NIST Special Publication 1129 

Summary of the 2011 Workshop on 

Research Needs for Full Scale Testing 

to Determine Vulnerabilities of 

Decking Assemblies to Ignition by 

Firebrand Showers 

Samuel L. Manzello 

Sayaka Suzuki 
NIST Special Publication 1129 

Summary of the 2011 Workshop on 

Research Needs for Full Scale Testing 

to Determine Vulnerabilities of 

Decking Assemblies to Ignition by 

Firebrand Showers 

Samuel L. Manzello 

Sayaka Suzuki 

Fire Research Division 

Engineering Laboratory 

 

 

August 2011 

U.S. Department of Commerce 

Rebecca M. Blank, Acting Secretary 

National Institute of Standards and Technology 

Patrick D. Gallagher, Under Secretary of Commerce for Standards and Technology and Director 
Certain commercial entities, equipment, or materials may be identified in this 

 document in order to describe an experimental procedure or concept adequately. 

Such identification is not intended to imply recommendation or endorsement by the 

National Institute of Standards and Technology, nor is it intended to imply that the 

entities, materials, or equipment are necessarily the best available for the purpose. 

National Institute of Standards and Technology Special Publication 1129 

Natl. Inst. Stand. Technol. Spec. Publ. 1129, 67 pages (August 2011) 

CODEN: NSPUE2 
Table of Contents 

1. Introduction 1

1.1 Objective of This Workshop 1

1.2 Session Agenda 1

2. Results of Discussions 2

2.1 Exposing Deck Assemblies to Firebrand Showers 2

2.2 Summary 8

3. References 10 

4. Acknowledgements 11 

Appendix1 Workshop Attendee List 12

Appendix2 Presentations 13

Appendix3 SFM Standard 12-7A-4 58
1. Introduction 

1.1 Objective for this workshop 

The Engineering Laboratory (EL) at the National Institute of Standards and Technology (NIST) 

in Maryland has a research effort seeking a better understanding of disastrous Wildland-Urban 

Interface (WUI) Fires (http://www.nist.gov/index.html). 

Firebrands are known to be a major cause of structure ignition of WUI fires in the United States 

(USA). To this end, NIST has developed an experimental apparatus, known as the NIST 

Firebrand Generator (NIST Dragon), to investigate ignition vulnerabilities of structures to 

firebrand showers [1-2]. The experimental results generated from the marriage of the NIST 

Dragon to the Building Research Institute’s (BRI) Fire Research Wind Tunnel Facility (FRWTF) 

in Japan have identified the vulnerabilities that structures possess to firebrand showers for the 

first time [3-4]. The detailed experimental findings are being considered as a basis for 

performance-based building standards with the intent of making structures more resistant to 

firebrand attack. 

In support of building construction methods to reduce disastrous wildfire losses, NIST planning 

is underway for a new series of experiments scheduled to investigate the vulnerabilities of 

decking assemblies to firebrand bombardment using the NIST Dragon installed in the FRWTF at 

BRI in Japan. Input is desired for this experimental series from interested parties in California 

(e.g. building officials, Office of the State Fire Marshall (OFSM), code consultants, construction 

industry, and product manufacturers) since large WUI fires have occurred in this state recently. 

Specifically, guidance is desired in order to conduct experiments that will have the potential to 

provide the scientific basis for improvements for existing codes and development of new codes. 

To this end, the Los Angeles (LA) Basin Chapter of the International Code Council 

(ICC; http://www.iccsafe.org) hosted a workshop on June 15, 2011 in Norwalk, CA. The 

workshop was moderated by Mr. Ruben Grijalva, former CALFIRE director and Mr. Stuart 

Tom, Certified Building Official (C.B.O.) from the city of Glendale, CA, served as the official 

note taker. Mr. Neville Pereira, LA Basin ICC Chapter President, arranged the venue and 

cation. 

e 

resented at recent conferences [6-7] and the June 2011 ASTM E05 research review [8]. 

.2 Session Agenda 

 Fire Marshal and Former CALFIRE Director (Presentation is provided in Appendix 

2). 

lo

This is a follow-up of the successful workshop held in 2010 to generate input for an experimental 

series focused on exposing siding treatments, glazing assemblies, and eaves to wind driven 

firebrand showers using the NIST Dragon [5]. Input was considered from that workshop to 

complete a series of full scale experiments in the fall of 2010. Results of those experiments wer

p

1

• Overview of the WUI problem in California, delivered by Mr. Ruben Grijalva, Former 

State

1 
• Overview of NIST WUI Research and in particular structure ignition research, delivered 

y Dr. Samuel L. Manzello, EL-NIST (Presentation is provided in Appendix 2). 

d by Dr. Samuel L. Manzello, EL-NIST (Presentation is provided in 

ppendix 2). 

• roup input, discussion, and exchange of information. 

. Results 

.1 Input related to importance of exposing decking assemblies to firebrand showers 

eries of questions was asked of the audience. 

pecific questions asked from the group included: 

of wall assembly used to attach decking (vertical wall or 

wall assembly be non-combustible in order to consider influence of 

sed for decks in California? 

nk vs. Channel? 

 wall assembly? 

terns? 

• Is a railing needed for the experiments? 

b

• Summary of proposed experimental campaign to determine vulnerabilities to decking 

assemblies to firebrand bombardment using the NIST Dragon installed in the Fire 

Research Wind Tunnel Facility (FRWTF) at the Building Research Institute (BRI) in 

Japan, delivere

A

G

2

2

NIST presentation about decking assemblies is summarized below (see page 3). Since NIST 

considered many facets of decking assemblies, a s

S

• Thoughts on type 

reentrant corner)? 

• How about the depth of the deck assembly? 

• What about the height of decking assembly? 

• Should the 

deck only? 

• What materials are most commonly u

o What is not commonly used? 

• Are the profiles of the decking board important? Pla

• What about the framing used to support the deck? 

o What about ledger board to attach deck to

• What about deck board orientation, or pat

2 
8ft

8ft

27 in

Front view Side view

8 ft

27 in

2ft

Supported by 2x6 Douglas‐Fir

wall

wall

eave

eave

deck

deck

Wall with siding, decking and eave

Board Materials

• Wood (t

• Composite

reated wood or wood which is naturally resistant to 

decaying)

– Treated pine

– Cedar

– Redwood

– Ipé

– Wood/plastic

– Fiber/PVC

• Plastic

• Metal

3 
Profiles

Profiles‐‐‐Depends on materials

Plank ‐‐‐wood or composite Channel‐‐‐composite

Spacing    betweenboards                5mm

betweenboard ends         1/8”

betweenboard andwall  1/4”

4 

Framing

2 ft

8 ft

Made from 2 x 8

16 in

wall

support support
Patterns

wall

outside

standard opposed angled or diagonal

Which pattern isthe easiest for firebrands to be stuck with? Or no difference?

Railing

• Railing is needed??

• If yes, 

– surface of deck is 30 inches above the ground

– railing is 36 inches above the surface of deck 

– a sphere with a diameter of 4 inches cannot pass 

through the space between each rail or any gaps

wall

decking

railing

wall

decking

railing

5 
Discussion and Input from Attendees (General Comments) 

The Office of the State Fire Marshall (OFSM) in California adopted the test method known as 

State Fire Marshall (SFM) STANDARD 12-7A-4 [9]. The current version, accessed from the 

California Building Standards Commission Website (http://www.bsc.ca.gov/default.htm), is 

reproduced in appendix 3. 

• The focus of the group discussion was on the burning brand test; specifically SFM 

STANDARD 12-7A-4 Part B. 

• The under deck test was not the focus of this workshop at this time. 

• Before proceeding to the detailed discussion regarding testing input, some general 

comments were made as to what is the issue with the current SFM test method. Is new 

testing required? 

• Regarding the SFM burning brand test, NIST made the following points: 

o The SFM test method is intended to determine the response of decks to firebrand 

exposure. 

o The simulation of firebrand exposure is very similar to the ASTM E108 [10] 

roofing test. 

o ASTM E108 has been used for more than 100 years and brand exposure has never 

been revisited. 

o Namely, a firebrand is simulated by placing a burning wood crib (either Class A, 

Class B, or Class C firebrand) on top of a section of a deck assembly under an air 

flow. 

o Test standard does not simulate the processes observed in real Wildland-Urban 

Interface (WUI) fires. 

o The dynamic process of multiple firebrands attacking decking materials as a 

function of time is not taken into account in this standard. 

o Firebrand showers have been observed in actual WUI fires over and over again. 

o Based on firebrand attack from real WUI fires, it is expected that multiple 

firebrands would accumulate within gaps/crevices of decking materials. 

o In addition to not simulating a dynamic firebrand attack, no attempt is made to 

relate the size and mass of the firebrand used in this standard to actual firebrands 

produced from burning vegetation and structures. 

o What evidence is provided to suggest that this test is a ‘worst-case’ firebrand 

exposure? 

o Based on the development of the NIST Dragon technology coupled to a full scale 

wind tunnel facility at BRI in Japan, it is now possible to expose decking 

assemblies to wind driven firebrand showers. 

o Recently, using the NIST Dragon, the danger of a dynamic firebrand attack has 

been demonstrated for ceramic tile roofing assemblies [3]. 

o Based on these experiments, it was observed that ceramic tile roof assemblies 

were vulnerable to ignition from a dynamic firebrand attack. 

o These experiments provided the first confirm of this vulnerability documented in 

the field [11]. 

6 
o Another key issue is that the firebrand size and mass produced using the NIST 

Dragon has been tied to those measured from full-scale tree burns and an actual 

WUI fire [11]. 

o NIST conducts post-WUI fire damage surveys as well (work of Mr. Alexander 

Maranghides of NIST [12]); decks have been observed to be an ignition 

vulnerability based on post-fire damage surveys. 

o NIST is interested in using the NIST Dragon technology to determine 

vulnerabilities of building components to wind driven firebrand showers. 

o Before NIST developed the Dragon in 2006, no capability to expose building 

components to wind driven firebrand showers on realistic scale. 

o NIST is interested in providing scientific basis for new building codes/standards. 

o NIST Dragon Research has been focused on parametrically investigating building 

component vulnerability to wind drive firebrand showers. 

 So far, experiments conducted for vents, eaves, siding, glazing in 

conjunction with observed vulnerabilities seen in post-WUI fire surveys 

• Participants pointed out that: 

o SFM standard testing did not necessarily do a good job simulating actual fire 

storm conditions. 

o ASTM E-108 – Class “A” firebrand is not an ember. 

o Individual embers behave differently than standard brands (Class A/B/C brands 

are wood cribs; see ASTM E108 [10]). 

o Showers of embers behave differently than standard brands. 

o Accumulation, intrusion, etc, are different ignition mechanisms. 

o Chapter 7A of the California Building Code [9], where the decking test is listed, 

was the best that was possible based on the information that was available at the 

time. 

o At the time that Chapter 7A [9] was developed, discussion occurred and 

consensus was reached with regard to the test method. 

o Also at that time, there was an agreement that new research and science needs to 

be utilized to either substantiate that test method or modify the test method. 

o NIST now has the capability to compare the SFM brand test to NIST Dragon and 

understand differences. 

Discussion Input from Attendees (Specific Deck Testing Comments) 

• NIST subsequently presented plans for decking experiments; detailed comment follows: 

• NIST parametric approach to date is a key to understanding vulnerabilities. 

• Use the NIST Dragon to compare to the SFM Standard; use the same configuration but 

compare results between the Class A Brand to the flying firebrands from the Dragon. 

• Install the deck in a realistic configuration; attached to wall assembly since the NIST 

experiments can consider full scale assemblies. 

• The exterior wall used in the experiments should be non-combustible; this way the test is 

specific to the decking material. 

• Construct reentrant corner and install deck samples for testing in such a configuration; 

place a window on one of the walls and see if fire produced from burning deck (assuming 

that the deck ignites) can produce window breakage. 

7 
• Regarding materials, the following suggestions were obtained: 

o Consider Douglas Fir. 

o Fire retardant treated wood not commonly used for decks; not recommend for 

NIST experimental campaign. 

• Comments on the orientation of the deck boards: 

o The diagonal installation probably does not need to be tested. 

o The standard installation is the same orientation as the SFM Standard. 

o The opposed installation may create a different result particularly when evaluating 

the up-slope wind direction. 

o Manufacturer’s installation instructions do NOT specify orientation. 

• Use manufacturer’s instructions when spacing and installing the boards on the deck; deck 

installed is generally manufacturer specific. 

• Typical deck installation will include a ledger board attached directly to the house: 

o Ledger against exterior building wall without a gap (common construction 

practice) 

o Ledger against exterior building wall with a gap (also common practice); may 

facilitate ember accumulation. 

• When comparing the SFM Standard to the NIST Dragon experiments, use materials 

which passed the SFM Standard and use materials which failed the SFM Standard; this 

will help provide a relative comparison between the two test methods. 

• Use CALFIRE’s WUI Products Handbook to see which decking materials passed brand 

test. 

• No consensus as to whether a railing should be used. 

• Does the fact that a typical deck is located over a slope rather than a level surface make a 

difference in the results? Can the wind flow coming up-slope beneath the deck have a 

more significant impact on the ignition of the deck? 

2.2 Summary 

In WUI fires, decks have been observed to be an ignition vulnerability based on post-fire damage 

surveys. Current standard test methods do not simulate the dynamic process of multiple, wind 

driven firebrands bombarding decking assemblies. Before the development of the NIST 

Firebrand Generator (NIST Dragon) and the subsequent coupling of this device to the Fire 

Research Wind Tunnel Facility (FRWTF) at the Building Research Institute (BRI) in Japan, 

there were no experimental methods to actually generate wind firebrand showers in a controlled, 

laboratory setting to quantify these vulnerabilities [1-4]. 

Therefore, full scale tests are planned to quantify the vulnerabilities of decking assemblies to 

firebrand showers using the NIST Dragon coupled to BRI’s FRWTF. Decks have been observed 

to be an ignition vulnerability based on post-fire damage surveys. This publication summarizes 

the results obtained from a workshop that was held in June, 2011 by NIST to provide input on 

the type of decking assemblies commonly found as well as the type of configuration that may be 

useful to expose to wind driven firebrand showers. The focus has been placed on the state of 

California since many large WUI fires have occurred there over the past 10 years [13]. These 

findings will be considered as NIST develops their experimental plans. The results of the full 

8 
scale tests will be reported and may serve as the basis for developing reduced scale test methods 

for decking assemblies as well as providing the scientific basis for building code change. 

9 
3. References 

[1] S.L. Manzello, J.R. Shields, J.C. Yang, Y. Hayashi, D. Nii, On the Use of a Firebrand 

Generator to Investigate the Ignition of Structures in WUI Fires, In Proceedings of the 11th 

International Conference on Fire Science and Engineering (INTERFLAM), Interscience 

Communications, London, (2007) pp. 861-872. 

[2] S.L. Manzello, et al., On the Development and Characterization of a Firebrand Generator, 

Fire Safety Journal, 43: 258-268, 2008. 

[3] S.L. Manzello, Y. Hayashi, T. Yoneki, Y. Yamamoto, Quantifying the Vulnerabilities of 

Ceramic Tile Roofing Assemblies to Ignition during a Firebrand Attack, Fire Safety Journal, 

45:35-43, 2010. 

[4] S.L. Manzello, S.H. Park, J.R. Shields, Y. Hayashi, S. Suzuki, Comparison Testing Protocol 

for Firebrand Penetration Through Building Vents: Summary of BRI/NIST Full Scale and NIST 

Reduced Scale Results, NIST TN 1659, January 2010. 

[5] S.L. Manzello and S. Suzuki, Summary of Workshop on Research Needs for Full Scale 

Testing to Determine Vulnerabilities of Siding Treatments and Glazing Assemblies to Ignition 

by Firebrand Showers, NIST Special Publication 1111, 2010. 

[6] S.L. Manzello, S. Suzuki, Y. Hayashi, Exposing Siding Treatments and Walls Fitted with 

Eaves to Wind-Driven Firebrand Showers, Fire and Materials Conference, San Francisco, CA, 

February, 2011. 

[7] S.L. Manzello, S. Suzuki, and Y. Hayashi, Exposing Glazing Assemblies to Firebrand 

Showers, Japan Association for Fire Science and Engineering, Tokyo, Japan, May, 2011. 

[8] S.L. Manzello, Quantify Structure Vulnerabilities to Ignition from Firebrand Showers, 

ASTM E05 Research Review, Anaheim, CA, June 13, 2011. 

[9] California Building Standards Commission Website (http://www.bsc.ca.gov/default.htm). 

[10] ASTM E108 Standard Test Methods for Fire Tests of Roof Coverings, ASTM International, 

West Conshohocken, PA, 2003. 

[11] E.I.D. Foote, J. Liu, and S.L. Manzello, Characterizing Firebrand Exposure During 

Wildland-Urban Interface (WUI) Fires, Fire and Materials Conference, San Francisco, CA, 

2011. 

[12] A. Maranghides, W.E. Mell, A Case Study of A Community Affected by the Witch and 

Guejito Fires, NIST TN 1635, April, 2009. 

[13] W.E. Mell, S.L. Manzello, A. Maranghides, B. Butry, and R. Rehm, Wildland-Urban 

Interface Fires: Overview and Research Needs, Int’l J. Wildland Fire, 19: 238-251, 2010. 

10 
4. Acknowledgements 

Mr. Ruben Grijalva, former State Fire Marshal and former CALIFRE director gave a 

presentation on overview of WUI problem in California and moderated this workshop. His 

excellent help is really appreciated. Mr. Stuart Tom, C.B.O, served as the official note taker and 

Mr. Neville Pereira, LA Basin Chapter President, arranged the venue and location. Their great 

help is really appreciated. The valuable input of all participants is warmly appreciated. The 

Science and Technology Directorate of the U.S. Department of Homeland Security sponsored the 

production of this material under Interagency Agreement IAA HSHQDZ-10-X-00288 with the 

National Institute of Standards and Technology (NIST).

11 
Appendix 1 

Attendance List

No. Name (Alphabetical by last name) Organization 

1 Brent Berkompas Fire Vent Safety Association 

2 Laura Blaul Orange County Fire Authority 

3 Tom Christopher Laguna Beach Fire Department 

4 Tom Czlapinski California Redwood Association 

5 Chris Dicus California Polytechnic University at San Luis Obispo 

6 Ken Dunham Lumber Association of California and Nevada 

7 Tom Fabian Underwriters Laboratories (UL) 

8 Ethan Foote CALFIRE (unable to attend, reviewed presentations and 

provided post-workshop input) 

9 Scott Franklin Scott Franklin Consultants 

10 Chris Freeman Ganahl Lumber Company 

11 Rich Geary Hoover Treated Wood Products 

12 Ruben Grijalva Former California State Fire Marshall; Former 

CALFIRE Director 

13 Chip Herr Timber Tech 

14 Bill Hendricks Safer Building Solutions 

15 Tim Hummel California Timberline, Inc. 

16 Joe Lozano Boise Cascade 

17 Ian MacDonald Southern California Fire Prevention 

Officers/CALCHIEFS 

18 Samuel Manzello NIST 

19 Rodney McPhee Canadian Wood Council 

20 Pete Melchtry Ganahl Lumber Company 

21 Don Oaks Southern California Fire Prevention 

Officers/CALCHIEFS 

22 Mark Pawlicki Sierra Pacific Industries 

23 Neville Pereira LA Basin ICC Chapter President 

24 Steve Quarles IBHS/University of California Cooperative Extension 

25 Alan Schall Azek 

26 Kevin Scott International Code Council (ICC) 

27 Kuma Sumathipala American Wood Council 

28 Stuart Tom City of Glendale, California 

29 Jon Traw ASTM E05.14.08 - WUI Exposures Chairman 

30 Steven Winkel The Preview Group 

12 
13 

Appendix 2 

Presentations delivered in workshop 
Introduction

Past Present & Future Past, Present & Future

Ruben Grijalva

Former State Fire Marshal Former State Fire Marshal

Former CAL FIRE Director

State Fire Marshal

Issues

State Building Standards and ICC
State Fire Marshal

Issues

Wildland Urban Interface Building Standards

Fire Siege

Direct Protection Area

Of California’s 100 million acres:

• 1/3 is CAL FIRE protection

• 1/3 is federal protection

• 1/3 is local protection
Fire Siege

Initial Attack Philosophy

Fire Protection Objective: Suppress 95% of Fire Protection Objective: Suppress 95% of

all wildfires to 10 acres or less

Fire Siege

Pre-Season Preparation

Go ernor’s E ec ti e Order Governor’s Executive Order
Fire Siege

Pre-Season Preparation

700 More Firefighters 700 More Firefighters

Fire Siege

Pre-Season Preparation

4 0 Staffing on State Engines 4.0 Staffing on State Engines
Fire Siege

Pre-Season Preparation

200 Defensible Space Inspectors

Fire Siege

Pre-Season Preparation

3 Year Contract with DC 3 Year Contract with DC-10
Fire Siege

Pre-Season Preparation

Hit fires fast hit them with lots of Hit fires fast, hit them with lots of

resources, large air tanker assets 

t b k b t th d to backup boots on the ground

CAL FIRE Resources

Northern 21 Units

6 Contract Counties Region

804 fire stations

Sacramento

Headquarters

227 state

577 local government

39 Conservation Camps

S th

198 fire crews

Air Attack Southern

Region

Air Attack

13 air attack bases

9 helitack bases
Fire Siege

Conditions

• CA has various micro climates

• Santa Ana Wind Event

• Sustained wind speeds Sustained wind speeds – 40-60 MPH

• Wind gusts – up to 100 MPH

• Fuel moistures drop to single digits – 9%-12%

• Dead and dying trees and brush from freeze, 

disease, and infestation

A 7-Day graph of average Relative Humidity at Fremont Canyon RAWS Day graph of average Relative Humidity at Fremont Canyon RAWS

RH fell sharply early on the 21st, and has now been <12% for 2 1⁄2 days.
MAXIMUM WIND GUST 

A 7-Day graph of maximum wind gusts at Fremont Canyon RAWS Day graph of maximum wind gusts at Fremont Canyon RAWS

The sharp spike seen early on Sunday Oct. 21 is the Santa Ana onset.

Fire Siege

Fire Conditions

Perfect Storm Perfect Storm

• Wind driven

• Fuel driven Fuel driven

• Topography driven

• Structure to structure driven

• Direct flame, radiant heat, ember driven
Fire Siege

What Works Well

California Mutual Aid System

Fire Siege

What Works Well

Mobilize a massive amount of Mobilize a massive amount of

personnel in a condensed period 

of time. 
October Fire Siege 2007

What Worked Well

Multi-State Response The State Response. The

number of different fire 

d t ti l d departments involved approx. 

1,148.

October Fire Siege 2007

What Worked Well

Total firefighters: 15,616

Engines: 2 585 Engines: 2,585

Strike Teams/Task Forces: 263

D 225 ozers: 225

Handcrews: 298

Watertenders: 284

O e ead pe so e , 0 verhead personnel: 1,707
Fire Siege

Lessons Learned

Need for Better Land Use / Need for Better Land Use /

Planning / Prevention

Fire Siege

Lessons Learned

Need for more local resources / Need for more local resources /

staffing / surge capacity
Fire Siege

Lessons Learned

Need for streamlined resource Need for streamlined resource

re-deployment system

Fire Siege

Preventing the Next Firestorm

Better Land Use / Planning Better Land Use / Planning
Fire Siege

Preventing the Next Firestorm

More Fuels Treatment More Fuels Treatment

Fire Siege

Preventing the Next Firestorm

Building Construction with Ignition Building Building Construction Construction with Ignition Ignition

Resistant Materials
Fire Siege

Preventing the Next Firestorm

Adeq gy uate Local Emer uate Local Emergency

Response Resources

Fire Siege

Preventing the Next Firestorm

Increase Surge Capacity
Fire Siege

Preventing the Next Firestorm

Too much reliance on suppression Too much reliance reliance on suppression suppression

efforts alone will not work!

Th K t S i P ti The Key to Success is Prevention, 

Build Smarter with good Land Use 

Planning!
Quantifying Structure Vulnerabilities to 

Ignition from Firebrand Showers Ignition from Firebrand Showers

Dr. Samuel L. Manzello

Mechanical Engineer

Fire Measurements Group

Engineering Laboratory (EL) Engineering Laboratory (EL)

National Institute of Standards and Technology (NIST)

Gaithersburg, MD 20899-8662 USA

samuelm@nist gov; +1 samuelm@nist.gov; +1-301-975-6891 (office) 6891 (office)

Decking Workshop

June 15th, 2011

Special Thanks

• Dr. Sayaka Suzuki (NIST)

• Dr. Yoshihiko Hayashi (BRI)

• Mr. Ruben Grijalva

• Mr. Stuart Tom

• Mr. Neville Pereira
Wildland-Urban Interface (WUI) Fires

Of the 10 largest fire loss incidents (> $1B) in U.S. 

history 5 were WUI fires - all within the last 17 years

WUI – structures and wildland vegetation coexist

history, 5 were WUI fires - all within the last 17 years

Proven risk assessment and mitigation tools are needed Proven risk assessment and mitigation tools are needed

Structure Ignition in Urban and WUI Fires

• Firebrands major cause of ignition

• Understanding g firebrand ignition of structures –

important to mitigate fire spread Australia/Japan/USA

Objective: Investigate ignition of structures 

to firebrand showers to firebrand showers
Partnerships

• BRI - Japan 

• US Department of Homeland Security

Customers

• CALFIRE

• AS( ) TMManzello voting member)

• ASTM E05.14 External Fires

• Results useful for: 

– ASTM CALFIRE ICC NFPA ISO I I d t H ASTM, CALFIRE, ICC, NFPA, ISO, Insurance Industry, Homeowners

International Collaboration

BRI (Japan) and BFRL BRI (Japan) and BFRL-NIST (USA) NIST (USA)

• Research focused on how far firebrands travel for 40 yrs!!

• Firebrands: generation, transport, ignition

Research focused on how far firebrands travel for 40 yrs!!

• Nice Academic Problem – Not helpful to design structures

• V l bl i t h fi b d t t t Vulnerable points where firebrands may enter structure

• Unknown/guessed!

• Difficult to replicate firebrand attack! Difficult to replicate firebrand attack!

• Entirely new experimental methods needed!

Goals

Science - Building Codes/Standards; Retrofit construction

Design structures to be more resistant to firebrand ignition
Building Research Institute (BRI)

• Fire Research Wind Tunnel Facility (FRWTF) Fire Research Wind Tunnel Facility (FRWTF)

• Unique facility – investigate influence of wind on fire

– Constructed more than 10 years before IBHS wind tunnel

BRI

Fire Research Wind Tunnel Facility

(FRWTF)

NIST Dragon NIST Dragon

First Generation Device

Firebrand size/mass commensurate to full scale tree burns

and actual WUI fire (2007 Angora Fire) 
Roofing Studies

Current Roofing Standards

Roofing test: ASTM E108; UL 790 Roofing test: ASTM E108; UL 790

Does not simulate dynamic firebrand attack!

12 mi/hr

(5.3 m/s)

Japan/USA

Use This Test!

Mitchell &Patashnik [2007 ] – possible correlation homes ignited

i 2003 C d Fi ith th h fitt d ith i til fi in 2003 Cedar Fire with those homes fitted with ceramic tile roofing
Ceramic Roofing

Ag g , ( pp ) ed Roofing Simulated: OSB, then tiles (no tar paper)

U∞ ( /) m s OSB/TP/CT OSB/TP/CT OSB/TP/CT OSB/CT OSB/CT

No Bird Stops

OSB/TP/CT

With Bird 

Stops

OSB/CT

No Bird Stops

OSB/CT

With Bird 

Stops

7 SI NI SI to FI SI

9 SI NI SI to FI SI

New Roofing Construction: OSB, Tar Paper, then Ceramic Tiles

Ceramic Roofing

Ag g , ( pp ) ed Roofing Simulated: OSB, then tiles (no tar paper)

U∞ ( /) m s OSB/TP/CT OSB/TP/CT OSB/TP/CT OSB/CT OSB/CT

No Bird Stops

OSB/TP/CT

With Bird 

Stops

OSB/CT

No Bird Stops

OSB/CT

With Bird 

Stops

7 SI SI SI to FI SI

9 SI SI SI to FI SI

New Roofing Construction: OSB, Tar Paper, then Ceramic Tiles

Pine Needles/Leaves Under Tiles
Detailed Investigation of Firebrand Detailed Investigation of Firebrand

Penetration through Building Vents

Firebrand Penetration Through Vents

Experiments conducted in 2007

ator Location

‘Engineer’ a Firebrand Distribution

Direct Firebrand Flux towards vents of Structures

Vent location

rebrand Genera

Top View of Structure

Wind Flow Direction

Firebrand Flux

Fir

Wind Flow Direction

Firebrand Goes Through

Gable Vent

Screen Behind Vent

Three sizes tested 6 mm , 3 mm , and 1.5 mm
Research Plan • Quantify firebrand penetration through building vents Quantify firebrand penetration through building vents

• Full scale experiments at BRI

• Only full scale wind driven testing in the world

• C t NIST d d l t t Compare to new NIST reduced scale tests (D ’ LAIR) (Dragon’s LAIR)

• Wind driven firebrand attack at reduced scale

• 6 mesh sizes (5.72 mm to 1.04 mm)

• Four types of ignitable materials behind mesh

• Cotton,

• Shredded Paper, Shredded Paper,

• OSB – Wood Crevice (filled with shredded paper)

• OSB – Wood Crevice (bare – no shredded paper)

BRI/NIST Full Scale Experiments

20 x 20 mesh (1.04 mm) is shown
Summary of BRI/NIST Results

• SI – Smoldering Ignition; FI Smoldering Ignition; FI – Flaming Ignition Flaming Ignition

• NI – No Ignition

• Each case – three repeat experiments

Mesh Paper Cotton Crevice Crevice with 

paper

4 x 4

(5.72 mm) SI to FI SI SI SI to FI (paper)( ) SI ( ) OSB

8 x 8

(2.74 mm) SI to FI SI SI SI to FI (paper)

SI (OSB)

10 x 10

(2 0 mm) SI to FI SI NI SI to FI (paper)(2.0 mm) (SI OSB) (SI OSB)

14 x 14

(1.55 mm) SI SI NI SI (paper)SI (OSB)

16 x 16

( ) SI SI NI NI (1.35 mm) SI SI NI NI

20 x 20

(1.04 mm)

Two tests: NI; 

One test SI

Two tests: SI

One Test NI NI NI

Mesh Effectiveness

BRI/NIST f ll l d NIST d d l BRI/NIST full scale and NIST reduced scale tests - mesh i ff i h is not effective

(a) Front view

Mesh not effective!

(b) Side view

Wind Wind

Firebrands burning down and passing 

through the mesh

Firebrands arriving on the mesh
Exposing Siding Treatments, Walls Fitted with Eaves,

and Glazing Assemblies to Firebrand Showers

Research Plan

• Determine siding treatment vulnerability to firebrand showers

• Do firebrands become trapped within corner post/under siding itself?

• Determine gg y y lazing assembly vulnerability to firebrand showers

• Do firebrands accumulate inside corner of framing of glazing assemblies, 

and lead to window breakage?

• Determine eave vulnerability to firebrand showers

• Do firebrands become lodged within joints between walls/eave 

overhang?

• Determine if fine fuels adjacent to structure can produce ignition

First e periments e er cond cted First experiments ever conducted
Workshop Held For 

Testing p In ut in CA

Industry

Fire Service

CALFIRE/OSFM

Building Officials

Code Consultants 

Siding Treatments • Corner - believed that firebrands may become trapped within the believed that firebrands may become trapped within the

corner post and under the siding itself

• OSB, moisture barrier applied (OSB dried; 11 % )

Image of vinyl siding (from bottom) 

after firebrand exposure at 7 m/s
Siding Treatment Results

Polypropylene siding is newer to the market; used as has the look/feel of cedar siding

U∞ (m/s) Vinyl Siding

OSB Sheathing

Vinyl Siding

OSB Sheathing

Polyproplylene 

Siding

Polyproplylene 

Siding

Polypropylene siding is newer to the market; used as has the look/feel of cedar siding

OS S eat g

Dried

OS S eat g

Not Dried

Sd g

OSB Sheathing 

Dried

Sd g

OSB Sheathing 

Not Dried

7 Siding Sidi Sidi lt d Sidi lt d

melted/holes

Burns on Tyvek

OSB NI

Siding 

melted/holes

Burns on Tyvek

OSB NI

Siding melted

Burns on Tyvek

OSB NI

Siding melted

Burns on Tyvek

OSB NI

9 Siding 

melted/holes

Burns on Tyvek

OSB SI

Siding 

melted/holes

Burns on Tyvek

OSB NI

Siding melted

Burns on Tyvek

OSB NI

Siding melted

Burns on Tyvek

OSB NI

OSB SI OSB NI

Eave Vulnerability • A very important, long standing question is whether firebrands may 

b l d d i hi j i b ll d h h become lodged within joints between walls and the eave overhang

• There are essentially two types of eave construction commonly 

used in California and the USA

• Open eave

• Boxed in eave

• In op, y en eave construction, the roof rafter tails extend beyond the 

exterior wall and are readily visible

• In the second type of eave construction, known as boxed in eave 

construction, the eaves are essentially enclosed and the rafter tails 

overhang

, y

are no longer exposed

Firebrand accumulation in eaves

Does this really happen?? Wind direction

Side view
Typical Open Eave Construction

• Since the open eave construction is thought to the worst possible 

situation, this configuration was used

• Common construction type used in CA shown Common construction type used in CA shown

Walls Fitted With Eaves

Images of eave assemblies constructed for testing Images of eave assemblies constructed for testing

Open eave construction is thought to the worst possible situation, 

this configuration was used

Vent holes: 50 mm (2”)

fitted with mesh 2.75 mm opening

Wall Size: 2.44 m by 2.44 m

Eave Overhang: 61 cm (2 ft)
Wall Fitted With Eave 

Exposed to Firebrand Showers

CFD Simulations

Only air profiles shown

Under eave, little or no flow velocity required to drive firebrands 

into joints between eave and wall assembly into joints between eave and wall assembly

EXPERIMENTS NEEDED UNDER HIGHER WIND SPEEDS
Wall Fitted With Eave Results

• The number of firebrands arriving at the vent locations increased 

as the wind speed increased as the wind speed increased

• Yet was very small as compared to the number of firebrands that 

bombarded the wall/eave assembly bombarded the wall/eave assembly

U∞ (m/s) Open Eave With No Vents Open Eave with Vents

7 No Accumulation No Accumulation 11 Firebrands Arrived at Vents 11 Firebrands Arrived at Vents

9 No Accumulation 28 Firebrands Arrived at Vents

Wall Fitted With Eave Results

• The base of the wall actually ignited due to the accumulation of 

firebrands (9 m/s)

• It was very easy to produce ignition outside the structure since 

many firebrands were observed to accumulate in front of the 

structure during the tests

• Although some firebrands were observed to enter the vents, the 

ignition of the wall assembly itself demonstrates the dangers of 

wind driven firebrand showers

• The base of wall assembly ignited without the presence of other 

combustibles that may be found near real structures (e.g. mulch, 

vegetation)
Glazing Assemblies

D fi b d b t d l t i id th f th Do firebrands become trapped, accumulate inside the corner of the 

framing of glazing assemblies, and lead to window breakage?

Vertically and Horizontally Sliding Window Assemblies

Wi d Si 91 b 91 Window Size: 91 cm by 91 cm

Firebrand Accumulation Firebrand Accumulation

in Front of Obstacles
Firebrand Accumulation

Wood Boards Placed 

In Front

Easily Ignited!!!

Fine Fuels Near Structure

W ll I it d Wall Ignited
Obstacles in Flow

1 m by 2 m 1 m by 2 m 2 m by 1 m 2 m by 1 m

3 m by 3 m

Firebrand Production from Building Components
Work in Progress

• Fi b d ti f Firebrand generation from:

• Structure Components

NIST Reduced Scale Building NIST Reduced Scale Building

NIST Dragon’s LAIR
NIST Dragon’s LAIR (Lofting and Ignition Research)

Couple ‘Baby Dragon Baby Dragon’ with wind tunnel with wind tunnel

Reproduced results from full scale tests

Typical experiment using 

Dragon’s LAIR

A 14 x 14 (1.55 mm) mesh 

Summary of NIST Results

• SI – Smoldering Ignition; FI Smoldering Ignition; FI – Flaming Ignition; NI Flaming Ignition; NI – No Ignition No Ignition

• Velocities behind mesh matched to full scale experiments

• Mesh assembly – same area as full scale experiments – 1600 cm2

Mesh Paper Cotton Crevice Crevice with 

paper

4 x 4

(5 72 mm) SI to FI SI to FI SI SI to FI (paper)(5.72 mm) SI (OSB) SI (OSB)

8 x 8

(2.74 mm) SI to FI SI SI SI to FI (paper)

SI (OSB)

10 x 10 SI to FI SI NI SI to FI (paper)

(2.0 mm) SI to FI SI NI p p(SI OSB)

14 x 14

(1.55 mm) SI SI NI SI (paper)

SI (OSB)

16 16 x

(1.35 mm) SI SI NI NI

20 x 20

(1.04 mm) NI SI NI NI
Continuous Feed Baby Dragon

• G t ti enerate continuous 

firebrand showers

Coupled with Dragon’s LAIR

• Coupled to

Dragon’s LAIR 5 cm

14 Gt 1

Φ=10 cm

Φ=15.25 cm

Conveyor belt system

Ability to rate materials 119 cm

14 cm

Gate 2

Gate 1

13 cm

30°

24 cm

To firebrand exposure 119 cm

89 cm

68 cm

40 cm

Burner (to propane cylinder)

13 cm

Φ=10 cm 25 cm

21 cm

Mesh for Mesh for Blower

firebrands

Improved NIST Dragon’s LAIR 

(Lofting and Ignition Research) (Lofting and Ignition Research)

Conveyor Firebrand Injection 

into Wind Tunnel

Expose materials to continuous, wind driven firebrand showers

Gates Burner
Improved NIST Dragon’s LAIR

Cedar SI of Cedar

IGNITION REGIME MAPS

150

200

(s)

I iti R i

100

moldering Ignition 

Ignition Regime

Ignition 

Not Observed 

at Lowest 

Feed 

of 11.7 g/min

Cedar Firebrands

50

Time to S

m

No Ignition Regime

0

0 20 40 60 80

Feed Rate (g/min)

Developing Rapid Response Instrumentation

Packages to Quantify Structure Ignition Packages to Quantify Structure Ignition

In Wildland-Urban Interface (WUI) Fires
Field deployable instruments – heat flux wind speed firebrand generation

WHAT IS THE NEW TECHNICAL IDEA?

Field deployable instruments heat flux, wind speed, firebrand generation

Q tif WUI Fi E Quantify WUI Fire Exposures

Heat Flux as Fire Approached

100

120

Total Heat Flux Gage 

DFT

80

kW/m

2

] 40

60

at Flux [

k He

20

0

4:05:00 4:05:20 4:05:40 4:06:00 4:06:20 4:06:40

Time [h:m:s]
Recent Impacts

• State of New Jersey using NIST video in training courses 

• Worked with CALFIRE as part of a task force (invitation only) to reduce mesh size 

used to cover building vent openings to lessen the potential hazard of firebrand entry 

into structures into structures.

• Changes were formally adopted into the 2010 California Code of Regulations, 

Title 24, Part 2, Chapter 7A, and are effective January, 2011

• “Your research will certainly further our understanding of the risks of flying embers 

during a wildfire event, and will help guide us as we make recommendations to our 

policyholders on how to better protect their home from the threat of wildfires”

Stan Rivera – Chartis Insurance (http://www.chartisinsurance.com)

• Work has garnered the attention of Australian Government. 

• ABCB is joint initiative of all levels of Australian Government 

• ABCB has requested a formal partnership with NIST to assess Australian 

Standards to see whether they can account for ignition vulnerabilities observed 

by firebrands 

• IBHS has used NIST’s Dragon concept for use in their wind tunnel facility to generate 

firebrand showers

Recent Publications
Recent Publications

Summary

• NIST Dragon coupled to BRI’s FRWTF

• Capability to experimentally expose structures to wind driven 

fi b d h f fi t ti ! firebrand showers for first time!

• Structure vulnerability experiments conducted for:

• Roofing (cermaic/asphalt)

• Vents/mesh (gable/different mesh sizes)

• Siding (vinyl, polypropylene, cedar)

• Eaves (open) Eaves (open)

• NIST Dragon’s LAIR Facility

• Capability to expose materials/firebrand resistant technologies 

to wind driven firebrand showers to wind driven firebrand showers

• With newly developed Continuous Feed Baby Dragon, potential 

to evaluate and compare relative performance
Decking Vulnerabilities 

Front view Side view

eave

eave

wall

8 ft 8 ft wall

deck

27 in 27 in

deck

8 ft

2 ft

Supported by 2x6 Douglas‐Fir

8 ft

Wall with siding, decking and eave
Board Materials Board Materials

• Wood ( y treated wood or wood which is naturally resistant to 

decaying)

– Treated pine

– Cedar

– Redwood

– Ipé

• Composite

– Wood/plastic

– Fiber/PVC

• Plastic

• Metal

Profiles

Profiles‐‐‐Depends on materials materials

Plank ‐‐‐wood or composite Channel‐‐‐composite

Spacing    between boards                5mm

between board ends         1/8”

between b d oar and wall  1/ ”4
Framing

wall

2 ft

t support

8 ft

16 in support pp

Made from 2 x 8

Patterns

d d d

outside

standard opposed angled or diagonal

wall

Which pattern is the easiest for firebrands to be stuck with? Or no difference?
Railing

• Railing is needed??

• If yes, 

– surface of deck is 30 inches above the ground

– raili i 36 i h b th f f d k iling is 36 inches above the surface of deck

– a sphere with a diameter of 4 inches cannot pass 

through the space between each rail or any gaps

wall

d k

wall

decking decking

railing railing
Appendix 3 

SFM STANDARD 12-7A-4 

12-7A-4.1 Application. The minimum design, construction and performance standards set forth 

herein for unloaded decks are those deemed necessary to establish conformance to the provisions 

of these regulations. Materials and assemblies that meet the performance criteria of this standard 

are acceptable for use as defined in California Building Standards Code. 

12-7A-4.2 Scope. This standard evaluates the performance of decks (or other horizontal ancillary 

structures in close proximity to primary structures) when exposed to direct flames and brands. 

The under-deck flame exposure test is intended to determine the heat release rate (HRR) and 

degradation modes of deck or other horizontal boards when exposed to a burner flame simulating 

combustibles beneath a deck. The burning brand exposure test is intended to determine the 

degradation modes of deck or other horizontal boards when exposed to a burning brand on the 

upper surface. 

12-7A-4.3 Referenced document. 

1. ASTM D 4444, Test Methods for Use and Calibration of Hand-Held Moisture Meters. 

2. ASTM E 108, Test Methods for Fire Tests of Roof Coverings. 

3. California Building Code, Chapter 7A. 

4. UL 790, Standard Test Methods for Fire Tests of Roof Coverings. 

12-7A-4.4 Definitions. 

1. Deck boards. Horizontal members that constitute the exposed surface of the ancillary 

structure. 

2. Deck surface area. The test specimen area defined by the overall specimen length and width 

after assembly. 

3. Heat release rate. The net rate of energy release as measured by oxygen depletion 

calorimetry. 

12-7A-4.5 Test assembly. 

1. Size. The overall size of the test deck shall be nominally 24 x 24 inches (610 x 610 mm) 

unless width variation of deck boards requires an increase in overall deck width (i.e., the 

direction of joists) in order to meet the overall dimensions. The length of individual deck boards 

shall be 24 inches (610 mm). 

58 
2. Joists. The deck is supported by two nominal 2 x 6 Douglas-fir joists running perpendicular to 

the deck boards, and constructed with a 16-inch (406 mm) center-to-center spacing. A 

comparable species that may be more commonly used for structural framing of decks in a given 

region can be substituted for Douglas-fir. 

3. Deck board spacing and fastening. Edge-to-edge spacing and method of attachment shall 

conform to the manufacturer's installation recommendations. The front deck board shall be flush 

with the ends of the joists, and the rear deck board shall overhang the end of the joists by 1 inch 

(25 mm). 

3.1. In the absence of recommended installation guidance, the edge-to-edge spacing shall 

be 3

/16 inch (5 mm) with boards mechanically attached to the joists using deck screws. 

3.2. If nominal 6-inch-wide deck boards are used, a total of 5 boards shall be used for 

each deck. Changing the board width could change the number of deck boards. 

12-7A-4.6 Materials. 

1. Cross-sectional dimension. All deck board materials are to have cross-sectional dimensions 

equivalent to use in service. 

2. Description. The material under test should be described as completely as possible (unit 

weight, thickness, width, and general information regarding composition). 

3. Condition of test material. Prior to testing, all materials (deck boards and joist material) shall 

be conditioned to a constant weight or for a minimum of 30 days at 73 ± 4 °F (23 ± 2 °C) and 50 

± 5 % relative humidity, whichever occurs first. Constant weight shall be defined as occurring 

when the change in test material weight is less than or equal to 2 percent in a 24-hour period. 

12-7A-4.7 PART A. Under-deck flame test. 

12-7A-4.7.1 Equipment. 

1. Burner. A 12 x 12 inch (300 x 300 mm) sand diffusion burner shall be used. Natural gas, 

methane or propane shall be supplied to the burner through a metered control system. The gas 

supply to the burner shall produce a net heat output of 80 ± 4 kW throughout the flame exposure. 

Burner output can be determined from HRR or calculated from the gas flow rate, temperature, 

and pressure. 

2. Oxygen depletion calorimeter. The equipment shall include a hood, associated ducting, and 

instrumentation to provide HRR data by oxygen depletion calorimetry. 

12-7A-4.7.2 Test system preparation. See Figure No. 1. 

1. Deck support assembly. The assembly that holds the test deck over the burner. 

2. Baffle panels and joist support. Horizontal metal plates to support the deck joists along their 

59 
full length, and also to confine burner flames to the underside of the deck boards located between 

the support joists. 

3. Back wall. Ceramic fiber board or another noncombustible panel product for the back wall 

material. Total height of the back wall shall be 8 feet (2.4 m). 

4. Ledger board. A 4-foot-long (1.2 m) simulated 2 x 6 ledger board shall be constructed of 

layers of ceramic fiber board (or other noncombustible panel product) and attached to the wall at 

a height slightly below the overhang of the rear deck board of the test deck. 

12-7A-4.7.3 Conduct of tests. 

1. Airflow. The test shall be conducted under conditions of ambient airflow. 

2. Number of tests. Conduct the test on three replicate assemblies. 

3. Burner output verification. Without a deck in the apparatus, set the output of the burner to 

80 ± 4 kW. Conduct a verification run of 3 minutes to ensure the heat release rate, and then turn 

off the burner. 

4. Measurement of heat release rate. HRR is measured during the tests with a properly 

calibrated oxygen depletion calorimeter. Since HRR is typically a post-test analysis, this criterion 

for Acceptance may be determined at the end of the test. 

5. Burner positioning. Center the burner directly under the middle deck board, midway between 

the joists. The distance from the top of the burner to the bottom of the deck boards shall be 27 

inches (690 mm). 

6. Moisture content. Measure the moisture content of the wooden members of the assembly 

using a moisture meter (ASTM D 4444). 

7. Procedure. 

7.1 Ignition. Ignite the burner, controlling for a constant 80 ± 4 kW output. 

7.2. Flame exposure. Continue the exposure for a 3-minute period. Extinguish the 

burner. 

7.3. Continued combustion. Continue observation for an additional 40 minutes or until 

all combustion has ceased. 

8. Observations. Note physical changes of the deck boards during the test, including structural 

failure of any deck board, location of flaming and glowing ignition, and loss of material (i.e., 

flaming drops of particles falling from the deck). It is desirable to capture the entire test with a 

video recorder to allow review of the details of performance. 

12-7A-4.7.4 Report. The report shall include a description of the deck board material and the 

60 
time of any degradation (effective net peak heat release rate, structural failure, flaming drops or 

particles falling from the deck) during the test. 

1. Calculated rate of heat release. The effective net peak heat release rate (HRR) shall be 

calculated as follows: 

1.1. During the first 5 minutes of the test (the 3 minutes during which the ignition source 

burner is operating and the immediately following 2 minutes) the effective net peak HRR 

of the test assembly shall be reported as: effective net peak HRR = (peak heat release rate 

- 80 kW) / (deck surface area). 

 

1.2. During the remaining test duration the effective net peak heat release rate of the test 

assembly shall be reported as: effective net peak HRR = (peak heat release rate) / (deck 

surface area) 

12-7A-4.7.5 Conditions of Acceptance. Should one of the three replicates fail to meet the 

Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet 

the Conditions of Acceptance. 

1. Effective net peak heat release rate of less than or equal to 25 kW/ft2

 (269 kW/m2). 

2. Absence of sustained flaming or glowing combustion of any kind at the conclusion of the 40-

minute observation period. 

3. Absence of falling particles that are still burining when reaching the burner or floor. 

12-7A-4.8 PART B. Burning brand exposure. 

12-7A-4.8.1 Equipment. 

1. Wind tunnel. The wind tunnel shall have the capability of providing 12 mph (5.4 m/s) airflow 

over the deck assembly. 

2. Anemometer. Device for measuring airflow across the deck. 

3. Burner. Gas-fueled burner for brand ignition. 

12-7A-4.8.2 Test system preparation. See Figure 2. The ASTM E 108 "A" brand roof test 

apparatus is to be used, with the following modifications: 

1. Deck support. The deck shall be supported horizontally with the center 60 inches (150 mm) 

from the front opening of the wind tunnel and the joists parallel to the airflow and resting on two 

transverse metal supports. The top surfaces of these supports, no more than 3 inches (75 mm) 

wide, are at the same height as the floor of the wind tunnel. 

2. Fragments. Burning fragments shall be free to fall to the floor of the room. 

61 
12-7A-4.8.3 Conduct of tests. 

1. Number of tests. Conduct the test on three replicate assemblies. 

2. Moisture content. Measure the moisture content of the wooden members of the assembly 

using a moisture meter (ASTM D 4444). 

3. Procedure. Adhere to ASTM E 108 "Standard Test Methods for Fire Tests of Roof 

Coverings" (burning brand test, "A" brand), with apparatus modified as described above in "Test 

system preparation" and the following procedure: 

3.1 The air velocity shall be calibrated using the 60-inch (1.5 m) framework spacing, with 

a smooth noncombustible calibration deck at a 5-inch per 12-inch horizontal incline 

positioned 60 inches (1.5 m) from the front opening of the wind tunnel. All other 

measurement details shall be followed as specified in Sections 4.4.2, 4.4.3, and 4.4.4 of 

ASTM E 108. Although ASTM E 108 specifies calibration to be conducted with the 33-

inch (840-mm) framework spacing used for the intermittent flame test set up, tests have 

shown that at the nominal 12 mph setting, there was not difference in measured velocity 

between the 33- and 60-inch framework spacing. 

3.2 Mount the test specimen at a zero horizontal incline positioned 60 inches (1.5 m) 

from the front opening of the wind tunnel. 

3.3 Ignite the "A" brands as specified in Section 9.4 of ASTM E 108 as reprinted here: 

1. Each 12- x 12-inch (300 x 300 mm) face for 30 seconds. 

2. Each 2.25- x 12-inch (57 x 300 mm) edge for 45 seconds. 

3. Each 12- x 12-inch (300 x 300 mm) face again for 30 seconds. 

3.4 Center the burning brand laterally on the deck with the front edge 2.5 inches (64 mm) 

from the entering air edge of the deck. 

3.5 Continue the exposure for a 40-minute period or until all combustion of the deck 

boards ceases. The test shall be terminated immediately if flaming combustion 

accelerates uncontrollably (runaway combustion) or structural failure of any deck board 

occurs. 

Heat Release Rate is not monitored because of the impracticability with the specified 

airflow. 

4. Observations. Note physical changes of the deck boards during the test, including 

deformation from the horizontal plane, location of flaming and glowing combustion, and loss of 

material (i.e., flaming drops of particles falling from the deck). It is desirable to capture the entire 

test with a video recorder to allow review of the details of performance. 

12-7A-4.8.4 Report. The report shall include description of the deck board material, and the 

time of any degradation (accelerated combustion, board collapse, flaming drops or particles 

falling from the deck). 

12-7A-4.8.5 Conditions of Acceptance. Should one of the three replicates fail to meet the 

62 
Conditions of Acceptance, three additional tests may be run. All of the additional tests must meet 

the Conditions of Acceptance: 

1. Absence of sustained flaming or glowing combustion of any kind at the conclusion of the 40-

minute observation period. 

2. Absence of falling particles that are still burning when reaching the burner or floor. 

FIGURE 1. DECK TEST ASSEMBLY (UNDER DECK-FLAME) 

FIGURE 2. DECK TEST ASSEMBLY (BURNING-BRAND)

63