Building Construction Flashcards
Construction Types : Type I - Type II - Type III - Type IV - Type V -
- Fire resistive
- Noncombustible or protected noncombustible
- Exterior protected (masonry or ordinary)
- Heavy Timber
- Wood frame
What provides the basis for understanding the differences between buildings in a jurisdiction?
History of building construction
What factors affect the configuration and materials used at structures in any specific time and place?
Technology and economics
When does the building process begin?
When a developer or project owner perceived a need
What is the final consideration in the building design process?
Landscaping
When can the building’s engineer design proceed?
When financing has been secured
Who witnesses system tests?
The fire inspector
What is a building code?
A body of law that determines the minimum standards that buildings must meet in the interest of community safety and health
What is the most widely used model building code in the US published by who?
International Building Code (IBC) published by International Code Council (ICC)
How are many codes developed?
In reaction to catastrophic incidents
The most prominent occupational safety standards and regulations come from who?
NFPA and US Occupational Safety and Health Administration (OSHA)
Who maintains a national map that indicates location and frequency of fire fatalities?
The US Fire Administration
When is combination of construction classifications likely?
Older buildings renovated
What does occupancy and use affect?
Fuel load
As a general rule, greater quantities of fuel or highly volatile fuels will generate what?
Higher heat release rate
What is the first line of defense in many buildings?
An automatic fire protection system, especially an automatic sprinkler system
Effort to increase the energy efficiency of structures and their components in known as?
Green design
Primary hazard of green design?
The tendency of components to increase the combustibility of the overall building
What often determines a buildings overall appearance and size?
Funds
What is an essential consideration in the design of fire protection systems?
What is the primary concern?
- water availability
* water quantity needed for the fire protection systems flow rate
What are the two methods in which fire spread is often expressed in terms of heat transfer?
Convection and radiation
What is one factor in determining whether a fire will progress to an exposure?
What factors are also relevant?
- fire temperature
* flames height and width
Under fire conditions, a buildings structural integrity is related to what?
The fire resistance and combustibility of its construction materials
Tracking permits is particularly useful in what?
Construction of large structures
NFPA 220 : three digit code
First digit -
Second digit -
Third digit -
- fire resistance (in hours) of exterior bearing walls
- fire resistance of structural frames or columns and girders that support loads on more than one floor
- fire resistance rating of the floor construction
Type I construction :
Bearing walls, columns, beams -
Floor construction -
Roof deck and construction supporting roof-
Interior partitions exposing stairwells and corridors -
Partitions separating occupancies and tenants -
- two to four hours, as specified by the local code and construction classification
- two or three hours
- one to two hours
- as specified by the local code, usually one to two hours
- as specified by local code
Type I buildings are most commonly constructed using?
Protected steel frame and reinforced concrete
Type II construction :
Materials used -
Steel and concrete block, glass and aluminum can be used with a limited structural role
Some building codes contain a provision to omit the fire resistive rating for a roof construction for some occupancy types when the roof is located ?
More than 20ft above the floor
Type II - A (protected) requires what?
That structural components have a one hour fire resistance
Type II - B (unprotected) : most common characteristic of unprotected, noncombustible construction?
Use of unprotected steel
Type III construction, also know as?
Frequently constructed with?
• Exterior protected;
“Ordinary construction”
• exterior walls of masonry
Type III construction commonly used what size joists for floor construction?
Nominal 2 x 10 inch joists
What is a fundamental fire concern with Type III construction?
The combustible concealed spaces that are created between the floor and ceilings joists and between studs in partition walls when they are covered with interior finish materials
Important distinctions between Type III and Type IV ?
- in Type IV construction the beams, columns, floors and roof are made of solid or laminated wood with dimensions greater than in Type III construction
- concealed spaces are not permitted between the structural components in Type IV construction
Which is only construction type that doesn’t include A and B subdivisions?
Type IV; designation 2HH
Type IV (heavy timber) construction requires minimum nominal dimensions of what for floor construction?
6 inch x 10 inch
What is the fundamental problem with Type V construction?
The presence of extensive concealed voids
The fire load is ?
Maximum amount of heat that can be released if all fuel in a given area is consumed
The product of the weight of the combustibles multiplied by their heat of combustion, expressed in pounds per square feet
The international building code defines a noncombustible material as being?
In the form and which used and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors, when subjected to fire or heat
What is the most commonly used test for determining combustibility?
ASTM E136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750°C
The severity of a fire is a factor of ?
The faster the the available fuel burns ?
Another factor?
- Fire load plus the rate at which the fuel burns.
- The faster the available fuel burns, the greater will be the heat release rate (HRR) A greater heat release rate results in a faster developing fire.
- Another factor is the rate at which fuel and the available oxygen combine
What is the most common method used to determine fire resistance?
Laboratory testing
Test results will be classified as either ?
Fire resistance ratings are developed for ?
- load bearing or nonload bearing
- Restrained in unrestrained floor and ceiling assemblies because in restraints of fax the extent to which assembly may expand or rotate at its ends when exposed to hide temperatures, affecting its ability to support a load
What is the only standardized test method currently universally accepted by building codes? What does it test?
- ASTM E-119
* evaluate the ability of structural assemblies to carry a structural load and to act as a fire barrier
What is the most commonly used method of satisfying building code requirements for structural fire resistance?
NFPA 251 standard time temperature test
To calculate the structural supports needed to allow a building to a withstand common forces, what are categorized and calculated?
Loads

The direction of forces from loads acting on the interior of structural members is expressed as?
Stress
The forces within a structural support system that resist applied loads are referred to as what?
Reactions R
When a structural support system can support a load equal to or greater than the applied loads, what exists?
Equilibrium
What is the most common load opposed on a structure?
Gravity
What are additional forces added to the structure that will increase the load that must be supported by a building supports, and in turn the soil beneath the structure?
- Vibration
- Temperature
- Shrinkage
Stresses within a material are classified according to the direction of the force: (3)
- Tension
- Compression
- Shear
What is important because material properties have unique tolerances?
Direction of the interior stresses
Unique stresses are caused by external load alignments including : (3)
- Axial load
- Eccentric load
- Torsional load
The lending institutions’ technical requirements will necessitate a review of the architect’s design drawings and may include what? Such as?
• Engineering documents
- Land surveys
- Preliminary budgets
- Soil test reports
If a building official rejects a proposed building design, an architect may appeal the decision to who?
Board of Appeals
A technique known as what may be used to shorten the construction type. How?
- Fast track construction
* Overlapping the design and construction phase
During inspections, the following building features may be tested for function and compliance with standards and codes:
- Materials (such as concrete)
- Systems (such as fire pumps)
- Components (such as emergency generators)
Areas of refuge may include : (3)
- Stairway landing in a smoke proof enclosure
- Balcony located adjacent to an exterior stair
- Protected vestibule adjacent to an exit enclosure
The type of foundation used will be determined partially by ?
Soil’s strength, resistance to strain, and stability
Other building site factors that influence the overall building height and the practicality of below grade space include : (3)
- Level of water table
- Frost line
- Presence or absence of a solid bedrock layer
All new construction is a product of ?
It’s place and time
Factors that influence a building’s condition at any given time include? (4)
- Older codes
- Materials
- Construction methods
- Maintenance over time
What must be considered early in the design process?
Public utility availability
Buildings are repositories of wealth and are frequently constructed why?
As investment tools because they provide security, and because energy and resources are expended in the construction of buildings
NFPA 80 Recommended Practice for Protection from Exterior Fire Exposure, describes three levels of exposure based on the potential severity of the exposing Fire :
Based on what?
- light
- moderate
- severe
Based on the fire load and the flame spread rating of the wall and ceiling finishes of a burning building
Where do exposure fires remain a significant problem?
Older urban environments with closely spaced combustible construction
Under fire conditions, a buildings structural integrity is related to?
The fire resistance and combustibility of its construction materials
What do design deficiencies refer to?
Any failure to provide a level of fire safety appropriate to the ultimate use of the building, regardless of the reason
Design deficiencies including : (4)
- Oversight
- Incorrect assumptions
- Oversimplification
- Underestimation
What is a resource that can be used by firefighters to develop knowledge of building construction in their jurisdiction?
Building permit process
Preincident plans should include : (6)
- Occupancy type
- Industrial processes conducted on site
- Hazardous materials in the vicinity
- Location and function of fire protection system controls and outlets
- Building access routes
- Utilities present
A jurisdictions GIS can potentially provide tools for functions including : (4)
- Evaluating department performance
- Dispatching emergency responses
- Code enforcement
- Zoning and taxing
What influences the strategies that will be effective at a structural fire?
Building construction types
Three primary strategies in a fire incident?
- Offensive
- Defensive
- Transitional
Factors that influence Fire behavior : (4)
- Basic building classifications
- Occupancy classifications
- Fire or fuel load
- Fire resistance
Type II - B (unprotected)
The speed at which unprotected members will fail, however, depends on the following factors : (3)
- Ceiling height of the building
- Size of the unprotected steel members
- Intensity and duration of the exposing fire
What is a critical factor when determining the fire safety requirements of a space?
Fuel load; the total quantity of combustible material in a compartment
The fire load will vary depending on what?
The heat of combustion of the fuel load
The fire load can be used for what?
An estimate of the total potential heat release or thermal energy to which a building may be subjected if all combustibles become fully involved in fire
Fire resistance describes several properties of a material, including : (5)
- Thermal conductivity
- Combustibility
- Chemical composition
- Density
- Dimensions
What does fire resistance indicate?
The ability of a structural assembly to maintain its load-bearing capacity and structural integrity under fire conditions
The fire resistance rating can be evaluated and expressed how?
Quantitatively and expressed in time units including hours and fractions of hours
The fire resistance ratings incorporated into the building codes include minimum requirements for structural components such as : (5)
- Beams
- Columns
- Walls and partitions
- Floor and ceiling assemblies
- Roof and ceiling assemblies
Fire doors and windows will have fire resistance ratings specific to ?
Their function and location
Primary points of failure for the test are :
fire resistance)(4
- Failure to support an applied load
- Temperature increase on the unexposed side of the wall, floor, and roof assemblies of 250°F above ambient temperatures
- Passage of heat or flame through the assembly sufficient to ignite cotton waste
- Excess temperature on steel members
Fire resistance ratings for test specimens, standard interval times?
15mins, 30mins, 45mins, 1hour,
1-1/2hours, 2hours, 3hours, and 4hours
What does E-119 test NOT test for?
- Info about performance of assemblies constructed with components or lengths other than those tested
- Evaluation of the extent to which the assembly may generate smoke, toxic gases, or other products of combustion
- Measurement of the degree of control or limitation of the passage of smoke or products of combustion
- Measurement of flame spread over the surface of the tested material
- The effect on fire endurance of openings in an assembly such as electrical outlets and plumbing openings unless specifically provided for in the construction tested
• Fire behavior of joints between building elements such as floor-to-wall or wall-to-wall connections
Materials used in ASCE/SFPE 29, Standard Calculation Methods for Structural Fire Protection : (5)
- Structural steel
- Plain and reinforced concrete
- Timber and wood
- Concrete masonry
- Clay masonry
What is the most critical aspect of engineering design?
Accommodating the type and magnitude of the forces to which the structure will be subjected
Where is sand content in soil particularly relevant?
When surveying sites with high seismic activity
Simple soil pressure formula :
P=CWH
P - pressure
H - depth of soil
W - density of soil
C - numerical constant that depends on the physical properties of the soil
Primary design consideration of beams?
Their ability to resist being deformed from applied loads
Materials used in beams?
- Steel
- Wood
- Reinforced concrete
Fire Door Classifications : Class A - Class B - Class C - Class D - Class E -
- Openings in fire walls
- Openings in vertical shafts and openings in 2hr rated partitions
- Openings between rooms and corridors having a fire resistance of 1hr or less
- Openings in exterior walls subject to severe fire exposure from the outside of a building
- Openings in exterior walls subject to moderate or light exposure from the outside
During inspections, the following building features may be tested for function and compliance with standards and codes :
- Materials (such as concrete)
- Systems (such as fire pumps)
- Components (such as emergency generators
Where required, the area of refuge must be equipped with two-way communication so occupants can call for assistance. FFs must be prepared to respond to anyone calling for assistance. Areas of refuge may include arrangements such as :
- Stairway landing in a smoke proof enclosure
- Balcony located adjacent to an exterior stair
- Protected vestibule adjacent to an exit enclosure
All new construction is a product of its place and time. Factors that influence a building’s construction at any given time include :
- Older codes
- Materials
- Construction methods
- Maintenance over time
Unfortunately, building codes are limited in their scope because :
- Codes cannot address every situation that may arise
- Codes are subject to political processes, competing interests, and economic priorities
- Codes can only provide a baseline level of protection for the most commonly encountered situations
Design deficiencies refer to any failure to provide a level of fire safety appropriate to the ultimate use of the building, regardless of the reason but including :
- Oversight
- Incorrect assumption
- Oversimplification
- Underestimation
Offensive strategies address :
Defensive strategies address :
- Life hazards
- Structural stability
- Risk (benefit outweighs risk)
- Volume of fire
- Structural deterioration
- Risk (risk outweighs benefit)
- Structural conditions
Type I construction can be of what rating?
Either 4-4-3 or 3-3-2
Concealed spaces in Type III construction must contain ?
Appropriate fire stops
Basic method of construction in a Type V building consists of ?
Fire resistance?
- Wood frame to provide the primary structural support
* Many Type V structures are required to have a 1hr fire resistance for structural components
What are used together in building codes to establish limitations on the permissible heights and open areas of the building?
Building construction and occupancy type
Classifying buildings according to what facilitates ?
Classifying buildings according to occupancy facilitates the administration of a code
The IBC has how many classifications of occupancies? Subgroups?
NFPA?
- 10
- 26
• 12
The IBC also separately addresses one and two family dwellings, how many stories? What code are they governed by?
Not more than three stories high; the International Residential Code (IRC)
What is a critical factor when determining the fire safety requirements of a space?
Fuel load, the total quantity of combustible material in a compartment
Fire resistance indicates ?
The ability of a structural assembly to maintain its load bearing capacity and structural integrity under fire conditions
What are the three methods to determine fire resistance?
- Laboratory testing (most common)
- Development of mathematical models based on data collected during nonstandard testing
- Use of statistical data to determine probability of fire resistance based on standard test results
The failure point of steel will depend on ? Other factors ?
The application of the component. Other factors include maximum temperatures indicated for identified points in the assembly, and the average overall temperature
The standard test (E-119) evaluates what?
The ability of structural assemblies to carry a structural load and to act as a fire barrier
Standard based on calculation methods based in part on data obtained over time during laboratory testing on materials?
ASCE/SFPE 29, Standard Calculations Methods for Structural Fire Protection
What factor significantly influences structural plans?
Gravity-related factors
Loads applied to the exterior structural member create ? Based on?
Internal stresses within the member based on the placement of the load
The total stresses within structural members must be ?
Lower than the failure point of the material for the structure to remain intact
Factor of safety -
Ratio of the failure point of a material to the maximum design stress; indicates the strength of a structure beyond the expected or actual loads
Load types can meet multiple categories that are based on factors such as ?
- Change over time
- Load application velocity
- Weight distribution
Loads applied to buildings may be classified according to ?
Rate of speed at which they are applied to a structure
Kinetic energy of wind :
E = 1/2mv squared
In designing buildings to withstand wind forces, what is used as the primary consideration? Other factors considered?
- Direct pressure
- Wind velocity
- Static air pressure
- Wind direction perpendicular to the building
In addition to horizontal wind effects and building design, engineers must account for complex factors including:
- Building height
- Surrounding terrain
- Adjacent urban development
Wind forces are particularly dangerous against walls with insufficient supports. Common locations where walls may be insufficiently braced include :
- Construction sites
- Demolition sites
- Fire-damaged buildings
What type of force applies the most complicated load that must be accommodated by structural design?
Seismic forces
The overall effect of the seismic load against a structure depends on ?
The acceleration of the ground beneath the building more than the total movement
Most significant force generated by an earthquake?
Lateral loads that create horizontal motion
Directional movement that seismic loads create :
- Lateral
- Torsional
- Resonant
Three types of accommodations for seismic forces :
- Expansion joints
- Damping mechanisms
- Base isolation
What influences the degree to which it is affected by seismic activity?
A building’s basic architecture
What do damping mechanisms do?
Absorb resonant energy as the structure begins to move
Expansion joints are often installed in what type of construction material?
Concrete
Two different types of base isolation?
Shear systems and sliding systems
Two types of structural stiffening?
- Shear walls and cross bracing
* Structural support redundancy
Shear walls and cross bracing are effective against ?
Ground motions with a relatively long (slow) vibrational period
Redundant structural members use what, that have a greater ability to absorb energy?
Continuous joints; greater ability to absorb energy in contrast to joints with less support
When is the soil load evaluated?
During the design process
Soil exerts what type of load against a foundation?
Lateral load (pressure)
The pressure exerted by the soil against the foundation is ?
The force of the foundation against the soil ?
- Active soil pressure
* Passive soil pressure
When is sand content in soil particularly relevant?
When surveying sites with high seismic activity
Basic equation used to determine soil pressure :
P = CWH
Common support systems for beams :
- Simply supported beams
- Restrained beams
- Cantilever beams
- Overhanging beams
- Continuous beams
Top flange of beam carries what type of stress?
Bottom?
Web?
Where is max. point of shear stress?
- Compressive
- Tensile
- Neutral axis; max. point of shear stress
Doing what to a beam increases the efficient use of material and reduces weight of the beam?
Shaping it
The stresses on the elements of an I-beam can be calculated how ?
Mathematically
Arches are a curved structural member with primarily what type of stresses?
They produce what type of force at their end supports?
- compressive interior stresses
* inclined forces
Steel stud wall construction, studs are placed ?
They are frequently provided with what for stability?
Historically, associated with?
- 12 to 16 inches apart
- Diagonal bracing
- 2 inch x 4 inch wood studs
Post and beam construction framing uses a series of vertical elements to support horizontal elements that carry ?
Transverse loads
Distinctive characteristic of post and beam framing?
The spacing of the vertical posts and the cross-sectional dimension of the members, because the dimensions are often greater than used in stud wall construction
Rigid frame structural system is characterized by?
They are often?
- Columns and beams reinforced to transmit the bending stress through the joints
- Single story in height with gabled roof
In rigid frame construction, what will be the last portion of the assembly to fail under fire conditions?
The joints will be the last portion of the assembly to fail under fire conditions
Surface systems consist primarily of ?
An enclosing, waterproof surface; the stresses resulting from the applied loads occur within the bearing wall structures
What are shell structures?
Rigid, three dimensional structures having thin components, as compared to other structural material dimensions
Stairs that are not part of the means of egress are often referred to as ?
Convenience stairs
Buildings that are four or more stories may be required to include?
One stairway that extends to the roof for access to mechanical equipment and is identified by signage in the stairway
Special requirement for circular stairs?
Min. run width?
- The small radius of the full circle is greater than or equal to the widest part of the stair tread
- 10 inches
Exit stairs, as a component of the required means of egress, must meet strict requirements to ensure safe passage during building evacuation. Features include :
- Fire resistance rating of the enclosure
- Separation when exterior stairs are utilized
- Features to ensure safety during both no emergency and emergency use
Protected stairs must resist ?
Measures indicated in building codes to protect stair enclosures include :
• Products of combustion
- Limited penetrations in the enclosure for light, fire protection, and environmental control
- Required self- or automatic-closing Fire-rated doors
- Separation from the rest of the building
- Stairway vestibules
Building codes have traditionally required a min. of one smokeproof stair enclosure for stairs serving buildings of ?
More recently, codes also require protection for stairs serving floor levels how far BELOW the level of exit discharge?
- Five stories or more
* 30 feet
Building codes have traditionally required what for stairs serving buildings five stories or higher?
Smokeproof stair enclosure
Conveyor systems often penetrate fire barriers, and are protected by features such as :
- Fire doors
- Shutters
- Water spray fixed fire suppression systems
What is a primary safety hazard at conveyor penetrations during a fire?
Incomplete door or shutter closure
Safeguards against incomplete closure include :
- Automatic stop controls
- Breaks in the conveyor
- Multiple layers of doors or shutters
Vertical penetrations for escalators serving how many floors must be protected?
Draft stop depth?
- More than two floors
* 18 inch deep draft stop
Two most common type of power used in elevators ?
Hydraulic and electric
Hydraulic elevators upper limit?
Other consideration?
- About six stories
* No brakes
Four common styles of elevators are :
- Drum elevators, intended for passenger use
- Traction elevators, intended for passenger use
- Machine Room-Less (MRL) Elevators, intended for passenger use
- Dumbwaiters, intended for cargo use
What type of elevators are the most common type of elevator in buildings over six stories?
Traction elevators
Passenger safety devices found on elevators may include :
- Terminal device
- Buffers
- Speed-reducing switch
- Overspeed switch
- Car safeties
Elevator hoist way enclosures usually are required to be a fire rated assembly of how much, depending on building height?
1 or 2 hr rating
Elevator and stair shafts are built early in the construction process and often use ?
Shear walls
When used as a means of egress, an elevator’s shaft must be equipped with what, suitable to the height of the structure?
Safety lights and fire ratings
The elevator operations are sequenced in the following order :
- When the elevator stops at the correct level, the driving vane attached to the car door holds the door open
- As the car door opens, the vane strikes a roller that releases the hoist way door lock
- The car doors then push the hoist way doors completely open
- When the co troller signals the doors to close, a weight forced the hoist way doors closed, the driving vane moves away from the roller and the hoist way doors are relocked
What type of elevator has top exits on all?
On hydraulic elevators, a top exit may be provided if ?
- Traction
* Depending on whether the system is equipped with a manual lowering valve
Some top panels on elevators are designed to be opened ?
Some open from inside, but ALL can be opened from the outside and all open outward
Duct detectors are typically provided for fans with capacities of ? to stop these systems under fire conditions and minimize unwanted smoke movement
Exceeding 2,000 cubic feet per minute
Fuels used in fuel-fired heating equipment can include ?
Other types of heating equipment use ?
- Natural gas or oil
* Electricity or steam
Systems that use extensive ducting are of great interest to fire protection engineers and firefighters because disadvantages include :
- Pathways for communication of heat and smoke through the building
- Penetrations of fire-rated assemblies that can destroy the integrity of the assembly
- Dedicated use of substantial amounts of space
HVAC ducts must be enclosed in a fire rated shaft enclosure.
Less than 4 stories -
Four stories or greater -
- 1hr
* 2hr
What does a HVAC system operating in smoke control mode do?
Discharges smoke through the exhaust fan from the fire floor to the outside without returning air to the supply fan
Any equipment, such as fans and ducts, used to exhaust the products of combustion must be capable of withstanding the anticipated temperatures. Other factors the designer must anticipate include :
- Fire size
- Outside weather conditions
- Volume of a fire zone
- Max. pressure differences across barriers, such as stairwell doors
Primary disadvantage of manual operations of HVAC smoke control?
Slower actuvation
Depth of a curtain board ?
Distance?
- Should not be less than 20% of the ceiling height
* Should be spaced so that they are not farther apart than eight times the ceiling height
The method used to determine the vent area requires ?
Analysis of the rate of heat release of the fuel, the ceiling height, and the depth of the curtain boards
Smoke towers require the following expensive concessions :
- Location on the periphery of the floor plan
- Dedicated floor space in the building
- Corridor access to the stairwell
In compensated stairwell systems, the adjustments used in modulation can affect the following :
- Speed of the fan
- Inlet vanes
- Variable pitch fan blade
- Number of fans operating
How is overpressure relief in a stairwell accomplished?
The use of dampers that open to the outside, reliving excess pressure in the stairwell
High voltage equipment defined as -
Low voltage -
- 600v or higher
* Less than 600v
Two most common cooling methods used in transformers?
Air and oil
Older transformer cooling oils contain?
Highly hazardous Polychlorinated Biphenyls (PCB)
When transformers are inside, codes require that the transformer rooms or vaults be enclosed in ___ construction if not protected by automatic sprinklers or ___ with sprinklers.
- 3hrs
* 1hr
Flame spread over a specific material can be measured and predicted in degrees known as the surface-burning characteristics of the material when evaluating the following :
- Composition, orientation, thickness of material
- Ventilation
- Shape and size of a compartment
- Finish material on the ceiling or wall
The most significant factor that determine’s a fuel’s burn rate is ?
Another factor?
- The combination of the fuel and available oxygen
* The manner in which an interior finish is mounted
Types of fire retardant coatings available include :
- Intumescent coatings
- Mastics
- Gas-forming paints
- Cementitious and mineral fiber coatings
The standard test used for measuring the surface burning characteristics of interior finish materials is ?
ASTM E-84 or the Steiner Tunnel Test
Interior finishes are tested to derive several measures of a material’s flammability including ?
The flame spread rating and the smoke developed rating
Flame spread ratings ___ are not permitted in occupancies.
Over 200
What is the smoke developed rating?
A measure of the relative visual obscurity in an area because of the smoke generated by a burning material
Codes do not allow a combination of materials that have a smoke developed rating of?
Exceeding a maximum smoke developed rating of 450
The smoke developed rating test does not measure other important smoke quality data, such as :
- Heat
- Irritation
- Toxicity
- Volatility
A recently developed large scale test for interior finishes, developed to accommodate materials that may not remain in place during the ASTM E-84?
NFPA 286 Standard Methods of Fire Tests for Evaluating Contribution of Wall and Ceiling Interior Finish to Room Fire Growth
The International Building Code (IBC) allows interior finish materials to be tested in accordance with NFPA 286 instead of ASTM E-84. However, the code then establishes specific acceptance criteria :
- Flame spread to the ceiling of the test chamber must be noted
- The flame cannot spread to the outer extremity of the sample
- Flashover cannot occur
- Limitation of the peak rate of heat release below 800kW
- Limitation of the maximum amount of smoke released
Fire flow -
The amount of water required to extinguish a fire in a timely manner
Fire walls must have ___ to serve as an absolute barrier to a fire and structural collapse on either side of the wall?
Sufficient fire resistance and structural stability
Freestanding fire walls are usually found in what type of buildings?
They must be able to resist a lateral load of?
- Type III or V ; maybe Type II
* At least 5 pounds per sq. ft.
Tied walls are erected where?
At column line in a building of steel frame or concrete frame construction
The ICC allows fire walls with fire resistive ratings of ?
Historically ?
- 2, 3, 4hrs
* 4hrs
4hr rated firewalls must be constructed of ?
Masonry or concrete
Fire partitions -
Usually erected from where to where?
- Interior walls that do not qualify as fire walls but are used to subdivide a floor or area of a building.
- Usually erected from a floor to the underside of the floor above
What is the main difference between enclosure walls and partition walls?
Enclosure wall -
Partition wall -
- Function
- Enclosure - block vertical spread
- Partition - block horizontal spread
Enclosure walls are required to have a fire resistance rating of what, depending on the height of the building?
One or two hours
Enclosure walls in stairwells in buildings four stories or lower -
In buildings taller than four stories -
- 1hr fire rated
* 2hr fire rated
Most common construction materials used for enclosure walls :
- Gypsum board with steel or wood studs
- Lath and plaster
- Concrete block
- Hollow clay tile enclosure walls (older fire resistive buildings)
The development of the steel framed high rise building led to the existence of ?
Modern curtain walls are frequently used in buildings with ?
- The curtain wall, a style of wall designed to separate the interior environment from the exterior environment
- Concrete frames
Most common means for protecting openings through fire rated walls ?
Fire doors
Fire doors are rated in increments of
time -
1/2hr and 1/3hr doors are primarily used in?
- 20mins to 4hrs
* smoke barriers and openings to corridors
Letter designation of fire doors?
Type of opening, or in older system, the door itself
Fire doors : Class A - Class B - Class C - Class D - Class E -
Class A - openings in fire walls
Class B - openings in vertical shafts and opening in 2hr rated partitions
Class C - openings between rooms and corridors having a fire resistance of 1hr or less
Class D - openings in exterior walls subject to severe fire exposure from the outside of a building
Class E - openings in exterior walls subject to moderate or light exposure from the outside
Four types of fire rated doors :
- Rolling (overhead) doors
- Horizontal sliding fire doors
- Swinging fire doors
- Special fire doors
Rolling (overhead) doors are constructed of interlocking steel slats with other operating components including:
- Releasing device
- Speed governor
- Counterbalance mechanism
- Wall guides
Most horizontal sliding doors are of what construction?
Metals often used?
• Metal clad or tin clad doors with wood core that provides insulation, covered in sheet metal that protects wood from the fire
- Steel
- Galvanized sheet metal
- Terneplate
Swinging fire doors commonly protect ?
Available ratings?
- Stairwell enclosures and corridors
* 20mins to 3hrs
Wood swinging fire doors include hardware that can be referred to as ?
“Builder’s hardware” or “fire door hardware”
A door hold open device can be used with ?
Swinging, sliding, or rolling fire doors
Door closers can be used with ?
Sliding or swinging doors
First type of fire rated glazing available?
Wired glass
Most common application of fire rated glazing?
Fire doors
Doors with ratings up to ___ can be equipped with glazing.
3 hours
Restrictions regulate the allowable area of glass in fire doors. Fire doors with ratings of 1-3hrs can have glass panels of what size?
Fire doors with ratings of 3/4hr can have a total glass area?
Fire doors with ratings of 1/2 or 1/3hr can have fire rated glass area?
- Up to 100 sq. in. area per door
- Consistent with their listing below a states max. area
- Up to max. area to which they were tested
Usually, the mechanism of closing louvers is the release of ?
Fusible links
Swinging doors with ratings up __ can be equipped with louvers.
1 1/2hrs
A fire door will be likely to fail to close when the following components are damaged :
- The door closer
- The door itself
- Door guides
Fire doors are tested in accordance with ?
NFPA 252 Standard Methods of Fire Tests of Door Assemblies and ASTM E-152
For fire doors, the primary criterion for acceptability is ?
Parameters include :
Second criterion for acceptability ?
• Fire door must remain securely in its frame during flame test
- Some warping of door is permitted
- Intermittent passage of flames is permitted after the first 30mins. of test
- Surface temperature rise is not regulated on the unexposed side of the door for most of the doors tested.
- The fire door assembly must remain in place when subjected to a hose stream immediately following the fire test
Doors with a ___ hour rating may not be subjected to the hose test depending on intended application.
1/3hr
Water table -
Highest level of ground water saturation of subsurface materials
Frost line -
Common depth at which ground water in soil will freeze
Two strategies used to assess soil?
Test pits and test borings
Test pits may reach a depth of ?
What does permit to be observed and measured?
- 8ft
* Strata (layers) of the soil to be observed and measured
When are test borings used?
What information can they provide?
How?
- When a test pit may not reach deep enough
- Info on the bearing capacity of the soil, water table, and soil samples
- Number of impacts required to reach a given distance will provide information about the soil strata
What will influence the require depth of the foundation?
Size of the structure
What does the increased area of footing do?
Reduces the compressive stresses on the soil
Shallow foundations : (3)
- Basement
- Crawl space
- Monolithic
Specialized types of footings :
What are they matched to?
- Wall footing
- Column footing
- Grillage footing
The loads supported above them
Other types of slab foundation :
- Mat slab foundation
* Floating foundation
Piles -
Piers -
• Piles are driven into the ground and support a load by transferring the load either through friction with the surrounding soil, or through contact with rock or other stable soil layers
• Post-and-pier foundations are a system of upright posts mounted to wedge-shaped concrete piers that transfer the weight of the structure to the ground.
Drilled shaft and poured concrete, post attached
Types of movement in building settlement :
- Settlement - downward movement
- Heaving - upward movement
- Lateral displacement - outward movement
Causes of differential settlement :
- Nonuniform soil conditions under the foundation
- Footings of different sizes
- Footings placed at different elevations
- Unequal loads on footings
Types of wood used in construction :
- Spruce
- Fir
- Pine
Dimensional lumber is available in what lengths and increments?
8 to 24 feet in 2 ft. increments
The moisture content of lumber can be controlled to any level; most structural lumber has ?
19% or less
Moisture is expressed ?
In terms of specific gravity
Factors that affects wood strength?
- Moisture
- Load direction
- Type of fasteners
- Applied position in respect to the grain of the wood
Advantages to engineered wood?
Disadvantages?
- Strength and cost efficiency
* Quick and unpredictable failure in fire conditions when unprotected
What type of wood joints can be used to transmit tensile strength?
Scarf and finger joints
Finished beams :
Thickness -
Depths -
Lengths -
- 3/4 to 2 inches
- 3 to 75 inches
- 100 feet
When are Glulam beams frequently used?
In heavy timber construction where greater length components are required
Structural composite lumber (SCL) uses what?
The outer fibers of a log as well as the inner portions traditionally used
Laminate Veneer Lumber (LVL) is made up of what?
What are they used for; size?
- Uses sheets of veneer peeled from the outer portion of the log. These sheets of veneer are laminated in parallel alignment.
- LVL is used in I-joists and beam sections that are 1 3/4 to 3 1/2 inches thick
Parallel strand lumber (PSL) is made up of?
Used for; size?
- Made from veneers that are not as uniform as those used in LVL. These veneers produce odd shaped strands that are coated with adhesive and cured under pressure
- 2 to 8 feet in length
- PSL is the strongest of the three SCL products and can be used for heavily loaded columns and long spans
Laminated strand lumber (LSL) is made of?
Size and used for?
- Made with long strands of wood up to 12 inches in length
- Strands are bonded with resin in a steam pressing process
- LSL typically used for short-span beams and columns
Thermoplastic composite lumber is a combustible product with a flame spread of ?
Rating of 80
Plywood sheet sizes -
4 feet by 8 feet
Plywood is used for applications including :
- Sheathing
- Concrete formwork
- Webs of composite beams
- Hulls of ships
Nonveneered panels are made of engineered wood formed into sheets using ?
Resin, heat, and/or pressure
Make up and strand orientation of Oriented strand board (OSB) ?
Widely used for?
- Uses long, strand-like wood particles compressed and glued into three to five layers. Strands are oriented in the same direction in each layer.
- Sheathing and subfloor in wood frame buildings
Particleboard construction?
Used for?
- Wood particles bonded with synthetic resin under heat and pressure. Individual wood particles can range in size from 1 inch to very fine
- Particle board panels may be single layer or multiple layer
- Manufactured in sizes up to 8 x 40ft
- Used in lateral force resisting diaphragms and flooring in mobile/manufactured flooring
Composite panels serve several functions including ?
Insulation and structural support
R-values -
a measure of the ability of a material to insulate
Structural insulated panel (SIP) consists of ?
Outer wood panels (usually OSB) with a plastic foam core between the panels
Materials used for fire stopping :
- 2 inch nominal lumber
- Gypsum board
- Cement fiber board
- Batts or blankets of mineral wool, glass fiber, or other approved material
Locations where fire stopping is required :
- Within stud walls at the ceiling and floor levels
- At the connection points between vertical stud wall spaces and horizontal spaces
- Between stair stringers
- Behind fascia and other architectural features
Usual requirement is for attic space to be subdivided into areas of ?
3,000 sq. ft
Most common sheathings?
- Plywood
- OSB
- Particleboard
- Exterior gypsum sheathing
Noncombustible materials used for insulation include :
- Glass wool and rock wool in the form of batts or blankets with combustible paper or foil coverings
- Fiberglass
- Some older vermiculite and bay insulation that may contain asbestos
Two types of solid-fill foam insulations ?
- Urea formaldehyde
* Polyurethane foam
Veneers must be tied to the wood frame at intervals of ?
16 inches
A typical means of adding or increasing fire resistance ?
Through the use of 5/8 inch gypsum board attached to studs and ceiling joists
Wood panel products are graded for ?
The grade stamp indicates?
- Their structural use and their exposure durability
* It’s intended structural application and its suitability for exposure to water
One serious and fundamental drawback to wood?
It’s combustibility
Pyrolysis is the thermal decomposition of wood and begins at what temp?
Somewhere below approx. 392°F
Initial products of pyrolysis are ?
Release of water retained in the wood and carbon dioxide
The heat of combustion of a fuel is ?
The total amount of thermal energy that can be released if the fuel is completely burned
When an item is burned thoroughly, the thermal energy released during the fire can be calculated as ?
The weight of the item multiplied by the heat of combustion
Two main methods of fire retardant treatment ?
Surface coating and pressure impregnation
What fire retardant treatment is used primarily to reduce the flame spread rating of wood?
Surface coating
Most fire retardant chemicals operate by?
Accelerating the formation of charring in the wood when the wood is exposed to heat. The charring reduces the formation of volatile gases in the wood and slows flaming combustion.
Applicable requirements for ignition-resistant construction may include :
- Fire resistant roof coverings to protect against flaming embers
- An exterior wall that is either noncombustible or that has a 1hr fire resistive rating when exposed from the outside
- Limitation on the size of attic and under floor vents and their protection with corrosion-resistant screens
The specific requirements for ignition-resistant construction will vary with the severity of the hazard in a given area. Factors used to evaluate the hazard severity in a given location include :
- Ground slope
- Clear space around property
- Water supply
- Climate
An engineer designing heavy timber construction will account for factors including:
- Likelihood of the collapse of roof or floor decks
- Methods used to join the joists, beams, and columns
- Integrity if timber connections under fire conditions
- Suitability of protection of connectors
Other wood construction types that may be encountered include :
- Pole construction
- Log construction
- Prefabricated panel construction
Most wood frame buildings do not exceed how many stories?
Three stories
In Type IV construction, the support columns are ?
Beams ? (Except roof beams)
- 8 x 8 inches
* Not less than 6 x 10 inches
Post and beam framing -
Wood frame construction with columns (posts) and beams that use dimensions smaller than those used in heavy timber framing but greater than those used in light frame construction
The flanges of wood I-beams can be made of ?
The vertical webs?
- Laminated veneer lumber or solid wood lumber
* Range of thicknesses of plywood, laminated veneer lumber, or oriented strand board
Heavy timber trusses use members of what size?
Internal support columns?
Beams (except roof beams)?
- Up to 8 or 10 inches
- Not less than 8 x 8 inches thick
- Not less than 6 x 10 inches
Most common style of connector between heavy timber members?
Steel gusset plates with through bolts
Heavy timber joint that is artistic?
Mortise and tenon joint
Primary benefit of masonry components?
Their durability and inherent resistance to weather, fire, and insects
Most common types of stone used in construction include :
- Limestone
- Sandstone and brownstone
- Granite
- Marble
- Slate
Bricks are produced from ?
Hardness is dependent of ?
Three courses of brick height?
- Variety of locally available clays and shales
- Materials used in its composition
- 8 inches
Most common concrete masonry unit?
Hollow concrete block
Most common size of hollow concrete block?
8 x 8 x 16 inches
Mortar is available in how many types with compressive strengths ranging from?
- Five basic types
* 75 psi to 2,500 psi
Most mortar is produced from a mixture of?
- Portland cement
- Hydrated lime
- Sand
- Water
The code classification of buildings with masonry components depends on ?
The fire resistance of the joists, beams, and rafters that span the exterior load bearing walls and interior columns, and transfer the live loads of the building to those walls and columns
The traditional and most basic masonry structure includes ?
Exterior load-bearing masonry walls that support the interior wood floors and roof constructed of wood joists and rafters
Ordinary construction is also known as?
Masonry, wood joisted
The weight that a wall can support will depend on ?
The width of the wall and whether it is reinforced or nonreinforced
In an ordinary nonreinfoeced load-bearing wall, the strength and stability of the wall are derived from ?
The weight of the masonry and horizontal bonding of each wythe of wall to other wall components
The height of the building and the method of construction used will affect what?
The thickness of masonry wall
Non-reinforced masonry walls are usually limited to a max. height of ?
Six stories
What is one way to identify the method of construction of masonry walls?
Existence of header courses
Load bearing masonry walls may be constructed to a height of ___ stories or more with a wall thickness of ___ when using reinforced masonry.
- 10 stories or more
* Only 12 inches
Common support for masonry walls? (Reinforced)
Series of vertical steel rods placed between two adjacent wythes of brick wall
Concrete block brick faced (CBBF) masonry construction -
Brick wythe is commonly used in combination with a concrete block wythe. Metal tie rods may be placed between the brick wythe and the concrete block wythe in a CBBF wall for reinforcement. The cavity between the wythes is filled with grout
A parapet is an extension of a masonry or steel wall that projects above the roof how far?
1 ft or more
Primary two metals alloyed in steel?
Iron and carbon
How much carbon does common structural steel have?
Cast iron?
- 3/10 of 1%
* 3-4%
Basic properties of steel include :
- Strongest of the common building materials
- Non-rotting, resistant to aging, and dimensionally stable
- Consistent quality from controlled industrial manufacturing process
- Relatively expensive, but strength and other qualities enable it to be used in smaller quantities than other materials
One inherent disadvantage to steel?
Tendency to rust when exposed to air and moisture
The following elements added to steel will alter the composition of the material and contribute and increase specific attributes:
- Molybdenum - strength
- Vanadium - strength and toughness
- Manganese - resistance of steel to abrasion
The rolling process consists of repeatedly passing ingots of steel heated to ___ between large rollers until the intended shape is achieved.
2,200°F
Cold rolled steel (CRS) is used for ?
CRS studs can be used for ?
- Members that have thin cross sections, such as floor and roof decking and wall studs.
- Interior non-load bearing partitions or for exterior bearing walls
The amount of expansion for slender members (steel), such as beams and columns, can be determined through a property known as ?
Linear coefficient of thermal expansion
An unrestrained steel beam 20 ft long can expand how far ?
1.4 inches
What is the most significant characteristic of steel to the fire service?
The deterioration of steel strength at elevated temperatures
The speed of failure of steel depends on several factors :
- Type of steel
- Mass of the steel members
- Load supported by the steel
- Types of connections used to join the steel members
- Intensity of the exposing fire
Steel is a good conductor of heat because it is a heavy material, having a density of?
490 pounds per cubic feet
Temperature which is hot enough to weaken steel to its yield point?
1,200°F
A steel column encased in 3 inches of concrete with a siliceous aggregate would have a fire resistance rating of?
4hrs
Most commonly used SFRMs are ?
Spray-applied fire-resistive materials
Mineral fiber or expanded aggregate coating such as vermiculite and perlite
Cementitious materials are produced in various formulations :
- Portland cement
- Gypsum
- Perlite
- Vermiculite
Gypsum board is available in what two types?
Regular or type X
Gypsum includes approx. what percentage of trapped water?
20%
Intumescent coatings will expand how much ?
Fifteen to thirty times its original volume
15-30x
Commonly used method of protecting a steel floor or roof assembly?
Most common method?
- Membrane ceiling
* Mineral tiles in a steel framework suspended by wires
The basic method by which steel is used in the design of buildings is the construction of?
Structural framework that supports the floors, roof, and exterior walls
The design of the connections in steel-framing buildings is important for what two reasons?
- The connection of a beam to a column transfers the loads between members
- Connections determine the rigidity of the basic structure
Beam and girder steel frames can be classified as ?
- Rigid
- Simple
- Semi-rigid
Rigid frame -
Connections between the beams and columns are designed to resist the bending forces resulting from the supported loads and lateral forces
Simple frame -
The joints are designed primarily to support vertical force
Semi-rigid frame -
Not completely rigid but possess enough rigidity to provide some diagonal support to the structure
Two commonly encountered applications of the basic steel truss?
- Joist girder
* Open web joist
Joist girders -
Heavy steel trusses used to take the place of steel beams as part of the primary structural frame
The top of the rigid frame is know as ?
The points where the inclined members intersect ?
What type of joints are they?
- Crown
- Knees
- Rigid
Gable roof rigid frame must have what for structural rigidity?
Must be braced diagonally
Steel arches can be constructed to span distances how far?
In excess of 300 feet
Wire for use in bridge cables can have strengths as high as ?
300,000 psi
Most common steel column cross sections :
- Hollow cylinder
- Rectangular tube
- Wide flange shape similar to the cross section of an I-beam
The possibility of buckling in an individual column is ? (Steel)
A function of its length, it’s cross section, and the method by which the column is supported at its top and bottom
Slenderness ratio :
Comparison of the height or length of a structural component and the width/thickness of the component
The slenderness ratio compares ?
The unbraced length of a column to the shape and area of its cross-section
In general, columns (steel) used for structural support in buildings should not have a slenderness ratio greater than ?
120
A common floor design in steel frame buildings uses ?
Lightweight concrete with a minimum thickness of 2 inches supported by corrugated steel decking. The corrugated steel, is in turn, supported by open-web steel joists
How are light gauge joists produced?
Cold rolled steel
Steel joists are produced with depths of ?
And spaced ?
Depths of 6-12 inches;
spaced 16-48 inches apart
Two most common materials used in fire resistive construction?
- Protected steel
* Reinforced concrete
Primary purpose of gusset plate ?
Steel members
- Strengthen connection
* Increase the steel mass at connection, decreasing the possibility of failure
In gabled rigid frame structures, what will be the strongest part of the frame and last part to fail?
The knee joint between the roof and the wall
Concrete is ?
The hardened form of cement produced from Portland cement, coarse and fine aggregates, and water
Coarse aggregates ?
Fine ?
Gravel or stone; sand
What makes up a large percentage of the total volume of concrete?
Aggregates
Types of admixtures and their purposes :
- Shale or clinker - reduce the density of concrete
- Superplasticizers - produce a mixture that flows more freely
- Coloring - added for aesthetic or safety reasons, such as indicating electrical cables
Primary advantages of concrete :
- Produced from locally available and low cost raw materials
- Fundamentally noncombustible
- Performs well under mild to moderate fire conditions
- Good insulating properties
Ultimate compressive strength of reinforced concrete ?
2,500-6,000psi
Reinforcing components can include ?
Reinforced concrete
- Steel reinforcing bars (rebar)
- Wire mesh
- Fiberglass additives
Most commonly used size of rebar ?
5 (0.625 inches)
Vertical reinforcing bars are known as ?
They provide?
Stirrups; resist diagonal tension
The systems (pre/post-stressed concrete) use reinforcing cables and rods made of high strength steels that can yield at temperatures as low as ?
752°F
The single most important factor in determining the ultimate strength of concrete is ?
Water-to-cement ratio
Too much water in concrete mixture?
Final product sill not achieve desired strength
Hardening of concrete involves a chemical process known as ?
As the concrete hardens, what releases?
- Hydration; in which water combines with the particles of comment to form a microscopic gel
- This gel releases heat of hydration
Concrete in the process of curing must be maintained at ideally, what temperature?
Concrete cured at or above 100°F?
- Between 50° and 70°F
* Sill not reach its proper strength
Slump test -
Method of evaluating the moisture content of wet concrete by measuring the amount that a small, cone shaped sample of the concrete slumps after it is removed from a standard sized test mold
The fire resistance of a concrete assembly is affected by such variables as :
- Concrete density
- Concrete thickness
- Concrete quality
- Supported load
- Depth of concrete over the reinforcing bars
Primary cause of spalling?
The expansion of the moisture within concrete when heated or frozen
The expansion of water as steam or ice in concrete creates what type of force in concrete?
Tensile
The extent of spalling depends on?
Severity?
- Amount of moisture in the concrete and the length of time the concrete has been in place
- Duration and intensity of the components’ exposure to fire
Flat slab concrete frame -
Slab ranges in thickness of ?
Where do sheer stresses develop?
- Construction technique using concrete slabs supported by concrete columns
- 6 to 12 inches
- In the concrete where the slab intersects the supporting columns
Flat plate -
Plain floor slab about 8in. thick that rests on columns spaced up to 22ft. apart and depends on diagonal and orthogonal patterns of reinforcing bars for structural support because the slab lacks beams.
Simplest and most economical
Slab and beam framing (concrete) -
- Concrete slab supported by concrete beams. Extremely lightweight, best suited for light loads.
- Slabs can be as thin as 2 inches
- Sometimes referred to as concrete joist construction
- Highly susceptible to fire. Fireproofing necessary
- Concrete beams run mainly one direction - one-way reinforced slab
Waffle construction -
Slab and beam concrete framing featuring concrete beams running in two directions is known as a two-way slab construction. Aka waffle construction
Where are waffle construction used?
Spans are short and floor loadings are high
From a construction standpoint, precast concrete structures have more in common with ___ than with cast-in-place concrete buildings.
Steel framed buildings
Precast concrete slabs for floor systems :
- Solid slabs
- Hollow-core slabs
- Single tee slabs
- Double tee slabs
Solid slabs are used for short spans -
Tee slabs -
- Up to approx. 30ft.
* Up to 120ft.
Tilt up construction requires that what maintain structural integrity?
Roof assembly
Types of supports for precast concrete beams?
How are the precast beams secured to the column?
- Corbels (brackets) cast into the columns
- Short steel beam cast into the poured column
• Through the use of steel angles cast into the columns or through the use of post tensioned steel cables
Roofs can be classified into three styles :
- Flat
- Pitched
- Curved
Low slope roofs have a slope up to ?
Medium to high ?
• 3/12
• 4/12 to 12/12
(12/12 equates to a 45 degree angle)
What determines the design of pitches roofs?
- Climate
- Function
- Aesthetic
Simplest pitched roof?
Shed roof
Common roof style that consists of two inclined surfaces that meet at their high side to form a “ridge”
Gable roof
Style that slopes in four directions and has a degree of slope similar to a gable roof
Hip roof
Slope in two directions, but there will be a break in the slope on each side
Gambrel roofs
Has a break in the slope of the roof on all four sides
Mansard roof
Roof style that slopes in two directions-basically a two shed roofs that meet at their low eaves
Butterfly roof
Style designed to provide light and ventilation.
Monitor roof
A style also once commonly used on industrial buildings for light and ventilation
Sawtooth roofs
Curved roofs are most frequently supported by ?
Arches and bowstring trusses
Lamellas are most commonly made of wood, and vary in thickness from ?
Lengths?
- 2 x 8 inches to 3 x 16 inches
* 8 to 14 feet
The simplest system of flat roof support uses ?
Ordinary wood joists supported at either end by load-bearing walls
Conventionally framed roofs use what type of lumber?
Dimensional lumber
Conventional framing components :
- Rafters
- Ridge boards
- Collar ties
- Ceiling joists and rafter ties
If the architect desires to leave the underside of the roof exposed without joists, what must used to support the rafters?
Structural ridge beam
Conventional roof framing fasteners common to this type of roof structure :
- Nails and screws at connection points
- Heavy bolts or brackets in heavy timber
- Architectural hardware for exposed beams
In conventionally framed roofs, ridge beams are how much larger than the rafter?
Wood rafters vary in size from ?
They’re spaced ?
- One size larger
- 2 x 4 inches to 2 x 14 inches
- 12 to 24 inches apart
Lightweight wood trusses -
2 x 4 or 2 x 6 and individual trusses would be spaced 2 to 4 ft. apart
Bowstring trusses, what type of connections at the joints does it use?
Split-ring connector at all joints
What type of trusses are most common types used for pitched roofs?
Fink and Pratt trusses
Where is roll roofing material applied?
Roof decking
What type of roof decks are not nailable?
Cast-in-place concrete
May be accommodated with wood nailing strips imbedded in the concrete at intervals of 3 feet or similar strips drilled and anchored or placed between rigid insulation panels if rigid insulation is used
The type of roof covering used depends on ?
- Form of the roof structure
- Slope on the roof
- Local climate
- Appearance desired
Flat roof component layers :
- Wear course
- Drainage layer
- Membrane
- Insulation
- Vapor barrier
- Roof deck
Three general categories of roofing membranes :
- Built up membranes
- Single ply membranes
- Fluid applied membranes
Built up membranes -
- Use several overlapping layers of roofing felt saturated with a bituminous material that may be either tat or asphalt
- Layers of roofing felt are cemented together with hot bituminous roofing cement
- Roofing felt 3 feet wide
- Four layers is common design
- Usually last 20yrs if manufacturers specs followed
Single ply membrane -
• Single membrane laid in sheets on the roof deck. Made from several materials
• Sheets 10 or 20 feet wide and up to
200 feet long
• Most common synthetic rubber material, ethylene propylene diene monomer (EPDM) Other materials PVC and CPE
Fluid applied membranes -
- Useful for buildings with curved roof surfaces such as domes that would be difficult to cover with materials
- Material is applied as liquid and allowed to cure
- Materials used - neoprene, silicone, polyurethane, butyl rubber
Modern asphalt shingles are ___ based.
Most common size ?
- Fiberglass
* 12 x 36 inches
Difference between wood shingles and shakes?
Wood shingles -
Shakes -
- Their method of production
- Shingles are thin, tapered slabs of wood that are sawn from pieces of a tree trunk
- Shakes are manually or machine split from the wood and are thicker than shingles
How are slate tiles produced?
Life expectancy?
Weight?
- Produced from hard rock that has a tendency to split along one plane
- 150yrs
- 8 to 36 lbs per sq. ft.
Test to evaluate the fire hazards of specific roof coverings -
NFPA 256 Standard Methods of Fire Tests of Roof Coverings, also designated
ASTM E-108
Two developments that made high rise buildings possible and practical at end of 19th century ?
Use of steel frame construction and elevators
One unavoidable problem with standpipe systems ?
Variation of pressure in tandem with building height (hydrostatic pressure)
Another unique alarm feature in high-rises is a requirement for a two way fire department communication system. The system operates between locations including:
- Fire command center (central control station); spare telephone handsets are often provided in the fire command center
- Landings of enclosed exit stairways
- Areas of refuge
- Elevators and elevator lobbies
- Emergency generator
- Fire pump rooms
All model building codes require smoke proof exit enclosures and all stairs serving floors ____
75ft or higher
Codes maintain mandatory provisions for the recall (Phase I Operstion) of all passenger elevators with vertical travel ? in the event of fire
Greater than 25 feet
Where is the elevator control and information panel located?
Adjacent to the elevator bank
The damage an explosion may inflict on a structure depends on ?
- Max. pressure developed
- Rate of pressure rise
- Duration of the peak pressure
- Resistance of the confining structure
The max. pressure reached during an explosion may exceed how many time atmospheric pressure?
10x
Ideally, explosion vent panels should not weigh more than ?
3 pounds per sq. ft
Newer building codes require that a minimum of one lighted stairway be provided when building construction reaches a height above how high?
Four stories or 50 feet
Standpipe risers must be extended up as construction progresses, specially on high rise buildings, and low rise buildings how high?
More than 3 stories
Building and fire codes typically require that standpipes be extended before construction reaches __ the lowest level of the fire department access
40 feet above
The top hose outlet should be within hoe many stories of the uppermost level that has a secure floor?
Within one story
In newer buildings with sprinkler systems, building and fire codes require valves controlling the water supply for sprinkler systems with how many sprinkler knees be monitored at a constantly attended location?
More than twenty sprinklers
Calculations during the design phase include :
- Building code requirements
- Engineering standards and practices
- Local weather, seismic, and flood data
- Redundancies and safeguards as relevant
When is the structural design, including calculations, typically evaluated?
During the plan review process before construction begins
Until the final members of the structural frame are in place, the frame is vulnerable to what type of loads?
Vertical and horizontal
Most dangerous time in a building’s lifespan?
During its demolition
International Building Code Origin :
The International Building Code is the successor to three earlier model codes -
- The Uniform Building Code (UBC) published by International Conference of Building Officials (ICBO)
- The Standard Building Code published by Southern Building Code Congress International
- The Building Officials and Code Administrators (BOCA) National Building Code published by the Building Officials and Code Administrators International
Primary fire hazard associated with Type IV construction?
The relatively large amount of fuel present in structural supports. In additions, the interior of the building may have traces of oils and residues from previous industrial use
Test for determining combustibility -
Test for determining fire resistance -
Test for measuring surface burning characteristics of interior finish material-
- ASTM E-136
- ASTM E-119
- ASTM E-84
What is of particular interest to building and fire prevention inspectors in regards to what the ASTM E-119 test, does NOT test for?
Fire behavior of joints between building elements such as floor-to-wall or wall-to-wall connections
Rigid frame buildings are often ?
Single story with gabled roofs
What consists primarily of an enclosing, waterproof surface; the stresses resulting from the applied loads occur within the bearing wall structures
Surface systems
In addition to the batteries used for the systems associated with the primary use of the building, types of battery systems found in and on buildings include :
- Small uninterruptible power supplies (UPS) containing lead-acid batteries, near fire alarm system control panels, under desks, or next to computers in many offices
- Battery charging room for battery-powered vehicles, such as storage, manufacturing, and golf club houses, in the building or on the property
- Cellular equipment with independent battery backup systems hosted on talker buildings
What influences the type of foundation, and therefore the type of building that can be built at a given location?
Soil properties
What is Laminated Veneer Lumber (LVL) used for?
I-joists and beam sections that are 1 3/4 to 3 1/2 inches thick
What is Parallel Strand Lumber (PSL) used for?
Heavily loaded columns and long spans (strongest of the three SCL products)
What is Laminated Strand Lumber used for?
Short spans beams and columns
The core of composite panels can be made of ? (3)
- reconstituted fiber
- paper honeycomb
- plastic foam
What are exterior insulation and finishing systems (EIFS) for?
To increase the insulative properties of a building
Why are spam ratings different for roof sheathing and sub flooring?
Because roof supports are often spaced wider apart than floor supports
When does the International Building Code permit the use of fire retardant treated wood in Type I and Type II construction?
Non-load bearing partitions where the required fire resistance is two hours or less
Applicable requirements for ignition-resistant construction may include :
- fire resistant roof coverings to protect against flaming embers
- exterior wall that is either noncombustible or that has a 1hr fire resistive rating when exposed from the outside
- limitation on the size of the attic and under floor vents and their protection with corrosion resistant screens
The construction of a platform frame building begins with the following steps :
- Attach a wood sill to the foundation, usually with bolts
- Attach a header and floor joists or trusses to the sill
- Attach sub flooring to the floor joists to form a deck
The first floor wall framing with a top and bottom plate is usually laid out horizontally in the floor deck and then raised into its vertical position. When the first floor walls are in position and braced, the second floor joists are erected on the top plates of the first floor walls
Identifiable features of heavy timber framing include :
- Trusses or beams can be used to support the roof
- The exterior walls are nonload-bearing panels with an exterior siding that may include any of the several materials including corrugated sheet metal
- Internal support columns are not less than 8 x 8 inches and the beams (except roof beams) are not less than 6 x 10 inches
What are wood I-beams frequently used for?
Joists and rafters in the framing of roofs
Portland cement consistency’s chiefly of?
Calcium and aluminum silicate
Where do shear stresses develop in concrete flat-slab frame?
Where the slab intersects the supporting column
Components of roof decks include?
- sheathing
- roof planks or slabs
- purlins
What is the vapor barrier designed to do?
Reduce the diffusion of interior moisture into the insulation layer
What are the type of thermal insulations for flat roofs?
- Poured or rigid
* Poured can be Portland cement or gypsum
How many layers of roofing felt is common design?
Four layers
High Rise Construction Type :
In reinforced concrete construction, the floors will be ?
In steel-frame buildings, the floors will be?
- concrete slab
* lightweight structural concrete placed over corrugated steel
All model building codes require what in all buildings serving 75 feet or higher?
Smokeproof exit enclosures in ALL stairs serving floors 75 feet or higher
Atriums : current codes calibrate the exhaust capacity to maintain the smoke layer at a specified height above the highest walking level serving the system. What is the required exhaust capacity based on?
The magnitude of the expected fire and the height from the floor to the bottom of the lowest-allowable smoke layer
Several different methods of venting atriums can be found, depending on when a particular building was built. For example, some codes now waive the requirements for sprinklers where the ceilings of atriums are ?
More than 55ft above the floor
When a vestibule outside of stairways will be used to provide areas of refuge, the area must be separated from the rest of the floor by a smoke barrier. The typical smoke barrier consists of min. ___ fire rated enclosure.
1hr fire rated enclosure
NFPA 241 requires the presence of what extinguisher during roofing operations as a precaution against the ignition of combustible materials?
20 B rated
The following resources may be consulted for more information while evaluating an area for its likelihood to develop one of these three hazards :
- Recorded history of the area
- Environmental impact reports and zoning regulations
- Soil reports may identify many existing conditions
The removal of large amounts of underground water or oil over many years beneath built up areas.
Subsidence
The collapse of the ground surface into an underground cavity created as ground water dissolves water soluble rock formations.
Sinkholes
Compressive strength of mortar ?
75psi - 2500psi
Compressive strength of concrete?
2500psi - 6000psi
Fire endurance of steel beams and columns with light insulation formula :
R = {[(C1 x M) + C2] x I} / D
R = fire endurance in minutes
M = mass of members in lb/ft
D = heated perimeters in inches
I = thickness of protection in inches
