Post 2004 Hurricane Field Survey Post 2004 Hurricane Field Survey

Evaluation of the Relative Performance of the Standard Evaluation of the Relative Performance of the Standard

Building Code and the Florida Building CodeBuilding Code and the Florida Building Code

Kurt Gurley – UFJeff Burton – IBHS

Makola Abdullah – FAMUForrest Masters – FIUTim Reinhold – IBHS

Project Goal

• Determine if 2002 code change reduced the vulnerability of residential single family homes

• Quantitative rather then anecdotal– Physical damage– $ Loss ratio– Behaviors (mitigation & evacuation)

• Stratify results by wind speed and code

Additional Objectives

• Include and contrast structures in each of the areas impacted by 2004 storms

• Subject targets – site built single family– Post Andrew, pre-Florida Building Code

• 1994 – 2001 (‘old’)

– Post Florida Building Code • 2002 – 2004 (‘new’)

Methodology

• Pre-arranged appointments with randomly selected homeowners to gather damage information– Interview homeowner– Inspect property

• Prior knowledge of – home details ( Yr of construction, Roof / Wall type, etc.)– home location relative to peak 3-second wind speeds

• NO prior knowledge of damage– no visual bias to sample selection– to determine ‘average’ damage and $ loss

Tools

• Access to wind swath maps – Vickery: Applied Research Associates– Powell: NOAA

• Access to county databases:– Home location– Homeowner– Year of construction– Roof cover (asphalt, tile)– Roof type (hipped, gable)– Wall type (masonry, wood frame)– Appraised value pre-2004 storm season

Wind Swath Maps

Ivan

Jeanne

Frances

Charley

GIS Database - Charlotte County

• All Single family units 2002 - 2004 ‘new’

GIS Database – Stratifications

• ‘old’ units with tile roofs – Punta Gorda Isles

Stratified Sampling Procedure

• Overlay wind swath maps with homes that fit desired characteristics (age, roof cover, etc.)

• Randomly select homes across desired wind swath contours

• The homeowners contacted by phone in random order (25% success rate)

Survey Details: Inspection

• Digital photograph s– All angles and corners of subject– Surrounding terrain

• Distance to adjacent large objects in all directions

• Sketch elevations and plan view

Survey Details: Inspection

• Attic inspection– Sheathing type and thickness– Sheathing nail size, edge and field spacing– Gable end bracing– Roof to wall strap installation

• Garage inspection– Pressure rating, bracing

• Location, size and type of every window and door – includes protection details & damage

Survey Details: Interview

• Evacuation behavior

• Mitigation behavior (shutters)

• Indicate damage on elevation sketches– Water penetration– Roof cover failure– Soffit failure– Window and / or shutter failure

• Scan any damage pictures

• Insurance reimbursement information

Survey Details: Interview

•Data entered directly into

handheld PDA

•Upload to access database

Charley Surveyed HomesCharley 126Surveyed Homes

2002-2004

1994-2001

3-Sec Gust(MPH)

Frances and JeanneFrances & Jeanne 33Surveyed Homes

2002-2004

1994-2001

3-Sec Gust(MPH)

Wind speed verified through portable weather stations

Ivan Surveyed Homes

2002-2004

1994-2001

3-Sec Gust(MPH)

Ivan 36Surveyed Homes

Survey Demographics

Total # samples = 195

CharleyTotal = 126

IvanTotal = 36

Frances / Jeanne

Total = 33

Zone 8110 - 120

Zone 10130 - 140

Zone 11140 - 150

Zone 8 110-120

Zone 8 110 - 120

Old codeSBC

’94 – ‘98 1 22 10 10 5

’99 – ‘01 10 23 14 10 12

New codeFBC

’02 – ‘04 11 12 23 16 16

Water Penetration: Charley (All)

Old New

Total Water Damage Charley

0%

10%

20%

30%

40%

50%

60%

70%

Total 1994-98 1999-01 2002-04

Water Penetration: Charley (11)

Old New

Charley Water Damage: Zone 11

0%

10%

20%

30%

40%

50%

60%

70%

Total 1994-98 1999-01 2002-04

Water Penetration: All stormsZone 8 (110 – 120 mph 3 sec. gust)

Old New

Water Penetration All Storms: Zone 8

0%

10%

20%

30%

40%

50%

60%

70%

Charley Frances & Jeanne Ivan

Total

1994-98

1999-01

2002-04

Water Penetration: All stormsType of penetration

Old New

Water Damage by Location

0%

10%

20%

30%

40%

50%

60%

no damage ext windows ceiling nearexterior walls

Interiorportion of

ceiling

interior walls exterior walls floor neardoor

1994-98

1999-01

2002-2004

Water PenetrationResults Summary

• Water penetration by code: – It is not clear from the study that the FBC

provides improvement in preventing water penetration.

– 1994 – 1998 more likely to have ceiling damage

Window Protectionby storm and age

Old New

All Storms: Percent Protected

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Charley Frances & Jeanne Ivan

Total

SBC

FBC

Window Damage: 110 – 120 (8)by storm per window

Old New

Damage Type By Storm: Zone 8

0%

1%

2%

3%

4%

5%

6%

Unprotected &Damaged

Unprotected &Breached

Unprotected w/Water Damage

Protected &Damaged

Protected &Breached

Protected w/Water Damage

Charley

Frances & Jeanne

Ivan

Window Damage: Charley data by zone per window

Old New

Hurricane Charley: Damage by Wind Zone and Type

0%

2%

4%

6%

8%

10%

12%

Unprotected &Damaged

Unprotected &Breached

Unprotected w/Water Damage

Protected &Damaged

Protected &Breached

Protected w/Water Damage

Zone 8

Zone 10

Zone 11

Window Protection: 2004 and Future Use

Old New

Window protection use in 2004 and future storms

% of homes in that region that used left column protection in 2004(% that intend to use protection in future seasons)

Charley Ivan Frances / Jeanne

No protection 60 %(11%)

58%(33%)

16%(16%)

Plywood 7%(13%)

36%(36%)

13%(6%)

Shutters 27%(74%)

6%(27%)

(53%)(72%)

Impact Glass 7%(3%)

0%(3%)

19%(6%)

Window ProtectionResults Summary

Mitigation effectiveness – shutter use:

A significant percentage (3 - 4%) of unprotected windows were damaged in the highest wind zone (140 – 150 mph) in Charley, while protected windows experienced significantly less damage.

At the lower wind zone 8 (110 – 120 mph gust), protected windows permitted almost no damage, while the percentage of damaged unprotected windows was small but consistent among storms.

Soffits by Age Group: All data

Soffit Damage For All Storms and Wind Zones

0%

10%

20%

30%

40%

50%

60%

No Damage 0<25% 26-50% 51-75% 76-100%

'94-98

'99-'01

'02-'04

Soffit DamageResults Summary

Soffit performance with age of construction: Increased likelihood of soffit damage with

increasing age of structure (over the surveyed range 1994 – 2004).

Roof Cover: Charleyby zone and cover type

Hurricane Charley: Boolean Overall Roof Cover Damage by Type and Breakdown by Wind Zone

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

All Shingle Tile

Roof Cover Type

Pe

rcen

t D

ama

ged

% overall damaged

% damaged Zone 11

% damaged Zone 10

% damaged Zone 8

Roof Cover (all types): Charleyby age and quantity

Hurricane Charley: Overall Roof Cover Damage by Year Built

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

No Damage > 0 - 2% 3 - 5% 6 - 10% 11 - 25% 26 - 50%

Percent Cover Loss

Per

cen

tag

e o

f H

om

es w

ith

sai

d C

ove

r L

oss

1994-98

1999-2001

2002-04

Roof Cover (Tile): Charleyby age and quantity

Hurricane Charley: Tile Roof Cover Damage by Year Built

0%

10%

20%

30%

40%

50%

60%

70%

No Damage > 0 - 2% 3 - 5% 6 - 10% 11 - 25% 26 - 50%

Percent Cover Loss

Per

cen

tag

e o

f H

om

es w

ith

sai

d C

ove

r L

oss

1994-98

1999-2001

2002-04

Roof Cover (Shingle): Charleyby age and quantity

Hurricane Charley: Shingle Roof Cover Damage by Year Built

0%

10%

20%

30%

40%

50%

60%

No Damage > 0 - 2% 3 - 5% 6 - 10% 11 - 25% 26 - 50%

Percent Cover Loss

Per

cen

tag

e o

f H

om

es w

ith

sai

d C

ove

r L

oss

1994-98

1999-2001

2002-04

Roof Cover (Tile): Charley (11)by age and quantity

Hurricane Charley: Wind Zone 11 Tile Roof Cover Damage by Year Built

0%

10%

20%

30%

40%

50%

60%

70%

No Damage > 0 - 2% 3 - 5% 6 - 10% 11 - 25% 26 - 50%

Percent Cover Loss

Per

cen

tag

e o

f H

om

es w

ith

sai

d C

ove

r L

oss

1994-98

1999-2001

2002-04

Roof Cover - TileResults Summary

Tile roof cover performance: Few surveyed tile roof homes of any age group had

no cover damage Higher probability of field tile loss in ’94 – ‘01 homes

compared to new construction

2002 – 2004 15% had tile damage exceeding 5%, (mostly ridge cap loss)

1999 – 2001 60% had over 5% damage 44% over 10% damage 22% over 25% damage

1994 – 1998 60% had 6-25% damage

Roof Cover (Shingle): Charley (10)by age and quantity

Hurricane Charley: Wind Zone 10 Shingle Roof Cover Damage by Year Built

0%

10%

20%

30%

40%

50%

60%

No Damage > 0 - 2% 3 - 5% 6 - 10% 11 - 25% 26 - 50%

Percent Cover Loss

Per

cen

tag

e o

f H

om

es w

ith

sai

d C

ove

r L

oss

1994-98

1999-2001

2002-04

Roof Cover - Shingle Results Summary

Shingle roof cover performance by age of construction: For highest wind zone 140 - 150 Distinct difference in shingle performance by age

1994 - 1998 significant quantities of shingle damage 1999 – 2001 less damage 2002 – 2004 small quantity of damage on average

1994 – 1998 Every shingle house surveyed in zone 11 had shingle damage, all had at least 10% shingle loss, and most had between 25 and 50% loss.

2002 – 2004 30% of shingled houses had no shingle damage, and the wide majority of those that had damage lost less than 5 % of their shingles.

Shingles: Regional Comparison

Summary of Boolean Shingle Damage by Storm and Wind Zone

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Charley - 11 Charley - 10 Charley - 8 Frances/Jeanne - 8 Ivan - 8

% shingle roof cover damaged

Roof Cover - ShingleResults Summary

Shingle roof cover performance by wind speed:

Charlotte County 110 – 120 mph : 32% of homes had shingle damage 130 – 140 mph : 65% 140 – 150 mph : 79%

Roof Cover (Shingle): Charley (8)by age and quantity

Hurricane Charley: Wind Zone 8 Shingle Roof Cover Damage by Year Built

0%

20%

40%

60%

80%

100%

120%

No Damage > 0 - 2% 3 - 5% 6 - 10% 11 - 25% 26 - 50%

Percent Cover Loss

Per

cen

tag

e o

f H

om

es w

ith

sai

d C

ove

r L

oss

1994-98

1999-2001

2002-04

Roof Cover (Shingle): Ivan (8)by age and quantity

Hurricane Ivan: Shingle (and Overall) Roof Cover Damage by Year Built

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

No Damage > 0 - 2% 3 - 5% 6 - 10% 11 - 25% 26 - 50%

Percent Cover Loss

Pe

rce

nta

ge

of

Ho

me

s w

ith

sa

id C

ov

er

Lo

ss

1994-98

1999-01

2002-04

Roof Cover (Shingle): Frances (8)by age and quantityHurricane Frances & Jeanne: Shingle Roof Cover Damage by Year Built

0%

10%

20%

30%

40%

50%

60%

70%

No Damage > 0 - 2% 3 - 5% 6 - 10% 11 - 25% 26 - 50%

Percent Cover Loss

Per

cen

tag

e o

f H

om

es w

ith

sai

d C

ove

r L

oss

1994-98

1999-2001

2002-04

Roof Cover - Shingle Results Summary

Shingle roof cover performance by region: 110 – 120 mph 3 sec. gust

Charlotte County (32% of homes damaged) St. Lucie County (80%) Escambia County (50%)

Charlotte County suffered less quantity of damage on average than those in the Ivan and Frances / Jeanne regions.

Concluding Remarks

• Major findings

– Demonstrate: • Effectiveness of window protection• Improvement in shingle performance• Tile: older more likely to experience field tile damage• Some aging effects on roof cover performance

– Support efforts to improve:• Water Intrusion standards• Tile roof cover installation standards• Ridge cap installation standards• Soffit installation standards