Ch 05 Features of Fire Protection

5 Features

of Fire Protection

Objectives (1 of 2)

• Understand the basic concepts of fire protection and building construction

• Identify the basics of fire behavior, including fire spread

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• Explain the ways in which smoke and fire containment is achieved

• Describe the various types of fire protection systems

Objectives (2 of 2)

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Building Fire Protection: A Short History (1 of 2)

• Historically, fire containment was a primary objective of the fire fighter.

• Modern building codes reduce conflagrations.

• Reduced conflagrations contributed directly to human safety.

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Building Fire Protection: A Short History (2 of 2)

• Compartmentation also contributed to human safety.

• Firefighting concerns

• Egress for occupants

• Fire fighter safety

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Fire Terminology (1 of 3)

• Noncombustible Buildings

• Material that does not aid combustion

• Buildings contain noncombustible and combustible components

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• Fire-rating

• Fireproof

• Flameproof

• Self-extinguishing

• Flammable

• Fire retardant

• Fire resistance

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• The meaning of fire terms vary.

• The conditions of testing vary.

• Inflammable

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Fire Resistance Distinguished (1 of 2)

• Rated fire resistance

• Inherent fire resistance

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Fire Resistance Distinguished (2 of 2)

• The criteria for fire resistance are imprecise.

• Risk/benefit calculation often cannot be done.

• The protected combustible classification provides no safety for the fire fighter.

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Fire Behavior, Fire Fighters, and Buildings

• Concealed Fire

• Bursts out of a hidden void

• As dangerous as a building collapse

• Difficult to simulate in training exercises

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Rapid Development of a Fire

• Flashovers

• Backdrafts

• Flameovers

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Preventing Fatalities

• Ventilation is essential in limiting risks to fire fighters operating inside the building.

• Ventilation can cause backdrafts, flashovers, or flameovers.

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After a Fire

• Research abnormal situations

• Investigate unusual heat, smoke, or burning

• Revamp fire command and attack procedures

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Fire Growth

• Influenced by building construction

• Influenced by the materials lining the walls and ceilings of the space

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Flame Spread

• Also known as fire growth

• Still a problem for fire prevention staffs

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Examples of Fire Growth

• Cocoanut Grove nightclub fire in Boston

• Soldier’s hostel in Newfoundland

• Mercy Hospital in Iowa

• Dorothy Mae Apartments

• Elliott Chambers Boarding House

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Combustible Tile Ceilings

• Suspended from ceiling

• Creates a void in which explosive carbon monoxide gas can be generated and stored

• Creates a violent explosion

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Examples of Fires Involving Combustible Tile Ceilings

• Silver Spring, Maryland, in 1977

• Orlando, Florida

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Building or Content Hazard? (1 of 2)

• Building Problem

• Hidden

• Exposed

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Building or Content Hazard? (2 of 2)

• Contents Problem

• Furnishings

• Interior finish, including decorations

• Mercantile stock

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Hidden Building Elements

• Batt Insulation

• Is fiberglass or rock-wool insulation with various thicknesses

• Laid in ceilings and must be kept free of light fixtures

• The paper vapor seal gives a phenomenal flame spread.

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Other Hidden Building Elements and Examples (1 of 3)

• A supermarket with a combustible ceiling

• An electrical fire that ignited the vapor seal of the insulation

• A torch set fire to the paper vapor seal on the insulation

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• Combustible fiberboard

• Foamed-plastic insulation

• Old air-duct insulation

• Electrical insulation

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• Tennessee Valley Authority’s Browns Ferry Nuclear Power reactor fire

• Telephone company building, New York City, 1975

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Interior Finish

• Plaster

• Matchboarding

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Modern Interior Finishes

• Increase fire extension by surface flame spread

• Generate smoke and toxic gases

• Add fuel to the fire

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Low-Density Fiberboard

• Bagasse

• Often erroneously ignited by a plumber’s torch

• Fire often goes undetected until it erupts violently.

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Combustible Acoustical Tile

• Fiberboard punched with holes

• Used to cover deteriorated plaster ceilings

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Industry Opposition

• St. Anthony’s Hospital fire

• April 1949

• 74 deaths in the fire, mostly infants

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Void Spaces

• Formed by suspended ceilings of combustible tile

• Fire can burn undetected until it bursts out furiously.

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Remodeled Ceiling Hazards

• Code requires that a new ceiling meet flame spread requirements.

• Code does not require the removal of the old ceiling.

• Fire can build and burst out from between the old and new ceilings.

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Adhesive

• Corridor ceilings made of combustible acoustical tile glued to gypsum board

• The MGM Grand Hotel fire in 1980 was linked to the 12 tons of adhesive used to attach tiles to the ceiling.

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High Density Fiberboard• Rocky Flats Nuclear Weapons Plant

• Very dense fiberboard was selected for radiation shielding.

• Tested via the blow torch test, which is considered inadequate

• Long continued heat from spontaneously ignited plutonium ignited the fiberboard.

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Paper• U.S. Atomic Energy Commission

• Project had a temporary snow roof of hemp-reinforced bituminous impregnated paper.

• This paper has a very high flame spread rating.

• A stove could have ignited the materials, but was removed.

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Fabrics

• Flames spread rapidly on gasoline- and paraffin-impregnated canvas.

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Cork and Rattan

• Cork on the ceiling as decoration

• Cork paneling

• Rattan ceilings

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Wood

• Very popular and common

• The unexposed side of plywood can burn unobserved and protected from fire department streams.

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Plastics

• Rigid-foamed polyurethane

• Used for interior finish in many houses

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Plastics Related Fires

• 1971 fire in a French nightclub

• Fire in a disco in Dublin, Ireland

• Expo ’67 in Montreal, Canada

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Aircraft Interiors

• Aircraft fires are exacerbated by plastic seats and other interior fittings.

• August 1990; FAA standards increased for fire and heat resistance.

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Acoustical Treatment

• Flame spread consequences of materials used are not always known.

• Station nightclub in West Warwick, Rhode Island

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Open-Plan Offices

• Where do the corridors begin and end?

• Corridors should have rated walls and doors.

• “If there is no wall there is no room.”

• It is all a corridor.

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Carpeting

• Now used on walls and ceilings

• 1980 fire in the Las Vegas Hilton Hotel

• Carpeting on daycare center walls is dangerous.

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Alterations

• Be aware of building alterations with interior finish materials that would not have been permitted during construction.

• Combustible paneling

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Decorations and Contents

• Christmas trees were common fire hazards.

• Decorations and furniture are difficult to control from a fire prevention perspective.

• Halloween haunted houses are a concern.

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Fires from Decorations

• Six Flags Haunted Castle in New Jersey

• Girls’ dormitory in Rhode Island

• A water treatment plant under construction

• Smithsonian Institution National Museum of Science and Technology

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Today’s Fire Loads

• Both fire loads and rates of heat release are increasing.

• Solid and foamed plastics replacing wood, cotton, wool, and other materials have often unrecognized hazards.

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First Interstate Bank Fire

• Floor had open spaces crammed with computers and related equipment.

• Rapid fire spread

• Fire Research Division of the National Institute of Standards and Technology (NIST) report discusses this fire.

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Hotel Remodeling

• Mattresses and furniture are removed from rooms and stored in hallways.

• Targets for arson

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Regulations

• Little on national level, but some state and municipal involvement

• State of California

• City of Boston

• Port Authority of New York and New Jersey

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Certification of Interior Designers

• New York State requires two examinations

• One on interior design itself

• The other on building codes and fire safety

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Residential Fire Tests

• National Bureau of Standards (NBS)

• Conducted fire tests on the contents of typical residential basement recreation rooms

• Study the full report.

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Available Films

• National Fire Protection Association (NFPA) produced movies

• Fire: Countdown to Disaster

• Fire Power

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Difficulties

• Materials used in building interiors can be confusing.

• Specific information is required to make an accurate assessment.

• Don’t make assumptions.

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Control of Rapid Fire Growth (1 of 4)

• Eliminate high flame-spread surfaces.

• Foreign ships may contain combustible trim and veneer.

• U.S. merchant ships severely limit the combustibility of construction materials and surface finishes.

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• Cut off extensions

• Some codes require a metal door sill separating more flammable materials.

• Effective only if the door is closed

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• Coat the material

• Fire-retardant surface coatings are effective only if applied as specified and not too thinly.

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• Wooden materials can also be formulated to be flame resistant.

• One manufacturer has produced structural glass-fiber-reinforced plastics.

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Testing and Rating Materials

• First attempts at testing

• Failed due to inexact, legally unenforceable language

• Developing adequate tests

• Tests must be consistent

• Tests also should be reproducible

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NFPA 255• Commonly referred to as the Steiner

Tunnel Test

• Sample 25 feet long and 2 feet wide forms the top of a tunnel or long box.

• A gas fire is lighted at one end; fire progresses along the underside.

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NFPA 255 Test Results

• Class A: 0–25

• Class B: 26–75

• Class C: 76–200

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Building Codes

• Most rely on the tunnel test standard

• Class A flame-spread rating for corridors and exit ways

• Less restrictive requirements for offices

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Running the Tunnel Test

• “Smoke developed” is measured and indexed.

• Calculated by measuring the obscuration as the smoke passes a photoelectric cell

• Materials with ratings of 300 or more generate substantial amounts of smoke.

• This testing standard is widely accepted.

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Fire Rated

• Term often causes confusion in the building trades.

• Term is without a specific meaning.

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The Radiant Panel Test

• NBS developed the American Society of Testing and Materials (ASTM) E162, Radiant Panel Flame Spread Test.

• Samples measure only 6 by 18 inches.

• Is more fully described in the NFPA Fire Protection Handbook

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Factory Mutual Corner Test

• Corner test • Simulates an actual

fire within the corner of a building

• Walls are up to 25 feet high.

• The exposure fire is a pile of pallets.

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Carpet Tests

• Floor covering is contributing factor in a number of serious fires.

• Current standards require the passing of the screening test.

• Seven out of eight samples must pass the test.

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Test for Spreading Flames

• NFPA 253: Standard Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source

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Radiant Flux Test

• Radiant Flux Test (NFPA 253) measures resistance to flame spread.

• Test gives the critical radiant flux (CRF) of the sample.

• The higher the CRF number, the less flammable the carpeting

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Classes of Interior Floor Finish Ratings

• Class I: ≥ CRF minimum of 0.45 watt/sq cm

• Class II: ≥ CRF minimum of 0.22 watt/sq cm

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Don’t Be Mousetrapped

• Be wary of conducting your own tests.

• Leave testing to the experts.

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Research

• Present efforts to improve building codes

• Continued challenges

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Fire and Smoke Containment

• Products of Combustion

• Distinctions must be made among smoke, particles, and fire gases.

• Smoke and toxic gases are more significant as fire killers than is thermal exposure.

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Smoke

• First warning of most fires

• Does considerable damage

• May reduces visibility to zero

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Gases

• Can cause injury or death

• Carbon monoxide (CO) can paralyze or slow human ability to function or escape.

• Hydrogen Cyanide (HCN) is as great a danger as CO.

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Toxic Effect of Gas

• A product of concentration and exposure time

• Habel’s Rule

• CO is the most common toxic fire gas.

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Other Fire Gases

• Nitric acid and hydrochloric acid

• Polyvinyl chloride (PVC)

• Nitrocellulose base film in commercial motion pictures and x-rays

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Flammability

• Gases can accumulate in any enclosed area.

• Overpressures occur when gases ignite.

• Gas ignites when sufficient oxygen is available.

• CO detonation can blow buildings apart.

• CO is flammable.

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Smoke vs. Gases

• Have different physical effects on people.

• Old-style filter masks let odorless CO through.

• CO can stratify above a fire, creating death clouds.

• Smoke particles can plug up screens.

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Smoke Damage

• Water damage is often considered the most expensive byproduct of fire suppression.

• Smoke damage may be the most expensive byproduct of a fire.

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Contaminated Smoke

• Cost of cleanup can be astronomical.

• Radioactive material can damage living tissue.

• Polychlorinated biphenyls (PCBs)

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Corrosion

• Equipment, brickwork, and concrete can be damaged by corrosive products of combustion.

• Plastics can form corrosive acids when combined with hydrogen and oxygen.

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Gravity

• Pulls down on surrounding heavier, colder air, causing lighter, heated air to rise upward

• Gravity vents

• Mechanical vents

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Containment of Fire (1 of 4)

• Compartmentation

• Creating fire areas no larger than one floor

• All connections between floors designed to stop the spread of fires.

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• Sprinklers above stairway openings

• Required by some fire departments

• No proof that this will prevent the extension of fire

• Will not stop smoke and gases

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• Self-closing doors

• Considered a nuisance

• Stairway doors are often blocked open with wooden wedges.

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• Enclosing stairways

• Open grand staircase was a crowning architectural feature.

• After 1940s, an effort was made to enclose open stairways.

• Stairway is a transmitter of smoke and heat.

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Fire Door Closure Devices

• Self-closing

• Automatic

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Inspections of Closure Devices

• Should include

• Operating fire doors and shutters

• Counterweights

• Doors

• Hardware

• Fusible links

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Problems with Closure Devices

• Closure devices may be completely inadequate to control smoke movement.

• Many people block open self-closing doors.

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Smoke-Sensitive Releases

• Door latch system can be triggered automatically.

• Heavy doors are held by mechanical latches.

• Doors can be controlled individually.

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Horizontal Exits and Smoke Barriers

• Horizontal exits reduce travel distances and subdivide floors.

• Smoke barriers give occupants a smoke-free area

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Escalators

• Strong resistance to enclosing escalators

• Water spray nozzles can be directed downward through the opening.

• A line of sprinklers can be located around the escalators.

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Public Education

• Misinformation from movies and TV• Backdraft

• Defending Your Life

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Smoke Detectors

• Detectors are often missing or out of service.

• Two types: ionization and photoelectric

• Fire protection and fire detection are not synonymous.

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Unwarranted Alarms

• Alarms transmitted erroneously

• Some cities have instituted penalties for repeated, unwarranted alarms.

• Can be a disincentive for reporting a fire

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Ventilation (1 of 2)

• Compartmentation

• Can cut off a fire

• Can create unventilated compartments

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Ventilation (2 of 2)

• Makes building habitable for occupants and fire fighters

• New Law Tenement House Act

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Fire

• Book published in 1903 included

• A design for automatic vents tripped by fusible links

• Exception to “Don’t vent till you have water.”

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Theaters

• Designed so that a fire could occur and the occupants would be protected from the combustion products.

• Automatic vents above the stage reduce the pressure on the proscenium fire curtain.

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Holland Tunnel

• Designed to reduce the maximum amount of CO that could be generated by auto exhausts to an acceptable level

• Airflow required would be 50 mph.

• Triple tunnel arrangement

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Eurotunnel “Chunnel”

• A service tunnel between the two train tunnels is kept at a higher pressure than the train tunnels to exclude smoke.

• Access is provided through “smokeproof” doors.

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Fire Department Ventilation

• Consisted of opening and breaking windows and cutting holes in the roof

• Smoke ejectors were developed to increase the volume of airflow.

• Fans were used to exhaust smoke, generally during overhaul.

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Fire Protection Systems

• Automatic sprinkler systems

• Standpipe systems

• Fire Alarm detection and communication systems

• Smoke management systems

• Other fire protection systems

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Automatic Sprinkler Systems

• Sprinklers were once almost exclusively installed in factory and mercantile buildings.

• Now, sprinkler designs have been developed specifically for multiple dwellings and single-family homes.

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Types of Sprinkler Systems

• Wet pipe

• Dry pipe

• Preaction

• Deluge

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Design and Operation of Sprinkler Systems

• Hydraulically designed

• Only a certain number of heads operating

• Each head flows a specific amount of water

• Prewetting

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Density and Demand

• Density is the unit rate of water application to an area or surface; expressed in gallons per minute per square foot (gpm/ft2)[(L/min)/m2].

• Demand area is the gpm/ft2 required within a sprinkler system.

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Sprinkler Installation Incentives (1 of 3)

• Typical code incentives• Heights and areas

• Construction of corridors and tenant separations

• Interior finishes

• Travel distances to exits and exit widths

• Standpipe requirements

• Fire detection systems and draftstopping in attic spaces

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• Site development incentives• Fewer fire hydrants with greater spacing

• Reduced fire flow, small supply pipe

• Increased allowable distance from public access way

• Street width reduction

• Cul-de-sac allowances

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• Tax or insurance incentives• Elimination of value of sprinkler system from

assessed valuation

• Property tax rebates

• Elimination of water department fees

• Insurance premium reductions

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Opposition to Sprinklers

• Not everyone supports automatic sprinklers.

• Some claim that sprinklers are ugly.

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Popular Misconceptions About Sprinkler Systems (1 of 2)

• The sprinkler system will discharge on even a trifling fire.

• The entire building will be drowned when the sprinklers go off.

• The pulling of a manual fire alarm box will set off all the sprinklers.

• The pipes might leak.

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Popular Misconceptions About Sprinkler Systems (2 of 2)

• Smoke is the big killer so smoke detectors are better than sprinklers.

• We have smoke detectors and the fire department is right down the block.

• Sprinklers cause damage to libraries.

• Smoke detectors set off all the sprinklers.

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Fire Activities to Correct Erroneous Opinions

• Sprinkler demonstrations

• Sprinklers and flammable liquids

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Fire Service Misconceptions (1 of 2)

• Building is sprinklered; there is no problem.

• Supplying the fire department connection (FDC) is a secondary operation.

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Fire Service Misconceptions (2 of 2)

• Sprinklers should be shut down as soon as possible to prevent excessive water damage or to clear the air.

• Residential sprinklers are the same as other sprinkler systems.

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The Fire Department and Sprinklers

• Fire chiefs support automatic sprinklers.

• Sprinkler protection often is traded off for concessions.

• Fire department should take action when notified of a sprinkler shutoff or other disabling functions.

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Non-Working Sprinklers

• What should happen when the fire department learns that a sprinkler system is out of service?

• Fire department should have no hesitation in shutting a building until sprinklers are fixed.

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Why Were Sprinklers Installed?

• Determine reasons for installation.

• What might happen if system not working?

• Don’t hesitate to close building until system problems are corrected.

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Fire Department Policy

• Fire department notification

• Formal legal action

• Informal action

• Authority to modify requirements

• Formal personnel instruction

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Fire Department Instruction

• Should provide an understanding of why sprinklers were installed

• Should cover fire department policy

• Should provide knowledge of situations that decrease efficiency of sprinklers

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Company-Level Inspections

• Water supply or water distribution problems

• Some systems depend solely on the city water main pressure to provide adequate sprinkler flow.

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Sprinkler Fraud

• A sprinkler contractor in California was discovered to have installed unconnected sprinklers that were simply glued to the ceiling.

• Inspection of sprinkler systems should look beyond the obvious.

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Management

• Management is managing the fire department, rather than managing the fire problem.

• Have sprinkler system protocols in your standard operating procedures (SOPs).

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Special Situations• Most flammable liquids float on water. • Flammable liquids have a high Btu (British

thermal unit) content.• Flammable liquid containers can result in a

BLEVE (boiling liquid expanding vapor explosion).

• Runoff water may create a significant contamination problem.

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Protection of Glass Fire Barriers

• Wetting must occur early to avoid thermal shock to hot glass.

• Window treatments should not be installed between the glass and the sprinklers.

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Early Suppression Fast Response (ESFR) Sprinklers

• Early discharge of a larger quantity of water

• Sprinkler orifice is 0.75 inches; conventional sprinklers are 0.5 inches.

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Standpipe Systems

• Fixed networks of piping and hose valves

• Installed in tall and/or large buildings to provide quick fire attack

• Classes are I through III.

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Standpipe Operations

• Class I through III used throughout 1980s.

• One Meridian Plaza fire

• Need for thorough preplanning

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Standpipes Water Supply Classifications

• Automatic-wet standpipe system

• Semiautomatic-dry standpipe system

• Manual-dry standpipe system

• Manual-wet standpipe system

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NFPA 72: National Fire Alarm Code Initiating Devices (1 of 2)

• Manual pull stations

• Spot type smoke detectors

• Line type smoke detectors

• Duct smoke detectors

• Spot type heat detectors

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NFPA 72: National Fire Alarm Code Initiating Devices (2 of 2)

• Line type heat detectors

• Gas detectors

• Flame detectors

• Water flow switches and water pressure switches

• Supervisory switches

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Indicating Devices

• Strobes, horns, chimes, buzzers, and sirens

• Speakers and lamps

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Panels

• No design standards

• Small red and yellow lights may give you information.

• Devices often are grouped by zones.

• Fire alarm systems that are positioned with fire fighter communication systems are not very useful.

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Preplanning Considerations

• Area(s) protected by the system

• Types of detection and other initiating devices

• Location of alarm panel and any remote annunciators

• Type of panel and type of zoning

• Silence switch

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Smoke Management Systems

• Smoke control

• Purge

• Zoned smoke control

• Air flow

• Original design and testing criteria

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Design Requirements and Guidelines

• International Building Code

• NFPA 92A

• NFPA 92B

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Control Panel

• Most use toggle switches to turn on/off various parts of the system

• Beware of a wrong flip of a switch.

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Preplanning Knowledge• System and the type of smoke

management

• Location and extent of system

• System design criteria

• A step-by-step sequence of system operation

• Location and description of control panel

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Firefighting Considerations

• Assess the system operation.

• When activating a system manually, let all fire fighters know so they will not be endangered.

• Leave a fire fighter with a radio at the system controls.

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Other Fire Protection Systems

• Dry chemical and foam

• Carbon dioxide and clean agent

• Halon

• Water mist or water spray

• Total flooding or local

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Summary (1 of 3)

• Fire containment is a primary objective of fire fighters.

• Terms describing combustibility and flammability are not always used accurately or in a technically accurate way.

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Summary (2 of 3)

• Collapsing buildings are a hazard to fire fighters, but concealed fires and rapid fire spread are also very hazardous.

• Fire growth and spread are influenced by building construction.

• Fire loads and rates of heat release are higher today.

Summary (3 of 3)

• Compartmentation creates fire areas no larger than one floor.

• Venting makes the conditions inside a fire building somewhat habitable.

• Fire suppression and detection systems are critical to fire protection.

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Ch 05 Features of Fire Protection