Bc.. Flashcards
Permits the designer to cast the concrete in a wide variety of shapes
Cast in place concrete
Concretes ultimate compressive strength can be varied from
2500 to 6000 PSI
Most cast in place concrete is proportioned at ——and then mixed in a——
Central bulk plants
mixing truck
If the concrete is vibrated excessively as it is placed in the forms———— results
Segregation of the aggregate
The——— of concrete is significant to firefighters
Quality
Concrete that is of poor structural quality will behave poorly under fire conditions by
Spalling and even breaking apart
The single most important factor in determining the ultimate strength of concrete is
The water to CEMENT ratio
Concrete: if too much water has been used in the mix the final product will
Not achieve its desired strength
The presence of excess moisture in the concrete produces spralling in the concrete due to
Freezing conditions or the heat of a fire
When concrete arrives at the job site it’s quality is checked by administering a test known as
Slump test
Concrete with excessive slump will
Fail the test and may be rejected by the structural engineer
Another method of testing concrete is to make small test cylinders of a concrete batch and subject them to
Compression testing
Concrete framing systems: to provide for the transfer of loads and forces from one placement to the next the reinforcement steel will
Overlap the joints
Common cast in Place structural systems
Flat slab
slab and beam
waffle construction
Flat slab concrete frame is a simple system that consist of
Concrete slab supported by concrete columns
Flat slab concrete frames: in a building that will have heavy live loads the area around the column is reinforced with additional concrete in the form of
Drop panels or mushroom capitals
Flat slab concrete frames: the slab of concrete varies in thickness from
6-12 inches
Flat slab concrete frames: if the building will support light loads additional reinforcing is not necessary. this system is known as
Flat plate
A slab and beam frame consists of a concrete slab supported by
Concrete beams
Slab and beam framing: the framing system is———-and is best suited for———–
Extremely lightweight
buildings with light floor loads
Slab and beam framing: slabs in this type of construction can sometimes be ———- inches
As thin as 2
Slab and beam framing- sometimes referred to as
Concrete joist construction
Slab and beam framing: When the concrete beams run mainly in one direction the framing is known as
One way reinforced slab
Slab and beam concrete framing can also feature concrete beams running in 2 directions. such a system is known as
Two-way slab construction
Slab and being framing: the two-way framing system is used where
spans are short and the floor loading’s are high
Buildings using———- systems are often highly susceptible to fire damage due to their thin nature
Slab and beam
Waffle construction this design provides a thicker slab while eliminating the
Weight of unnecessary concrete in the bottom half of the slab
Waffle construction: reinforcing steel placed in the bottom of formwork provides reinforcement in 2 directions. slabs of this type therefore are also known as
Two-way slabs
Some precast components such as ———–are cast at the site and moved into position
Tilt up panels
Advantages to using precast concrete
- Higher degree of quality control
- work can proceed more quickly
- precast concrete sandwich panels can be produced using poly styrene core
A major disadvantage to using precast concrete is the need to
Transport the finished components to the job site. transportation increases costs and limits the size of the SHAPES that can be precast
Precast concrete buildings can be built using whole precast modular units but it is more common to
Assemble precast parts into a framework for a building
From a construction standpoint precast concrete structures have more in common with ———-than———
Steel framed buildings
cast in place concrete buildings
Type of construction in which concrete wall sections (slabs) are cast on the concrete floor of the building and are then tilted up into the vertical position
Aka
Tilt up construction
tilt slab construction
Precast concrete slabs for floor systems can be cast in standard shapes that include
Solid slab
hollow core slab
single tee slab
double tee slab
Solid slabs are used for SHORT spans up to ———while the tee slabs can be used for stabs up to——–
Approximately 30 feet
120 feet
A common form of construction used with precast concrete is known as
Tilt up construction
In tilt up construction————- are cast at the job site in————–
Reinforced wall panels
horizontal casting beds
Tilt up: integrity of the roof is critical under fire conditions. failure of a roof can result in ——————–resulting in collapse
Outward horizontal forces against the wall
Precast structural elements are usually——- than corresponding cast in place components
Lighter
In a precast concrete structure the ———— are a critical aspect of structural engineering
Connections between the individual components
In the simplest of precast designs
Slabs need to be
Precast slabs simply rest on a bearing wall or column
Laterally tied together to resist horizontal forces
When precast beams are to be supported by columns the beams may be supported by
Corbels cast into the column
——–Is a ledge that projects from the column and supports the beam
Corbel also known as a bracket
A very common application of precast concrete is in the construction of
Parking garages
Buildings supported by concrete frame are usually enclosed by
A non-bearing curtainwall
A————–tends to conceal the structural details of a building and makes it difficult to accurately identify the structural system by observation alone
Curtain wall
It is difficult to know with certainty if a concrete frame building was constructed with
Ordinary reinforcing
or
posttensioned reinforcing
Some building systems such as————and——— may appear to be concrete when they are not
Stucco
exterior insulation finish systems (EIFS)
Non-bearing exterior wall attached to the outside of a building with a rigid steel frame. usually the front exterior wall of a building intended to provide a certain appearance
Curtain wall
———That are not properly protected can be a major contributors to the vertical spread of smoke and fire in a building
Pipe Chase also called Chase
Concrete is a fundamentally——– material that performs well under fire conditions. it is noncombustible and has good——– properties
Fire resistive
Insulating
Concrete structural elements usually retain their ——-and concrete slabs and walls act as——-
Integrity
good fire barriers
The greater the ———-over the reinforcing steel the greater it will protect the steel
Depth of concrete
Prestressed concrete systems may be somewhat ————-than ordinary reinforced concrete
More vulnerable to failure
Prestressed concrete systems may be somewhat more vulnerable to failure than ordinary reinforced concrete. this increased vulnerability is due to the fact that
The reinforcing cables and rods used in prestressed systems are made of high-strength steels that have lower your point temperatures. They can yield at a temperature of around 752°F.
Concrete structural systems can have fire resistance ratings from
1 to 4 hours
The fire resistance of a concrete assembly is affected by
- Density
- thickness
- quality
- load supported by the concrete
- depth of concrete cover over reinforcing bars
Structural lightweight concrete has a lower density than ordinary concrete and has a lower
Thermal conductivity.
better insulator
Not use for loadbearing members
Cast in place concrete buildings have an advantage over precast buildings because the——– provides an inherent restraint to movement of the intersecting members such as columns and beams.
Continuity of the assembly
Very common design used for one story Mercantile and industrial buildings
Precast wall panels that are horizontally braced by exposed steel roof beams
When openings exist in concrete slabs or walls the ability of the concrete to act as a barrier is lost unless the opening is protected by a appropriately rated assembly such as
Fire door or shutter
Just as with other types of construction concrete buildings are not designed to withstand the force of
An explosion
Spalling of concrete is caused primarily by
The expansion of the excess moisture within the concrete when it is either heated or when it FREEZES
Spalling: the expansion causes sections of the concrete surface to violently disintegrate resulting in———–or——— of the material surface
Explosive pitting
chipping destruction
As a general observation, concrete that is of——— will perform poorly when exposed to a fire
Poor quality structurally
The extent to which concrete undergoes spalling depends on ————and———–
The amount of excess moisture in the concrete
the length of time that has passed the concrete was placed
New concrete that is not completely cured is subject to ———–when exposed to a fire
More severe Spalling
The severity of Spalling also depends on the ——–and——-of the structures exposure to the fire
Duration and severity
Because concrete has relatively good insulating properties it tends to———– and ———similar to the manner in which a Masonary oven releases heat
This general affect is referred to as
Retain the heat of an exposing fire and release it slowly.
heat sink effect
Generally perform well under fire conditions
Reinforced concrete structures
Reinforced concrete structures fire resistance is affected by
The quality of the concrete
Spalling of concrete will result in failure of the—— and——-
Reinforcing bars and structural assembly
Roofs function as the———— for the interior of the building
Primary sheltering element
The significance of roofs in——-and————has long been recognized
Fire protection
firefighting operations
The combustibility of —————–was one of the first fire hazards addressed in the earliest fire regulations adopted in colonial America
thatched roofs
In modern times fires that communicate from building to building by way of ————-continue to plague some communities
Combustible wood shake shingles
Today more roofs are being used as part of ——-with solar panels and even gardens
Green design
———in particular represent a new element of safety hazard during emergency operations
Solar panels
Firefighters have to work on roofs either to——– or——-
Combat a fire involving a roof
ventilate the products of combustion from within the structure
Sometimes it is desirable to use a roof as a ———-for attacking a fire involving a neighboring structure
Vantage point
Firefighters must be familiar with all aspects of roof construction including
- Materials
- means of support
- architectural styles
and such functional aspects as the use of a roof to support ventilation equipment
Fundamental safety points regarding roofs
- Not as strong as floors
- inherent concealed spaces between the ceiling and roof deck
- over time loads maybe added to the roof
- subject to wear and deterioration from the elements
The fact that a roof is a———— can frustrate efforts to control a fire from above
Waterproof covering for a building
If the roof collapses into a structure it will form a
Waterproof covering over buried fire
From a firefighting standpoint the roofs of buildings can be classified into three styles:
Flat pitched and curved
Flat roofs are found on ALL types of buildings including
Large area warehouses, factories, shopping centers, and schools
It is possible to construct a roof that is completely horizontal but this design presents a
Drainage problem
Many flat roofs are provided with a slight slope typically from
Front to rear to facilitate drainage
Many large buildings have roofs sloped towards drains in the
Center of the roof
Flat roofs: master stream: may overload the roof structure and
Cause it to collapse
———-Are the easiest roofs on which firefighters can work
Flat roofs
——can provide a false sense of security and are not without potential dangers
Flat roofs
Pitched roofs have inclined surfaces. they may be categorized into
Low slope roofs
and
medium to High slope roofs
Bc: Low slope roofs have a slope of
Tactics: on low pitch roofs( —to—-) a power saw may be used to make the cut
3 to 12, meaning for each 12 units of horizontal dimension the roof slopes upward 3 units
15 to 20°
Medium to high slope roofs have slopes of
4/12 to 12/12
A slope of 12/12 equates to
45° angle
Tactics: Balloon frame: the second floor joists rest on a small board (1x4inches) that is notched into the upright 2x4s called a
BC ballon frame: the joists that support the second floor are supported by ————that are recessed into the vertical stud
Ledger board
Ribbon board
If allowed to remain motionless for approximately ———–emit a low-level pre-alarm
go into full alarm approximately ———-after the pre-alarm sounds
30 sec
5-10 sec
Some structures such as certain churches and mansions have roofs with slopes of
18/12 or greater-too steep to work from a roof ladder
Pitched roofs are designed in a number of styles that are determined by
Climate
function
aesthetic considerations
Several commonly encountered pitched roof styles include
Gable hip gambrel mansard butterfly monitor saw tooth
Simplest pitched roof
Shed roof
Very common roof style that consist of two inclined services that meet at their highside to form a RIDGE
Gable roof
Style of pitched roof with squared ends in which the end walls of the building form triangular areas beneath the roof
Gabled roof
Pitched roof that has no gables. all facets of the roof slope down from the peak to an outside wall
Hip roof
Style of gabled roof on which each side slopes at two different angles. often used on barns and similar structures
Gambrel roof
Roof style with characteristics similar to both Gambrel and hip roofs. have slopes of two different angles and all sides slope down to an outside wall
Mansard roof
The v-shaped roof style resembling to opposing shed roofs joined along their lower edges
Butterfly roof
Slopes in four directions and has a degree of slope similar to the gable roof
Hip roof
Slope in two directions but there will be a break in the slope on each side. they are functional because the space created by the roof can be used as an attic or living space
Gambrel roof
Has a break in the slope of the roof on all four sides. can also be constructed with a FLAT DECK in which case is sometimes known as a———
Mansard roof
modern mansard or deck roof
Forms a projection beyond the building wall that creates a concealed space through which a fire can communicate
Mansard style roof
————Is sometimes added to the front of a flat roof building as an architectural detail
False mansard front
Firefighters may be exposed to danger while working under these structures which can collapse in large sections
Roof style that slopes in two directions- basically two shed roofs that meet at their low leaves
Butterfly roof
Room style similar to EXAGGERATED LANTERN ROOF having a raised section along the Ridge line providing additional natural light and ventilation
Monitor roof
Characterized by a series of alternating vertical walls and sloping roofs
Sawtooth roof
This type of roof is most often found on older industrial buildings to provide light and ventilation
Sawtooth roof
Designed to provide light and ventilation. were once very commonly used on factory buildings. Raised central section of the roof extends several feet above the surrounding roof surface
Monitor roof
Monitor roof: the vertical sides of this monitor section which are normally openable windows are known as
Clerestories
Sawtooth roofs: ideally the glass vertical sections should face north because the——– is more constant during the day and ———-can be avoided
Northern light
glare of the sun
A pitched roof is designed to
Shed water and snow
The pitch of a roof presents a major hazard to firefighters because the steepness of the roof results in
A lack of secure footing
The steepness of the roof result in a lack of secure footing, this hazard is increased when the roof is wet or covered with ice but also exist when the roof is dry because of
The loose or granular texture of some roof coverings
Curved roofs take their form from
The structural system used to support them
Curved roofs are most frequently supported by
Arches and bowstring trusses
When the area to be enclosed by the roof is circular a ————can be used
Dome
A dome can be thought of as an
Arch rotated 360°
A dome roof produces structural forces similar to those of an arch. that is ————exist at the base and a ————-exist at the top
Horizontal thrusts
compressive force
More architecturally spectacular curved roofs can be created using
Geodesic domes
lamalla arches
Special form of arched roof constructed of short pieces of wood
Lamella arch
Lamellas vary from
2x8-3x16
8-14 ft
The short Lamellas are bolted together in a diagonal pattern with a special plate known as a
“Lamella washer”
The curvature of the lamella arch results from the———– of the ends of the individual Lamellas
Beveling (inclining)
A geodesic dome is created using
Spheric triangulation
A geodesic dome can be constructed from
Wood steal concrete as well as plywood bamboo aluminum
A dormer is frequently provided in buildings with pitched roofs to————–by———-
Increasing the usable space in the attic by increasing the light and ventilation
Often become living space
Dormers
The traditional wood joisted roof uses solid wood joists that tend to lose their strength gradually as they burn. this loss of strength results in the roof becoming ————especially with a—————-
Soft or spongy before failure
wood to plank roof deck
In general firefighters should view any indication of advanced or heavy fire development as a warning sign that
The roof is weakening
In modern practice——————— are often used to support flat roofs
Box beams and I-beams manufactured from plywood
and
wood trust joists
The ———- of truss joists also permits the rapid spread of fire and directions perpendicular to the truss joists instead of simply going along the long dimension of the member
Open web design
Depending on the ——–unprotected lightweight open web joists can be expected to fail quickly in a fire
Fuel load with an occupancy
Because roofs are designed for lighter live loads than floors are it is not unusual for the MODERN FLAT roof to ————-noticeably as personnel walk across them
Deflect or vibrate
Flat roofs usually must be designed to support the weight of at least
A few workers so they can be accessed safely for maintenance
—————Are an indication of lightweight roof construction and firefighters should view such construction cautiously
The deflexion and vibration
A variation of the flat roof is a type known as the inverted roof. Inverted roofs differ from conventional roofs primarily in the location of
Their main roof beams
The design of the inverted roof creates a ———————–between the ceiling in the roof deck
Concealed space that may be several feet in height
Incline joist used to support some types of PITCHED roofs
Rafter
Rafters are the standard supports used in
Shed gable hip gambrel mansard style roofs
The basic design of a raftered roof results in
An outward thrust against the walls similar to the action of an arch
The outward thrust of the rafters is resisted by———— or——–
Ceiling or attic floor joists
collar beams that are in tention
If the architect desires to leave the underside of the roof exposed without joists————- must be used to support the rafters
A structural ridge beam
Inclined beam that supports a roof, runs parallel to the slope of the roof to which the roof decking is attached
Rafter
Would rafters vary in size from ———.
They can be spaced from———-depending on————-
2 x 4 to 2x14
12 to 24 inches apart
the span and design load
Very common roof support system
Trusses
All of its cords and diagonal members lie in the same plane. this configuration is typical of lightweight trusses
Monoplane truss
Ceilings are often suspended from a roof truss creating concealed spaces between———– and————-
The top and bottom chords
throughout the ceiling to the roof
——-Use a curved top chord. once commonly used for roofs and many remain in use
Bowstring trusses
Bowstring truss with a laminated top chord uses
Split ring connectors at all joints except the heel plates located at the ends of the truss
(Wood and steel trusses) ————–trusses are the most common types used for pitched roofs
Fink and Pratt-style
If a truss is too large to be transported as one unit it can be
Moved in sections and connected in the field
Because arches may be constructed from ————the behavior of the roof supported by an arch is basically determined by ———–
Masonary
laminated wood
steal
the material from which the arch is constructed
Laminated wood arches will behave much like——–
steel truss arches will react to a fire in a manner similar to a——-
Laminated beams
steel truss
There is one characteristic of some arch supported roofs that can cause a catastrophic failure under fire conditions. failure of the ————–will permit the arches to spread outward and the roof will collapse
Tie rods
Some arch roofs use a ———between the two ends of the arc to resist the ———–of the arch
Steel tie rod
outward thrust
The deck of a roof is the portion of roof construction to which the ————–is applied
Roof covering or “roofing”
The components of roof decks include
Sheathing
roof planks or slabs
purlins
Sometimes as in———- the roof deck serves as the roof support
Concrete deck roofs
————–Is frequently used in applications where is serves as both the deck and the exterior roof covering
Corrugated steel decking
A roof deck must be stiff enough that it does not———— under anticipated loads
Deflect excessively
From a construction standpoint the deck material should be ————-so that any insulation or roof covering can be attached
Clean and smooth
WOOD PANEL DECKING may have a thickness of——–inch on supports on ———— inches on center
1/2
24
WOOD PLANKS will have a minimum———–inch nominal thickness
1
Corrugated steel used in roof decking ranges from ———-the thinnest to ———–the thickest. The overall depth ranges from———
29 gauge
12 gauge
3/4”-2”
Corrugated steel decking can be used with a sheet of flat steel welded to the bottom to form——-
Cellar decking
(Roof deck materials)
gypsum has the advantage of being——–
“Nailable”
(Roof deck materials) PRECAST concrete can be made nailable by——–
Choosing appropriate aggregate
(Roof deck materials) —————–are not nailable
Cast in place concrete decks
When cast in place concrete is used as a roof deck some provision must be made for
Attaching the roof to the deck
If a multi story building is to have a FLAT roof the usual practice is to ———————because it is more economical.
It is possible to encounter exceptions to this general rule especially where————
Use the same structural system for the roof and the floors
And additional story has been added to an older building
————–Provides the water resistant barrier for the roof system
The roof covering
The type of roof covering used depends on
- form of the roof structure
- slope
- Local climate
- appearance desired
Hail can puncture
Asphalt shingles and roll roofing
Final outside cover that is placed on top of a roof deck assembly. includes composition or wood shake shingles, tile, slate, tin, or asphalt tarpaper
Roof covering
Overtime roofs are repaired and resurfaced meaning that firefighters may encounter more than one layer of ———on a given roof
Roof covering
Watertight material used to prevent the passage of moisture and water vapor into and through walls or roofs or in the case of personal protective equipment that prevents water from penetrating the clothing
Vapor barrier
Because flat roof drain more slowly than pitched roofs they usually require—————–than pitched roofs
More complex roof covering assemblies
A FLAT roof usually consists of several component layers that include the following
Vapor barrior thermal insulation roofing membrane drainage layer wear course
The vapor barrier is designed to reduce the diffusion of——- into the———
Interior moisture
insulation layer
A vapor barrier is needed when the average outdoor temperature———–and the indoor relative temperature is———
Below 40°
45% or greater at 68°
Reduces heat loss through the roof
Thermal insulation
Consists of a waterproof material that keeps out rain and snow from the interior of the building
Membrane of a roof
—–Roof covering that consists of a single layer of a waterproof synthetic membrane over one or more layers of insulation on a roof deck. also called——-
Membrane roof
single ply roof
—— use several overlapping layers of roofing felt saturated with a bituminous material that may be either tar or asphalt.
Builds up membranes
The three general categories of membranes used are
- Built up roof membranes
- single ply membranes
- fluid applied membranes
(Built up membranes) the number of layers of roofing felt varies but ———-layers is a common design
4
(Built up membranes) roofing felt usually is supplied in rolls ——- ft wide
3
Built-up roofs usually last for ———–if the manufacturer specifications are followed
20 years
———Roof consist of a single membrane laid in sheets on the roof deck
Single ply membrane
Single ply membranes are made from several materials. the most common is a
Synthetic rubber material (EPDM)
External covering on a roof that protects the roof from mechanical damage. the typical tar and gravel roof uses gravel
Wear course
—————-Are useful for buildings with curved roof surfaces such as domes that would be difficult to cover with other materials
Fluid applied membranes
Fluid applied membranes. usually——– coatings are applied
Several
The ——— permits the free movement of rainwater to the roof drains
Drainage layer
Depending on ——————the drainage layer can be the ballast layer in a single ply roofing system, a drainage fabric, or the aggregate used in a built up roofing system
The membrane material used
Protects the roof from mechanical abrasion
Wear course
Built-up roofs that use gravel as the wear course are commonly known as
“Tar and gravel roofs”
When a———– is used for the wear course it also increases the resistance of the roof to ignition by———
Gravel surface
flaming brands from adjacent buildings
Because the force of gravity is constantly pulling at the roof, the coverings used on a pitched roof must always be———– and provision must be made for this on the roof deck.
Secured to the roof deck or roof support
Roof coverings used on pitched roof’s are generally one of two broad categories
Shingle or tile roofs
metal roofs
(Shingles and tiles) their small size allows for movement between individual units cause by—–
Thermal expansion
And
shifting of the building structural system
The difference between wood shingles and shakes is
Their method of production
Thin tapered slabs of wood that are sawn from pieces of tree lumber
What shingles
Split from the wood either by hand or by machine and are thicker than shingles
Shakes
——-Produced from heavy sheets of asphalt impregnated felt made from rag, paper, or wool fiber. —————-is becoming common
Asphalt shingles
asphalt impregnated fiberglass felt
Asphalt shingles are available in several sizes but the most common size is
12x36”
Produced from hard rock that has a tendency to split along one plane
Slate
Slate Is a very durable material and can have a life expectancy of—-
150 years
Roof framing and decking that is heavier than normal may be required if ———is to be used
Slate
8-36 lbs/sq ft
Ancient material known to have been used for thousands of years
Clay tile
The ———-clay tiles are known as———–& are used to create imitation or genuine Spanish style architecture
Curved
“mission” tiles
Are frequently made to look like clay tile, slate, or even wood in color and texture
Concrete tiles
A major advantage of concrete tiles over wood tiles is
Their greater longevity
Shingles and tiles are usually attached to the roof with
Corrosion resistant nails
——-Are installed in an overlapping manner so that only about one third of the length of the shingle is actually exposed to the weather
Wood tiles
——–Are usually installed over and underlayment, which is a layer of roofing felt or synthetic covering
Asphalt shingles
——–Are popular architecturally because they produce a rustic appearance and maybe more resistant to wind damage than asphalt shingles
Wood roof shingles and shakes
(Wood roof shingles and shakes) their disadvantage is that
They pose a serious fire potential
What shingles and shakes can be ————–to reduce their combustibility and to meet model code requirements
Pressure impregnated with a fire retardant solution
Fire retardant shingles and shakes are shipped to the job site with
A paper label identifying them
Painting or staining fire retardant shingles or shakes can reduce the effect of the fire retardant especially if——
Oil-based materials are used
Asphalt shingles are fundamentally
Combustible
Asphalt shingles used for roofs are typically produced with a ————-that reduces their ease of ignition and permits their use under the provisions of building code
Grit surface
———–Are noncombustible and produce fire resistant roof coverings that have excellent resistance to flying brands.
Clay
Slate &
Cement tiles
The surface can become slippery posing a serious fall hazard. proper equipment and caution should be used at all times
Clay slate and cement tiles
Corrugated sheets of aluminum or steel are widely used on —————buildings
Metal roofs are also found on many buildings
Industrial and agricultural
Residential and commercial
——-Are generally strong enough to be installed without decking
In these cases the roofing sheets are supported by———
Corrugated roofing sheets
roof beams or purlins
(Metal roof coverings) the spacing between purlins can be from
2-6 ft
(Metal roof coverings)
———– are nailed to a deck beneath.
Flat roof coverings
One problem with metal roofing is the potential for ———when dissimilar metals are in contact
Galvanic action
Because of the severe fire danger that———- can pose, building codes impose restrictions on the combustibility of roofs of certain buildings occupancies or locations
Combustible roofs
The fire hazards of roof coverings are evaluated by test procedures contained in ———–standard method of fire test of roof coverings also designated as————
NFPA 256
ASTM E-108
(NFPA 256/ASTM E-108)
The test stimulates several fire exposure conditions for fires originating
Originating Outside a building
In the test Samples of roof coverings are attached to a wooden deck measuring
3ft 4in by 4ft 4in
There are six separate test procedures contained in NFPA 256. they include:
Intermittent flame burning brant flying brand rain weathering spread of flame
If the properties of a specific roof covering material are————- more than the minimum number of tests contained in NFPA 256 may be required
Subject to variation
Roof coverings that pass the required test procedures are classified
A B or C
(Fire ratings of roof coverings) the three classifications are based on the ---------------- class A roof coverings are effective against --------- class B roof coverings are effective against ----------- class C roof coverings are effective against -------------
Severity of fire the material can withstand
Severe
moderate
light
(Class ABC )
building codes use these three classifications to control
The flammability of roofs
Laboratories that test————–, such as underwriters laboratory publish a list of ————that have passed in NFPA 256 with their classifications in a manner similar to that of the fires resistance ratings described in chap 2
Roof coverings
roof coverings
A——Is a buildings first line of defense against the elements
Roof
A second roof constructed over an existing roof
Rain roof
When a fire enters this space. it can travel undetected in several directions and is exceptionally hard to ACESS and EXTINGUISH. the existence of two separate roofs can also impede rapid and effective VENTILATION.
Rain roof
A ——— involves the use of the roof surface as a building for a rooftop garden
Green ROOF
(Green roofs)
probably the greatest benefit is the increase in air-quality due to the ———–particularly in———
Oxygen-carbon dioxide exchange of growing plants
Urban areas
The layer of Earth required for a rooftop garden vary from
A few inches to 1 or 2 feet
(Green roof/rooftop garden)
depending on the depth of the soil been dead load can vary from
20 lb/sq ft
To
150 lb/sq ft
when a garden is planned for an existing roof the———– must be analyzed to ensure it’s adequacy
Existing structural system
(Green roof/rooftop garden)
obviously under fire conditions the increased load can hasten structural failure,particularly if ————Greenroofs can also interfere with———- and——–
The roof is combustible
ventilation practices
fire location indicators
A —————system produces clean and reliable energy that can be used in a wide variety of applications
Photovoltaic (solar energy)
(Solar energy)
————–can be laid on top of a roof or embedded in the roof
Photovoltaic cells in panels
Although solar energy represents a clean source of energy the ————-generated by the operation of the solar system represents a significant hazard For firefighters.
Electricity
Photovoltaic roofs
even if power to the building is shut off the—— retain a significant amount of energy
Panels
It is not safe to break photovoltaic cells or skylights that are
Actually solar powered
Photovoltaic roofs
the—— represent a significant tripping and falling hazard
Panels themselves
(Photovoltaic roofs)
In emergency conditions electrical shock, inhalation exposure, falls from roofs, and roof collapsed always represent serious safety considerations. for these reasons it is crucial that fire department——-
Conduct thorough preincident planning to identify the structures
(Photovoltaic roofs)
the fire department must preplan for————-on specific commercial and industrial buildings in their jurisdiction.
Structural emergencies
Air supported roof structures are often used in
Sports arenas and at colleges and universities
——–Provide protection from the elements and enable year-round use of the area under the roof
Air supported roofs
Air supported roofs
a typical use with this type of structure would be a
Sports practice facility
Air supported roofs
having doors open to provide firefighting access for lengthy periods could result in
Slow deflation of the structure
The structure of a roof is frequently penetrated for a number of reasons, such as for
Penthouses
skylights
vents
Roof hatches
Structure on the roof of a building that may be used as a living space, to enclose mechanical equipment, or to provide roof access from an interior stairway.
Penthouse
Room or building built on the roof which usually covers stairways or houses elevator machinery, and contains water tanks and/or hearing and cooling equipment. also called a bulkhead
Penthouse
Small structure erected on the main roof of a building
Penthouse
“bulkhead”
When a STAIRWELL is provided with a———– firefighters can gain rapid access to the roof to combat fires at the ROOF LEVEL
Rooftop penthouse
Any of a variety of roof structures or devices intended to increase natural illumination within buildings in rooms or over stairways and other vertical shafts that extend to the roof
Skylights
Some penthouses may not be directly accessible from——— and must accessed from——-
This is frequently the case with penthouses built for——
The Inside of a building
the roof
Elevator and mechanical equipment
Skylights are sometimes provided with ———to facilitate normal building ventilation
operable glass panes
For safety purposes building codes require———- in skylights
Wired glass or tempered glass
Skylights on modern buildings can be——
Plastic domes
Skylights provide a rapid means of ventilating heat and smoke but they usually do not have a provision for——–
Automatic venting
Skylights that feature———- must be approached with caution
Photovoltaic strips
The underside of a roof can be left exposed or have a ceiling installed depending on the ———of a building
Use and interior design
———-are usually built without ceilings
Warehouse and industrial buildings
————as a distinct building component usually do not play a structural role
Ceilings
Ceilings can be designed to control the ———-and the——— in a room
Diffusion of light
distribution of air
It is not uncommon for————- to have a new ceiling installed beneath an existing ceiling as a means of creating——–
Older buildings
new interior decor
Ceilings
the concealed space created in ———–may conceal the type of roof structure above
Fire resistive
or
noncombustible construction
The extent of fire development in roof spaces is hidden by———
this uncertainly complicates———-firefighting
A ceiling
interior
The combustibility of a roof can affect the communication of fire from—–
Building to building
A roof typically is not designed to support the same amount of——— as a floor; consequently——–should always be viewed very cautiously by firefighters
Live load
Roofs
Some newer types of roofs that feature photovoltaic cells may be too dangerous to ————without excessively endangering firefighters
Support roof operations
Breaking windows on the upper floors of a building requires
Careful coordination
Before windows are broken or any debris is released from an upper floor an——-needs to be established
All clear
———–And———need to be aware of what crews are doing at all times
Division commanders
company officers
Constant emphasis on ——–is a must
Safe practices
In the———- high-rise buildings existed primarily in larger cities
Early part of the 20th century
By the——– high-rises began to be constructed in many medium-sized communities
Second half of the 20th century
Today———- may be constructed in almost any community
Tall buildings
The growing proliferation of ————–poses a potential problem for almost any———;
———– are among the most challenging the fire department will face
High-rise buildings
fire official
high-rise incidents
High-rise buildings
———-can result in fires burning for extended periods before firefighters can complete staging and begin operations
Difficulty in gaining access
High-rise building
emergency operations require a greater level of ——-due to the large number of resources and personnel needed
Coordination
From a fire protection standpoint a high-rise building is any building that is beyond the effective reach of
Fire equipment located at street level
High rise- Any building that requires———on levels above the reach of fire department equipment often generally given as a building ————in height
Firefighting
more than 75 feet
Model building codes define a high-rise building as a building—-
This height is measured from the ————to the——–
More than 75 feet in height
Lowest level of emergency vehicle access
to
the floor of the highest occupied story
A jurisdiction may, because of limitations in firefighting resources, define a high-rise building as one—-
Exceeding 50 feet or five stories in height
The most obvious aspect of a high-rise building is that—————- are not possible beyond a certain height
Exterior means of fire attack and rescue
As ————–occupant safety and firefighting become increasingly dependent on the features of the building itself
Building height increases
As the firefighter becomes more dependent on ————-preincident planning takes on an even more important aspect of fire ground operations
Built in features
As the firefighter becomes more dependent on built-in features, ———–takes on an even more important aspect of fire ground operations
Pre-incident planning
High-rise buildings as they are known today began to be constructed———–
At the end of the 19th century
High-rise buildings as they are known today began to be constructed at the end of the 19th century. These buildings were made possible and practical by two developments:
Steel frame construction
the elevator
Without ——–the upper floors of a tall building become virtually inaccessible
Elevators
Buildings constructed —————–did not have the HVAC systems routinely provided today
75 or 80 years ago
Early high-rise buildings made use of——————- that permitted the vertical communication of products of combustion
Open stairwells and elevator shafts
The first model building codes that were introduced in the———– required——–
1920s and 1930s
Stairs and elevators to be enclosed
Most deadly fire in US history
Winecoff hotel fire
Automatic sprinklers and communication systems were not commonly provided until
The last quarter of the 20th century
The most significant and obvious feature of modern high-rise buildings is
Their height
The earliest high-rise buildings were rarely more than
10 or 12 stories
In the 1920s and 1930s several buildings were constructed exceeding
40 stories
New Yorks Empire State building
102 stories
constructed in 1930
Today buildings exceeding——– stories have become commonplace
60
Newer high-rise buildings often have
Multiple occupancies
Modern high-rise buildings
contemporary buildings ARE designed with ——-and MANY buildings are constructed without—–
Sophisticated HVAC systems
operable windows
Modern high-rise buildings
the fire department should arrange to meet with someone involved with the———– at the emergency scene for assistance with———
Engineering staff
building operations
Today high-rise buildings are of ———-construction
Fire resistive
Often a high-rise building will be constructed of a combination of
Reinforced concrete
protected steel frame
———–Often have a ———-housing the elevator shafts with the remainder of the frame being steel
Tall buildings
reinforced concrete core
Typically model building codes require ———– hour fire resistance for the structural frame of a high-rise building depending on the———— & ———-hour fire resistance for floor construction
2-3
Number of stories and occupancies
2
High rise construction
In reinforced concrete construction the floors will be——-
In steelframe buildings the floors will be———
Concrete slab
lightweight structural concrete placed over corrugated steel
The fire resistive construction used in high-rise buildings provides a high degree of—–
Structural integrity
Significant structural failure in high-rise buildings is
Extremely rare
Model building codes require several fire protection features for high-rise buildings these features always include:
- Automatic sprinklers
- voice evacuation system
- fire department communication system
and often some form of
-smoke control
Since the ———building codes have routinely required that high-rise buildings be equipped with automatic sprinkler systems as well as standpipe systems
Mid-1970s
Sprinkler and standpipe systems are typically supplied from
The Same vertical riser
(Sprinkler and standpipe systems) will be supplied by ——–located in the BASEMENT of the building
One or more fire pumps
In SEISMIC zones a ———–is required usually in the form of a—–
Secondary on-site water supply
storage tank
The——– in a high-rise building will be provided with individual floor control valves
Sprinkler system
———are a crucial aspect of fire protection in high-rise buildings
Standpipes
In buildings up to ———it might be possible to advance hose lines manually up stairwells
9-10 stories
The taller the building the more that FIREFIGHTING OPERATIONS are dependent on
the availability of standpipes
One on unavoidable problem with standpipe systems is
The variation of pressure with building height
HYDROSTATIC pressure
300 foot tall building the pressure variation been to elevation would be
130 psi
NFPA 14 installation of standpipe and hose systems-requires ———-to be installed at hose connections where the static pressure at a 1 1/2 inch hose connection exceeds 100 psi or when the static pressure exceeds 175 psi at larger outlets
Pressure regulating devices
(Pressure regulating devices)
————should verify that these devices are properly set at the time of the original installation
Fire inspectors
Pressure regulating devices
periodic test should be conducted to verify——-
Their proper maintenance
It is not unusual for taller high-rise buildings to have a population of————
for this reason the model building and fire codes require———– in high-rise buildings
Several thousand people
fire alarm systems
In a high-rise building it is not unusual for a fire alarm system to include————
the fire alarm systems provide ————-communication
Several hundred devices
alarm and emergency
Many modern high-rise buildings have——— alarm systems that automatically sound an alert followed by ——–on activation of any detector, waterflow device, or manual pull station
Voice
voice instructions
Voice evacuation systems are often zoned by—-
Floor
It is not uncommon to evacuate only - - - rather than the entire building
Floor of origin
floor above
floor below
Smoke detection in high-rise buildings typically includes——— arranged to prevent recirculation of smoke to other floors
Duct detectors
-
To initiate elevator recall
Elevator machine rooms
elevator lobbies
So model codes require Corridor smoke detectors in
Residential occupancies
All of these detection devices along with waterflow switches are required to be monitored through the
Fire alarm system
Smoke detectors in———- are not monitored through the fire alarm system
Individual residential units
Another unique fire alarm feature in high-rises is the requirement for a
Two-way fire department communication system
——-are often provided in the fire command center
Spare telephone handsets
Prior to the 1970s few if any buildings had any provisions for
Mechanical smoke control
Smoke control systems
a common approach using the mechanical equipment was called a
“Pressure sandwich” concept
This approach exhausted the floor of fire origin and pressurized the floors immediately above and below to contain the smoke to the floor of origin
Pressure sandwich
