Fire performance of houses - Phase 1 study of unprotected floor assemblies in basement fire scenarios

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Fire performance of houses - Phase 1 study of unprotected floor

assemblies in basement fire scenarios

Fire Performance of Houses

Phase 1 – Study of Unprotected Floor

Assemblies in Basement Fire Scenarios

NRC IRC Fire Research Program

NRC-IRC Fire Research Program

Joseph Su

May 29, 2009

Outline

ƒ

Background

ƒ

Objectives

ƒ

Experimental Program

ƒ

Key Findings

ƒ

Advent of new materials and innovative

Background

products/systems used in construction of houses

ƒ

Need to better understand performance and

impact on the life safety of occupants under fire

conditions

ƒ

CCBFC and CCCME requested NRC to

ƒ

CCBFC and CCCME requested NRC to

undertake research into fires in houses

Objectives

To better understand

•

the factors that affect the life safety of occupants

•

the impact of residential construction products and

systems on life safety of occupants

Experimental Program

ƒ

Multi-phase experimental studies planned

ƒ

Phase I – basement fires and unprotected floor

assemblies over basement

•

To study impact on the ability of occupants on upper storeys to

escape in the event of a basement fire

–

fire development

–

smoke movement & tenability conditions

–

structural integrity of unprotected floor assemblies

•

To determine the sequence of fire events

–

fire initiation

–

smoke alarm activation

–

onset of untenable conditions

–

failure of floor assembly above the basement

Test Facility

ƒ

A full-scale test house simulating a two-storey

detached single-family house with a basement

g

y

Basement

ƒ

Relatively severe, fast-growing fire to challenge the floor above

Thermocouples CO / CO2 / O2 Smoke Alarms Air Velocity Legend Pressure Video

Basement Ceiling – Unprotected Assemblies

Solid wood joists

Wood I-joists (LVL flanges)

Wood I-joists (FJL flanges)

First Storey

ƒ

State of doorway to basement:

Open

Closed

Legend Thermocouples CO / CO2 / O2 FTIR Smoke Alarms Smoke Density UP DOWN

•

Open

•

Closed

Air Velocity Pressure Video

First Storey

Loading on Test Floor Assembly

ƒ

OSB Subfloor

ƒ

0.95 kPa imposed load (20 psf, i.e. ½ NBC design load)

ƒ

Self-weight of test floor assembly

Second Storey

Fire Scenarios

Basement NW quadrant. 800 1000 Basement NW quadrant 800 1000

open basement doorway

closed basement doorway

Time (s) 0 200 400 600 800 1000 T e m per atur e ( ºC) 0 200 400 600 FS-1 UF-01 UF-03 UF-04 UF-05 UF-06 UF-06R UF-06RR UF-07 Time (s) 0 200 400 600 800 1000 T e m per atur e ( ºC) 0 200 400 600 FS-4 UF-02 UF-08 UF-09

Temperatures in basement fire room at 2 4 m height

Temperatures in basement fire room at 2.4 m height

ƒ

Relatively severe, fast-growing fire in the basement

ƒ

Very reproducible fire exposure

Measurements and Analysis

ƒ

Smoke alarm responses

E ti

ti

f ti

t

t

bl

diti

ƒ

Estimation of time to untenable conditions

ƒ

Structural response of floor assemblies

Smoke alarm

location

Basement

fire room

1

st

_storey

₂

nd

_storey

corridor

2

nd

_storey

bedroom

(open)

2

nd

_storey

bedroom

(closed)

type

I

P 2

I 3

P 4

I 5

P 6

I 9

P 10

I 7

P 8

Smoke Alarm Responses

type

I

P 2

I 3

P 4

I 5

P 6

I 9

P 10

I 7

P 8

Tests with open basement doorway

Test UF-01

-

40

75

85

125

135

140

150

200

205

Test UF-03

-

48

58

73

123

133

143

143

218

228

Test UF-04

-

30

65

85

115

130

160

225

230

250

Test UF-05

-

45

40

55

130

145

155

165

245

275

Test UF-06

-

45

75

85

115

125

130

200

230

255

Test UF-06R

-

38

58

78

113

123

138

163

198

223

Test UF-06RR

-

43

73

78

128

138

143

153

223

248

Test UF-06RR

-

43

73

78

128

138

143

153

223

248

Test UF-07

-

50

40

55

110

130

130

145

190

210

Tests with closed basement doorway

Test UF-02

-

42

72

97

172

182

212

n.a.

427

541

Test UF-08

-

50

85

95

205

205

220

210

515

515

Tenability Analysis

ƒ

Untenable conditions

•

Smoke obscuration (optical density measurements)

•

Toxic, asphyxiant gases (CO/CO

₂

/O

₂

measurements)

•

Heat (temperature measurements)

Tenability Analysis – gas measurements

closed basement doorway

open basement doorway

n

ce

ntr

a

ti

on

(

%

Vol

)

10

15

20

CO

₂

O

₂

c

e

n

tra

ti

on

(

%

V

o

l)

10

15

20

O

₂

Time (s)

0

100

200

300

400

500

Co

n

0

5

CO

Time (s)

0

100

200

300

400

500

Co

n

0

5

CO

₂

CO

Tenability Analysis – temperature measurements

closed bedroom 400

600 800

UF-06R _{closed bedroom} 400

600 800

UF-09

open basement doorway

closed basement doorway

200 open bedroom 200 400 600 800 2nd storey corridor 400 600 800 200 open bedroom 200 400 600 800 2nd _{storey corridor} 400 600 800

T

e

mperature (ºC)

T

e

mperature (ºC)

200 400 1st storey SW quadrant Time (s) 0 100 200 300 400 500 0 200 400 600 800 200 400 1st storey SW quadrant Time (s) 0 200 400 600 800 1000 0 200 400 600 800

Tenability Analysis – optical density measurements

closed basement doorway

open basement doorway

Optica

l De

nsity (m

-1

)

0

2

4

6

8

1.5 m above floor

0 9

b

fl

Op ti cal Den s ity (m -1) 0 2 4 6 8 1.5 m above floor 0 9 b fl

Time (s)

0

200

400

600

800

1000

0.9 m above floor

Time (s) 0 200 400 600 800 1000 0.9 m above floor

Tenability Analysis – estimation of time to

untenable conditions

ƒ

Depending on many factors

•

Fire characteristics and house geometry

•

Endpoints for tenability analysis (incapacitation used)

•

Occupant characteristics, activities, susceptibility,

thresholds/tenability limits

•

Each occupant likely to have a different time

ƒ

Tenability limit/threshold values used

•

Smoke obscuration: optical density (OD) = 2 m

-1

•

Smoke obscuration: optical density (OD) = 2 m

1

•

CO/CO

₂

or heat exposure: fractional effective dose approach

–

FED = 1 for a healthy adult of average susceptibility

–

FED = 0.3 for a more susceptible person

Tenability

Analysis

open

basement

O D > 2 m-1 O n s e t o f u n te n a b le c o n d itio n s F E D = 0 .3 S m o k e a la rm a c tiva tio n

In itia tio n o f fire

0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 F E D = 1 .0 S o lid w o o d jo ist (T e s t U F -0 1 ) W o o d I-jo is t A (T e s t U F -0 3 )

basement

doorway

0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 S te e l C -jo ist (T e s t U F -0 4 ) M e ta l-p la te w o o d tru s s (T e s t U F -0 5 ) W o o d I-jo is t B (T e s t U F -0 6 ) 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 W o o d I-jo is t B (T e s t U F -0 6 R ) W o o d I-jo is t B (T e s t U F -0 6 R R ) M e ta l w e b w o o d tru s s (T e st U F -0 7 )

Tenability

Analysis

Comparison:

open/closed

O D > 2 m-1 O n s et o f u n te n a b le c o n d itio n s F E D = 0 .3 S m o k e a la rm ac tiva tio n

In itia tio n o f fire

0 2 00 40 0 60 0 800 100 0 120 0 1400 F E D = 1 .0 O p e n d o o rw a y (T e st U F -0 1) C lo se d d o o rw a y (T e st U F -0 2)

open/closed

basement

doorway

0 2 00 40 0 60 0 800 100 0 120 0 1400 (T e st U F -0 2) 0 2 00 40 0 60 0 800 100 0 120 0 1400 O pe n d o o rw a y (T e s t U F -0 3 ) 0 2 00 40 0 60 0 800 100 0 120 0 1400 C los ed d oo rw a y (T es t U F -0 9 ) a ) S o lid w o o d jo ist T im e (s) T i ( ) T im e (s) 0 2 00 40 0 60 0 800 100 0 120 0 1400 O p e n d o orw ay (T e st U F -07 ) 0 2 00 40 0 60 0 800 100 0 120 0 1400 C los ed d oo rw a y (T es t U F -0 8 ) b ) W o o d I-jo ist A c ) M e ta l w e b w o o d tru s s T im e (s)

Tenability

Analysis

Comparison:

open/closed

O D > 2 m-1 O n s et o f u n te n a b le c o n d itio n s F E D = 0 .3 S m o k e a la rm ac tiva tio n

In itia tio n o f fire

0 2 00 40 0 60 0 800 100 0 120 0 1400 F E D = 1 .0 O p e n d o o rw a y (T e st U F -0 1) C lo se d d o o rw a y (T e st U F -0 2)

open/closed

basement

doorway

0 2 00 40 0 60 0 800 100 0 120 0 1400 (T e st U F -0 2) 0 2 00 40 0 60 0 800 100 0 120 0 1400 O pe n d o o rw a y (T e s t U F -0 3 ) 0 2 00 40 0 60 0 800 100 0 120 0 1400 C los ed d oo rw a y (T es t U F -0 9 ) a ) S o lid w o o d jo ist T im e (s) T i ( ) 0 2 00 40 0 60 0 800 100 0 120 0 1400 O p e n d o orw ay (T e st U F -07 ) C los ed d oo rw a y (T es t U F -0 8 ) b ) W o o d I-jo ist A T im e (s)

Tenability

Analysis

Comparison:

open/closed

O D > 2 m-1 O n s et o f u n te n a b le c o n d itio n s F E D = 0 .3 S m o k e a la rm ac tiva tio n

In itia tio n o f fire

0 2 00 40 0 60 0 800 100 0 120 0 1400 F E D = 1 .0 O p e n d o o rw a y (T e st U F -0 1) C lo se d d o o rw a y (T e st U F -0 2)

open/closed

basement

doorway

0 2 00 40 0 60 0 800 100 0 120 0 1400 (T e st U F -0 2) 0 2 00 40 0 60 0 800 100 0 120 0 1400 O pe n d o o rw a y (T e s t U F -0 3 ) 0 2 00 40 0 60 0 800 100 0 120 0 1400 C los ed d oo rw a y (T es t U F -0 9 ) a ) S o lid w o o d jo ist T im e (s) T i ( ) T im e (s) 0 2 00 40 0 60 0 800 100 0 120 0 1400 O p e n d o orw ay (T e st U F -07 ) 0 2 00 40 0 60 0 800 100 0 120 0 1400 C los ed d oo rw a y (T es t U F -0 8 ) b ) W o o d I-jo ist A c ) M e ta l w e b w o o d tru s s T im e (s)

Structural Response of Test Assemblies

TCs under insulated

pads on subfloor

e ra tu re (º C) 300 400 500 600 700 800

ƒ

Measurements on test assembly

t d t

i

ti

t fl

f il

Te mp e 0 100 200 300

Flame sensors at

subfloor T&G joints

Vol ts 0.0 0.5 1.0 1.5 2.0

to determine time to floor failure

•

Temperatures

•

Flame penetration

•

Deflections

•

Visual observations

Floor deflections

at 9 points

D e fl ec ti on (m m) -700 -600 -500 -400 -300 -200 -100 0

Structural Response of the Test Assemblies

ƒ

Deflection prior to floor failure

D

e

fl

e

c

ti

o

n

(m

m)

-300

-250

-200

-150

-100

-50

0

UF-01 UF-03 UF-04 UF-05 UF-06 UF-06R UF-06RR

Def

lection (m

m)

-300

-250

-200

-150

-100

-50

0

UF-02 UF-08 UF-09

a) Tests with open basement doorway

Time (s)

0

100

200

300

400

500

600

700

-350

UF-07

b) Tests with closed basement doorway

Time (s)

0

100

200

300

400

500

600

700

-350

Primary Mode of Floor Failure

ƒ

Solid wood joist assemblies

bfl

f il

(b

th

h)

•

subfloor failure (burn through)

•

most of the joists charred but still in place

ƒ

Engineered floor assemblies

•

joist or truss failure

Primary Mode of Floor Failure

Solid wood joist assemblies: subfloor failure (burn through)

Primary Mode of Floor Failure

Wood I joists A and B: web materials burned through

Wood I-joist B: breakdown at finger joints of lumber flanges

j

g

j

g

Primary Mode of Floor Failure

Steel C-joists: lost strength and deformed

Primary Mode of Floor Failure

O D > 2 m-1

O n s e t o f u n te n a b le c o n d itio n s F E D = 0 .3

S m o k e a la rm a c tiva tio n

In itia tio n o f fire

0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 F E D = 1 .0 S tru c tu re n o lo n g e r u s a b le fo r e g re s s S o lid w o o d jo ist (T e s t U F -0 1 ) W o o d I-jo is t A (T e s t U F -0 3 )

open

basement

0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 W o o d I jo is t A (T e s t U F 0 3 ) S te e l C -jo ist (T e s t U F -0 4 ) M e ta l-p la te -c o n n e c te d w o o d tru s s (T e s t U F -0 5 ) W o o d I-jo is t B (T e s t U F -0 6 )

basement

doorway

T im e (s ) 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 W o o d I-jo is t B (T e s t U F -0 6 R ) W o o d I-jo is t B (T e s t U F -0 6 R R ) M e ta l-w e b -c o n n e cte d w o o d tru s s (T e s t U F -0 7 ) O D > 2 m-1 O n s e t o f u n te n a b le c o n d itio n s F E D = 0 .3

S m o k e a larm a ctiva tio n

In itia tio n o f fire

0 2 00 400 600 800 1000 1200 1400 F E D = 1 .0 S tru ctu re n o lo n g e r u sa b le fo r e g re ss O p e n d o o rw a y (T e st U F -0 1) C lo se d d o o rw a y (T t U F 0 2)

Comparison

open versus

0 2 00 400 600 800 1000 1200 1400 (T e st U F -0 2) 0 2 00 400 600 800 1000 1200 1400 O p e n d o o rw a y (T e st U F -0 3 ) 0 2 00 400 600 800 1000 1200 1400 C lo s ed d oo rw a y (T e s t U F -0 9 ) a ) S o lid w o o d jo is t T im e (s )

open versus

closed

basement

doorway

0 2 00 400 600 800 1000 1200 1400 O p e n d o orw ay (T e st U F -07 ) C lo s ed d oo rw a y (T e s t U F -0 8 ) b ) W o o d I-jo is t A T im e (s )

O D > 2 m-1

O n s e t o f u n te n a b le c o n d itio n s F E D = 0 .3

S m o k e a larm a ctiva tio n

In itia tio n o f fire

0 2 00 400 600 800 1000 1200 1400 F E D = 1 .0 S tru ctu re n o lo n g e r u sa b le fo r e g re ss O p e n d o o rw a y (T e st U F -0 1) C lo se d d o o rw a y (T t U F 0 2)

Comparison

open versus

0 2 00 400 600 800 1000 1200 1400 (T e st U F -0 2) 0 2 00 400 600 800 1000 1200 1400 O p e n d o o rw a y (T e st U F -0 3 ) 0 2 00 400 600 800 1000 1200 1400 C lo s ed d oo rw a y (T e s t U F -0 9 ) a ) S o lid w o o d jo is t T im e (s )

open versus

closed

basement

doorway

T im e (s ) 0 2 00 400 600 800 1000 1200 1400 O p e n d o orw ay (T e st U F -07 ) 0 2 00 400 600 800 1000 1200 1400 C lo s ed d oo rw a y (T e s t U F -0 8 ) b ) W o o d I-jo is t A c ) M e ta l w e b w o o d tru s s T im e (s ) O D > 2 m-1 O n s e t o f u n te n a b le c o n d itio n s F E D = 0 .3

S m o k e a larm a ctiva tio n

In itia tio n o f fire

0 2 00 400 600 800 1000 1200 1400 F E D = 1 .0 S tru ctu re n o lo n g e r u sa b le fo r e g re ss O p e n d o o rw a y (T e st U F -0 1) C lo se d d o o rw a y (T t U F 0 2)

Comparison

open versus

0 2 00 400 600 800 1000 1200 1400 (T e st U F -0 2) 0 2 00 400 600 800 1000 1200 1400 O p e n d o o rw a y (T e st U F -0 3 ) 0 2 00 400 600 800 1000 1200 1400 C lo s ed d oo rw a y (T e s t U F -0 9 ) a ) S o lid w o o d jo is t T im e (s )

open versus

closed

basement

doorway

0 2 00 400 600 800 1000 1200 1400 O p e n d o orw ay (T e st U F -07 ) C lo s ed d oo rw a y (T e s t U F -0 8 ) b ) W o o d I-jo is t A T im e (s )

Key Findings

ƒ

Tests with an open stairwell to the basement

•

Fire events followed a chronological sequence:

–

initiation of the fire

–

activation of smoke alarms

–

loss of tenable conditions in open areas on upper storeys

–

finally structural failure of the test floor assembly

•

Untenable conditions for occupants in open areas on

t

h d t

i

t l th

upper storeys were reached at approximately the same

time regardless of the type of the test floor assemblies

•

The untenable conditions were reached before failure of

the test floor assemblies occurred

Key Findings (continued)

ƒ

Limited tests with a closed door to the basement

3 assemblies: solid wood joist, wood I-joist, metal-web wood truss

•

Reduced the rate of fire growth in the basement

•

Slowed the transport of combustion products from the

basement to the upper storeys

•

Delayed the time to reach tenability limits for occupants

on upper storeys

Dela ed the times for the test floor assemblies to reach

•

Delayed the times for the test floor assemblies to reach

structural failure

•

Metal-web wood truss assembly failed before tenability

limits were reached in open areas on upper storeys

Key Findings (continued)

ƒ

All tests

•

The time to reach failure for the engineered assemblies

was shorter than for the solid wood joist assemblies

•

Untenable conditions were not reached, for the duration

of the tests, in the second-storey bedroom where the

door to the bedroom was kept closed

•

Results support the NBC requirement for working

interconnected smoke alarms on each level of a house to

interconnected smoke alarms on each level of a house to

alert occupants as early as possible in the event of a fire

•

Results reinforce the importance of continued public

education on home fire safety, fire emergency

preparedness and immediate evacuation upon a fire alert

Fire Performance of Houses

Phase 1

Phase 1 Final Reports

Study of Unprotected Floor Assemblies in Basement Fire Scenarios

Summary

http://irc.nrc-cnrc.gc.ca/pubs/fulltext/rr/rr252/rr252.pdf

ƒ

Part 1

http://irc.nrc-cnrc.gc.ca/pubs/fulltext/rr/rr246/rr246.pdf

ƒ

Part 2

http://irc.nrc-cnrc.gc.ca/pubs/fulltext/rr/rr247/rr247.pdf

ƒ

Part 3

http://irc.nrc-cnrc.gc.ca/pubs/fulltext/rr/rr248/rr248.pdf

ƒ

Part 4

http://irc.nrc-cnrc.gc.ca/pubs/fulltext/rr/rr249/rr249.pdf

ƒ

Part 5

http://irc.nrc-cnrc.gc.ca/pubs/fulltext/rr/rr250/rr250.pdf

ƒ

Part 6

http://irc.nrc-cnrc.gc.ca/pubs/fulltext/rr/rr251/rr251.pdf

Further Studies

ƒ

Consortium project (2008-2010) – protected floor

assemblies in basement fire scenarios

•

engineered floor systems protected by gypsum board,

sprinkler or other measures

•

Impact of the protection measures on fire performance and

tenability conditions

ƒ

Fire Performance of Houses Phase 2 (starting 2011)

•

Innovative wall assemblies for single family houses

•

Innovative wall assemblies for single-family houses

Acknowledgments

ƒ

Project partners (Phase 1):

•

Canada Mortgage and Housing Corporation

Canadian Automatic Sprinkler Association

•

Canadian Automatic Sprinkler Association

•

Canadian Wood Council

•

Cement Association of Canada

•

City of Calgary

•

FPInnovations - Forintek Division

•

North American Insulation Manufacturers Association

Ontario Ministry of Community Safety and Correctional

•

Ontario Ministry of Community Safety and Correctional

Services/Office of the Fire Marshal

•

Ontario Ministry of Municipal Affairs and Housing

•

Wood I-Joist Manufacturers Association

Acknowledgments

ƒ

NRC-IRC project team:

•

J.Z. Su

N Bénichou

•

N. Bénichou

•

A.C. Bwalya

•

G.D. Lougheed

•

B.C. Taber

•

P. Leroux

•

G. Proulx

A Kashef

•

A. Kashef

•

C. McCartney

•

J.R. Thomas

Thank you!

Q

ti

?

Questions?