5 Fire Behavior And Building Construction Flashcards
Exposed interior surfaces of buildings including but not limited to fix your movable walls and partitions columns and ceilings commonly refers to finish on walls and ceilings but not floor coverings
Interior finishes
Building code usually exclude surface treatment such as paint and wallpaper no thicker than
1/28 “
Degree to which fire can spread over the surface of a material is technically referred to as the
Surface burning characteristics of the material
Speed of flame spread over interior finishes influenced by factors such as
Composition of material
Ventilation
The shape and space in which the material is installed
Whether the finish material is applied to ceiling or wall
Within product, quarter inch or less, will propagate flame faster one attached to studs with airspace behind it then when attached directly to more solid material such as gypsum. Building codes therefore require
Those materials with faster burning rights to be installed over noncombustible surface
Three classes of interior finishes
A, B, C
Class a material interior finish
0 through 25 flame spread rating are required in vertical exits of most occupancies
Interior finish class B material
26-75 flame spread rating required and hallways that provide exit access
Class C interior finish material
76-200 flame spread rate
Class a B or C interior finish materials may be required in other rooms and spaces depending on occupancy rooms of healthcare in assemblies for example will require
Either class a or B interior finish
HHR heat release rate
Total amount of heat produced or released to the atmosphere from the convective lift fire phase of a fire per unit mass of fuel consumed per unit time
A greater heat release rate results in faster developing fire. The faster the available fuel burns the
Greater the heat released rate will be
Flame spread rating
Numerical rating assigned to a material based on the speed and extent to which a flame travels over its surface
Steiner. Tunnel test
Unofficial name for the test used to determine the flames spread ratings of various materials
Assembly
All components or manufactured parts necessary for and fitted together to form a complete machine structure or system
Most commonly used method for evaluating surface burning characteristics
Steiner tunnel test
Interior finishes are tested to derive several measures of a materials flammability:
Flame spread rating and smoke developed rating
Steiner tunnel test is also identified as
ASTM standard E84, UL 753, NFPA 225, standard method of test of surface burning characteristics of building material
Flame spread rate of gypsum wallboard
10-15
Flame spread rate of treated Douglas fir plywood
15-60
Flame spread rating of mineral acoustical tile
15-25
Walnut faced plywood flame spread rating
171-260
Flame spread rating veneered woods
Approximately 515
To derive the numerical flame spread rating what is used as a baseline
Asbestos cement board and red Oak flooring
True/false Flame spread rating test is a means of comparing service flammability to standard materials under control test. It is not an absolute measure for fire spread
True
The tunnel test is not apply to which type of coverings
Floor coverings
Toxicity
Ability of a substance to do harm within the body
Volatility
Ability of a substance to vaporize easily at a relatively low temperature
What test is used to determine smoke developed rating
Tunnel test
A measure of the relative visual obscurity, determined by photo electric light cell, created by smoke from tested material
Smoke developed rating
Codes limit maximum smoke developed to
450
Smoke developed rating is not an indication of
Toxicity or volatility of the products of combustion for interior finish materials
for smoke developed The tunnel test is not detect or measure
Completely transparent product of combustion such as carbon monoxide
Fire retardant
Any substance except plain water, that is applied to another material or substance to reduce flammability or slow their rate of combustion by chemical or physical action
Several types of fire retardant coatings
Mastics, gas forming paints, cementitious and mineral fiber coatings, intumescent paint
Intumescent paint reacts how when exposed to heat
Creates a thick puffy coating that insulates would service from heat and excludes oxygen from wood
Mastic coating forms a
Thick noncombustible coding over surface of wood
Fire retardant coatings only affect the coated surface. They do not affect
The untreated backside of a panel
Immaterial listed as fire retardant coding does not increase fire resistance of
Structural components or assemblies unless it has also been tested and listed for that use
Some materials are more hazardous when in a real room than a tunnel test because
Flame spread is different over vertical surface that horizontal, walls and ceiling provide radiation of heat
Test procedures that incorporate the size and shape of real rooms collectively known as
Corner test
Active fire protection
Use of equipment such as automatic sprinkler system or fire alarms, and require power source for operation power source may be manual such as portable fire extinguishers
Passive fire protection
Relies on building construction and materials to contain fire or products of combustion, such as fire walls or stair enclosures
Compartmentation systems
Series of barriers designed to keep flames smoke and heat from spreading from one room to another. May be doors extra walls or partitions, fire stopping materials inside walls
Rated assembly
Assemblies of building components such as doors walls roofs and other structural features, because of occupancy, required by code to have minimum fire resistance rating
Compartmentation
Subdivision of building or floor levels by fire rated walls or partitions
Codes are required and some occupancies such as hospitals, so that people can be moved from fire area to protected part of the floor, or area of refuge this is known as
Defending in place, or sheltering in place
Firewall
Otherwise known as area separation wall or erected to limit the maximum spread of fire
Fire rated wall with a specific degree of fire resistance, built of fire resistant material and usually extending from the foundation up to and through the roof of a building. Designed to limit the spread of fire within a structure or between adjacent structures
Fire wall
Building codes typically allow elimination of firewalls when a building is
Equipped with automatic sprinkler system if criteria for occupancy height and other code requirements is met
Under severe fire conditions what must be anticipated on either side of a firewall
Structural collapse
Firewalls can be constructed as either
Freestanding walls, or as tide walls
Tied firewall
Firewall corrected in between steel frames or concrete frames such as garters or columns, either as is or continuing and rows of that sequence
Firewalls have ratings of
2-4 hours depending on occupancy
4 hour firewall usually must be constructed of
Masonry or concrete and have a three hour openings
In most buildings firewalls must be constructed of
Noncombustible material, exceptions made for type five buildings
Firewalls must extend beyond walls and roofs to prevent
Radiant heat of flames on either side of wall from igniting adjacent services. Accomplished by extending with parapet
The parapet height above a combustible roof is determined by code and varies from
18-36 inches
The combustibility of interior finishes affects the fire behavior in several ways
It can contribute to fire extension by flames spread over surface
Affects rate of fire growth
Adds to the intensity of a fire by contributing fuel
Can produce smoke and talks a gases adding life hazard
Fire partition
Fire barrier that extends from one floor to the bottom of the floor above or to the underside of the fire rated ceiling assembly. Lower-level protection than a firewall
Fire petitions are interior walls used to subdivided floor or area of building that do not qualify as
Firewalls
Fire partitions may not extend
Continuously through a building
Fire partitions can be constructed of different types of materials depending on required fire resistance. Five eights inch gypsum applied to both sides of 2 1/2 inch steel studs with yield what fire resistance
One hour
Wood stud partitions cannot be used for loadbearing partitions in fire resistant buildings because
Structural components in fire resistant the buildings need to be fire resistive
Enclosure walls are used to
Enclose such vertical openings as stairwells, elevator shafts, pipe chases, extending from floor to floor in a building
The purpose of enclosure walls is
To block the vertical spread of fire through a building and protect the egress in a stairway
Enclosure walls are required to have fire rating. Stairwells in a building three story or less are required to have how many hrs.
1 hour enclosure, 2 hour enclosures for buildings taller than three stories
Glazing
Glass or Thermo plastic panel and a window that allows light to pass
Light shafts are designed to let in natural light, however they can cause
Spread of fire from window to window vertically or horizontally
Curtainwall
Non load bearing exterior wall attached to the outside of the building with a rigid steel frame. Usually the front exterior wall of the building intended to provide a certain appearance. Only intended to separate inside from out
Curtain walls are not limited to steel frames they are also frequently used in buildings with
Concrete frames
Curtain walls that are made of aluminum and glass have what type of fire resistance
None
Noncombustible curtainwalls are allowed to have no fire resistance if they are
Spaced far enough from other buildings or face and open area such as a street
Curtain walls that are not fire resistive frequently extend from
The floor of one level to the ceiling
Fire door
Fire rated door designed to prevent the fire spread by automatically closing in covering a doorway in a firewall
Fire doors are rated for how many hours
Four, three, 1 1/2, one, three quarter, one half, 20 minutes
letter designations for fire doors
A, B, C, D, E
Class a fire door
Openings in firewalls
Class B fire door
Opening in vertical shafts and opening in 2 hour rated partitions
Class C fire door
Openings between rooms and hallways having a fire resistance of one hour or less
Class D fire door
Opening in Exterior wall subject to severe fire exposure from outside of a building
Class E fire door
Opening an extra wall subject to moderate or light exposure from outside
Half hour and 20 minute fire doors are primarily used in
Smoke barriers and openings to hallways
In firewalls of greater than two hour rating, code typically requires what rating fire door
Three or four hour
For two hour fire rated vertical enclosures what rating of fire door is required
1.5 hr
For one hour fire rated vertical shaft enclosures and exit enclosures what rated fire door is used
One hour
Hardware used on fire doors is referred to as either
Builders hardware, or fire door hardware
Builders hardware is applied to swing doors and consists of
Typical door hardware design for fire rating
Fire door hardware is used on sliding and swinging fire doors and is provided
With the door usually installed on it shipped with the door
Doors with what fire rating can be equipped with glass panels
Up to three hours
Fire doors with the rating of one, 1 1/2, and three hours can have glass panels up to what size
100 in.²
Fire doors with ratings of three quarter hour can have a tall glass area consistent with the rating for an individual piece cannot exceed
1296 in.²
Fire doors with rating of half or one third hour can have fire rated glass up to a maximum area of
What they were tested at
Automatic fire door
Normally held open, closes automatically under fire conditions when an alarm is activated
Self-closing fire door
Normally closed and will return to the closed position if it is opened and released
Fire door closer
Spring hinges for sprung device mounted at the top of the door and the frame that closes the door on its own when released
Fire door holder
Hold the door open until fire alarm releases the mechanism allowing the door to close. Example electromagnetic door holder
Fire door operator
Intended for use with slighting fire door mounted on either a level or inclined to track. Electronic operator opens and closes the door for normal use. Under fire conditions,fusible link disconnects door from operator and closes with spring or weight
Disadvantage to fusible link for closing a fire door
Although cheap, slower to operate and I can allow smoke through the door
Rolling steel fire door
Maybe located on one or both sides of the wall, intended for industrial occupancy or separating buildings. Usually closes with gravity after fusible link melts, or motor driven
Horizontal sliding fire door
Found an older industrial buildings. Usually held open it and slide into position along traffic either by gravity or counterweight
Sliding fire doors are typically would core she did in metal because
Would provides thermal insulation, sheet metal protects wood from fire. Vent holes required to allow vapor from wood offgassing to vent
Smooth galvanized sheet metal on the wood core door is known as
Kalamein doors
Fire doors made with galvanize steel, or terneplate (tin and lead) are known as
Tin clad doors
Swinging fire door
Typically for use with stairwell enclosures and hallways. Disadvantage, requires clear space to allow door to close. Advantage, good for pedestrian traffic
Special fire doors
For freight and passenger elevator, Service counter openings, security, dumbwaiters, chute openings
Horizontal folding fire door
Motor driven requires electrical power and signal from smoke detector or fire alarm. Battery operated for reserve power. Frequently used for open floorplans for firewall is not constructed like a lobby
Common reasons for fire door closure failure
Closing mechanism is damaged during fire closer door or guides damaged. Obstructed doors, intentionally held open
