NBSIR 79-1731

A Review of Fire Incidents,

Model Building Codes, and

Standards Related to

Wood-Burning Appliances

Richard D. Peacock

Center for Fire Research

National Engineering Laboratory

National Bureau of Standards

Washington, D.C. 20234

May 1979

Final Report

Prepared for U.S. Department of Energy

Washington, D.C. 20545

NBSIR 79-1731

A REVIEW OF FIRE INCIDENTS,

MODEL BUILDING CODES, AND

STANDARDS RELATED TO

WOOD-BURNING APPLIANCES

QOCO

Richard D. Peacock

Center for Fire Research

National Engineering Laboratory

National Bureau of Standards

Washington, D.C. 20234

May 1 979

Final Report

Prepared for U.S. Department of Energy

Washington, D.C. 20545

U.S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director

TABLE OF CONTENTS

Page

LIST OF FIGURES v

LIST OF TABLES vi

LIST OF ABBREVIATIONS vii

Abstract 1

1. INTRODUCTION 1

2. ACCIDENT DATA SOURCES 2 2.1 The National Fire Protection Association 3

2.2 The National Electronic Injury Surveillance System ... 3

2.3 The U.S. Fire Administration 4

2.4 The Flammable Fabrics Accident Case and Testing System . 4

2.5 The Massachusetts State Fire Marshal's Office 4

2.6 The Oregon State Fire Marshal's Office 5

3. FIRE INCIDENTS RELATED TO WOOD-BURNING EQUIPMENT 5

3.1 Causes of Fire Incidents 5

3.2 Incidents Associated with Wood-Burning Appliances ... 5

3.2.1 Activities of Persons Involved and Products

Involved 6

3.2.2 Age and Sex of Persons Involved 7 3.2.3 Severity of Injury 7

4. SUMMARY AND CONCLUSIONS FROM FIRE INCIDENT DATA 7

5. MODEL BUILDING CODES 8

5.1 Chimneys and Chimney Connectors 9

5.1.1 Construction 9

5.1.2 Clearances 10

5.2 Wood-Burning Units 11

5.2.1 Construction 11

5.2.2 Clearances 12

6. TEST METHODS 12

6.1 Installation of Appliances 13

6.2 Performance Tests 14

6.2.1 Structural Integrity Tests 14

6.2.2 Firing Tests 14

7. CONCLUSIONS 15

iii
TABLE OF CONTENTS (continued)

Page

8. ACKNOWLEDGEMENTS 16

9. REFERENCES 17

10. APPENDIX A A-l

11. APPENDIX B B-l

iv
LIST OF FIGURES

Page

Figure 1. Dollar loss estimates as reported in NFIRS solid

fuel fire incident data 20

Figure 2. Type of equipment involved as reported in NFIRS

solid fuel fire incident data 21

Figure 3. Factors leading to ignition as reported in NFIRS

solid fuel fire incident data 22

Figure 4. Solid fuel related fire incidents reported to the

Oregon State Fire Marshal's Office 23

Figure 5. Age and sex of persons injured in wood heating

related fires 24

Figure 6. Severity of injury of persons injured in solid fuel

related fires 25

Figure 7. Minimum clearances to heat producing appliances

without protection for combustible construction ... 26

Figure 8. Reduced clearances permitted with specific forms of

protection 27

Figure 9. UL 1482 strength test for chimney connector parts . . 28

Figure 10. UL 1482 impact test for glazings used as part of

doors 29

Figure 11. UL 1482 fire test installations 30

v
LIST OF TABLES

Page

Table 1 . Conditions leading to fires attributed to

wood-burning equipment 31

Table 2. Age and sex of persons involved in and causes

of accidents related to wood-burning equipment .... 32

Table 3. Severity of injury of persons involved in

wood-heating fire accidents 33

Table 4. Model building codes requirements for chimneys .... 34

Table 5. Model building codes requirements for chimney

connectors 36

Table 6 . Connector clearances with specified forms of

protection 37

Table 7. Recommended clearances for horizontal smoke pipe

from UL Bulletin of Research 27 [15] 38

Table 8. Model building codes requirements for masonry

fireplaces and factory-built wood-burning units . . . 39

Table 9. Minimum installation clearances for heat producing

appliances, solid fuel type 41

Table 10. Maximum allowable temperatures on combustible

surfaces adjacent to room heaters tested according

to UL 1482 [32] 42

vi
LIST OF ABBREVIATIONS

ASTM — American Society for Testing and Materials

BBC — Basic Building Code

BOCA — Building Officials and Code Administrators

CFR — Center for Fire Research

CPSC — Consumer Product Safety Commission

DOE — U.S. Department of Energy

FFACTS — Flammable Fabrics Accident Case and Testing System

ICBO — International Conference of Building Officials

NBC — National Building Code

NBS — National Bureau of Standards

NEISS — National Electronic Injury Surveillance System

NFC — National Fire Codes

NFIRS — National Fire Incident Reporting System

NFPA — National Fire Protection Association

SBC — Standard Building Code

SBCCI — Southern Building Code Congress International

UBC — Uniform Building Code

UL -- Underwriters Laboratories, Incorporated

USFA -- United States Fire Administration

vii

A REVIEW OF FIRE INCIDENTS, MODEL BUILDING CODES,

AND STANDARDS RELATED TO WOOD-BURNING APPLIANCES

Richard D. Peacock

Abstract

As a part of the Department of Energy program

to advance the technology for the utilization of fuel

wood as an alternate energy source for applications

ranging from single-family dwellings to apartment com- plexes and small industries, a review is presented of

fire incidents and fire deaths attributable to woodburning appliances. Initiated to establish accident

patterns and to determine the risks involved with the

use of wood-burning equipment, the survey represents

a compilation of approximately 11,800 fire incidents

including injuries and deaths associated with solid

fuel burning appliances. In addition, a review of

model building codes and of test methods currently

used to test or certify wood-burning equipment is

included to identify priorities for future research

in wood-burning safety.

Key words: Accident investigations; chimneys; coal;

creosote; fire departments; fire safety; heating

equipment; maintenance; stoves; wood.

1. INTRODUCTION

The Department of Energy is pursuing a program to advance the

technology for the utilization of firewood as an alternate energy source

for space heating and other applications in single-family dwellings,

apartment complexes, and small industries. It is important that the

potential fire risks associated with these uses be evaluated and that

appropriate codes, standards, recommended practices and test methods be

developed and implemented to assure an adequate level of fire safety.

To this end, the Center for Fire Research (CFR) at the National Bureau

of Standards (NBS) has undertaken a project sponsored by the Department

of Energy (DOE) to investigate the fire safety of wood-burning appliances

For the purposes of this study, a wood-burning appliance is considered to

be either a factory-built room heater or fireplace or a custom-built fire

place which burns wood and is designed for space heating, cooking, water

heating and the like.

The project is anticipated to be a multi-year effort with the

following objectives for the work during the first year:

1
• Review the available fire and explosion statistics and the available literature on the use of wood as a fuel;

• Review the methods presently used to test or certify the fire

safety of wood-burning appliances by organizations like the National Fire

Protection Association, Underwriters Laboratories, Incorporated, and

industry groups; and

• Review several representative building codes to identify requirements related to the construction, installation, and use of wood-burning

appliances. The literature and codes review should provide valuable

information about the fire risks presented by the use of various woodburning equipment. Based on this literature review, propose an experimental program to develop laboratory data which will contribute to a reduction of the potential fire hazard through revisions to existing

codes and standards.

This report presents an initial review of fire accidents and fire

deaths attributable to wood-burning equipment. Initiated to establish

accident patterns and to determine the types of risks involved with the use of wood-burning appliances, the survey represents a compilation of

fire accidents and deaths related to the use of wood-burning equipment.

In addition, a review of standards and test methods used to test or certify the fire safety of wood-burning appliances and a review of several

model building codes are included. The purpose of this review is to

determine the adequacy of existing codes and standards in addressing the

risks associated with wood-burning appliances and to identify priorities

for future research in wood-heating safety.

2. ACCIDENT DATA SOURCES

Several groups—the National Fire Protection Association (NFPA)

the U.S. Fire Administration (USFA) (formerly the National Fire

Prevention and Control Administration) and the Consumer Product Safety

Commission (CPSC)--maintain data collection systems that provide information on fire-related injuries, deaths and property losses attributable

to various products. Information contained within these data collection

systems include: time and location of accident; type of accident; nature

of injury or property loss; products involved directly and indirectly

with the incident; age, sex and health of the victim (if any); and so forth.

In addition, the Flammable Fabrics Accident Case and Testing System

(FFACTS) was developed by the National Bureau of Standards to establish

priorities for the study and potential regulation of the flammability of

fabric products. FFACTS is now a part of the data system maintained by

the Consumer Product Safety Commission.

2
While the majority of the 11,745 fire incidents analyzed came from

one data source, it should be recognized that there may be some overlap

in the data reported to different sources. Care was taken to separate

data sources in the analysis of the fire incidents presented in this study.

2.1 The National Fire Protection Association

An NFPA publication, "Using Coal and Wood Stoves Safely!," presents

a studv covering the selection, installation, use and maintenance of

coal and wood-burning equipment as well as chimney connectors and chimneys [1] . Fire hazards associated with solid fuel burning equipment

are reviewed along with descriptions of typical fires, deaths and injury

incidents associated with wood burning from reports to the NFPA Fire

Records Department. While these incidents only represent a very small

sample of all fire incidents involving wood-burning appliances and thus

cannot be used to project national injury estimates, they are still valuable in determining the nature of accidents involving wood-burning

appliances. Eighteen separate incidents of fire injuries and deaths are reported

2.2 The National Electronic Injury Surveillance System

The National Injury Information Clearinghouse within CPSC maintains

information sources "to collect, investigate, analyze and disseminate

injury data and information relating to the causes and prevention of

death, injury and illness associated with consumer products" [2], The

National Electronic Injury Surveillance System (NEISS) , maintained by

the National Injury Information Clearinghouse is the primary source of

information for the Commission on product— related injuries. The NEISS

system gathers data from statistically selected hospital emergency rooms located throughout the country. While these data can be used to make

statistically valid projections for injuries nationwide, reports are submitted only on product-related injuries receiving emergency department care [3]. Injuries treated in doctors’ offices, at home and through

direct hospital admission are not reported through NEISS. Again, however,

the data can be used to develop typical scenarios for accidents involving

wood-burning equipment. NEISS is comprised of two levels of information.

The first level, the surveillance data, includes information on the products involved as well as about the victim and the injury—age, sex, injury

diagnosis, body part involved, treatment data, locale, fire or motor vehicle involvement, occupational injury, and whether the victim was treated

and released, hospitalized or dead on arrival at the emergency room [4]

In addition, second level, in-depth investigations are conducted

to obtain further information on selected cases from the NEISS system

to provide details concerning the accident sequence and the cause of

injury. Death certificates also supply additional data on consumer

product hazards.

1 Numbers in brackets refer to the literature references listed at the

end of this paper.

3
A total of 71 in-depth accident investigations from the years 1973-

1978 and 96 death certificates on file with CPSC since July 1973 were

used in this study in addition to the NEISS estimates of national injury

statistics

2.3

The U.S. Fire Administration

The National Fire Data Center of USFA maintains the National Fire

Incident Reporting System (NFIRS) , a data system collecting fire incident data from numerous fire departments throughout the country. At

the time of this report, a total of 1,038,601 separate fire incident

records from 11 states were included. The data represent the calendar

years 1975 through 1977 and the first three quarters of 1978. Included

in each report are details on the equipment involved, the material first

ignited, the nature of the fire growth, the extent of damage including

dollar loss estimates and injuries or deaths associated with the fire.

A total of 11,534 incidents were attributable to solid fueled heating

appliances; this including both coal and wood-burning appliances. No

attempts were made to separate coal versus wood-burning appliances.

However, it is felt that since many appliances can use both fuels and

equipment designs are similar, the accident patterns should be similar.

2.4

The Flammable Fabrics Accident Case and Testing System

The NBS Flammable Fabrics Accident Case and Testing System (FFACTS)

now maintained by the Consumer Product Safety Commission, contains data

derived from case histories of accidental fires involving fabric items,

along with analysis of the actual fabrics involved in the accidents. An

earlier report by Hayes of NBS presented the findings of a study of space

heater involvement in fabric fires, which included wood heaters [5].

Space heaters of all kinds ranked sixth in the tabulation of direct sources

of fabric ignition in the FFACTS file. While space heaters are not a major

source of fabric fire injury, in terms of severity of personal injury they

appear to achieve some significance. There are twice as many deaths from

space heater incidents and additionally twice as many people hospitalized

as the average for all FFACTS ignition sources [5]. A total of 127 incidents involving space heaters are reported by Hayes. However, only four

involve wood heaters.

2.5

The Massachusetts State Fire Marshal's Office

In an analysis of solid fuel-related fires performed under contract

to CFR, Shelton reports on fire records on file with the Massachusetts

State Fire Marshal's Office from late 1977 through June 1978 [6]. A total

of 104 reports were on file as of June 1978, mostly covering fires which

occurred during the 1977-1978 heating season. The reports were analyzed by

Shelton to determine the probable cause of each fire. A copy of the

report is attached as appendix A.

4
2.6 The Oregon State Fire Marshal's Office

An analysis of 234 fires occurring in single-family dwellings during

the year 1977 reported to the Oregon State Fire Marshal's Office were

analyzed to determine the probable cause of the fire [7], In addition,

injuries, deaths and dollar loss are reported for the 234 fires included

in the study.

3. FIRE INCIDENTS RELATED TO WOOD-BURNING EQUIPMENT

3.1 Causes of Fire Incidents

An analysis of the data collected from the sources outlined above

indicates that a majority of the accidents arise from the unsafe installation and unsafe use of wood-burning equipment. Typical accidents

include

• The use of unvented equipment inside a dwelling;

• The installation of wood-burning equipment too close to combustible framing and furnishings;

• Placement of flammable solids and liquids too close to woodburning equipment;

• The use of flammable liquids to kindle a fire;

• Overloading of wood-burning equipment leading to operation well

beyond design limits;

• The ignition of clothing or other fabrics during loading,

unloading, cleaning or use of wood-burning equipment;

• Contact burns received from hot surfaces of wood-burning equipment ;

• The use of defective or improper chimneys for wood-burning

equipment; and

• The ignition of creosote and carbon deposits on the inside of

chimneys leading to very hot chimney fires.

3.2 Incidents Associated with Wood-Burning Appliances

Of the 11,534 residential solid fuel related fire incidents reported

in the NFIRS data base, 10,863 or 94% of the fires occurred in one- and

two-family dwellings. Only 671 fires occurred in larger residential structures. A dollar loss estimate of property loss was also known for 8,837

of the fires. Figure 1 illustrates the property loss in those cases where

there was a loss and the loss was estimated. The loss was under $1,000

5
in 72% of the fires. However, because of five fires in which the damage

was over $250,000, the average dollar loss was $12,700 for all cases in

which the dollar loss was known.

A wood-burning system is comprised of two or three essential parts:

the wood-burning unit itself, a chimney assembly connected to it, and for

free-standing heaters, a chimney connector joining the appliance and the

chimney. Figure 2 shows the fires associated with each of these components. The appliance was reported as the equipment involved in 6,300 (55%)

of the fires, followed by chimneys in 3,993 (35%) and chimney connectors

in 1,241 (10%) of the fires. An analysis of accidents involving these

assemblies is described below.

3.2.1 Activities of Persons Involved and Products Involved

The activity of the persons involved in accidents related to woodheating appliances is a major factor in understanding the risks associated with wood-burning equipment. After review of the accident histories

of the cases involving wood-heating equipment, the accidents were broken

down into 14 general categories: (1) the ignition of nearby combustible

materials including materials placed near equipment, wall and floor sur- faces too close to equipment, and building construction with insufficient

clearances to prevent ignition; (2) the ignition of the exterior of a structure by sparks released from a chimney; (3) the ignition of creosote

and carbon deposits on the inside of chimneys leading to very hot chimney

fires; (4) improper fueling or overloading of a wood-burning appliance

leading to operation well beyond design limits; (5) equipment malfunction

or poor design leading to equipment failure and fire escaping from the

firebox; and (6) the use of flammable liquids near a wood-burning appliance or to kindle a fire in an appliance. A small number of other specific causes included (7) the accidental ignition of clothing during loading and unloading of wood-burning appliances; and (8) stove backpuffing,

a small explosion which occurs when fuel- rich combustion gases mix with

oxygen upon door or air inlet opening. In addition, a number of fires were attributed to less specific causes such as: (9) lack of proper maintenance; (10) equipment design deficiency and improper equipment design;

(11) improper equipment operation; (12) the ignition of the dwelling

structure; (13) improper installation; and (14) the use of wood-burning

appliances with improper or defective chimneys including the use of insulated stovepipe through combustible walls and ceilings and the use of

cracked and broken chimneys. A number of cases were also noted where no specific cause could be identified.

Figure 3 and table 1 illustrate the conditions leading to fires

involving wood-burning appliances identified from the NFIRS data system.

Incidents where product malfunctions or design defects were involved

accounted for only 13% of the incidents. Overwhelmingly, conditions

related to the installation of the product were responsible for fire

accidents. The installation of appliances too close to combustibles or the placing of combustible materials nearby the heating appliance

accounted for 21% of the fires. Improper maintenance, including the use

6
of worn out equipment, accounted for 32% of the fires—together over 50%

of the fires where a cause was known. The ignition of the exterior of a building by sparks released from chimneys accounted for 11% of the fires

as did the ignition of structures without further details.

Shelton reports similar data from the Massachusetts State Fire

Marshal's Office. Roughly three-quarters of the fires reported were

attributed to unsafe installations and about one-quarter to unsafe

operation and maintenance. He reports only 2% of the fires were attributed to product defects or poor design [6].

In addition, in the analysis of fires reported to the Oregon State

Fire Marshal's Office related to solid fuel heating appliances shown in

figure 4, only two fires out of 234 were attributed to a defective stove

[7]. Roughly three-quarters of the fires were attributed to unsafe

installations and one-quarter to improper operation or maintenance.

3.2.2 Age and Sex of Persons Involved

The age and sex were known for 69 out of 100 persons involved in

accidents specified in the NEISS files and the NFPA publication "Using

Coal and Wood Stoves Safely ! " Figure 5 and table 2 show the age and sex distribution of persons involved in wood-heating accidents where

the age and sex of the victims were known. Young children were involved

more frequently in accidents than other individuals. Persons 10 years

old or younger were involved in 35 out of 69 accidents where the age was

known. Males outnumbered females in the accidents by a ratio of almost

2:1. Traditional use patterns of wood-burning appliances would support

these imbalances. In addition, other factors such as less familiarity

with equipment use, in the case of young children, and poorer judgment

and reactions in the case of both the young and the old make these people

more susceptible to accidental injuries.

3.2.3 Severity of Injury

According to the NFIRS data system, injuries were involved in only

125 out of the 11,534 fires and deaths in only 40. A total of 159

injuries and 65 deaths were recorded for non-fire service persons. For

accidents involving injuries, the NEISS data provides information on the

severity of injury. Figure 6 shows the extent of injury to persons

involved in solid fuel space heating ignition accidents, both wood fueled

and other fuels. Many of these injuries were quite serious. Forty- two

percent of the accidents involving wood-heating equipment were serious

enough to require hospitalization; a total of 19 persons died or 23% of

those persons involved.

4. SUMMARY AND CONCLUSIONS FROM FIRE INCIDENT DATA

Space heating, cooling and ventilation equipment account for only

7.5% of all burn injuries according to a recent study prepared for the

7
Consumer Product Safety Commission [8]. Of these, wood-burning appliances are only a part.

This study was conducted primarily to determine the nature of accidents involving wood-burning appliances. Overwhelmingly, the accidents were related to the installation of wood-burning equipment and insufficient personal attention in its use. From the standpoint of fire safety,

the most important areas for concern are:

• The ignition of adjacent combustibles from the heat from woodburning equipment;

• The ignition of building exteriors by sparks escaping from chimneys; and

• The use of wood-burning equipment with improper, defective, or poorly maintained chimneys and resultant chimney fires.

From this study, fire safety standards for wood-burning equipment

should include provisions addressing the following:

• Structural integrity of wood-heating units, tested at conditions

typical of actual use;

o Detailed instructions for the installation of equipment including

proper chimneys to be used and clearances to combustible surfaces in addition to information warning the consumer of the potential hazards involved

with the use of equipment including the use of flammable liquids, the

potential for burns from the hot surfaces of the stoves, and possible con- sequences resulting from overfueling; and

• The use of spark screens on chimney outlets or other means to prevent sparks and glowing embers from escaping from chimneys leading to fires

on the building exterior.

5. MODEL BUILDING CODES

Building codes, adopted by local and/or state jurisdictions, regulate

the construction of new buildings and the modification of existing buildings. Regulated and enforced by the adopting jurisdiction, the codes are designed to protect occupants and property from fire and insure structural

integrity of the building systems. A recent survey indicates that most of

the building codes adopted are patterned after one of the four model codes

[9].

As a part of this literature study, the four model codes were reviewed

to identify requirements related to the construction, installation and use of wood-burning appliances:

8
• The BOCA Basic Building Code/1978, published by the Building

Officials and Code Administrators International, Incorporated [10,11];

• The National Building Code, 1976 Edition, published by the

American Insurance Association [12];

• The National Fire Codes, 1978, published by the National Fire

Protection Association [13];

• The Standard Building Code, 1976 Edition with 1977 and 1978 amendments, published by the Southern Building Code Congress International,

Incorporated [14,15]; and

• The Uniform Building Code, 1976 Edition with 1977 supplement,

published by the International Conference of Building Officials [16,17].

All of the above codes contain provisions that regulate the con- struction and installation of masonry chimneys, masonry fireplaces,

factory-built chimneys and factory-built fireplaces, fireplace stoves,

room heaters, and other wood-burning appliances. These requirements are described below.

5 . 1 Chimneys and Chimney Connectors

A chimney used with any wood-burning system serves one important

purpose—to vent the heated products of combustion within the heating

unit safely to the outside of the building. The proper construction of

chimneys and the correct installation of chimney connectors and of

factory-built chimneys with proper clearances to combustible materials

is particularly important in preventing accidental fires. All of the

model building codes reviewed contain provisions governing the construction and installation of both masonry chimneys and factory-built chimneys. Some of the codes also contain provisions covering the construction

and installation of chimney connectors. Tables 4 and 5 summarize the

code requirements.

5.1.1 Construction

All of the model codes reviewed require that masonry chimneys be con- structed of solid masonry units or reinforced concrete with walls not less

than 4 in (10 cm) thick or of rubble stone masonry not less than 12 in

(30 cm) thick. In addition, all of the model codes reviewed specify that

chimneys should be lined with fire-clay flue lining (ASTM C 315) , or the

equivalent, with a thickness of not less than 5/8 in (1.6 cm), or with a liner of other material that will resist corrosion, softening or cracking

from flue gases at temperatures up to 1,800° F (980° C) . Flue linings

provide additional protection for chimneys from thermal stress and the

corrosive effects of hot flue gases [18,19,20]. Actual fire testing on masonry chimneys indicated a greater hazard from unlined chimneys than

from lined ones [21].

9
If multiple flues are included in a single chimney, the codes require

that there be a masonry separation at least 4 in (10 cm) thick, bonded

into the masonry wall of the chimney to separate each flue passageway.

Obviously, draft is also an important factor in chimney design. The

model building codes require that a chimney extend at least 3 ft (8.9 m)

above the highest point where they pass through the roof of the building,

and be at least 2 ft (0.6 m) higher than any portion of a building within

10 ft (3 m) . Insuring sufficient height above the roof will help prevent

downdraft and other wind effects.

For factory-built chimneys, the model codes reviewed all require that

the chimney be constructed of listed, approved factory-built components

installed in strict accordance with the terms of their approval and listing, and the manufacturer's installation instructions. Actual factorybuilt chimneys are subjected to testing to determine the structural integrity of the chimney and to determine proper clearances to combustible

surfaces. The test methods used are described in section 6.

Only two of the model codes, the BOCA Basic Building and Mechanical

Codes and the National Fire Codes, contain regulations governing the con- struction of chimney connectors used to connect a heating appliance to a chimney. The National Fire Codes specify that chimney connectors are

to be constructed of factory-built chimney material. Type L vent material,

or steel pipe having resistance to corrosion and heat not less than that

of galvanized pipe. Minimum thicknesses for connectors are specified

depending on the diameter of the pipe. The length of the connector

should be as short and as straight as possible [13], with horizontal

length less than 75% of the vertical height.

5.1.2 Clearances

Certain minimum clearances between chimneys and chimney connectors

and combustible materials must be maintained in order to prevent the

ignition of these materials from the heat transmitted from the hot chimney surfaces. All of the model codes reviewed contain requirements for

minimum clearances for chimneys. In addition, two of the codes also

include clearances for chimney connectors. For masonry chimneys, a clearance of at least 2 in (5 cm) from the outside face of a chimney is required

for all headers, beams, joists and studs. Combustible lathing, furring or plaster grounds may, however, be placed against a chimney within 1-1/2 in

(3.8 cm) of the corners. The requirements do not apply to chimneys placed

entirely on the outside of a building against the sheathing. Factorybuilt chimneys are installed with clearances as specified in the manufacturer's instructions. Since factory-built chimneys are to be tested and

listed by nationally recognized testing laboratories, the clearances specified for these chimneys are based on actual testing. Usually, 2 in (5

cm) of clearance is specified [22].

Clearances from chimney connectors depend on the material of construction. For single wall metal pipe, a clearance of at least 18 in (45 cm)

10
is required as shown in figure 7. For Type L vent piping, the National

Fire Codes allow a clearance of at least 9 in (23 cm) . These clearances

may be reduced with the use of specific methods of protection as outlined

in table 6 and figure 8, to as little as 3 in (8 cm)

Several experimental studies have been carried out to determine minimum allowable clearances to combustible materials. Voigt, in a 1933

publication, recommended a minimum clearance of 12 in (30 cm) for chimney

connectors of 9 in (23 cm), in diameter [23]. A more extensive study,

performed by Underwriters Laboratories in 1943, presents a number of

methods for protecting combustible surfaces [24]. Some of the data from

this study is shown in table 7. By comparing tables 6 and 7, the model

codes require more conservative limits than the UL testing would indicate

necessary. Mitchell [21] recommends a 2 in (5 cm) clearance for masonry

chimneys

5.2 Wood-Burning Units

All the model codes reviewed also provide requirements for the con- struction and installation of wood-burning firebox units including masonry

fireplaces, factory-built fireplaces, factory-built fireplace stoves, and

factory-built room heaters. Table 8 summarizes the requirements.

5.2.1 Construction

All of the codes reviewed contain guidelines for the construction of

masonry fireplaces. A minimum thickness of 8 in (20 cm) is specified for

all structural walls. If a lining of low-duty refractory brick (ASTM C

64), or the equivalent, at least 2 in (5 cm) thick, is provided, the total

thickness, including liner should be at least 8 in (20 cm). When such a liner, or other approved liner is not provided, the total thickness of

back and side walls should be at least 12 in (30 cm) . Two of the model

codes reviewed also allow the use of steel fireplace units—a firebox

liner of steel at least 1/4 in thick and an air chamber—installed with

masonry to provide a total thickness of at least 8 in (20 cm) . A minimum of 4 in (10 cm) of solid masonry should be used.

Two of the codes, the Basic Building Code and the Uniform Building

Code also include guidelines for fireplace depth. The Basic Building

Code specifies the depth of the fireplace to be 20 in (51 cm)

The

Uniform Building Code specifies a maximum of 20 in (51 cm).

A hearth extension is also required by all of the codes reviewed.

The hearth extension, constructed of brick, stone or other noncombustible

material, should extend a minimum of 16 in (40 cm), in front of the fireplace opening and at least 8 in (20 cm) on each side of the opening. For

fireplaces with an opening of 6 sq ft (0.56 m

2

) or more, the extensions

required are 20 in (51 cm) in front and 12 in (30 cm) on each side.

11
As with factory-built chimneys and chimney connectors, factory-built

fireplaces', fireplace stoves and room heaters are to be tested and listed

by a nationally recognized testing laboratory and installed in accordance

with the listing and the manufacturer's instructions. For factory-built

fireplaces and fireplace stoves, hearth extensions are to be provided as directed by the manufacturer. Factory-built room heaters are to be sold

with directions for the protection of combustible walls and floors, provided by the manufacturer.

5.2.2 Clearances

Minimum acceptable clearances between masonry fireplaces and com- bustible framing, wall surfaces, and woodwork are included in the model

codes. A distance of at least 4 in (10 cm) should be maintained between

the fireplace and combustibles. Combustibles should not be placed within

6 in (15 cm) of the fireplace opening. However, if fireplace walls are

at least 12 in (30 cm) thick, the facings or trim may be attached directly

to the fireplace.

Factory-built fireplaces, fireplace stoves and room heaters are to

be installed with minimum clearances as specified by the unit's listing

and the manufacturer's instructions.

As with any heat producing appliance, it is important that sufficient

clearances be provided between the hot surfaces of the appliance and any

combustible materials. Several references are available providing guidelines for minimum clearances. The NFPA Manual on Clearances for Heat

Producing Appliances includes recommended minimum clearances for appliances as shown in table 9. Usually, a clearance of 36 in (0.9 m) is

recommended. For heaters surrounded by an outer jacket arranged with

openings at top and bottom so that air circulates between the walls of

the heater [25], clearances of 24 in (61 cm) from the front of the appliance and 12 in (30 cm) from the sides and back of the appliance are recommended [26]. Clearances may be reduced with proper protection as described for chimney connectors in table 6.

Proper clearances are equally important with masonry fireplaces.

Tests performed on a particular masonry fireplace [27,28] indicated that

safe temperatures are easily exceeded on combustibles in contact with

outside surfaces of masonry fireplaces, even when an 8 in (20 cm) thick- ness of masonry is provided.

6. TEST METHODS

As outlined above, requirements for factory-built chimneys, chimney

connectors, fireplaces, fireplace stoves, and room heaters include testing and listing by a nationally recognized testing laboratory. A number

of test methods, developed by Underwriters Laboratories, Incorporated,

are used for the evaluation of these products. The test methods are:

12
• UL 103, Chimneys, Factory-Built [30];

• UL 127, Factory-Built Fireplaces [31];

• UL 737, Fireplace Stoves [32]; and

• UL 1482, Room Heater, Solid Fuel Type [33].

In general, the test methods outlined contain similar provisions

regulating the design, construction and installation of the appliances.

All contain provisions covering:

• Minimum information to be included in installation instructions;

• Materials of construction;

• Performance testing of units in three different fire tests; and

• Structural integrity of materials.

• For room heaters, employing blower assemblies, requirements are included covering safe electrical construction.

The review below will concentrate on the test method for solid fuel

room heaters, UL 1482. Many of the provisions outlined below are similar,

if not identical in the other UL test methods.

6.1 Installation of Appliances

The August 1978 draft of UL 1482 contains a number of requirements

relating to the installation and operation of solid fuel burning room

heaters. Information to be included in the manufacturer's instructions

accompanying each room heater is required as follows:

• The parts and materials required and the step-by-step process for

the installation of a room heater, accessories and its chimney connector;

• The parts or materials for floor protectors including minimum

areas covered;

• The size and type of chimney to be used with the room heater;

• Any limitations on installation, minimum clearances or construction;

• The size and material for chimney connectors and its attachment

to the chimney and room heater;

• Inspection , maintenance and cleaning of the chimney and chimney

connector;

13
Minimum clearances for the room heater and chimney connector;

• The safe disposal of ashes;

• Caution against the use of flammable liquids;

• Reference to the formation and removal of creosote buildup in

the chimney connector and chimney;

• The use of grates, andirons or other methods to support the

fuel;

• Operation and use of manual or thermostatic controls; and

• Operation and use of electrical assemblies.

6.2 Performance Tests

6.2.1 Structural Integrity Tests

UL 1482 contains a number of performance tests to determine the

structural integrity of components used in room heaters. If chimney

connector sections are supplied with the room heater, they are subjected

to a strength test as shown in figure 9.

The connector must not open up, break apart or become damaged when

subjected to three impacts from the sandbag pendulum. In addition, the

chimney connector must not be damaged when subjected to a 100 lb force

applied to parts intended to be field joined.

Room heaters are also subjected to stability tests to insure that

the product will not tip over in normal use. The minimum force necessary

to tip the unit over and the angle at which it tips is measured.

Glass used as part of a room heater door is subjected to an impact

test as shown in figure 10. The glass must withstand the test without

breaking or cracking. Glass panels must also withstand a water spray

test while heated to be acceptable.

6.2.2 Firing Tests

The UL Standards for factory-built fireplaces, fireplace stoves and

room heaters all contain details of three fire tests conducted with the

appliance installed in a test enclosure with clearances recommended by

the manufacturer (figure 11). The tests, simulating worst case conditions, are:

• A radiant fire test using a 6 in depth of charcoal briquettes

maintained for as long as necessary to obtain maximum temperatures;

• A brand fire test using nominal lxl Douglas fir strips con- structed into brands whose dimensions equal two-thirds of the hearth

14
area of the heater (again, the test is continued until maximum temperatures are reached) ; and

• A flash fire test conducted as a continuation of the brand fire

test by placing eight brands at one time in the heater.

Table 10 indicates the maximum temperatures allowable by the UL

tests on surfaces of the test enclosure, room heater or chimney connector parts at points of zero clearance to the enclosure and beneath a floor protector.

Maximum temperature rises are also specified for any part of the room heater or chimney connector including electrical assemblies, motors

and metals whose failure may cause the product to be unsuitable for use.

7. CONCLUSIONS

The results of a review of fire incidents involving wood-burning

appliances presented in this paper indicates that the major risks asso- ciated with the equipment are attributed to improper installation of woodburning appliances and insufficient personal care in their use. Only a small minority of fires were attributed to faulty equipment design or equipment malfunction.

All the model building codes reviewed contain requirements covering

the construction of masonry fireplaces and chimneys. Minimum clearances

to combustible materials are given for masonry appliances. Requirements

for factory-built appliances rely on testing and listing by nationally

recognized laboratories. Recommendations for minimum clearances for

factory-built appliances adopted by manufacturers are included in recommended practice manuals [26]. Actual clearances are, however, based on testing of the appliances. Clearances to combustibles may be reduced

with the use of specific forms of protection for the combustible surfaces.

Model Building Code Officials recognized the need for minimum installation instructions in a report prepared under contract to CFR. A copy of

the report is attached as appendix B.

Test methods used by laboratories for the listing of wood-burning

appliances contain provisions describing stringent material, installation

and performance requirements (fire and structural integrity) for factorybuilt appliances. Fires much larger than normal use are used to simulate

"worst case" conditions. These same requirements, applied to a particular

masonry fireplace, led to temperatures on nearby combustible surfaces in excess of those deemed acceptable for factory-built units [27,28].

Future research in the area of wood-heating safety should concentrate on the installation and use of wood-burning appliances. Existing

criteria for the installation and use of wood-burning appliances are based on data developed over 30 years ago and do not provide information

15
on many materials available in the current market or allow for any variations based on the use of alternate materials.

Possible areas for future research that may be needed to define

appropriate requirements for test methods include:

• Determination of typical firing rates for wood-heating equipment

and development of a standardized fuel source for this heat output;

• Study of the potential for ignition of combustible construction

and furnishings fiom the heat generated by wood-burning appliances;

• Study of methods for protecting combustible materials and surfaces from nearby wood-heating equipment; and

• Investigation of creosote formation and deposition in typical

situations and conditions leading to ignition in chimney fires.

In addition, the development of a public education program to alert users

of wood-burning appliances to the risks involved with the use of the equipment and to provide information on the safe installation of appliances is

important to insure that those installing appliances without building permits, etc., have the necessary information available for safe installation

and use.

8. ACKNOWLEDGEMENTS

This study was sponsored by the U.S. Department of Energy. The

support by DOE, and by the contract officers, Dr. Jorgen Birkeland and

Mr. J. Edward Manuel, is gratefully acknowledged. Thanks are also due

to Mr. Alan Gomberg and Mr. Stephan Leigh of the Center for Fire Research

who provided data from the NFIRS data base of the United States Fire

Administration.

16
9. REFERENCES

[1] Using Coal and Wood Stoves Safely!, NFPA Publication No. HS-8,

National Fire Protection Association, Boston, Massachusetts (1974).

[2] Consumer Product Safety Act, U.S.C. 2051, Section 5[a].

[3] NEISS Data Highlights, Vol. 2, No. 4, U.S. Consumer Product Safety

Commission (April 1978)

[4] The National Injury Information Clearinghouse, information brochure

published by the National Injury Information Clearinghouse, U.S.

Consumer Product Safety Commission.

[5] Hayes, W. D., Space Heater Involvement in Fabric Fires, Nat.

Bur. Stand. (U.S.), NBSIR 76-1014 (March 1976).

[6] Shelton, J. W. , Analysis of Fire Reports on File in the

Massachusetts State Fire Marshal's Office Relating to Wood and

Coal Heating Equipment, contract to the National Bureau of

Standards (U.S.), NBS-GCR-78-149 (November 1978).

[7] Solid Fuel Heating Appliances, Oregon Fire Incident Reporting

System, Office of the State Fire Marshal, Salen, Oregon, personal

communication.

[8] Ries, Peter W., Episodes of Persons Injured: United States, 1975,

U.S. Department of Health, Education and Welfare, Advance Data

Number 18 (March 1978)

[9] Bihr, J. E., Building and Fire Codes: The Regulatory Process, Fire

Standards and Safety, ASTM STP 614, A. F. Robertson, Ed. , American

Society for Testing and Materials (1977).

[10] The BOCA Basic Building Code/1978, Model Building Regulations for

the Protection of Public Health, Safety and Welfare, Seventh Edition,

Building Officials and Code Administrators International, Homeward,

Illinois (1978)

[11] The BOCA Basic Mechanical Code/1978, Model Mechanical Regulations

for the Protection of Public Health, Safety and Welfare, Third

Edition, Building Officials and Code Administrators International,

Homeward, Illinois (1978).

[12] The National Building Code, 1976 Edition, American Insurance

Association, New York, New York (1976)

[13] National Fire Codes, Vol. 9, Standard for Chimneys, Fireplaces,

and Vents, NFPA 211-1977, National Fire Protection Association,

Boston, Massachusetts (1978)

17
[ 14 ] Standard Building Code, 1976 Edition, Southern Building Code

Congress, International, Incorporated, Birmingham, Alabama (1976).

[15] Amendments to the Standard Building Code, 1977 and 1978 Revisions

to the 1976 Edition, Southern Building Code Congress, International,

Incorporated, Birmingham, Alabama (1978).

[16] Uniform Building Code, 1976 Edition, International Conference of

Building Officials (1976).

[17] 1977 Supplement to the Uniform Building Code, U.B.C. Standards,

Uniform Housing Code, Uniform Code for the Abatement of Dangerous

Buildings and the Uniform Fire Code, International Conference of

Building Officials (1977).

[18] Biggs, A. A., Fireplaces and Chimneys, U.S. Department of

Agriculture, Farmer's Bulletin, No. 1889 (September 1963).

[19] Shoub, Harry, Survey of Literature on the Safety of Residential

Chimneys and Fireplaces, Nat. Bur. Stand. (U.S.),

Miscellaneous Publication 252 (December 1963).

[20] Chimneys, Tests on Masonry Residential Type, National Board of

Fire Underwriters Special Interest Bulletin No. 14 (May 1960).

[21] Mitchell, N. D., Fire Hazard Tests With Masonry Chimneys, National

Fire Protection Association, NFPA No. Q 43-7 (October 1949).

[22] Shelton, J. W. and Shapiro, A. B., The Woodburner's Encyclopedia,

Vermont Crossroads Press, Waitsfield, Vermont (1976).

[23] Voigt, G. Q., Fire Hazard of Domestic Heating Installations,

Nat. Bur. Stand. (U.S.), NBS Research Paper RP 596

(September 1933) .

[24] Neale, J. A., Clearances and Insulation of Heating Appliances,

Underwriters Laboratories, Incorporated, UL Bulletin of Research

Number 27 (February 1943)

[25] National Fire Codes, Vol. 14, Standard Glossary of Terms Relating

to Chimneys, Vents, and Heat Producing Appliances, NFPA 97M-1972,

National Fire Protection Association, Boston, Massachusetts (1978) .

[26] National Fire Codes, Vol. 14, Manual on Clearances for Heat

Producing Appliances, NFPA 89M-1976, National Fire Protection

Association, Boston, Massachusetts (1978)

[27] Fact-Finding Report on Masonry Fireplace, Underwriters Laboratories,

Incorporated, File USNC 24 (June 1962).

18
[28] Fact-Finding Report on Masonry Fireplace, Underwriters Laboratories,

Incorporated, File USNC 24 (October 1962).

[29] Standard for Chimneys, Factory-Built Residential Type and Building

Appliance—UL 103, Underwriters Laboratories, Incorporated (March

1971).

[30] Proposed Fifth Edition of the Standard for Factory-Built Fireplaces,

UL 127, Underwriters Laboratories, Incorporated (February 1978).

[31] Standard for Safety, Fireplace Stoves—UL 737, Underwriters

Laboratories, Incorporated (May 1978).

[32] Proposed First Edition of the Standard for Room Heaters, Solid Fuel

Type, UL 1482, Underwriters Laboratories, Incorporated (January

1978)

[33] Appendix A, Proposed Revisions to the January 1978 draft of the

Proposed First Edition of the Standard for Solid Fuel Type Room

Heaters, UL 1482, Underwriters Laboratories, Incorporated (August

1978)

19
NUMBER

OF

FIRES

20

Figure

1.

Dollar

loss

estimates

as

reported

in

NFIRS

solid

fuel

fire

incident

data
NUMBER

OF

FIRES

21

Figure

2.

Type

of

equipment

involved

as

reported

in

NFIRS

solid

fuel

fire

incident

data
TOO CLOSE TO COMBUSTIBLES

0

r 3000

nr

NUMBER OF FIRES

EXTERIOR FIRE FROM SPARKS

CHIMNEY FIRES

IMPROPER FUELING

EQUIPMENT MALFUNCTION

USE OF FLAMMABLE LIQUIDS

OTHER

1000 2000 T* "T

IMPROPER MAINTENANCE

IMPROPER EQUIPMENT DESIGN

IMPROPER OPERATION

IGNITION OF STRUCTURE

IMPROPER INSTALLATION

IMPROPER CHIMNEY

Figure 3. Factors leading to ignition as reported

in NFIRS solid fuel fire incident data

22
23

Figure

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Solid

fuel

related

fire

incidents

reported

to

the

Oregon

State

Fire

Marshal's

Office
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CONSTRUCTION

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26

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29
Figure 11. UL 1482 fire test installations

30
Table 1

Conditions leading to fires attributed to

wood-burning equipment

Number of Fires

Ignition of Combustibles 1,895

Exterior Fire From Sparks 963

Chimney Fires 623

Improper Fueling Technique 578

Equipment Malfunction 457

Use of Flammable Liquids 126

Other 28

Improper Maintenance 2,875

Improper Equipment Design 1,050

Improper Operation 787

Ignition of Structure 702

Improper Installation 248

Improper Chimney 138

Total 10,470

31
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a

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g

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a

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Table 7

Recommended clearances for horizontal smoke pipe from UL

Bulletin of Research 27 [15]

Type of Protection Clearance With No Protection

18 in 9 in

1/2 in plaster 16 7

Sheet metal on asbestos paper 9 2

1/4 in asbestos board spaced down 1 in 84

Sheet iron spaced down 1 in 52

Sheet metal on 1/4 in asbestos board 4 2

Sheet iron on 1/8 in asbestos spaced 4 2 down 1 in

1 in rock wool in sheet metal pan 2 2

38
Model

building

codes

requirements

for

masonry

fireplaces

and

factory-built

wood-burning

units

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39
Model

building

codes

requirements

for

masonry

fireplaces

and

factory-built

wood-burning

units

4-1 . 1 1 X

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a) 4-4 cu rd

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CO

4-4 4-4 44 d •rH d

<u

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40
Table 9

Minimum installation clearances for heat

producing appliances, solid fuel type

Above

Top

From

Front

From

Back

From

Sides

Room Heaters

Circulating Type 36 24 12 12

Radiant or Other Type 36 36 36 36

41
Table 10

Maximum allowable temperatures on combustible surfaces

adjacent to room heaters tested according to UL 1482 [32]

Fire Test

Rad iant

Brand

Flash

Adjacent Surfaces

117°F (65°C)

117°F (65°C)

140°F (78°C)

1,2 Flue Gases

1, 000°F (538 °C)

3

1, 000°F (538°C)

3

1, 400°F (760°C)

4

Maximum temperatures apply to surfaces of the test enclosure, of the room heater or chimney connector parts at points of zero clearance

to the test structure, and beneath a floor protector.

Temperatures are maximum rises above ambient corrected to 77°F (25°C)

Temperatures may exceed 1,000°F (538°C) but not exceed 1,400°F (760°C)

for a cumulative period not exceeding 60 minutes for any 8-hour period

of the test.

Temperatures may exceed 1,400°F (760°C) but not exceed 1,700°F (927°C)

for a cumulative period not exceeding 10 minutes during the duration

of the test.

42
APPENDIX A

Analysis of Fire Reports • on File in the

Massachusetts State Fire Marshal's Office

Relating to

Wood and Coal Heating Equipment

Jay W. Shelton, Ph.D.

Wood Heating Consultant

36 Hawthorne Road

Williamstown, Massachusetts 01267

November, 1978

A-l
Notice

This report was prepared for the Center for Fire

Research of the National Engineering Laboratory,

National Bureau of Standards, under Contract No.

NB79NAAA1576. The statements and conclusions con- tained in this report are those of the author and do

not necessarily reflect the views of the National

Bureau of Standards or the Center for Fire Research.
Preface

This report was funded by the National Bureau of Standards (NBS)

Center for Fire Research (CFR) , as a part of the NBS investigation of

fire safety of wood-heating equipment sponsored by the Department of

Energy.

In this study reports from local fire departments to the

Massachusetts State Fire Marshal's Office concerning wood-stove related

fires are analyzed for the probable specific cause of the fire. The

results may be useful for indicating in which areas preventative actions

could be most effective.
Abstract

An analysis of solid-fuel related fires reported by local fire

departments to the Massachusetts State Fire Marshal's Office from late

1977 through June, 1978 indicates that of the fires attributed to specific causes, roughly 3/4 were attributed to unsafe installations, and

about 1/4 were attributed to unsafe operation/maintenance. In less than

2 percent of the fires was the cause attributed to defects or poor

design in the heating appliance itself. Thus, to the extent that the

local fire department reports are complete and reliable, it appears that

attention to installation, operation and maintenance is what has the

most potential for reducing fires.

AFor approximately the last year, the Massachusetts State Fire

Marshal's Office has been keeping a separate file of all solid-fuelheating related fires reported to the state office by the local fire

departments. As of June 1978, there were about 104 reports on file,

mostly covering fires which occurred during the 77-78 heating season.

These reports were analyzed for the probable cause of the fire,

the objective being to ascertain the percentage of fires attributable to

the following three categories of causes: installation (chimneys, chimney connectors, floor protection, clearances, etc.), operation/maintenance, and defects or poor design in the heating unit itself.

The reports themselves appear for the most part, to be cursory.

Many local fire departments do not have the expertise and/or time to con- duct a thorough investigation. These reports were essentially taken at

face value in this analysis.

Of the 104 reported fires relating to wood and coal heating systems,

74 were attributed by the local fire departments to a specific cause; i.e.,

more specific than "wood stove" or "overfired wood stove." These 74 cases

are further broken down in Table 1. Of these 74 cases, 71 percent were attributed to faulty installations, 16 percent were apparently due to poor

maintenance (e.g., chimneys not kept clean and furniture and rugs not kept

at safe distances from stoves) , 11 percent were attributed to operator

errors and one single fire was attributed to a "defective stove" with no details given. Since in this fire the house burned to the ground, it is

not clear how the determination was made that a defect in the stove caused

the fire.

The implication of the sample of reports is clearly that defects and

faults in the heaters themselves are not a major cause of fires. The most

important area of concern for preventing fires seems to be installations,

with operation/maintenance being the other important area.
Table c

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A- 

Table

1.

Fires

and

other

accidents

related

to

the

use

of

wood

heating

equipment

in

Massachusetts

on

file

in

the

State

Fire

Marshal's

Office

as

of

June

26,

1978,

covering

most

of

(and

mostly)

the

1977-78

heating

season.

The

total

sample

is

104

reports,

74

of

which

gave

usefully

specific

causes.

Determining

causes

of

fires

is

difficult,

particularly

when

the

building

is

totally

destroyed.

Many

of

these

local

fire

department

reports

are

admittedly

only

educated

guesses.
APPENDIX B

November 10, 1978

TO: Richard Peacock (COTR)

Fire Engineering Safety Division

Center for Fire Research

Room B22, Technology Building

NATIONAL BUREAU OF STANDARDS

FR: B. S. Trant, P.E.

Executive Director

COUNCIL OF AMERICAN BUILDING OFFICIALS

RE : Report on Meeting on Fire-Safety of Wood-Burning

Appliances - P. 0. #818552

The Council of American Building Officials and the three

model code organizations: Building Officials and Code

Administrators International, International Conference of

Building Officials and Southern Building Code Congress

International were pleased to participate in the meeting

on Fire-Safety of Wood-Heating Equipment on August 10, 1978.

The model code organizations were represented by Chuck Ramani,

ICBO; Frank Noonan, BOCA; Robert English, SBCCI and Shep Trant,

CABO.

In reviewing the accident survey it revealed that the majority

of accidents were caused by faulty installations, such as

improper clearance, too close to combustible materials and

combustible surfaces, defective chimneys and flues, the use

of flammable liquids and overloading of equipment; therefore,

it is recommended that minimum installation instructions be

developed and included with all wood-burning appliances.

Clearances now listed in the codes and standard could be a subject for research. With the increase use of wood-burning

appliances in an environment that may be different from that

considered in prior tests some of the characteristics may

change; therefore, research could be developed to determine

the proper clearances from the combustible surfaces and the

B-l
Fire-Safety of Wood-Burning Appliances

Page 2

reduced clearances that may be available for noncombustible

or protected surfaces. Additional areas of research that

were identified were:

1. Firing rates and substitutes for wood

cribs used as the fuel source in existing

test methods;

2. Additional studies into long-term effects

of the use of wood products;

3. Improved methods to measure heat;

4. Special hazards that need investigating are:

Other needs that were identified were the needs of some

basic criteria for wood-burning appliances and criteria

and instruction for installations since the majority of

these units are installed by home-owners rather than by

professionals

The model codes may have some slight variation in their

requirements for wood-burning appliances and equipment.

The information gathered from research projects would be

welcomed by the Board for the Coordination of the Model

Codes in order to develop one set of recommended requirments

and procedures that could be processed through the code

change procedure of the three model codes.

The model code organizations are pleased to have the

opportunity to work with the Center for Fire Research on

these issues and will make every effort to see that those

developments that require action by the model code organizations

are carried through the code change process.

Respectfully submitted:

a. creosoting;

b. use of glass doors;

c. rodent and bird proofing.

Executive Director B-2
NBS-114A (REV. 9-78)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 79-1731

a.Gov't Acfcasalon No.

4. TITLE AND SUBTITLE

A Review of Fire Incidents, Model Building Codes, and

Standards Related to Wood-Burning Appliances

5. Publication Date May 1979

7. AUTHOR^)

Richard D. Peacock

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. Pro

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

11. Contract/Grant No.

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State, ZIP)

U.S. Department of Energy

Washington, D.C. 20545

13. Type of Report & Period Covered

Final, 1978

• 15. SUPPLEMENTARY NOTES

I I Document describes a computer program; SF-185, FIPS Software Summary, is attached.

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant bibliography or

literature survey, mention it here.)

As a part of the Department of Energy program to advance the technology for the

utilization of fuel wood as an alternate energy source for applications ranging

from single-family dwellings to apartment complexes and small industries, a review is presented of fire incidents and fire deaths attributable to woodburning appliances. Initiated to establish accident patterns and to determine

the risks involved with the use of wood-burning equipment, the survey represents

a compilation of approximately 11,800 fire incidents including injuries and

deaths associated with solid fuel burning appliances. In addition, a review of

model building codes and of test methods currently used to test or certify woodburning equipment is included to identify priorities for future research in woodburning safety.

17. KEY WORDS (six to twelve entries ; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons)

Accident investigations; chimneys; coal; creosote; fire departments; fire safety;

heating equipment; maintenance; stoves; wood*

18. AVAILABILITY yy Unlimited

;

1 For Official Distribution. Do Not Release to NTIS _ Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003- XX Order From National Technical Information Service (NTIS), Springfield, VA. 22161 USCOMM-DC

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UNCLASSIFIED 59

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