Disaster Safety Review 2010 - Vol. 2

T h e I n s T I T u T e f o r B u s I n e s s & h o m e s a f e T y sVolume 9 - Summer 2010 | DisasterSafety.org

page 4

DIsasTersafeTyrevIew

Fortified

Inside FORTIFIeDs New existing

Homes programp. 18

Building Codes

Will Coastal Building Codes

Stand Up?p. 22

Research Center

From Concept to Reality

p. 24

Hurricane

predictions for the 2010 Season

p. 16

New IBHS Research examines Shingle Roof performance in Hurricane Conditions

DIsasTersafeTyrevIew

Julie a. Rochmanpresident & Chief Executive OfficerInstitute for Business & Home Safety

editorCandace Iskowitz

art DirectorAmy Kellogg

editorial Office4775 E. Fowler Ave., Tampa, FL 33617E-mail: [email protected]: (813) 675-1047Fax: (813) 286-9960

Disaster Safety Review is published by the Insti-tute for Business & Home Safety (IBHS) to further its mission of reducing the social and economic effects of natural disasters and other property losses by conducting research and advocat-ing improved construction, maintenance and preparation practices. Statements of fact and opinion contained in articles written by authors outside IBHS are their responsibility and do not necessarily reflect the opinion of IBHS or IBHS membership.

ISSN 1537_2294 Copyright IBHS 2010

Disaster Safety Review | 20102

Contents

3 Letter from the presidentJulie Rochman, President and Chief Executive Officer, Institute for Business & Home Safety

4 Surviving Natures Fury: performance of asphalt Shingle Roofs in the Real WorldZhuzhao Liu, Research Engineer, Institute for Business & Home Safety Hank Pogorzelski, Applied Statistician, Institute for Business & Home Safety Forrest Masters, Assistant Professor, Department of Civil and Coastal Engineering, University of Florida Scott Tezak, BSCP, Infrastructure Protection & Risk Assessment Team, URS CORPORATION Timothy Reinhold, Senior Vice President for Research, Institute for Business & Home Safety

16 2010 Hurricane Season Outlook publicly Released Forecasts*Compiled by Institute for Business & Home Safety

18 It Only Takes One Hurricane:Fred Malik and Candace Iskowitz, Institute for Business & Home Safety

21 Making a Case for proper Window and exterior Door InstallationsDick Wilhelm, Fenestration Manufacturers Assoc.

22 Will Coastal Codes pass the Test this Hurricane Season?Wanda Edwards, P.E., IBHS Director of Code Development

24 IBHS Research Center: From Concept to RealityAllison Dean Love, IBHS External Relations Consultant

26 Responding to the Risk in South CarolinaAnn Roberson, Manager, S.C. Safe Home

Disaster Safety Review | 2010 3

The 2010 Hurricane Season is underway. As readers of this edition of Disaster Safety Review (DSR) will note from the chart 2010 Hurricane Season Outlook Publicly Released Forecasts, on pages 14-15, there is broad consensus among meteorological experts that this will be a worse-than-average year for tropical storm systems. Experts from public, private and academic institutions all are forecasting multiple landfalls in the U.S. of severe (Category 3 or higher) hurricanes before the end of November.

Of course, to quote the great Yogi Berra, Its tough to make predictions, especially about the future. So, it is possible that we will see fewer storms than predicted by the end of the season. Or, perhaps 2010 storms will only threaten some sec-tion of the Gulf or Atlantic Coasts, but will dissipate or turn away from shore without causing grievous harm to people and property. However, we also should remember that it only takes one high-intensity storm making landfall in a densely popu-lated area to wreak havoc on a regional or national level, in addition to the trauma and displacement seen locally where an eye wall or storm surge have left their terrible marks.

As always, the Institute for Business & Home Safety (IBHS) works closely with our member insurance companies and partner organizations to provide high-quality, focused, science-based loss prevention and reduction information for home and business owners from Texas to Maine, who are particularly vulnerable to hurricanes. This year, we are making a special effort to educate and motivate occupants of commu-nities that lie further inland, so that they too will take action to mitigate wind and wind-driven water risk. We are doing this because we know that wind is wind, and Hurricane Ike and other recent storms have caused billions of dollars in wind and wind-driven water losses as far inland as Ohio (not generally a place where people have given a lot of thought to protecting themselves and their property against hurricanes).

Another reason that Hurricane Season 2010 stands out for IBHS is that we are moving into our new natural disaster research center in Chester County, S.C. The large test chamber at the center of this campus is equipped to meticulously repro-duce wind, hail, water and fire-based natural events includ-ing Category 1, 2, 3, and eventually 4 and 5, hurricanes. This new building science tool will allow IBHS researchers and our partners to significantly advance the state of knowledge about how best to build and retrofit residential and commercial struc-tures in vulnerable areas. and we can predict with absolute certainty that at least a couple of Category 3 hurricanes will occur in that building this October, as we dedicate the facility and make our much-anticipated public debut. Much more information about the IBHS lab can be found in this issue of DSR.

Without a doubt, the new IBHS research center will provide compelling, objective data that will be used to improve protection for homes, businesses, and communities in a variety of ways, including through enactment and enforcement of appropriate, strong building codes. To put ongoing efforts related to new construction in perspective, in this DSR, our building code expert, Wanda Edwards, offers an in-depth look

at the state of building codes including recent changes in hurricane-exposed states.

Taking a step back from codes in particular, we should note that land use decisions are critical to the amount and type of property exposed to hurricanes. And while loss mitigation advocates continually raise legitimate land use questions about siting development in highly vulnerable areas, local economic imperatives, such as the need for tax revenue and jobs often prevail over the desires of mitigationites, environmental-ists, and others who would rather not see residential and commercial property density continue to increase on barrier islands, and other locations that have been, and will be, hit by storms again and again. This means that new development will continue to occur in areas where repeated losses have been suffered. It also means that we cannot simply ignore all of the property currently sitting where it probably should not.

This brings us to retrofitting. Existing structures can be retrofitted to significantly reduce wind and water-related damage and losses. In this issue of DSR, IBHS Fortified Pro-gram Manager Fred Malik and IBHS Public Affairs Director Candace Iskowitz provide an overview of our FORTIFIED for Existing Homes program, which is taking off in several coastal states and in new and exciting ways.

Knowing how to protect a particular building and actu-ally taking steps to do that are two different things. Without a doubt, many people want to protect their homes, businesses, families, possessions, and communities but economically challenging times means that property loss mitigation com-petes with many other items considered essential to a family or business budget. One way to incentivize action by home and business owners is to provide financial assistance or offset costs in the form of government grants or credits applied to public or private insurance premiums. Some states, such as Florida and Alabama, have mandated credits for private insurers where structures are brought up to the latest code or beyond. Other states (e.g., Mississippi and North Carolina) are examining voluntary market incentives. Also, the federal government, through a variety of Executive Branch agencies and legislative proposals on Capitol Hill, is looking at expanding pre-disaster and post-disaster mitigation credits. We are very pleased that a true pioneer in this area, South Carolina Department of Insur-ance Public Information Officer and Executive Assistant to the Director Ann Roberson, is a contributor to this DSR.

One final thought: no matter how accurate forecasts are for 2010, we must continue and enhance ongoing efforts to identify, evaluate and promote effective methods of loss control and prevention for wind and wind-driven water, because another hurricane season will arrive in 2011 and 2012, and in every year to follow. Even Yogi Berra wouldnt argue with that point.

Julie RochmanPresident and Chief Executive OfficerInstitute for Business & Home Safety

Letter from the president


Surviving Natures Fury: performance of asphalt Shingle Roofs in the Real World

When Hurricanes Gustav and Ike raked the coast-lines of Louisiana and Texas in 2008, researchers from the Institute for Business & Home Safety (IBHS) and the University of Florida (UF) were presented with a valuable opportunity to investigate the performance of asphalt shingle roofs in real-world storm conditions.

Roof cover damage continues to be the most frequent source of hurricane-related insurance claims not related to storm surge. In order to minimize future losses, there must be a solid basis for understanding damage risks for current roofing products and for improving products and producing wind ratings that are meaningful for predicting performance in hurricanes and other severe wind events. This research addresses this need by taking a broader approach than what was attempted by prior post-hurricane disaster investigations. The analysis examined damage levels at relatively low wind speeds as a function of the age of the roof, the adoption and enforcement of modern building codes, and investigated the validity of questions concerning whether the current approach to the design of shingles that reduces uplift loads is adequate.

Twelve days and about 375 miles separated the landfalls of Hurricanes Gustav and Ike, which were the two most destructive hurricanes of the 2008 season. Gustav caused an estimated $3.5 billion in insured property damage after making landfall Sept. 1, 2008, in Cocodrie, La. On Sept. 13, Hurricane Ike made landfall along the north end of Galves-ton Island, Texas, causing $12.5 billion in insured losses.

Asphalt shingles historically have and are predicted to continue to dominate the roofing market, according to roofing industry data. Its likely that many homes located in the hurricane-prone areas from Texas to Maine, where there remains about $9 trillion worth of vulnerable insured coastal property, have this type of roof covering. Therefore, the findings from this research have broad implications. As wind speeds increase, so does the frequency and severity of the damage.

Clearly, this study just begins to address the issues associated with shingle performance in high winds. More research is needed both in terms of field investigations for events, where new wind-rated products are exposed to higher wind speeds, and in a controlled environment such as the new IBHS Research Center, where effects of aging and wind speed can be investigated on demand for a variety of products.

Zhuzhao Liu, Research Engineer, Institute for Business & Home Safety, 4775 E. Fowler Ave., Tampa, FL 33617, [email protected] Hank Pogorzelski, Applied Statistician, Institute for Business & Home Safety, 4775 E. Fowler Ave., Tampa, FL 33617, [email protected] Forrest Masters, Assistant Professor, Department of Civil and Coastal Engineering, University of Florida, 365 Weil Hall, Gainesville, FL 32611, [email protected] Scott Tezak, BSCP, Infrastructure Protection & Risk Assessment Team, URS CORPORATION, 260 Franklin Street, Suite 300 Boston, MA 02110, [email protected] Timothy Reinhold, Senior Vice President for Research, Institute for Business & Home Safety, 4775 E. Fowler Ave., Tampa, FL 33617, [email protected]


Surviving Natures Fury: performance of asphalt Shingle Roofs in the Real World

More than 40 percent of homes older than 5 years sustained damage to shingle roofs in relatively low 3-second gust wind speeds; cast-ing doubt on the validity of wind-resistance rating systems used to classify shingles.

Newer shingle roofs installed after adoption of the 2000 International Building Code in Febru-ary 2003 exhibited much less wind damage from the wind speeds produced by Hurricane Ike than older roofs in the same area. This could be attributed to a combination of age and code/product changes; more study is needed.

When roof cover damage was stratified by roof pressure zones identified in modern building codes, damage rates in lower uplift pressure zones were similar to or lower than damage rates in areas associated with higher uplift pressures. Consequently, there does appear to be a sound basis for the current approach to the design of shingles that reduces uplift loads on shingles by assuming equalization of wind pressures on the top and bottom surfaces.

The major findings from this research include:


Roof cover damage continues to be the most frequent source of hurricane-related insur-ance claims not related to storm surge. In fact, some 95 percent of residential wind-related insurance claims resulted in a payment for roof repairs following Hurricane Charley1. Post-disas-ter investigations conducted following hurricanes Hugo2 and Andrew and Iniki3 also emphasized the importance of minimizing roof cover damage to reduce subsequent water intrusion.

As part of a continued effort to explore and improve roof cover performance, IBHS and UF researchers conducted the following study of 1,412 single-family homes affected by Hur-ricane Gustav in Houma, La., and Hurricane Ike in two communities in Chambers County, Texas. Researchers set out to explore the amount of damage sustained to shingle roofs, identify trends in damage observations with regard to wind speeds, the age of the roof and its shape and code changes, and to create a database for use in roof performance analysis now and in the future.

This study builds upon prior post-hurricane damage surveys conducted by IBHS staff and other research organizations. Researchers have continually observed large variations in the extent of damage to shingle roofs. For example, an analy-sis conducted after Hurricane Charley in 2004 examined re-roofing permits issued for homes in Charlotte County, Fla., which were less than 15 years old. The analysis assumed that the home age could be used as a proxy for the age of the roof. The analysis revealed older roofs were more likely to be damaged at lower wind speeds4. In areas where the highest winds occurred, however, the replacement rate was reasonably constant regardless of age.

The previously referenced studies of roof damage in Hurricanes Hugo2 and Andrew and Iniki3 simply provided estimates of the frequency and severity of roof cover damage; but, did not attempt any further refinement of the damage data to look at age effects. These studies focused on the performance of buildings exposed to some of the highest wind speeds in Hurricanes Hugo and Andrew. There was no attempt to broaden the surveys to areas exposed to lower wind speeds and to look at damage levels as a function of wind speed. This study, attempts to lay the ground work for explorations of both of these functional relationships. Ultimately, both relationships need to be clearly established, so there is a solid basis for understanding damage risks for current roof-ing products and for improving products and producing wind ratings that are meaningful for predicting performance in hurricanes and other severe wind events.

The adoption of the 2009 International Residential Code prompted the replacement of ASTM D 3161 (modified to 110 mph), which is the older standard used to rate shingles for high-

wind applications, with ASTM D 7158. This new standard uses a two-step process to develop a rating for the wind resistance of shingles. The new rating process relies on an uplift coefficient for the shingle tab or edge and a direct measurement of the strength of the adhesive bond between the bottom of the top shingle and the top of the bot-tom shingle. The uplift coefficient is determined for winds blowing over the surface of the shingles and directed perpendicular to the exposed bot-tom edge of the tab or shingle bottom edge for architectural shingles. The uplift coefficient and the strength of the adhesive bond are used in an engineering analysis to produce an overall wind speed rating for the shingle application.

Classification 3-second gust Design Wind Speed

A 60 mph

D 90 mph

F 110 mph

G 120 mph

H 150 mph

TABLE 1: ASpHALT SHINGLE WIND-RESISTANCE CLASSIFICATIONS By DESIGN

WIND SpEEDS FROM ASTM 7158

The IBHS report Hurricane Ike: Natures Force vs. Structural Strength, which was released in 20095, raised questions about the validity of these ratings in real-world applications. This find-ing was based on the poor performance of shingles installed on 10 homes built to the IBHS FORTI-FIEDfor Safer Living standard and located on the Bolivar Peninsula in Texas4, which was bat-tered by Hurricane Ike in 2008. The roof covers on these homes were H-rated (suitable for design wind speeds of 150 mph), but performed poorly despite exposure to 3-second gust wind speeds that likely reached only 115 mph during Ike.

The persistent questions about roofing per-formance have made it the first focus of research at the multi-peril IBHS Research Center, which will come online in late 2010. A part of this research will include the validation of results by comparing roofing performance observed in the laboratory with field observations. This study, in conjunction with earlier work and future field investigations following the land fall of hurricanes, will provide the full-scale field observations needed to validate the laboratory tests.

A key question is whether the newer roofs which performed well when exposed to Hurricane Ikes winds, will perform as well in a future storm with similar magnitude winds after they have aged a few more years. A related question is how well would these roofs have performed in Ike, if the winds had been stronger and in line with the

100 to 110 mph gust wind speed rating, which would be required to meet the local design wind speed requirements for the area.

STUDY DeSCRIpTION

This study was conducted by IBHS in coop-eration with the UF and with assistance from the Federal Emergency Management Agency (FEMA), through their contract with the URS Corporation, to investigate damage to shingle roof covers in communities impacted by Hurricanes Gustav and Ike. A large number of photos and damage estimates were collected during onsite investigations. In addition, high resolution aerial photography was commissioned by IBHS for the Houma, La., area following Gustav and by FEMA for certain areas around Houston and Galveston, Texas, following Ike. Selected sites for this study were chosen based on the availability of local wind speed data. Since the vast majority of homes in these areas had shingle roofs, this study focused exclusively on the performance of shingle roofs.

The high-resolution aerial photos were ana-lyzed to determine the amount of shingle roof cover damage on each home and the location or locations of that damage. Various local and national Geographic Information Systems (GIS) were used in conjunction with the high-resolution aerial photographs to determine the address and/or parcel number for each of the single-family houses studied. This allowed matching of damage estimates from the aerial photographs with county or city information about the year of construction. The age of the home is used as a proxy for the age of the roofs in this study, for houses that were less than 15 years old at the time of the hurricanes. However, it was not possible to determine if any of the roof coverings were replaced on any of the homes surveyed; and, there is a chance that some of the homes in the 10 to 15 year age range may have been re-roofed as a result of Hurricane Rita in 2005.

The study objectives were as follows:

1. Quantify the amount of roof damage, if any, for each house; determine where the damage occurred relative to ASCE 7 wind pressure zones and the orientation of the surface or edge, where damage was observed relative to eight compass directions (N, NE, E, SE, S, SW, W, NW).

2. Create a database of roof damage suit-able for both immediate and long-term analysis (as future data is added) that includes attributes identifying wind speed(s), wind direction(s), building age, roof shape, and amount, location and orientation of damage.

3. Identify any trends in the damage obser-vations, which could be correlated with


Gustav

Ike

age, wind speed, roof shape, changes in codes and standards, ASCE 7 roof pres-sure zone, and orientation relative to the strongest winds in the storm.

ONSITe INVeSTIgaTION OF SHINgLe ROOF COVeRINg DaMage:

HURRICANES GUSTAV AND IKE (Figure 1)

Immediately following each storm, fac-ulty and students from UF conducted a rapid assessment of damage in the vicinity of mobile meteorological towers that had been deployed in advance of the hurricane. Since both of these storms primarily caused roof cover damage, the emphasis in the ground surveys was placed on determining the extent of this damage. The survey data were limited to the visible slopes of the roof, and it was frequently only possible to get a good look at three sides of the roof. Consequently, the ground-based data were primarily used to describe overall damage severity and served as a check against the aerial photo analysis.

Hurricane Gustav

Hurricane Gustav was the second most destructive hurricane in the 2008 Atlantic season and caused an estimated $3.5 billion in insured damage. It reached the Louisiana coast on the morning of Sept.1, making landfall near Cocod-rie. Researchers from IBHS and UF conducted a study to define the severity of the winds and wind-related roof cover damage throughout the areas around Houma, La. Five Florida Coastal Monitor-ing Program (FCMP) mobile instrumented towers were deployed to capture wind data and three towers (T1, T2 and T3) were erected within the Houma city limits. The mobile towers recorded wind speed and direction records for the time period during which the highest winds from Hur-ricane Gustav affected the area (Figure 4). The maximum gust wind speed captured by any of the mobile towers was 78 mph. The higher wind

speeds occurred for wind directions ranging from northeast through southeast.

After the storm, the UF faculty and stu-dents, who deployed the towers, split up into five teams and investigated damage to a total of 933 houses spread among the five yellow areas of Houma shown in Figure 2. The information collected included address, type of roof cover, roof shape, roof pitch, wall type and estimated average amount of roof damage as a percentage of the vis-ible roof area. The data on the extent of the roof cover damage was generally recorded in 5 percent increments of the visible roof surface area.

Summary data for damage frequency and severity obtained from the ground survey are listed in Table 2 and shown in Figure 3. Of the 933 houses investigated, 602 (65 percent) suffered some level of roof cover damage. The average roof

cover damage per home was 7.7 percent. Of the 602 homes with roof cover damage, the average roof cover damage was 11.9 percent.

Hurricane IkeHurricane Ike was the most destructive hur-

ricane in 2008 and caused an estimated $12.5 billion in insured property damage. Ike was sig-nificant due to the size of its cloud mass, the integrated kinetic energy it contained, and the fact that it produced high winds for an extremely long period of time throughout much of the impacted area. IBHS and researchers from UF, Texas Tech University, Florida International University, Loui-siana State University, and Clemson University, set up mobile towers and other wind instruments in advance of the storms land fall. Some support for these deployments was provided by FEMA through a contract with URS.

A community with 882 single-family homes, constructed between 1996 and 2008, in Baytown, Texas, was surveyed mainly by investigation teams from UF. This community is located 1.5 miles south of Interstate 10 and east of and adjacent to State Highway 146. The community lies between the indicated positions of mobile towers T2 and T3 shown in Figure 5. The eye of the storm passed directly over this community. T2 was located to the northwest of the community and T3 was located to the southeast of the community.

The maximum 3-second gust wind speed measured by T3 was 88 mph and occurred during the passage of the northern eyewall of the storm. FIGURE 1: TRACKS OF HURRICANES GUSTAV AND IKE

percentage of roof area damaged

Number of homes percentage of total homes

< 1% 332 36%

1% to 15%

Damage Level

Perc

enta

ge o

f Hom

es

FIGURE 3: DISTRIBUTIONS OF DAMAGE SEVERITy FOR HOMES WITH ROOF COVER DAMAGE


For this portion of the storm, the wind direc-tions were from the north-northeast through the east-northeast. The corresponding highest wind speeds measured at T2 were about 77 mph. After the eye had passed, the strongest winds in the southern eyewall of the storm were on the order of 75 mph at both tower locations, and the wind direction was approximately from the south through south-southwest as shown in Figure 6. The lower wind speeds recorded at T2, during the passage of the northern part of the eyewall, were the result of T3 being exposed to winds after they had passed over a portion of the community. During the latter part of the storm, the winds at both mobile tower locations were approaching over similar terrain.

aeRIaL pHOTO aNaLYSIS aND DaTaBaSe

Use of Aerial Photography in Investigation

A more comprehensive assessment of the roof cover damage was conducted using high resolution aerial photographs. The photographs made it possible to more accurately locate the areas where damage occurred, relative to both typical roof wind pressure zones defined in modern building codes and to compass orien-tation. For Hurricane Gustav, IBHS purchased post-hurricane high definition oblique aerial photographs of Houma, La., from AirReldan, Inc. The view restrictions of the oblique aerial photographs made it possible to view all of the necessary orientations for only 388 single-family houses with shingle roofs. For Hurricane Ike, the research was enhanced through the IBHS partnership with FEMA and its contractors, through which IBHS was able to obtain access to 6-inch GSD imagery acquired by FEMA and Pictometry International Corp.6 following the storm. The images afforded researchers vertical as well as oblique photography views [Figure 7], including but not limited to the sides of build-ings, which fostered the capability of performing accurate measurements of building features. Additionally, Pictometry provided researchers a program and a web application that could be used to locate, view, measure, and save Pictom-etry images. This program was used to assess the roof cover damage from Hurricane Ike.

A LARGE NUMBER OF SHINGLES BLOWN OFF

SEALANT BONDS

WIDESpREAD DAMAGE TO ROOF SHINGLES

WIND UpLIFT OF INDIVIDUAL TABS AND SHINGLES

HEAVy DAMAGE AS A RESULT OF SHINGLE AND SHEATHING LOSS

FIGURE 6: TypICAL TypES OF DAMAGE TO ROOF SHINGLES OBSERVED By ON-SITE INVESTIGATION TEAMS

FIGURE 7: HIGH DEFINITION AERIAL pHOTOGRApHS pROVIDED By FEMA/pICTOMETRy INTERNATIONAL CORp.


NeW

NeW! from the Institute for Business & Home Safety The coastal area from Texas to Maine is home

to tens of millions of people with $9 trillion

worth of insured property that is exposed

to the threat of hurricanes. Building science

research has identified the areas of a home

most at risk from hurricane-force winds

and rains. This brochure offers guidance for

strengthening these areas, which will lead

to a reduced risk of damage, fewer repairs,

and also may qualify homes for a desig-

nation through the IBHS FORTIFIED for

Existing Homes program.


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FIGURE 5: WIND SpEED AND WIND DIRECTION RECORDED By TOWERS T2 AND T3 IN HURRICANE IKE

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FIGURE 4: WIND SpEED AND WIND DIRECTION RECORDED By TOWERS T1 AND T2 IN HURRICANE GUSTAV


Database

The complete data set for this study includes 1,412 single-family homes. The majority of the homes in this sample (1,024) were affected by Hurricane Ike. The remaining homes in the sam-ple (388) were affected by Hurricane Gustav. All of the homes in the data set that were affected by Hurricane Gustav are located in Houma, La. The homes affected by Hurricane Ike came from two unincorporated areas of Chambers County, Texas. One area is a community with 882 single-family homes in Baytown and lies approximately 6 miles northwest of Trinity Bay. The second area is Beach City, which runs along the north-west coast of Trinity Bay. The Beach City data set includes all of the homes in Beach City con-structed between 1996 and 2008, according to Chambers County records. The Baytown and Beach City areas studied are about 6 miles apart and nearly the same distance from Hurricane Ikes track. Eighty percent of the Beach City houses are within a half mile and 92 percent are within a mile of the coast of Trinity Bay. The Baytown community studied is about 6 to 7 miles from the coast of Trinity Bay.

The data fields collected for each house include age of the home, roof shape, amount of roof cover damage in different roof pressure zones, and the orientation of the damage areas relative to one of eight compass points. The age of construction was determined from one of sev-eral databases, including county or city records when available and Zillow, an online real estate records source.

Wind load design specifications of ASCE 75 define wind loads on residential roofs using three different zones:

Zone1isthefieldormiddleareaoftheroof;

Zone2istheperimeterareaattheeave,edge and ridge; and

Zone3isthecornerareasandeave/edgeand edge/ridge intersections.

In high-wind events these zones experience different levels of uplift, which increase from low-level wind loads in Zone 1 to the highest wind loads in Zone 3. Earlier studies have suggested that roof cover damage is greatest at corners, edges and ridges2. If this is true, it would suggest that the current test methods, which employ winds blow-ing over a flat panel covered with shingles, may not provide the most critical loading. This could be a reason for discrepancy between expected and observed shingle performance in real-world conditions. To further explore this finding, the roof covering damage in the homes surveyed for this study was recorded by zone and orientation of the zone relative to compass directions, so that any correlation between damage location and wind direction could be investigated.

peRFORMaNCe OF SHINgLe ROOF COVeR

Overall Damage Statistics

Table 3 provides a general summary of the data sets obtained from the aerial photo analysis. The difference in the average damage between the Gustav and Ike data sets, which is illustrated by the last two rows of Table 3, may be due in part to the range of ages in the years of construction. The Beach City and Baytown data sets include homes affected by Ike that were constructed between 1996 and 2008, while the Houma data contains homes affected by Gustav that were constructed as early as 1935; but, none built after 2000. The ground survey damage estimates for the 933 homes surveyed in Houma produced somewhat higher average damage areas than the estimates obtained from the aerial photos. The differences may be due in part to the tendency to report damage at 5 percent increments and to a different and unknown difference in the age distribution of the homes in the data sets.

The average damage per exposure for homes in the Houma data set is similar to that of the combined Baytown and Beach City data sets, when comparing homes of the same age. This is illustrated in Figure 8.

0%

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1996 1997 1998 1999 2000

Baytown/Beach CityHouma

FIGURE 8: AVERAGE DAMAGE By AGE AND LOCATION

The majority of homes in the Hurricane Ike data set were constructed after 2001, and they received considerably less damage on average as compared to older homes. Unfortunately, because none of the Houma homes were constructed after 2000, it was not possible to determine if newer homes in that area experienced the same reduc-tion in damage.

Figure 9 presents the entire data set, includ-ing homes constructed after 2000, for which there are no homes in Houma, and homes built prior to 1996, for which there are no homes in Baytown or Beach City. Additionally, the data set contains no homes constructed from 1986 to 1990, and only three homes constructed from 1961 to1965, none of which were damaged.

The analysis showed a significant decline in the damage rate beginning with homes con-structed in 2002 and later. By 2005, the decline reached the point where very few homes built in 2005 or later experienced any observable level of roof cover damage. The damage rate also gradually declines with increasing age for homes built prior to 1996. This trend may be a result of the roof replacement rate on some older homes beginning in 1991 and increasing with each successive set of older homes.

The houses in the data set experienced a wide range of damage from no losses of roof covering to the maximum loss of 56 percent of the roof covering. In order to compare the number of houses with no or only slight damage to those that had more significant damage, each house was assigned a damage level classification rang-ing from 1 (no damage) to 5 (roof collapse). The

Hurricane Ike Hurricane gustavBeach City Baytown Houma, Aerial Houma, Ground

Total homes 145 879 338 933

year of construction 1996-2008 1996-2008 1935-2000 Unknown

Avg. age at time of storm 7.5 5 24 Unknown

Damaged homes 62 329 193 602

Damage rate 43% 37% 50% 65%

Avg. damage per home 1.5% 2.0% 4.5% 7.7%

Avg. damage per dam-aged home

3.5% 5.4% 9% 11.9%

TABLE 3: SUMMARy STATISTICS FOR THE DATA SET


definition and description of damage levels are summarized in Table 4.

The majority of homes constructed in 2002 or later suffered minimal damage. Few homes built in 2004 or later had roofs with damage to more than 1 percent of the covering.

Homes constructed in 1998 had the highest percentage of roofs with damage Levels 3 and 4. For homes built prior to 1998, there was a general trend of declining damage with each consecutive group of homes until the data set that included homes built from 1966-1970. This may reflect an increasing occurrence of roof replacement beginning in 1997. Homes built in 1997, how-ever, would have only been 11 years old at the time of Ike. Still, if the age of roof is a dominant risk factor, it is possible that the homes built in 1997 and before could have been re-roofed as a result of sustaining damage from Hurricane Rita in 2005.

Average areas of roof cover damage by year of construction are presented in Figure 10. The damage area percentage is based on all homes in the data set including those with no damage.

Aging Effects and Code ChangesTwo factors appear to have been involved in

the sharp decline in the average damage sustained by houses built in 2002 and later in Baytown and Beach City. These newer homes received an aver-age of just 0.3 percent damage compared to the average of 4.9 percent damage for all older homes in this area. This may be due to limited exposure to the aging effects of weather, but the homes also may have benefitted from the strengthening of building code requirements that accompanied the adoption of the International Residential Code (IRC) in 2000. It is possible that high-wind rated roof coverings were used on these homes since the IRC provisions require the installation of roof covers with a design wind speed rating that is appropriate for the area.

Damage by Roof ZoneAs noted earlier, any damage to the roof

covering was recorded by roof pressure zones as defined by ASCE 77 to facilitate the investiga-tion of correlations between damage location and uplift pressure. Table 5 presents the damage rate and average amount of roof cover damage for each of the three ASCE 7 roof pressure zones. The results are based on all the data for both hurricanes.

While the frequency of damage was similar for Zones 1 and Zone 2, and significantly less for Zone 3, when it did occur in Zone 3 it was more severe. Separation of damage by roof shape indicates that gable roofs are more likely to expe-rienced roof cover damage than hip roofs. The difference is most significant for Zones 2 and 3.

Age effects on damage

This study afforded researchers an opportu-nity to examine the effect of aging in high-wind conditions. As roofing materials age they become more susceptible to damage under these types of conditions. The data set includes homes that were constructed between 1935 and 2008. The age of the home, obtained by county property records, was used as a proxy for the age of the roof; since explicit data on the roof age was not available.

Although asphalt shingle roofing materials come with warranties that range from 20 to 45 years, and there are significant differences between the products, these figures frequently do not pro-vide an accurate assessment of expected roof life. Roofing materials often require repair or replace-ment years before their warranties would suggest. This is particularly true in hurricane-prone regions such as the Texas and Louisiana Gulf Coast.

Even without any exposure to another dam-age source, the effect of aging itself can result in a lifespan of 10 to 15 years for some roofing products. Despite the need, its unlikely that most homeowners with roofs of this age will take steps to replace their roof. For newer homes it is pos-sible to assume that the age of the roof is the age of the home. However, at a certain point in the lifespan of a home, often beginning at 15 years, the roof gets replaced and the assumption is no longer valid.

Figure 10, the graph depicting average roof damage, shows that the clearest pattern of damage increasing with age occurs in homes constructed from 1998 to 2008. The newest homes, those constructed between 2005 and 2008, sustained almost no damage. Average damage per exposure increases modestly with age beginning with homes constructed in 2004 and continues through homes constructed in 2002. This is followed by a large increase in damage for older homes, beginning with those constructed in 2001 and peaking in homes constructed in 1998.

The following information illustrates how well this damage trend and aging pattern holds when each data set is presented individually.

Figure 12 shows the average damage by year in the Houma data set, which contained no homes constructed after 2000. This data set shows no pattern of increasing damage with age. In fact, average damage per exposure tends to decrease slightly with age. This is likely due to the fact that the age of the homes in Houma is no longer a reliable proxy for the age of the roof.

The age of the homes in this study that were affected by Hurricane Ike in Texas range from 1 to 12 years, and therefore the age of the home is more likely to reflect the age of the roof. Figures 13 and 14 represent the average damage per exposure by year individually for the Baytown and Beach City communities. Each graph shows a sudden increase in average damage for homes constructed

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1935

1961-65

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1991-95 19

96199719981999200020012002200320042005200620072008

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rage

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FIGURE 10: AVERAGE DAMAGE AREA AS A pERCENTAGE OF TOTAL ROOF AREA By yEAR OF CONSTRUCTION

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96199719981999200020012002200320042005200620072008

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ent o

f Roo

fs D

amag

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FIGURE 9: ROOF COVER DAMAGE RATE By THE yEAR OF CONSTRUCTION

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961997199819992000

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FIGURE 12: AVERAGE DAMAGE By yEAR IN THE HOUMA DATA SET


in 2001, followed by a general trend of increasing damage for homes built in prior years.

One interesting trend was that the average dam-age per exposure peaks for Baytown homes built in 1998, but declines for those constructed in 1997 and 1996. Aerial photography analysis showed this decline may due more to the location of the homes and the density of the tree cover surrounding them than their age. These homes are located at the west side of the community and are surrounded by other houses and high density woods, which may have shielded them from the higher winds.

Effect of wind direction

Wind effects, including uplift pressures and flow near the roof surface, depend on wind direction, roof pitch and surrounding conditions. Generally, large suction occurs on leading roof corners, edges and ridge areas. Prior research studies following hur-ricanes have found that greater demands can be expected to occur at these locations on the roof. This study sought to also assess the effects of wind directionality on the vulnerability of these areas.

The Baytown data set was divided into three groups based on year of construction: homes built in 2005 or later; homes built from 2002 to 2004; and homes built prior to 2001. The average damage on different roof areas of each group was calculated for eight directions and results are shown in Figure 15. The high wind speeds recorded by mobile towers in Hurricane Ike for Baytown homes were concentrated

Zone 1 Zone 2 Zone 3Damage rate 39% 40% 25%

Average damage for dam-aged homes

7.3% 6.3% 9.0%

Average damage for all homes

Hip 2.8% 2.4% 1.9%

Gable 3.2% 3.3% 3.9%

Total 2.8% 2.5% 2.2%TABLE 4: DAMAGE RATES AND AVERAGE DAMAGE AREA FOR SHINGLE ROOF COVERS By zONES.

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19961997199819992000

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Year Built20012002200320042005200620072008

Beach City

FIGURE 14: AVERAGE DAMAGE By yEAR IN BEACH CITy

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1996199719981999200020012002200320042005200620072008

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FIGURE 13: AVERAGE DAMAGE By yEAR IN BAyTOWN at east-northeasterly and south-southwesterly directions. While damage was observed on nearly all

roof surfaces for older homes, the average damage on roof areas facing the incident wind directions is higher than for other roof areas. The distributions and damaged observed clearly demonstrate that roofs on older homes were more sensitive to wind direction than roofs on newer homes.

Relationship to Earlier StudiesIt should be emphasized that the data obtained in this study corresponded to relatively low

wind speeds with the measured peak gusts in the area ranging between 75 and 88 mph. As wind speeds increase, so does the frequency and severity of the damage. The analysis of damage presented in this study used a fairly fine breakdown of damage levels into smaller area increments in part because the winds were relatively low. The change in roof damage area statistics associated with increased wind speeds is illustrated in Figure 16.

The damage classifications and overall results for Hurricanes Gustav and Ike were:

Damage 1% of the roof area Frequency = 73%

1% < Damage < 5% of the roof area Frequency = 11%


Damage > 15% of the roof area Frequency = 5%

Or, divided into the categories reported for Hurricane Hugo2,

Little or No Damage Frequency = 58%

Damage < 15% Frequency = 37%

15% < Damage < 40% Frequency = 4%

Damage > 40% Frequency = 1%

In comparison, roof cover damage observations for Hurricane Hugo2 where 3-second gust wind speeds in the areas studied ranged between 110 and 135 mph used the following damage classifications and produced the following results:

Damage 1% of the roof area Frequency = 49%



Damage > 15% of the roof area Frequency = 7%

The analysis of roof cover damage for Hurricane Andrew3 where 3-second gust wind speeds likely exceeded 155 mph and possibly reached 175 mph in some areas used the following damage classifications and produced the following results:

Damage < 33% Frequency = 18% to 23%

33% < Damage < 67 % Frequency = 23% to 30%

Damage > 67% Frequency = 36% to 47%

These numbers offer dramatic evidence of the rapid increase in damage frequency and amount of damage expected as wind speed increase. Clearly, this study for Hurricanes Gustav and Ike just begins to address the issues associated with shingle performance in high winds. More research is needed both in terms of field investigations for events where new wind-rated products are exposed to higher wind speeds and in a controlled environment such as the new IBHS Research Center, where effects of aging and wind speed can be investigated on demand for a variety of products.


ROOFING continued on page 27

continued on page 25

AVERAGE DAMAGE AREA FOR zONE III (CORNER AREA)

AVERAGE DAMAGE AREA NEAR RIDGE END AVERAGE DAMAGE AREAS ALONG GABLE EDGES

AVERAGE DAMAGE AREAS FOR zONE I (CENTER AREA)

AVERAGE DAMAGE AREA ALONG ROOF RIDGE AVERAGE DAMAGE AREAS ALONG ROOF EAVES

FIGURE 15: AVERAGE DAMAGE ON DIFFERENT ROOF AREAS OF BAyTOWN HOMES IN DIFFERENT DIRECTIONS

Level DescriptionLevel 1 (Satisfactory performance)

Roof system displays good performance in the storm. No obvious damage is observed to the shingles. There are some small pieces of shingles missing following the storm. The total area of loss of roof cover is less than 1% of total roof area.

Level 2 (Slight Damage)

There are a lot of small pieces of roof cover blown off in the storm. The total area of loss of roof cover is more than 1% and less than 5% of total roof area. (1 to 5 shingles would be damaged in a typical 10-ft square.)

Level 3 (Moderate Damage)

The loss of roof cover is more than 5% of the total roof area. Whole pieces of roof cover were blown off by the storm. The roof sheathing is typically exposed.

Level 4 (Heavy Damage)

The roof cover is heavily damaged. The loss of roof cover is more than 15% of total roof area. Some roof sheathing may be blown off; but, the roof system still can provide effective lateral support for structure.

Level 5 (Collapsing)

Significant structural damage to the roof possibly including a partial or total collapse of the roof. The roof system cannot effec-tively provide lateral support for buildings walls.

TABLE 5: THE DEFINITION AND DESCRIpTION OF DAMAGE LEVELS

2010 Hurricane Season Outlook publicly Released Forecasts*


eQeCaT Catastrophe ModelingThe following is based on EQECATs near-term model, which provides frequencies of hurricane landfalls based on the climatology of the warm phase of the Atlantic Multi-decadal Oscillation (AMO), in addition to a long-term model that provides fre-quencies of hurricane landfalls based on the climatology of the entire historical record since 1900. The near-term model provides EQECATs best estimate of hurricane risk given that the AMO is in the warm phase, which has been the case since 1995.

Storms and conditionsEQECAT does not provide seasonal forecasts of hurricane activity, due to the uncertainties involved in such fore-casts at the lead times required by its clients (in many cases several months prior to the start of hurricane season).

U.S. Landfall*Near-term probabilities for at least one major hurricane land-fall (Category 3, 4, or 5):

Gulf Coast, Texas through Alabama: 30% (long-term equivalent is 25%)Entire Florida coastline: 28% (long-term equivalent is 20%)East Coast, Georgia through Maine: 23% (long-term equivalent is 18%)U.S. Gulf and Atlantic coastline: 61% (long-term equivalent is 51%)

accuWeather Inc.Storms and conditions18-21 Named storms; 15 in Western Atlantic or Gulf of Mexico5-6 Hurricanes; 3 will affect Gulf Coast

LandfallEntire U.S. coastline = 82-3 Major landfalls

18-21

Colorado State Univ., Department of atmospheric ScienceStorms and conditions10 Hurricanes (yr. avg. 5.9)18 Named storms (yr. avg. 9.6)5 Major hurricanes (Cat-egory 3+) (yr. avg. 2.3)

Landfallprobabilities for at least one major hurricane landfall (Category 3+):

Entire U.S. coastline = 76% (avg. last century 52%)U.S. East Coast, including peninsula Florida = 51% (avg. last century 31%)Gulf Coast from the Florida pan-handle westward to Brownsville, Texas = 50% (avg. last century 30%)Caribbean = 65% (avg. last century 42%)

18

*Forecasts as of June 21, 2010

2010 Hurricane Season Outlook publicly Released Forecasts*


N.C. State UniversityStorms and conditions15-18 Named storms in Atlantic; 5-7 Gulf Coast8-11 Atlantic hurricanes; 2-4 Gulf Coast hurricanes

LandfallAtlantic = there is an 80% chance of one of the named storms making landfall; there is a 70% chance that the storm that makes land-fall will be a hurricane.Gulf Coast = 3-6 landfalls; there is an 80% chance that at least one of the storms making landfall will be a hurricane; there is a 55% chance that a major hur-ricane will make landfall.

15-18National Oceanic and atmospheric administration Climate prediction CenterStorms and conditions8-14 Hurricanes14-23 Named storms3-7 Major hurricanes

NOAA Accumulated Cyclone Energy (ACE) index, which accounts for the intensity and duration of named storms and hurricanes during the season = 155%-270% of the median. According to NOAAs hurricane season classifications, an ACE value above 117% of the 1950-2000 median reflects an above-normal season. An ACE value above 175% of the median reflects an exception-ally active (or hyperactive) season.

LandfallNOAA does not make seasonal hurricane landfall predictions.

14-23

Tropical Storm Risk (TSR)Storms and conditionsOverall Atlantic Basin18 Named storms (yr. avg. 10.4)10 Hurricanes (yr. avg. 6.1)4 Major hurricanes - Category 3+ (yr. avg. 2.7)

U.S. landfall5.7 Named storms (yr. avg. 3.2)2.5 Hurricanes (yr. avg. 1.5)The TSR forecast anticipates the 2010 Atlantic Hurricane Season has a 93% probability of above average hurricane activity.

18

United Kingdom Meteorological OfficeThe forecast is made using informa-tion from two dynamical global seasonal prediction systems; the Met Office GloSea4 system and ECMWF system 3. Both systems simulate the ocean-atmosphere processes and interactions that determine tropi-cal storm development. Multiple forecasts are made (using ensemble forecasting methods) to allow estimation of the range of likely outcomes. In contrast to the dynami-cal methods used in this forecast, statistical prediction methods, which have traditionally formed the basis of most published predic-tions, do not model atmospheric processes. They rely on past rela-tionships between storm numbers and preceding observed conditions (e.g. preseason SST patterns).Storms and conditions

North atlantic20 Named storms (1990-2005 avg. 12.4)Accumulated Cyclone Energy* (ACE) index = 204 (1990-2005 avg. 131)ACE is a measure of the collec-tive intensity and duration of all tropical storms over the season and includes storm lifetimes and intensities as well as total numbers over the season.

20

Map courtesy NOAA


It Only Takes One Hurricane:FORTIFIeD Solutions for protecting Your Home

BY FRED MALIK AND CANDACE ISKOWITZ INSTITUTE FOR BUSINESS & HOME SAFETY

From Texas to Maine residents are being cautioned about this years hurricane sea-son, which is forecast to be above average in terms of the number of named storms and major hurricane activity [See Page 16 for the hurricane forecast chart]. Regardless of how many hurricanes actually develop, it only takes one making landfall to result in a disaster for the areas residents, businesses and local communities.

For years, the public has looked to prop-erty insurers to provide the financial resources to re-build homes and businesses and replace belongings after a hurricane. Financial compensa-tion, however, can only replace or repair material things. No amount of money can surmount the insecurity that comes with being displaced from your home, having your life disrupted, and most certainly, the loss of a loved one. There is, however, an affordable solution that will help homeown-ers better protect their property against natural disasters.

The Institute for Business & Home Safetys FORTIFIED suite of programs gives homeowners the option of building stronger from the ground up or retrofitting their existing property against hurricanes and other disasters. Now, an innovative program in Alabama, which could be a model for other states, makes it even more affordable for homeowners in vulnerable Mobile and Baldwin counties to choose FORTIFIED.

Why FORTIFIeD is Right for alabama

Alabama residents know all too well the power of hurricanes.

In 2009, Alabama ranked seventh in the nation for the number of major wind and water related disasters affecting its residents with 53. Since 2000, the state has been struck by a com-bined six hurricanes and tropical storms; the losses experienced during these storms were not limited to Alabamas coast; damage from wind and wind-driven rain extended far inland. 2004 and 2005 brought Hurricanes Ivan and Katrina to the state and resulted in a combined $3.8 billion (2010 dollars) in insured property losses. Forecasters are warning the 2010 hurricane season could mirror conditions experienced in 2005.

In response to this repeated exposure and widespread damage, the Alabama Legislature took a progressive step in 2009 and enacted legislation

to provide incentives to property owners and property insurers to harden residential structures. Alabama Act 2009-500, (now codified as Ala. Code 27-31D-1), requires insurance com-panies doing business in Alabama to provide a premium discount or insurance rate reduction to property owners who build, rebuild, or retrofit their homes according to specific standards to better withstand hurricanes and other catastrophic windstorm events. These standards include the 2006 International Residential Building Code, the IBHS FORTIFIED for Safer Living program for new construction, and the newly created FORTI-FIED for Existing Homes retrofit program. The retrofit program is now being piloted in Mobile and Baldwin counties in Alabama with the roll out of the Hurricane Designation, which offers three levels of designation (Bronze, Silver and Gold). Offering different levels of designation is designed to appeal to various price points among homeowners.

The FORTIFIED for Existing Homes Des-ignation provides tangible evidence that a home is built and /or retrofitted according to standards that bring critical elements and systems in the house up to, and sometimes beyond, those used in new hurricane-resistant construction. The FOR-TIFIED approach is incremental to keep costs manageable, while tackling the vulnerabilities that lead to damage in common, weaker storms such as a Category 1 hurricane. As the levels progress to include more extensive retrofit requirements, the hurricane resistance of the home increases to add protections against less frequent but more intense storms, such as a Category 2 or greater. This approach provides a common sense path toward making a house more resilient when a hurricane strikes.

Alabama is the first state to recognize, through legislation, and to attempt to balance meaningful risk reduction for property insurers in exchange for substantial reductions in annual wind premiums for property owners. The Ala-bama Department of Insurance (ALDOI) has established benchmark reductions, ranking the standards qualifying for the highest credits to lowest as follows:

1. FORTIFIED for Safer Living (code-plus new construction standard)

2. FORTIFIED for Existing Homes Gold Designation

3. FORTIFIED for Existing Homes Silver Designation

4. FORTIFIED for Existing Homes Bronze Designation

5. 2006 International Resi-dential Building Code

At this time these credits are limited to the

coastal counties of Mobile and Baldwin, both of which border the Gulf of Mexico.

Field evaluations Uncover Structural Weaknesses

An initial evaluation of homes in these coastal areas by IBHS engineering staff produced sub-stantial evidence of the need to encourage hom-eowners to take the necessary steps to limit future hurricane damage.

IBHS staff conducted field trials in April and put a number of randomly selected houses in Baldwin and Mobile counties through the FORTIFIED evaluation process, which is the first step toward participation in the FORTIFIED for Existing Homes program. The average age of the houses evaluated was 71/2 years. Each property possessed certain architectural details or elements that increased its vulnerability to hurricane damage. The FORTIFIED program offers solutions to strengthen each of the structural weaknesses identified but, the variety of issues encountered during the evaluations confirmed IBHS commitment to having knowledgeable individuals conduct careful inspections as part of the program.

Here are some of the specific findings from the field evaluation trial:

100percentofthesamplehouseslackeda secondary water barrier on the roof, which would afford protection against water intrusion if the primary roof covering is damaged or torn off during a hurricane.

100percentofthehouseslackedopen-ing protection or had inadequate open-ing protection to prevent damage from flying debris and water intrusion during a hurricane.

75percentofthehousesweremissingroof to wall connectors that are required by modern, engineering-based building codes to keep a house intact during hur-ricane conditions.

A key element of the new FORTIFIED for Existing Homes program is the use of quali-fied professionals, certified by IBHS, to conduct these types of evaluations on properties as hom-eowners apply to receive a designation. Once an application is submitted, a homeowner hires an evaluator to review their property and a cus-tom Current Condition Report is generated in conjunction with IBHS. The report identifies the propertys key vulnerabilities and provides details of how to achieve each of the programs three levels of designation. This will not only help the homeowner achieve the highest level of hurricane protection they can afford, but also provide them with options if they are considering


Strength isnt always obvious.

DisasterSafety.org/FORTIFIeD

future renovations.Once a homeowner has reviewed the report

and is committed to investing in making their home FORTIFIED, the program requires in-progress inspections during the retrofit process to ensure that the workmanship and products used meet program standards. By participating in a FORTIFIED program, property owners can be comfortable that their investment will achieve their desired results.

program expansion planned

In May, seven professionals were selected by IBHS to take part in the first evaluation training program in Alabama. Prior to enrolling in the training program, IBHS reviewed their qualifica-tions in accordance with a rigorous set of operat-ing standards. All seven completed the training and are now certified to conduct FORTIFIED for Existing Homes Evaluations. The evalua-tions can take up to one hour and each evaluator is capable of performing four evaluations a day. A list of certified evaluators is available on the IBHS website, www.DisasterSafety.org/fortified, where homeowners also can submit an online application.

Thanks to media coverage and word of mouth, IBHS is receiving a steady stream of appli-cations from Alabama homeowners interested in achieving a FORTIFIED for Existing Homes Hurricane Designation. It is believed that the number of certified evaluators now available is adequate to keep up with the current program demands.

The Alabama pilot program continues through the end of summer. The program then will be expanded to include properties nation-wide. IBHS staff is now working to develop cri-teria and other program elements to expand the program to include designations for protection against earthquakes, flooding, freezing weather, hail, high winds, internal water and fire damage, and wildfire.

As the program grows, it will enable a sig-nificant number of at-risk homeowners to harden their properties against damage. This will pro-mote greater community resiliency and reduce recovery costs after natural disasters. With a vari-ety of retrofit options perfect for nearly every price point, the only question is, Can any homeowner really afford not to have their house FORTI-FIED?

For more information on any of the IBHS FORTIFIED suite of programs, contact Fortified Program Manager Fred Malik at [email protected] or (813) 286-3400.


Making a Case for proper Window and exterior Door InstallationsDICK WILHELM FENESTRATION MANUFACTURERS ASSOC.

Following the damage wrought by the active 2004 and 2005 hurricane seasons along the Gulf Coast, the Florida Home Build-ers Association (FHBA) set out to try to deter-mine the causes of excessive water intrusion that plagued so many homes and businesses.

FHBA contracted with Joseph W. Lstiburek, Ph.D., P.E., to conduct a study of the issue. Dr. Lstibureks research noted that although windows and doors themselves under the Florida Building Code are subject to the requirements of an ASTM standard, the interface between the window and door and the wall assemblies currently are not.

The report recommended water managed window and door installation requirements be developed and the Florida Building Code altered to require them. The Florida Building Commis-sions Hurricane Research Advisory Committee (HRAC) held hearings in 2006 to address the recommendations of Lstibureks report.

The HRAC decided to first address roof-ing issues associated with hurricane damage, and requested the window/door industry tackle water intrusion at the interface. As a result of that request, the Fenestration Manufacturers Association (FMA) and the Window and Door Manufacturers Association (WDMA) teamed up to address water intrusion and the American Architectural Manufacturers Association (AAMA) agreed to address testing standards applicable to windows and doors.

The associations created the FMA/AAMA Advisory Board to review work done by the FMA/AAMA/WDMA Installation Committee. The committee was to evaluate, develop and test best management practices for the proper installation of windows and exterior doors in extreme wind and water environments, such as those experi-enced.

The installation committee quickly estab-lished that proper field installation of windows and exterior doors significantly enhances the resis-tance to water intrusion around the opening. This could be facilitated by controlling tolerances, the variations in dimensions from the ideal of the rough opening in Concrete Masonry Unit (concrete block) wall construction, improved sill design, and improved flashing and sealant procedures. The committee concluded that the

installation of the windows or exterior doors may become compromised by the installation of secu-rity systems, shutters, or other components and cladding.

One of the best ways to deal with this issue is to bring together the various trades responsible for the wall system. This approach is based on the existing relationships between the FMA/WDMA/AAMA, which have worked with masons as well as the stucco industry in an attempt to understand each trades unique issues and to devise best instal-lation practices that do not interfere with their ability to produce good workmanship.

Often window installers are not the products manufacturer and the manufacturers installa-tion instructions are not followed. The result can be water intrusion. The question then becomes, how can we as an industry get the word out that achieving performance objectives for windows and exterior doors not only requires the selec-tion of appropriate window and door products; but, also must include installation according to industry-approved practices?

Addressing this issue assists in meeting the Institute for Business & Home Safetys (IBHS) goals for loss prevention/reduction.

FMA/WDMA/AAMA have jointly devel-oped and tested standard protocols to guide installers, architects and builders in the methods recommended to perform installations. These protocols have been peer reviewed by the FMA/WDMA/AAMA members. Unlike previous instal-lation standards, such as ASTM E2112, these regionally specific protocols provide concise, easy to follow, pictorial guidelines that could be fol-lowed by any reasonably skilled installer.

Windows and exterior doors are systems that are subject to the most stringent testing and certification of all components and cladding of a building. To make them perform in the expected fashion, it is critical to follow proper installation protocols. To date, FMA protocols have been developed, tested and published addressing the installation of windows into wood frame construc-tion (FMA/AAMA 100-07) and surface barrier masonry construction (FMA/AAMA 200-10 and FMA/WDMA 250-10) located in extreme wind and water environments. These protocols have been submitted to the Florida Building Commis-sion for their review as proposed amendments to the 2010 Florida Building Code.

The FMA/WDMA/AAMA Installation Committee continues to move forward with addressing the installation of exterior doors with the FMA/AAMA/WDMA 300 and 400 series. Sliding glass doors have been given considerable attention, given the widespread use of the product in condominiums located along the southeastern U.S. and Gulf Coast.

FMA/WDMA/AAMA looks forward in tak-ing part in bridging the gap between construction

trades affecting the window/wall interface, work-ing with the building commissions, architects, builders, installers and building officials to gain an understanding of the importance of a best installation practices. We also look forward to working with the IBHS in any fashion to assist the organization and its member insurance com-panies in developing improved systems based approaches for assuring improved building per-formance.

Dick Wilhelm is the executive director of the Fenestration Manufacturers Association and represents the Window and Door Manufacturers Association in the Southeast and Gulf Coast. Contact him at (850) 294-7963 or [email protected].


Will Coastal Codes pass the Test this Hurricane Season?BY WANDA EDWARDS, P.E. IBHS DIRECTOR OF CODE DEVELOPMENT

The quality of building codes and the level of enforcement that is in place before a hurricane hits are good barometers for how well the built environment may perform under these extreme weather conditions.

A state or communitys decision to adopt and enforce the wind provisions of modern building codes is one of the first steps toward preparing new properties to better withstand the threat of hurricanes. Building codes provide minimum acceptable standards used to regulate design, construction and maintenance of buildings to protect the health, safety and general welfare of the buildings users.

When it comes to high-wind protections, the International Code Council (ICC) has developed the most widely adopted set of codes. The wind provisions of the codes have been updated several times during the past decade to reflect the latest building science.

There are design elements included in the wind provisions of the code that are most impor-tant to the overall performance of a structure during a hurricane, including:

1. Using the design wind speed designated on the ASCE 07 maps

A structure should be designed for the correct wind speed as shown on the map developed by the American Society of Civil Engineers (ASCE). Using the correct wind speed ensures that the proper design loads are incorporated into the creation of a structure. This improves its capacity to withstand the loads imposed during a high-wind event.

2. Design criteria for one and two family dwellings and townhomes

The code requires that construction in regions where the basic wind speeds equal or exceed 100 mph in hurricane-prone regions, or 110 mph elsewhere in accordance with the ASCE wind maps, shall be designed according to one of the following:

AmericanForestandPaperAssociation(AF&PA)

Wood Frame Construction Manual for One- and Two-Family Dwellings (WFCM); orSouthern Building Code Con- gress International Standard for Hurricane Resistant Residential Construction (SSTD 10); orMinimum Design Loads for Buildings and Other Struc-tures (ASCE-7); or

AmericanIronandSteelInstitute(AISI)

Standard for Cold-Formed Steel Framing Prescriptive Method For One- and Two-Family Dwellings (COFS/PM) with Supplement to Standard for Cold-Formed Steel Framing Prescriptive Method For One- and Two-Family Dwellings

Concreteconstructionshallbedesignedin accordance with the provisions of the IRC

3. Providing windborne debris protection

The code defines the windborne debris region as areas within hurricane-prone regions within one mile of the coastal mean high water line, where the basic wind speed is 110 mph or greater; or where the basic wind speed is equal to or greater than 120 mph. Within this region, protection may be provided one of three ways: Impact-resistant glazing, hurricane shutters or plywood panels that have been precut and have the hardware provided.

4. Using wind-rated roof coverings

The 2006 Inter-national Building and Residential Codes first incorporated wind-rated shingles tested to ASTM D3161, marking a vast improvement over shingles installed to previous codes. The 2009 International Residential Code upgraded this standard with ASTM D 7158, which uses a two-step process to develop a rating for the wind resistance of shingles. Roof cover damage continues to be the most frequent source of hurricane-related insurance claims not related to storm surge. In fact, IBHS research found some 95 percent of residential wind-related insurance claims resulted in payment for roof repairs following Hurricane Charley in 2004.

5. Eliminating the partially enclosed design method (incorporated in the 2006 IBC and IRC)

The partially enclosed design method does not provide protection opening, and does not incorporate the glazing or other opening coverings into the load resistance of the design. This design method assumes that a structure will lose the opening material, and the building will become pressurized due to winds blowing into the build-ing. The building is designed to withstand the resulting pressures. This method was eliminated because a building suffers so much damage when the openings are breached that it is not financially feasible to perform the necessary repairs.

Maine Inamunicipalitythathasmore

than 2,000 residents and had adopted any building code by Aug. 1, 2008, the Maine Uniform Building and Energy Code must be enforced beginning Dec. 1, 2010.

Inamunicipalitythathasmorethan 2,000 residents and had not adopted any building code by Aug. 1, 2008, the Maine Uniform Building and Energy Code must be enforced beginning July 1, 2012.

Basecodewillbethe2009Inter-national Building Code (IBC) and International Residential Code (IRC). No amendments have yet been made.

New York Mandatorystatewidecodeand

mandatory statewide enforce-ment with the exception of New york City.

Basecodeisthe2006IBCandIRC. Codeweakeningamendment:

allows partially enclosed design, deleted requirement that homes in the 100 mph wind zone be designed to one of the design standards listed in the code.

Connecticut Mandatorystatewidecodeand

mandatory statewide enforce-ment.

Basecodeisthe2003IBCandIRCwith no weakening amendments.

Massachusetts Mandatorystatewidecodeand



lowered design wind speed; allows partially enclosed design.

Rhode Island Mandatorystatewidecodeadop-

tion and mandatory statewide enforcement.

Basecodeisthe2006IBCandIRC. Weakenedwindprovision

amendments: lowered wind speeds, deleted a requirement that homes in the 100 mph wind zone be designed to one of the design standards listed in the code.

New Hampshire Mandatorystatewidecodeadop-


Basecodeisthe2009IBCandIRCwith no weakening amendments.

Maryland Mandatorystatewidecodeand


Basecodeisthe2009IBCandIRC. Weakenedthecodebyallowing

local jurisdictions to amend it.

Virginia Mandatorystatewidecodeadop-



does not require structures in the 100 mph wind zone to be designed to the one of the stan-dards listed in the code.

Delaware Nomandatorystatewidecode

adoption or mandatory statewide enforcement.

North Carolina Mandatorystatewidecodeadop-


Basecodeisthe2006IBCandIRC. Codeweakeningamendment:do

not require structures in the 100 mph wind zone to be designed to one of the standards in the code; weakened the windborne debris provisions of the code.

Georgia Mandatorystatewidecodeadop-

tion, but enforcement decisions are made at the local level.

Basecodeisthe2006IBCandIRC.

Alabama Nomandatorystatewidecodeor


Texas Nomandatorystatewidecode adoption or mandatory statewide enforcement.

South Carolina Mandatorystatewidecodeadop-


Basecode2006IBCandIRCwithno weakening amendments.

Florida Mandatorystatewidecodeadop-


Basecodeisthe2006IBCandIRC.

Louisiana Mandatorystatewidecode adoption and mandatory statewide enforcement. Codeweakeningamendment: does not require structures in the 100 mph to be designed to one of the stan-dards listed in the code. Basecodeisthe2006IBC

and IRC.

Mississippi Nomandatorystatewidecodeor


New Jersey Mandatorystatewidecodeand


Basecode2006IBCandIRCwithno weakening amendments.


State by StateThe mandatory application and enforcement of these codes and the adoption of local amendments, which affect the building code regulatory process and the protections it provides, vary by state. What follows is a state-by-state analysis of the building codes in hurricane-prone jurisdictions.


IBHS Research Center: From Concept to RealityBY ALLISON DEAN LOVE IBHS ExTERNAL RELATIONS CONSULTANT

It has been about a year since ground was broken on a state-of-the-art research facility in rural South Carolina that will change the face of windstorm-related hazards research, specifically as it relates to wind-driven hail, wildfire ember transport, high- wind exposure and hurricane resilience.

With construction scheduled to be com-pleted in July, the IBHS Research Center is perched to move from concept to reality thanks to the diligent support of many IBHS insurance company members.

Our founding members should be very proud to be associated with the creation of the new research center, said IBHS presi-dent & Chief Executive Officer Julie Rochman. This lab is a tre-mendous asset that will produce significant and tangible short- and long-term benefits for the insurance industry, residential and commercial property owners, and for the building science community.

Momentum is building in advance of the grand opening events in Octo-ber, which will include the first dem-onstration test to showcase the labs wind capabilities. In preparation, IBHS engineers, under the guidance of Dr. Tim Reinhold, IBHS senior vice president of research and chief engineer, and IBHS Director of Research Dr. Anne Cope, are in the process of conducting scientific com-missioning of the facility.

With the equipment and safety checks nearly completed, IBHS engineers are gearing up to begin the rigorous process of validating the abil-ity of the facility to reproduce various types of wind flow conditions and wind effects on struc-tures, said Reinhold.

Wind capabilities at the multi-peril research facility include the ability to generate extra-trop-ical and hurricane-force winds, lateral shear such as that which might be expected at the edge of a tornado vortex, and thunderstorm frontal winds that can be generated by taking the fan array from a very low level wind to full speed in a matter of a few seconds. Researchers also will be able to simulate hail storms, wildfire wind-driven ember attacks, and wind-driven rain conditions.

The inaugural test on Oct. 7 will be performed as part of a private dedication ceremony for the facility, with the research centers founding mem-bers in attendance. The test will involve two side-by-side 1,300 square foot townhomes. One of the homes will be built to conventional construction

standards. Its performance will be compared to a second home built to IBHS FORTIFIED for Safer Living standard. The test will illustrate how it is possible to achieve a higher level of performance during a wind-related event with relatively little difference in construction costs.

The town-home floor plans are modeled after an existing FORTIFIED home located in Bloomington, Ill.

Real world application of the scientific research findings generated at the lab will lead to more durable, sustainable communi-ties. The research findings also will provide an objective, sound foundation for the development of solid public policy, such as enhanced building codes, as well for improving building products and systems. The building science conducted will demonstrate the effectiveness, affordability and true long-term cost-savings of better-built structures for individual homeowners and society at large.


Responding to the Risk in South CarolinaBY ANN ROBERSON MANAGER, S.C. SAFE HOME

It has been more than 20 years since South Carolinians were repairing and rebuilding their lives and property after Hurricane Hugos devastating winds and rains pummeled coastal and inland areas. In 1989, that storm resulted in $4.2 billion in insured losses, which by todays calculations would easily add up to a $7.5 billion price tag.

During the past two decades, the state has experienced tremendous growth, particularly in coastal counties. By 2030, the population is pre-dicted to grow to more than 5.4 million people many of whom will be living in harms way. Currently, South Carolina has approximately $200 billion in insured property values along the coastline.

State officials realize its not a matter of if, but when, the state will be struck by another major storm. In preparation, the state has taken proac-tive steps and is much better prepared for storms with the development of sophisticated forecasting technology, enhanced emergency preparedness plans, and better, stronger built homes.

It is equally important that individual hom-eowners do their part to plan and prepare for the next hurricane or other disaster. From home inventory reports to family emergency plans, it is critical to plan now for what tomorrows storm may bring or take away. South Carolina offers its residents a few incentives to encourage them to strengthen their homes against hurricanes.

A major catalyst for these incentives was cre-ated in 2007, with the S.C. Legislatures passage of the Omnibus Coastal Property Insurance Reform Act. The Act was created as part of an effort to

address the growing issues concerning the availability and affordabil-

ity of coastal

property insurance coverage. One reform was the creation of Catastrophe Savings Accounts, which allows homeowners to set aside money that is not subject to state-income tax, to pay for qualified catastrophe expenses. Another reform was the development of individual state income tax credit opportunities to help offset the costs associated with strengthening homes. These are just two examples of the reforms that were estab-lished by the law.

The Act also established the S.C. Safe Home Program, which has enabled homeowners to apply for grants to protect their houses against hurricanes and also has had a positive effect on the local economy. This program awards grants up to $5,000 to help homeowners retrofit their property. As of June 17, 2010, the program had awarded more than 1,100 grants totaling more than $4.4 million to coastal S.C. homeowners to help them address the following retrofits: roof covering construction, roof deck attachment, roof-to-wall connections, secondary water bar-rier installation, and protection for all openings including garage doors.

Approximately 76 percent of the grant recipi-ents have used the grant funds to help strengthen their roofs through retrofitting. Interestingly, many of these roofs were installed after Hur-ricane Hugo in 1989 and 1990, but were not subject to the current statewide building code. All of these roofs lacked a secondary water barrier, enhanced nailing pattern, braced gable-ends, and the appropriate wind-rated shingle based upon the geographic location of the home.

The program has also helped homeowners to replace their windows. Homeowners who have opted to use impact-rated windows have reported, on average, a 29 percent savings in their energy costs.

Research shows that houses retrofitted through S.C. Safe Home are more attractive risks to insurance companies. Homeowners have

reported premium reduction

sav

Disaster Safety Review 2010 - Vol. 2

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