*Bk 29- Building Construction Flashcards
Lightweight truss construction- Strength is obtained from multiple members that are in ___________ and ___________
Compression and tension
A single lightweight truss structural member can span how far?
70 feet
The amount of time that a structure can be considered structurally strong is dependent on what 3 factors?
- Type of construction
- How long fire has been burning
- Fire intensity
What are the six types of roof styles explained in book 29?
- Gable
- Flat
- Hip
- Bridge truss
- Arch truss
- Sawtooth
Gable roofs (conventional)- size and span of rafters? Include steep pitch roof.
- 2x6” or larger. 16” to 24” on center
2. Steep pitch- 2x6”. 36” on center
What gauge is the most common metal gusset plate?
How long are the prongs?
- 18 gauge
2. 3/8”
Lightweight trusses- Eighteen-gauge “roof truss clips” may be found nailed to the bottom chord of every how many trusses?
3-5 trusses
Common “on-center” spacing for truss rafters is?
24” on center
Can interior partition walls support the truss at any point along the bottom chord?
No
What are the strong areas of a conventional gable roof?
Ridge and bearing wall
Newer roofs use ______inch or ______ inch plywood as a decking instead of 1 x 4 inch or 1 x 6 inch space sheathing
3/8 or 1/2”
What are the dimensions of decking used in space, straight and diagonal sheathing?
1x4” or 1x6”
What type of rafter is utilized where two roof lines join together?
Valley rafter
Gable (conventional)- size of ridge board (if present)
1x6” or 2x6”
Hip (conventional)- size and span of rafters? Include steep pitch.
Size of ridge board?
- 2x6” or larger. 16, 24” on center
Steep pitch- “Rough cut” 2x3 or 2x4”. 36” on center - Ridge- 2x6” or larger
What are the strong areas of a conventional hip roof?
Ridge board, valley rafters, hip rafters, and the area where rafters cross the outside walls
Bridge truss roof- Wooden truss members are what size?
2x12” lumber
In truss construction, the top chord is in _______ and the bottom chord is in _______
Compression or tension?
- Compression
2. Tension
Bridge truss- What is the rafter size? What type and size sheathing will you find?
Rafters- 2x6” or larger
Sheathing- 1x6” diagonal or straight
Per the earthquake ordinance, what cutoff year would you find straight sheathing?
What about diagonal sheathing?
- Pre 1933
2. Post 1933
Bowstring arch truss- size of arch members?
Rafter size?
Sheathing size?
- 2x12” or 2x14”
- 2x6” or larger
- 1x6” straight or diagonal (1933)
Lamella arch roof- size of wood framing?
Size of sheathing?
- 2x12”
2. 1x6” sheathing
Lamella arch roof- total roof collapse may occur if fire removes more than ______% of the roof structure.
20%
Which arch truss roof uses metal tie rods to offer lateral support for the walls of the building?
Tied truss arch
Tied truss arch- size of tie rods?
5/8” diameter
Tied truss arch- size of top chord members?
Rafter size?
Sheathing size?
- 2x12” or larger
- 2x10” or larger
- 1x6” straight or diagonal (1933)
What is the primary hazard of a tied truss arch roof?
Failure of metal tie rods and turnbuckles
Sawtooth roof- size of rafters?
Size of sheathing?
- 2x8” or larger
2. 1x6” or 1/2 plywood
Conventional flat roof- size of rafters?
Size of sheathing?
- 2x6” or larger
2. 1x6” or plywood (newer)
What are the four types of construction for a lightweight flat roof?
Wooden I-beam
Open web
Metal gusset plate
Panelized
What thickness is plywood found in on a newer conventional flat roof?
3/8” to 5/8”
Wooden I-beam- size of chords?
Material and size of stem?
- 2x4” or 2x3”
2. 3/8” plywood or OSB
What is the term for when the joints of the plywood on a roof are staggered (every 4’) similar to a masonry wall?
Diaphragm nailing
What is the common on-center spacing for wooden I-beam, metal gusset plate, open web trusses?
24”
How far are nailing blocks spaced apart?
4’ apart
The steel tube web members in an open web truss roof are prefabricated to what size?
1-2”
Open web roof- span of trusses?
70’ possible
What gauge are metal gusset with prongs that produce 3/8” penetration?
18 gauge
Metal gusset plate roof- up to what span in possible?
80 feet
Metal gusset plate roof- commercial building plywood thickness?
Plywood thickness for dwellings?
- 1/2”
2. 3/8” or 1/2”
What are the four major components that make up a panelized roof?
- Beams
- Purlins
- Rafters
- Plywood
What is the thickness of plywood used on panelized roofs?
1/2”
Panelized roof- what are the sizes and spans of the beams?
Size: 6x36”
Span: 12-40ft
On a panelized roof, beams may be bolted together to provide lengths well in excess of how many feet?
100ft
On a panelized roof, what are the sizes and spacing of purlins?
Size: 4x12”
Span: 8ft
On a panelized roof, what are the sizes and spacing of joists?
Size: 2x4”
Spacing: 24”
The 3 strengths (walkable) of a panelized roof are?
- Beams
- Purlins
- Perimeter of building
One of the hazards listed on a panelized roof are the beam span supports of hollow steel pipe. What size are these supports?
4”
In an Open Web Bar Joist roof, the top and bottom chords are usually made from steel of what thickness?
1/8”
In an Open Web Bar Joist roof, web supports are a solid steel bar of what thickness?
5/8”
In an Open Web Bar Joist roof, buildings may have bar-joists used as girders spaced up to how many feet?
45 ft
In an Open Web Bar Joist roof, how many feet apart are the joists to accept corrugated metal decking?
8’
According to book 29, steel begins to lose its strength at how many degrees F?
1000 degrees F
On a lightweight concrete roof, an air-entrained mixture of sand, cement and, occasionally, pea gravel is pumped on top of the corrugated metal decking and wire mesh to a thickness of how many inches?
3-4”
What are the dimensions of the wire mesh used on a lightweight concrete roof?
4x4” and 6x6”
Lightweight concrete roofs are used on buildings when what is desired?
Additional insulative properties (airports, freeways, ect)
What type of roof should a rotary saw be used to cut ventilation holes?
What two types of blades should be used?
- Lightweight concrete roofs
2. Diamond or carbide tip
Buildings that are primarily constructed of metal can be categorized into what two construction types?
- Corrugated
2. Metal beam
When exposed to sufficient heat, metal beams can expand how many inches per 100’
9”
Concrete tilt up buildings can be up to how many stories in height?
5
What are the two types of masonry construction types?
Brick and block
Masonry buildings constructed prior to 1933 have brick exterior walls how thick?
13”
Masonry buildings constructed prior to 1933 can have parapets how high above the roofline?
How high can the parapet be if used as a facade?
- 3 ft
2. 5 ft or more
Masonry buildings constructed prior to 1933 have what type of sheathing?
Straight sheathing
Masonry buildings that were built after 1933 are required to have exterior walls how thick?
9”
Masonry buildings that were built after 1933 have what type of roof sheathing?
Diagonal sheathing
What year required a concrete bond-beam cap to be laid on top of lowered parapet walls along public ways and exits on pre-1933 buildings
How thick was the bond beam?
- 1959
2. 4-6”
What year required pre-1933 parapet walls not be higher than 16 inches including the bond-beam cap?
1959
A retrofitted pre-1933 brick building should have parapet walls no higher than how many inches including the bond-beam cap?
16”
What year caused rafter tie plates to be implemented on pre-1933 brick buildings?
1959
In the 1959 retrofit for pre-1933 brick buildings, exterior walls were drilled at the roof rafter level and a steel anchor bar/rod was installed every how many feet and attached to the existing roof rafter?
4 ft
What year caused the modification on pre-1933 brick buildings to render the “fire cut” on roof rafters ineffective?
1959
After what year caused the anchoring of walls to floor and roof systems on pre-1933 brick buildings?
1971
After what year caused the strengthening of roof construction on pre-1933 brick buildings? (Plywood, metal straps, ect)
1971
Pre-1933 brick building: deeply recessed window frames expose how many inches of brick to the exterior?
8”
After how many rows of brick is laid before one row is laid on end to create a “kings row”?
4-7
Unreinforced masonry buildings may have metal straps that run the width of the roof. The straps are usually found how far back from the front and rear walls?
1/3 the distance of the building
What are the primary hazards with unreinforced masonry construction?
Wall, roof, and floor collapse
Unreinforced masonry- Exterior walls may suddenly collapse (during
fire conditions) how far outward from the building?
At least equal to the height of the wall
Unreinforced masonry- On arch typed roofs, what sides of a building are a primary danger for collapse?
Front and rear
Unreinforced masonry- On arch typed roofs, where are the safe areas when dealing with wall collapse?
- Corners of building
2. Distance equal to at least the height of the wall
Unreinforced masonry- in addition to metal straps running the width of the building, they can also be found how far from the walls?
3-4 feet
Convention or lightweight roof/floors for concrete block construction?
Lightweight
An identifiable style of construction on the exterior of a building that will conceal and spread the travel (extension) of fire is known as?
Facade
What is often utilized to conceal equipment and machinery on flat roofs?
Facade
What four things should be considered when confronted by facade?
- Overhang
- Facade height
- Supported or unsupported
- Height from roof
Unless proven otherwise, expect any facade to be constructed without __________ and open to the _________ of the building
- Fire stops
2. Attic
If a facade is exposed to fire, expect the facade to collapse outward how far?
At least the distance of the facade overhang
What 5 things on a building can be used to help identify where a roof line is located?
- Scuppers
- Attic vents
- Equipment seen on roof
- Windows
- Rafter tie plates
Balloon construction can be utilized in buildings of up to how many stories?
4
In bungalow construction, “old type” of lightweight construction utilized what size members for rafters and ridge board?
- 2x3 or 2x4” rafters
2. 1x6” ridge board (optional)
A building which does not utilize horizontal fire blocking in the walls and plates between multiple floors separating the attic from open vertical runs in the walls is known as what type of construction?
Balloon construction
____________ construction utilizes fire blocking in the wall (studs which eliminate open vertical pathways to the attic)
Platform
Wires which are suspended on ceramic insulators and pass through ceramic tubes when it is necessary to run the wires through studs or plates are known as what type of wiring?
Knob and tube
During a fire in an older building that uses knob and tube wiring, emphasis must be placed on eliminating what?
Electrical service
What three general time periods that can be used to classify building construction?
- Pre-1933
- 1933 to late 1950
- 1950’s to present
To ensure effective and safe fireground operations, personnel must address what four factors when dealing with lightweight construction?
- Identification
- Communication
- Time
- Operations
A working knowledge of building construction provides a safe foundation for effective, timely, and safe fire ground operations in what four areas?
- Structure integrity
- Ladder placement
- Forcible entry / search and rescue
- Ventilation feasibility
When a personal size up (analyzing the situation) is applied to a structure fire, one of the first considerations should be the ____ and _____ of the building
Type and Construction
When conducting a BUILDING size-up, “undress” the building in your mind. Our size-up will focus on what four areas?
- construction style
- roof styles
- construction methods (frame/stucco, masonry, etc.)
- age of building
Construction members for mill/timber may be ____ inch by ____ inch
8x8
After what year required new masonry construction to have exterior walls at least nine inches thick and utilize cement and reinforced with steel rebar?
Post 1933
After what year required new masonry construction have all joists and rafters be anchored to exterior walls? This is usually accomplished by bolting a “ledger board” to a masonry wall and attaching the joist and rafters to the ledger board with metal hangers.
Post 1933
In present day, unreinforced masonry buildings will share all or a portion of what trademarks?
- rafter tie plates
- bond beam on parapet / over windows / between floors
- deeply recessed windows
- windows with arched or straight lintels
- The lime mortar between the bricks is white, porous, sandy, and may be easily rubbed away
- kings row
Conventional construction utilizes structural members that depend on _______ for strength.
Size
