional doors
Recommendation - Ensure sectional rolling doors are properly installed and  
reinforced to prevent catastrophic door 
failure and building pressurization. Replace or retrofit existing doors that 
lack  adequate resistance.
Action Required by: Designer, Critical Facility Manager/Owner.


The following data relate to WINDOWS AND SHUTTERS:

Building Component - Shutters
Recommendation - Install shuttering system on all exterior glazing that is not 
windborne  debris resistant. Install power-operated 
shutters or laminated glass, or apply an engineered film system to the glazing 
and  frame on upper-level floors.
Action Required by: Designer, Contractor, Critical Facility Manager/Owner.

Building Component - Windows
Recommendation - Implement window protection systems to protect critical 
facilities from windborne debris.
Action Required by: Critical Facility Manager/Owner, Designer.


Matrix #4.
Recommendations Specific to Critical and Essential Facilities (refer also to 
other matrices)
These recommendations are related to Flood Hazard.

The following data relates to FOUNDATIONS AND STRUCTURES:

Building Component - General
Recommendation - Do not open shelters located in potential storm surge 
inundation zones until after the hurricane makes landfall.
Action Required by: Government Official, Critical Facility Manager/Owner.

Building Component - General
Recommendation - Elevate new structures in flood prone areas to the 500-year 
(0.2 percent annual exceedance) flood level, or higher 
based on ASCE 24.
Action Required by:  Designer, Contractor, Government Official, Critical 
Facility Manager/Owner.

[END OF MATRICES)


Acronyms

AAF Aluminum Association of Florida.
ANSI American National Standards Institute.
ASCE American Society of Civil Engineers.
ASOS Automated Surface Observing System.
ASTM American Society for Testing and Materials. 
BFE Base Flood Elevation.
BPAT Building Performance Assessment Team. 
CMU Concrete masonry unit.
EHPA Enhanced Hurricane Protection Area.
EIFS Exterior Insulation Finishing Systems.
EOC Emergency Operations Center. 
FBC Florida Building Code.
FEMA Federal Emergency Management Agency.
FIRM Flood Insurance Rate Map.
FL DCA Florida Department of Community Affairs.
FRSA Florida Roofing, Sheet Metal and Air Conditioning Contractors Association, 
Inc.
HMTAP Hazard Mitigation Technical Assistance Program.
HUD U.S. Department of Housing and Urban Development.
HVAC Heating, ventilation, and air conditioning.
IBC International Building Code.
ICC International Code Council.
IRC International Residential Code.
LPS Lightning Protection Systems. 
MAT Mitigation Assessment Team.
mph miles per hour.
MWFRS main wind force resisting system.
NFIP National Flood Insurance Program.
NHC National Hurricane Center.
NOAA National Oceanic and Atmospheric Administration.
NWS National Weather Station.
PCS Property Claim Services.
SBC Southern Building Code.
SESP Statewide Emergency Shelter Plan (prepared yearly by the FL DCA Division of 
Emergency Management for the 
state of Florida).
SFHA Special Flood Hazard Area.
SPRI Single Ply Roofing Institute.
TAS Testing Application Standard.
TRI Tile Roofing Institute.
URM unreinforced masonry.


Glossary

100-year flood - The flood elevation that has a 1-percent chance of being 
equaled or exceeded each year. 

100-year flood elevation - Elevation that flood waters would reach as a result 
of a 100-year flood.

ASCE 7 - National design standard issued by the ASCE, Minimum Design Loads for 
Buildings and Other Structures, which gives current requirements for dead, live, 
soil, flood, wind, snow, rain, ice, and earthquake loads, and their 
combinations, suitable for inclusion in building codes and other documents.

ASCE 24-05 - National ASCE standard, Flood Resistant Design and Construction, 
which outlines the requirements for flood resistant design and construction of 
structures in flood hazard areas.

Base Flood Elevation (BFE) - Elevation of the 100-year flood. This elevation is 
the basis of the insurance and floodplain management requirements of the 
National Flood Insurance Program.

Building envelope - The entire exterior surface of a building, including walls, 
doors and windows, which encloses or envelops the space within.

Cladding - A protective or insulating layer fixed to the outside of a building 
or another structure.

Coastal A Zone - The portion of the SFHA landward of a V Zone in which the 
principal source of flooding is storm surge, not riverine sources. Coastal A 
Zones may therefore be subject to wave effects, velocity flows, erosion, scour, 
or combinations of these forces. The forces in Coastal A Zones are not as severe 
as those in V Zones but are still capable of damaging or destroying buildings or 
inadequate foundations. A Zone areas are subject to breaking waves with heights 
less than 3 feet and wave run-up with depths less than 3 feet. It is important 
to note that FIRMs use Zones AE, A1-30, AO, and A to designate both coastal and 
non-coastal SFHAs. 

Critical/essential facilities - Facilities that, if flooded, would present an 
immediate threat to life, public health, and safety. Critical/essential 
facilities include, but are not limited to, hospitals, emergency operations 
centers, fire and police stations, water systems, and utilities.

Erosion - Process by which flood waters lower the ground surface in 
an area by removing upper layers of soil.

FBC 2001 - FBC 2001, effective on March 1, 2002, regulates the construction, 
erection, alteration, modification, repair, equipment, use and occupancy, 
location, maintenance, removal and demolition of every public and private 
building, structure or facility or floating residential structure, or any 
appurtenances connected or attached to such buildings, structures or facilities 
in Florida.

Freeboard - The additional height of a structure above design high water level 
to prevent further damage.

Hurricane - An intense tropical weather system with a well defined circulation 
and sustained winds of 74 mph or higher. 

Load path - The process of carrying vertical force in a building from the roof 
down to the soil.

Pier foundation - Vertical support member of masonry or cast-in place concrete 
that is designed and constructed to function as an independent structural 
element in supporting and transmitting both building loads and environmental 
loads to the ground.

Pile foundation system - Vertical support member of wood, steel, or precast 
concrete that is driven or jetted into the ground and supported primarily by 
friction between the pilings and surrounding earth. Piling often cannot act as 
independent support units and therefore are often braced with connections to 
other pilings. 

Recovery Advisory No. 1 - Issued by FEMA, this advisory recommends practices 
for use of roofing underlayment as an enhanced secondary water barrier in 
hurricane-prone areas.

Recovery Advisory No. 2 - Issued by FEMA, this advisory recommends practices 
for installing asphalt roof shingles that will enhance wind resistance in high-
wind, hurricane-prone areas.

Recovery Advisory No. 3 - Issued by FEMA, this advisory recommends practices 
for designing and installing extruded concrete and clay tiles that will enhance 
wind resistance in hurricane-prone areas. 
 
Saffir-Simpson Scale - Measures a hurricanes present intensity on a 1-5 scale 
to give an estimate of the potential property damage and flooding expected along 
the coast from a hurricane landfall. Wind speed is the determining factor in the 
scale. A Category 1 hurricane is the weakest, with winds from 74-95 mph, and a 
Category 5 hurricane is the strongest, with winds over 155 mph.  

Scour - Process by which flood waters remove soil around objects that obstruct 
flow, water from rainfall or snowmelt. 

Slab-on grade foundation - Type of foundation in which the lowest floor of the 
house is formed by a concrete slab that sits directly on the ground. The slab 
may be supported by independent footings or integral grade beams. 

Soffit - An architectural element at the roof overhang. Special Flood Hazard 
Area Portion of the floodplain subject to inundation by the base flood.

Storm surge - Rise in the level of the ocean that results from the decrease 
in atmospheric pressure association with hurricanes and other storms. 
 
TAS 110 - Standard number 110-2000 of the FBC, which covers testing requirements 
for physical properties of roof membranes, insulation, coatings, and other 
roofing components. 

Tropical storm - An organized system of strong thunderstorms with a defined 
circulation and maximum sustained winds of 39-73 mph. 

V Zone - The portion of the SFHA that extends from offshore to the inland limit 
of a primary frontal dune along an open coast, and any other area subject to 
high-velocity wave action from storms or seismic sources. The FIRMs use Zones 
VE, V1-30 to designate these Coastal High Hazard Areas. V Zones are subject to 
breaking waves 3 feet or higher. 

Zones X, B, and C - These zones identify areas outside of the SFHA. Zone B 
and shaded Zone X identify areas subject to inundation by the flood that has a 
0.2-percent probability of being equaled or exceeded during any given year. This 
flood is often referred to as the 500-year flood. Zones C and unshaded Zone X 
identify areas above the level of the 500-year flood.


References and Resources

ASCE. 2000. Flood Resistant Design and Construction, ASCE 24-05. January 2000.

ASCE. 2002. Minimum Design Loads for Buildings and Other Structures, ASCE 2-02. 
December 2002.

FEMA. 1993. Hurricane Andrew in Florida  Observations, Recommendations, and 
Technical Guidance: A Building Performance Assessment, FIA-22. February 1993. 
Washington, DC. 

FEMA. 1993. Hurricane Iniki in Hawaii-Observations, Recommendations, and 
Technical Guidance: A Building Performance Assessment, FIA-23. March 1993. 
Washington, DC.

FEMA. 1996. Hurricane Opal in Florida: A Building Performance Assessment, FEMA 
281. August 1996. Washington, DC.

FEMA. 1997. Hurricane Fran in North Carolina  Observations, Recommendations, 
and Technical Guidance: A Building Performance Assessment, FEMA 290. March 1997. 
Washington, DC.

FEMA. 2000. Coastal Construction Manual, FEMA 55. May 2000. Washington, DC. 

FEMA. 2000. Design and Construction Guidance for Community Shelters, FEMA 361. 
July 2000.

FEMA. 2004a. Design Guide for Improving School Safety in Earthquakes, Floods, 
and High Winds, FEMA 424. January 2004. 
Washington, DC.

FEMA. 2004b. Data Gathering for Expedited Implementation of Mitigation Projects 
in the Aftermath of Hurricane Frances, Preliminary Draft. September 2004. 
Washington, DC.

FEMA. 2004c. Roof Underlayment for Asphalt Shingle Roofs, Recovery Advisory No. 
1. September 2004. Washington, DC.

FEMA. 2004d. Asphalt Shingle Roofing for High-Wind Regions, Recovery Advisory 
No. 2. September 2004. Washington, DC.

FEMA. 2004e. Tile Roofing for Hurricane-Prone Areas, Recovery Advisory No. 3. 
November 2004. Washington, DC.

FEMA. 2005a. Six Months After Hurricane Charley Assistance Continues to Flow to 
Victims and Communities, Two Weeks Left to Ask for Aid. 
http://www.fema.com/news/newsrelease.fema?id=16503 
Release date: February 9, 2005. Release number 1539-371. Site accessed February 
17, 2005.

FEMA. 2005b. Florida Disaster Aid Now Stands at $4.4 Billion. 
http://www.fema.gov/news/newsrelease.fema?id=16722
Release date: March 10, 2005. Release number 1539-399. Site accessed March 
10, 2005.

FEMA. 2005c. FEMA Provides Nearly $500 Million for Damaged Public Facilities. 
http://www.fema.gov/news/newsrelease. fema?id=16683 Release date: February 22, 
2005.
Release number 1539-383. Site accessed March 1, 2005.

FEMA. 2005d. Mitigation Assessment Team Report: Hurricane Charley in Florida, 
FEMA 488. Washington, DC.

FEMA. 2005e. Mitigation Assessment Team Report: Hurricane Ivan in Florida and 
Alabama, FEMA 489. Washington, DC.

FEMA. 2005f. Hurricane Jeanne Rapid Response Florida Riverine High Water Mark 
Collection, Draft. January 2005. Washington, DC.

FEMA. 2005f. Hurricane Jeanne Rapid Response Florida Coastal High Water Mark 
Collection, Draft. January 2005. Washington, DC.

National Hurricane Center. 2004a. Tropical Cyclone Report. Hurricane Charley. 
October 18, 2004. Revised January 5, 2005. 
http://www.nhc.noaa.gov/2004charley.shtml Site accessed February 16, 2005.

National Hurricane Center. 2004b. Tropical Cyclone Report. Hurricane Frances. 
December 17, 2004.
http://www.nhc.noaa.gov/2004frances.shtml Site accessed February 11, 2005.