(AI)Building Construction Related To Fire 4th Flashcards
What are the factors that influence fire behavior?
Basic building classifications, occupancy, fire or fuel load, fire resistance
These factors are critical in understanding how fire interacts with different types of structures.
How many major classifications are buildings grouped into?
Five
The classifications help in assessing fire safety and construction standards.
What is Type I construction?
Fire resistive
This type involves materials that can withstand high temperatures for extended periods.
What is Type II construction known for?
Noncombustible or protected noncombustible
Type II construction uses materials that do not ignite easily.
What does Type III construction entail?
Exterior protected (masonry)
This type features noncombustible exterior walls but allows combustible materials inside.
What characterizes Type IV construction?
Heavy timber
This construction type utilizes large wooden members for structural integrity.
What is Type V construction commonly known as?
Wood frame
Type V construction allows all major structural components to be combustible.
Fill in the blank: The major classifications are further divided into ____ or ____ subclassifications.
2 or 3
This division helps in further categorizing buildings based on specific fire safety features.
In NFPA, how is each classification designated?
By a 3 digit number code
This coding system helps in quick identification of building types.
What does the first digit in NFPA classification indicate?
Fire resistance rating of walls
This rating is essential for understanding the structural integrity during a fire.
What is the fire resistance rating for Type I bearing walls?
2-4 hours
This indicates the time the walls can withstand fire before failure.
True or False: The fire resistive components of a building provide for fire extinguishment.
False
They do not extinguish fires but help to contain them.
What must be used to protect steel in fire resistive designs?
Insulating material
Protection is necessary to maintain steel’s integrity during a fire.
What is the maximum height above the ground where fire-resistive rating can be omitted for roofs?
20 ft
This rule applies to certain occupancy types.
Fill in the blank: Type II-A construction requires structural components to have a ____ fire resistance.
One-hour
This requirement is essential for maintaining safety standards.
What does Type III construction allow for its interior structural members?
Partially or wholly combustible
This flexibility can affect fire spread within the structure.
What is the minimum nominal dimension required for Type IV floor construction?
6”x10”
This dimension is thicker than required in Type III and V constructions.
What is the primary use of modern heavy timber wood frame construction?
Aesthetic purposes
Many buildings are designed for visual appeal using heavy timber.
What is the fundamental problem with Type V construction?
The presence of extensive concealed voids
These voids can allow fire to spread rapidly and pose significant risks.
What are the two major classifications of occupancy according to NFPA 5000?
12
These classifications help in determining safety measures for different building types.
What does the fire load represent?
The maximum amount of heat that can be released if all fuel is consumed
Understanding fire load is crucial for fire safety assessments.
Fill in the blank: The allowable tensile strength of wood is typically ____ PSI.
700
This value is important for engineers when designing wooden structures.
What is the moisture content of most structural lumber?
19 percent or less
Moisture content can significantly affect the strength of wood.
What do engineered wood products provide?
Advantages of strength and cost efficiency
They are often used in modern construction for these benefits.
True or False: Laminated wood members can be produced in depths ranging from 3 to 75 inches.
True
This versatility allows for various construction applications.
What is the most commonly used test for determining combustibility?
ASTM E 136
This test is essential for assessing materials used in construction.
What does the fire resistance rating indicate?
The ability of a structural assembly to maintain its load bearing capacity and structural integrity under fire conditions
This rating is crucial for ensuring safety in building designs.
What standard test is used to evaluate the fire endurance of building construction materials?
ASTM E-119
This test provides critical data for building safety codes.
What are the disadvantages of wood members in fire conditions?
Unpredictable failure, fire
Wood members can behave unpredictably when exposed to fire without protection.
What are laminated wood members produced by joining flat strips of wood with glue known as?
Glue-laminated beams
The thickness of the finished beams varies from ¾ inch to 2 inches.
What are the depth and length ranges for laminated members?
3”-75” in depth, up to 100’ in length
Laminated members can be produced in various dimensions.
What types of joints can be used to join laminated members?
Butt, scarf, finger
The butt joint is easy to produce but not suitable for tensile forces.
Under fire conditions, laminated components may have comparable _______ to solid-wood components when protected.
Structural integrity
Glulam beams are frequently used in what type of construction?
Heavy timber construction
They are utilized where greater length components are needed.
Glulam beams react similarly to _______ under fire conditions.
Solid timber
What has current research indicated about the heat of a fire on the adhesives used in contemporary glulam beams?
No effect
What is the group of products known as SCL?
Structural composite lumber
This includes laminated veneer lumber (LVL), parallel strand lumber (PSL), and laminated strand lumber (LSL).
LVL finds application in I-joist and beam sections ranging from ___ to ___ inches thick.
1 ¾” to 3 ½”
PSL is made from the outmost veneers peeled from a log and ranges from ___ to ___ feet in length.
2 to 8
LSL uses strands of wood up to ___ inches long and is typically used for ____ beams and columns.
12”, short-span
What is thermoplastic composite lumber made from?
Wood fiber and polyethylene or polyvinyl chloride (PVC)
Thermoplastic lumber is not intended for use in the _______ of a building.
Structural framing
What is the flame spread rating of thermoplastic lumber?
80
Non-veneered components should not be trusted to ______ if exposed to fire conditions.
Maintain structural integrity
What are plywood panels made up of?
Several thin layers rotary sliced from rotating logs and glued together
Non-veneered panels are made up of engineered wood formed into sheets using what methods?
Resin, heat, and/or pressure
What are examples of non-veneered products?
- Oriented strand board (OSB)
- Particleboard
- Waferboard
OSB uses long strand-like wood particles that are compressed and glued into ____ to ____ layers.
3 to 5
Particle board can be manufactured in sizes up to ___ by ___ feet.
8x40’
What is waferboard similar to but has largely been replaced by?
Particleboard, OSB
Composite panels consist of a face and back panel of plywood or OSB bonded to a ______ material.
Central core
What materials can the core of composite panels be made from?
- Reconstituted fiber
- Paper honeycomb
- Plastic foam
What consists of outer wood panels (usually OSB) with a plastic foam core between the panels?
Structural insulated panel (SIP)
What are new developments in SIPs regarding fire resistance?
Use of foams such as polyurethane instead of polystyrene
Construction of SIPs is difficult to identify without what?
Pre-incident survey or opening a wall
Materials used for firestopping include what?
- 2” nominal lumber
- Gypsum board
- Cement fiber board
- Batts or blankets of mineral wool, glass fiber, or other approved materials
In balloon-frame buildings, firestopping must be provided in addition to what?
Structural members
Modern synthetic building wraps are much more fire resistant than what?
Felt or tar paper
What do exterior insulation and finishing systems (EIFS) increase?
Insulative properties
What are noncombustible materials used for insulation?
- Glass wool
- Rock wool with combustible paper or foil covering
- Fiberglass
What types of loose fill material can insulation take the form of?
- Granulated rock wool
- Mineral wool and glass wool
- Cellulose fiber and shredded wood treated with water-soluble salts
What are two types of solid fill foam insulations?
- Urea formaldehyde foam
- Polyurethane foam
Materials used for roofing include what?
- Aluminum
- Asphalt/shingles
- Cement board
- Plywood
- Stucco
- Stone
- Wood boards
- Wood shingles
- Vinyl siding
What is a veneer in wood-frame buildings?
An exterior brick or stone layer
Veneers must be tied to the wood frame wall at intervals of ___ inches.
16
The interior walls of wood frame buildings can be left exposed in small buildings such as ___ or ___.
Garages, sheds
A wood frame building can be classified as Type V-A if it is provided with protection to achieve a __ ___ ___.
1-hour fire resistance
An automatic sprinkler system may permit the elimination of the 1 hour structural fire resistance for what?
Wood frame buildings
What is not often used in modern construction because it requires a large amount of labor?
Plaster
Materials used as manufactured components include what?
- Adhesives
- Dimensional lumber
- Metal fasteners
- Panels
Lumber can be graded for what factors?
- Structural strength
- Appearance
What does a grade stamp on the back of a structural panel indicate?
Its intended structural application and suitability for exposure to water
What is pyrolysis?
The thermal decomposition of wood
It begins at a temperature somewhere below approximately 392 F.
The initial products of pyrolysis include the release of ____ and ____.
Water, carbon dioxide
The heat of combustion is measured in what units?
British Thermal Units (BTU) or kilojoules per gram
What has a great significance in fire fighting?
Surface-to-mass ratio
Treated wood resists ignition and has higher fire endurance compared to what?
Nontreated wood
Building codes permit the use of fire-retardant treated wood for certain applications in which types of construction?
Type I and Type II
What are the two main methods of fire retardant treatment of wood?
- Pressure impregnation
- Surface coating
Most fire retardant chemicals operate by ______ the formation of _____ in the wood when exposed to heat.
Accelerating, charring
Fire retardant treatments most commonly used are combinations of what?
- Inorganic salts
- Organic salts
Examples of chemicals that can be used for fire retardant treatment include:
- Ammonium phosphate
- Ammonium sulfate
- Boric acid
- Zinc chloride
- Sodium dichromate
- Borax
Fire-retardant treatments used in the 1980s were somewhat ______.
Hydroscopic
Fire resistive finishes will delay the entrance of fire into void spaces as long as they are ______.
Uncompromised
Fire may spread ______ to and ______ to the truss joints.
Parallel, perpendicular
What can create an area of concern regarding fire in a building?
Unfinished ceiling over a basement space
Applicable requirements for ignition-resistant construction may include fire resistant _____ _____ to protect against flaming embers.
Roof coverings
What is the limitation on the size of attic and under floor vents?
Protection with corrosion-resistant screens
Factors used to evaluate the hazard severity in a given location include:
- Ground slope
- Clear space around property
- Water supply
- Climate
The fire resistance of heavy timber columns and beams has been tested with the standard _____ _____ ___.
ASTM E-119 fire
This equation for timber members is applicable to nominal dimensions of ____ or greater.
6 inches
An engineer designing heavy timber construction will account for factors including:
- Likelihood of collapse of roof or floor decks
- Methods used to join the joist, beams, and columns
- Integrity of timber connections under fire conditions
- Suitability of protection of connectors
The wood framing systems can be broadly classified into two basic types:
- Light wood framing
- Heavy timber framing
What can support wood framing systems?
- Beams
- Trusses
Other wood construction types that may be encountered include:
- Pole construction
- Log construction
- Prefabricated panel construction
Smaller wood frame structures may be constructed using only ______ _____.
Carpentry techniques
What type of analysis is required for large or custom-designed wood structures?
Engineering
Most wood frame buildings do not exceed ____ stories.
3
In contrast, engineered wood structures can be built ____ stories high.
Several
Light wood framing uses nominal lumber that is ___ at its smallest.
2 inch
The floors are supported by what?
- Solid joist
- Truss joist
- Wood I-joist
In balloon frame construction, the exterior wall studs are continuous from the foundation to the roof, and joists that support the second floor rest on ______ recessed into vertical studs.
Ledger boards
The vertical combustible spaces between studs in balloon frame construction provide a channel for the rapid travel of fire between ______.
Building levels
A fire in a balloon frame building can be difficult to ______.
Control
Shrinkage in lumber occurs to a greater degree in the _____ dimensions than in its length.
Cross-sectional
The continuous studs of balloon framing have the advantage of minimizing the effects of ______ _____.
Lumber shrinkage
Historically, balloon frame refers to the fragile appearance of the thin, closely spaced ____ compared to the more massive members used in earlier construction styles.
Studs
Balloon framing has not been widely used since the ____.
1920s
In platform framing, the exterior wall vertical studs are not continuous to the second floor, also known as what?
Western framing
From a construction standpoint, platform frame buildings are ______ to erect than balloon frame.
Easier
Platform framing is more prone to ______ than balloon framing.
Shrinkage
This vertical movement can create undesirable effects such as cracking of plaster and misalignment of ____ and ____ openings.
Door, window
Modern use of ______-______ lumber minimizes the effects of shrinkage.
Kiln-dried
Identifiable features of heavy timber framing include:
- Trusses or beams to support the roof
- Nonload-bearing exterior walls
- Internal support columns not less than 8x8 inches
- Beams not less than 6x10 inches
The two primary differences between Type IV and Type III are:
- Type IV has thicker dimensions of wood structural members
- Type IV does not allow concealed spaces
Post and beam framing is a form of wood frame construction with columns and beams that use dimensions smaller than those used in heavy timber but greater than what?
Light-frame
Structural members in post and beam framing are spaced according to what?
The loads they are rated to support
The interior wood surface in post and beam framing is usually left ____.
Exposed
Architecturally, the exposed surface creates an attractive, rustic finish used in what type of buildings?
Rustic style dwellings and small storage buildings
Box beams and I-beams can be manufactured using a range of thickness of what?
- Plywood
- Laminated veneer lumber
- Oriented strand board
The flanges of the I-beam can be made of what?
- Laminated veneer lumber
- Solid wood lumber
In an I-beam, the flanges resist common bending stress and the web provides what?
Shear resistance
Wood I-beams are frequently used for what?
Floor joists and rafters in the framing of roofs
Why is the replacement of dimensional lumber with engineered wood products becoming more common?
Because the components are economical, resource efficient, and can be custom-built with few application limitations
What are the components that resist common bending stress and provide shear resistance?
Flanges and web
What type of engineered wood products are frequently used for floor joists and rafters?
Wood I-beams
The replacement of dimensional lumber with engineered wood products is becoming more common because the components are ______, ______, and can be ______.
Economical, resource efficient, custom built
Engineered wooden joists known as ______ are constructed of three engineered wood components that are bonded together to form an ______ cross section.
I-joist, I-shaped
I-joists are increasingly common in floor supports in ______ and ______ occupancies.
Residential, non-residential
A primary safety limitation of engineered wood systems is the possibility of ______ under fire conditions.
Swift collapse
What type of trusses have become popular for roof framing where the spans are small to moderate?
Light frame trusses
Light wood frame truss members use a series of _____ nominal members that align in the same ____.
2-inch, plane
In light wood frame construction, ______, ______, or screws may be adequate.
Nails, staples
Heavy timber trusses use members up to _____ or _____ inches and are mainly used for their ______.
8 to 10, appearance
The most common style of connector between heavy timber members are ______ with through bolts.
Steel gusset plates
Designers must plan connections that accommodate the forces that transfer from ______ to ______.
One member to another
In modern construction, ______ are used only in rare cases where the designer desires an ______ appearance.
Mortise and tenon joints, artistic
This method of joining members is highly ______ and therefore costly.
Labor intensive
A ______ uses a bolt with a thrust washer through the split ring to hold the members together.
Split-ring connector
A split-ring truss uses a short circular piece of ______ within and between two adjacent wood members to ______ between the members.
Steel, transfer the load
Simply using ______ or ______ to connect wood has a serious limitation.
Screws or bolts
This type of connection tends to concentrate the load application and result in ______ of the wood at the point of application and an ______ use of the wood.
Deformation, inefficient
Structural collapse may occur regardless of ______.
Fire
