Flashcards in Essentials Ch 4 Deck (66):
What content of wood affect how wood reacts to fire conditions?
Size and moisture
How much does pressure treated wood weaken the wood's load carrying ability?
As much as 25%
What building materials are generally used to create veneer walls?
Brick and stone (veneer walls are walls with a surface layer of attractive material laid over a base of common material)
Difference between cast iron and wrought iron:
Cast - 19th century, stands well with heat, but shatters when cooled, bolted or screwed
Wrought - 18th century, riveted or welded together
Steel structural members lengthen when heated. A ____ ft beam may elongate by as much as _____ inches when heated from room temperature to ______ º F. Failure of steel structural members can be anticipated at temperatures near or above ______ºF.
50 / 4 / 1000 / 1000
To reduce the effect of heat on steel structural members, ________ materials such as _____ concrete or _______ _______ is used.
Fireproofing / sprayed-on / sprayed-on insulation
Reinforced concrete is internally fortified with rebar / wire mesh giving the material the _______ strength (ability to withstand pressure on the surface) of concrete along with the ______ strength (the ability to withstand being pulled apart or stretched) of steel.
Compression / tensile
Reinforced concrete performs well under fire conditions, but it can lose strength through _______; prolonged heating can cause a failure of the ______ _____ the concrete and the steel reinforcement.
Spalling / bond between
Is gypsum organic or inorganic?
Inorganic; with a high water content
What are the two major model building codes in the US:
NFPA 5000, Bldg and Construction Safety Code
International Code Council's (ICC) International Building Code (IBC)
What types of buildings may be exempt from local building codes?
Manufactured homes and state/federal blogs
Every building is composed of the following building elements (regardless of Type):
List the Types of building construction:
Type I -fire resistive, highest level of fire protection as well as collapse; walls, floors, ceilings have a 3-4 hour fire rating
Type II - Noncumbustile/Limited Combustible, materials that will not contribute to fire development or spread, 1-2 hour fire rating
Type III - Ordinary Construction (found in older schools and mercantile, business and residential structures.
Type IV - heavy timber/mill construction; large dimensioned lumber- greater than 8 inches thick fire resistance rating of 2hours;
Type V - Wood/Stick Frame - load bearing walls entirely wood
Manufactured homes make up _____% of all housing sales in the US.
List the 5 categories of factory built homes:
Manufactured Homes (steel undercarriage)
Modular Homes - sectional pieces attached together on a foundation
Panelized Homes -
Pre-Cut Homes - individual parts custom cut; assembled on site
Hybrid Modular Homes -
There are many occupancy classifications:
Single use / Separated Use
Usually interior, that supports only its own weight
Wall assemblies consist of:
Bottom plate, top plate, vertical studs, and horizontal braces sandwiched between two surfaces made of gypsum or lath and plaster.
Partition wall is a wall that:
Separates space into rooms
Party wall is:
A load bearing wall shared by two adjacent structures
_____ walls and _____ walls are the most difficult to penetrate when attempting to force entry.
Exterior / Fire
Common roof shapes:
Pitched, folate, arched
Most pitched roof construction involves ______ or ______ that run from the ______ _____ to the top of the outer wall at the eaves level.
Rafters / trusses / ridge line
Common roof styles:
Mansard, Gambrel, Gable, Hip, Sawtooth Shed, Lantern Butterfly
Four type of arched roof include:
Bowstring, Ribbed, Diagonal grid (Lamella) and pleated barrel.
Roofs are made up of three main components including the:
Roof supporting structure
Roof deck or sheathing
There are two general types of roof supports used in residential and commercial construction:
Beams and truss assemblies
What are the sections of lumber located directly under the roof decking and what are the sizes?
Beams; made of solid members, 4 X 4 inch or larger
______ ______ assemblies may be conventional framing construction on site or premanufactured assemblies built in a factory and shipped to site.
Roof trusses, consisting of top and bottom cords and webbing
Types of trusses:
Parallel cords, pitched chord, arched truss, bowstring truss
What are used to support flat roofs and floors?
Box beams, I-beams (wide flange beams)
What portion of wood trusses will fail?
Slender members used to manufacture a truss and open web design permits rapid spread of fire
What is a cockloft?
Concealed space between the top floor and the roof of a structure
Under fire conditions what are concerns for a green roof (which includes the dead load):
Interfere with ventilation practices
Effects of high velocity winds and uplift wind pressures
Roof drainage which can add weight (collapse hazard)
Exposure hazard that may be created by dry vegetation (rooftop)
Need for a clear space between vegetation and fire walls that penetrate the roof
Why is photovoltaic roofs a significant hazard for firefighters?
The electricity generated by the solar power panels; the retained energy even if power is off, tripping hazard
Rain roofs are:
A second roof constructed over an existing roof (to ventilate properly, must cut through both roof structures
Weight of the structure, structural members, building components, and any other features permanently attached to the building that are constant and immobile.
Items within a building that are movable but are not included as a permanent part of the structure; merchandise, occupants, and the water used for fire suppression
Force placed upon a structure by the addition of stuff
Are HVAC units considered a dead load or live load?
Dead load, items that add weight to a building
Means of egress has three separate and distinct parts:
Access or convenience stairs are:
Not part of means of egress system (may not be built with fire spread resistance), typically connect no more than two levels
Protected stairs have a fire rating of how many hours
1 - 2 hour rating, two or more floors
How do smokeproof stair enclosures protect the stairwell from smoke?
Mechanical ventilation system by pressurizing the shaft
Generally, the following 5 types of doors are used in modern building construction:
Lexan and Plexiglas are often used to:
Provide additional security and in framed glass doors
T / F A fire door is rated for the door?
False, the entire assemble - door seal, frame, door, hardware
Most fire doors will be constructed of ______ and may _____, _____, or ______ into place when released.
Metal; roll, slide or swing
T/F Rolling steel fire doors can be used in means of egress?
What is the disadvantage of a swinging fire door?
The need for space to swing
Display Windows, picture windows and dead lights are what type of window?
There are two primary types of dangerous conditions that may be posed by a particular building:
Conditions that contribute to the spread and intensity of fire
Conditions that make the building susceptible to collapse
Fuel load is the:
Maximum heat that can be produced if all the combustible materials, both contents and the building materials, in a given area burn
Experience has shown that unprotected engineered steel and wooden trusses can fail after _____ to _____ minutes of exposure to fire.
5 - 10minutes
Engineered trusses can fail from ______ ____ ___ ____, without any _____. For steel trusses, ______º is the critical temperature.
Exposure to heat alone; flames; 1000º
Web members of a truss design, are used to form a series of _____ that transfer _____ from the bottom chord and ______ from the top chord of the truss onto the ________ walls.
Triangles, tension, compression, load bearing
One difference with bowstring trusses is that the __________ forces within the top chord act to force the _______ walls _____ as well as ______. Another difference is that the space between the trusses is _____ than that found between other types of trusses.
Compressional, load bearing, outward, downward, greater
Trusses constructed prior to the 60s have a common code deficiency; the bottom chord members may have ______ _____ _____ to support code-prescribed roof loads.
Inadequate tensile strength
Structural collapse concerns:
Length of time fire burns
Stage of the fire
Amount of water used to extinguish fire
Checking the ceiling at intervals, approximately ____ ft
Collapse potential increases during the ______ stage as heat increases in the upper levels of the space and flame spreads to and consumes the combustible structural members.
In the _____ stage, and during posts suppression activities, collapse becomes very likely due to the weakened state of structural members and the _______ of water.
Decay / buildup
Every gallon of water adds ______ lbs of weight to floors that may already be weakened.
It's estimated that 250 gym ads ____ ____ of water per minute.
What type of construction will most likely to collapse?
Type III- ordinary construction, collapse zone of 1 1/2 times the height.
All intermediate Flor structures attached to the wall studs are:
Ballon frame construction - limited fire stops