Chapter 3 Building Construction Flashcards
As the size of structural members is reduced, what fireground factor is also reduced?
Time
What are the four major components of a building construction size-up?
- Construction styles
- Construction methods
- Roof styles
- Age of the building
What are the two major construction styles as outlined in this chapter?
Conventional and
Lightweight construction
Brick buildings constructed up until the 1930s are commonly classified as what sort of construction?
Unreinforced masonry construction
What are the six most common roof styles?
- Gable
- Hip
- Flat
- Bridge truss
- Arch
- Sawtooth
What are the primary hazards of unreinforced masonry construction?
Wall, roof, and floor collapse. Resources must be placed out of the potential collapse zone.
What are two hazards of older frame-wood buildings?
Balloon construction and
knob-and-tube wiring
What four factors should be considered when evaluating a fascia?
- Overhang
- Height
- Supported or unsupported
- Height from the roof
Steel exposed to fire begins to lose its structural integrity at what temperature?
1000 degrees F
For purposes of size-up, buildings can be classified into what general time periods?
Pre- and mid-1930s
1930s-to late 1950s
late 1950s-to present
A size-up consist of what 3 distinct parts?
Analysis
Decision
Implementation
The type and construction of a building will indicate what? (5)
Rate of burn Avenues of fire spread Problems on fire containment Structural integrity Time necessary
Conventional construction gets its strength from what?
The size of the structural members
Lightweight construction gets its strength from what?
Multiple members being in compression or tension.
The strength of one member is dependent on the sum of the other members
Bridge truss roofs are on commercial buildings primarily constructed when?
1920s-1940’s
Arched roof (bowstring) was constructed primarily during when?
early to mid 1900s
Arched roofs usually fail how?
in sections
What is a Lamella arched roof?
egg crate, geometric or diamond-patterned roof
What does the Tied Truss arched roof use to offer lateral support to the walls of the building?
Metal tie rods
What are the hazards of Tied Truss arched roof?
Weak roof
Early failure rate
Collapse without warning
What are the 3 primary factors in recognizing wood truss construction?
- roof shape
- long unsupported spans
- occupancy type
What components make up the wooden I-beam? (3)
Top chord
bottom chord
stem
How are nailing blocks used to strengthen flat roof, wooden I-beam construction?
Placed perpendicular to the top chords and spaced 4 ft on-center
What does an Open-Web flat roof construction consist of?
A top and bottom wooden chords cross connected by steel-tube members
What 4 major components make up a Panelized flat roof?
- Beams (wood or metal)
- Purlins
- Joists (2x4)
- Plywood decking (1/2 inch)
How far apart can the beams on a panelized flat roof be?
12 to 40 feet apart
How far apart are the purlins on a panelized flat roof?
Normally what size are they?
8 ft. on center
4x12 inches
What is a Nonstructural lightweight concrete flat roof?
corrugated metal with a 3”-4” mixture of sand, cement, and possibly pea gravel on top.
What are the 6 categories that buildings can be divided into?
- Metal
- Concrete
- Masonry
- frame-stucco
- frame-wood
- Curtain
Modern high-rise buildings and multi-story office buildings typify what type of construction?
Metal Beam
How tall can a Concrete (Tilt-up) building be?
Up to 5 stories high
What are the characteristics of pre-1933 masonry construction buildings? (6)
- Mortar consisting of sand and lime-no cement
- Lack of rebar
- Exterior brick walls 13” thick
- Parapet around roof
- Floor and Roof joists that are “let” into a cavity
- Roof and floor joists are “fire-cut”
What revisions characterize masonry structures built post-1933? (4)
- Cement in mortar
- Rebar in masonry walls
- Exterior walls at least 9” thick
- Joists and rafters must be tied in to ext. walls
In 1959, what retro-active corrections were required on unreinforced masonry construction buildings? (3)
- Concrete cap on parapets
- Parapets not higher than 16”
- Steel anchor bars or rods installed through ext. walls, rendering “fire-cuts” ineffective
In 1971, what 2 retro-active corrections were put in place and designed to prevent exterior walls from collapsing outward?
- Anchoring walls to floors and roofs
2. Strengthening roof construction
What is a “King Row” and why is it used?
a of bricks that are laid on end, every 4th to 7th row of bricks.
Used for additional strength.
What is a fascia?
a horizontal member used for cosmetic purposes on the face of a building.
What are the most difficult windows to force?
jalousy
What is a gusset plate and how far does it penetrate?
18 gauge steel. penetrates 3/8”
