Ch 4 Classifying Buildings - NFPA 220 Flashcards
Will burn, flammable
Combustible
Materials that have about 1/2 the heat potential of wood or not over 3500 BTU/lb
Limited-combustible
The length of time to burn through a given material, rated in minutes or hours
Fire resistance rating (FRR)
The length of time it takes to burn across the surface of a given material-rated in minutes or hours
Flame spread rating (FSR)
(Not “Fire”)
Having a fire resistance rating of at least one hour based on its structural elements or protective envelope for the structural elements
Protected
A material that when exposed, or can be exposed in its natural state to the effects of heat, and or fire, will cause a degradation of its structural integrity
Unprotected
In NFPA 220 this Arabic number indicates the fire resistance of the exterior bearing walls
The first number
In NFPA 220, this Arabic number indicates the structural frame.
The 2nd number
In NFPA 220 this Arabic number indicates the floor construction
The 3rd number
What are the three numbers for NFPA 220?
- exterior bearing walls
- structural frame
- floor construction
220 is your BFF
In Type 1 construction (442 or 332) how many ways can steel structural members be protected?
Four
What are the four ways steel structural members must be protected in Type 1 construction?
- fire resistive concrete
- gypsum board
- a coating material is sprayed on the steel (vermiculite)
- an intumescent fire resistant coating is applied to the steel and applied like paint (.5 in thick, can expand 15-30 times) (popular for exposed steel)
This type of construction can be often found in conventional and modern, mid to high-rise buildings (commercial and residential) hospitals, schools, shopping centers, airports, and other similar types of large buildings that are often associated with public assembly.
Type 1 Construction (442 or 332)
Three categories of Type 1 buildings
- Center hallway
- Center core
- Combination of center core/center hallway configurations
These Type 1 buildings have stair shafts at either end of the building that is common to the hallways
Center hallway
These Type 1 buildings will place the elevators, stairs, and other necessary essentials in central core in the middle of a building with the hallways on each floor, arranged around the central core. These are referred to as “circuit hallways”.
Center core configuration
These Type 1 configurations are often found in larger buildings, and can have a center core with stairways and hallways that are common to the stair shafts at the ends of a building
Combination
Which type of construction should be those types in which the firewalls, structural elements, walls, arches, floors and roofs are approved non-combustible or limited combustible materials?
Type 1, Fire Resistive (442 or 332) OR Type 2, Noncombustible (222, 111, or 000)
In Type 2 construction, exterior walls fall into three general classifications:
Unreinforced masonry, reinforced masonry, and tilt-up or precast
A small space that is created when a roof is raised above the level of ceiling joists and rafters to provide a pitch for drainage. Common in older buildings (1800s and early 1900s)
Cock loft
A large space is created by a steep pitched roof arch, gable, etc) for drainage and or appearance. Normally large enough for storage, can be modified for additional living space and can contain HVAC
Attic
An attic space created by the open web nature of trusses. The voids can allow fire to easily extend in numerous directions
Truss loft
In this type of construction, the primary hazard is the combustible interior structural components and contents
Type 3
In this type of construction, the primary hazard is in the contents within the building
Type 1
What type of buildings are included in Type V?
(4)
- stacked log
- post and beam
- balloon frame
- western platform
(conventional legacy and
engineered wood)?
Likely the oldest type V buildings found in America
Stacked log
The strongest wood construction
Stacked log
This is the weak portion of post and beam construction
Mortise and Tenon joints, particularly the Tenon
This type of construction is known as Chicago construction?
Balloon frame
Floor joists are attached to a ribbon board (a type of ledger) (or girts) with what type of construction?
Balloon frame
The following characteristics are what type of construction:
- 2x 4’s, 16 inch on Center
- up to about three stories in height
- roof rafters spaced up to 3 feet on center
Balloon frame
The two primary structural components of post and beam (aka pole barn)
Corner post and horizontal beams (aka girts/ribbon boards)
This has become the most common type of wood construction
Platform construction
Platform construction provides intrinsic fire stopping from two elements
1) Fire blocking in the exterior walls between floor and ceiling joists, and 2) the double plate at the top of each floor (double plate eliminates void spaces)
Wood platform buildings can be subdivided into three categories
Conventional
Legacy
Engineered (lightweight)
(CLE)
Conventional platform construction was typical from
1800s through the late 1940s
The greatest fire spread concern in Conventional platform buildings is driven by:
- Contents
- Interior geometry (hall, stairs, etc.)
This type of platform construction is characterized by the use of solid milled wood lumber for the assembly of wall studs, floor joists, roof trusses, joists, and rafters (as opposed to engineered wood)
Legacy platform (1950’s)
Legacy and conventional platforms DIFFER in fire concerns with the advent of?
- Larger spaces
- Split levels
- Use of more soffits
Which type of platform construction uses a truss built only with solid wood and connections that are driven through the center mass of a joining spaces
Legacy - Craftsman built
Failure rate of conventional/legacy floors and failure rate of lightweight construction
Conventional/legacy - 15 to 20 minutes
Lightweight 5 to 7 minutes
This is nothing more than a continuation of a wall above a roofline, and can extend from 1 foot to 8 feet
Parapet wall
To achieve familiarization and/or rapid size up, firefighters must invest in a three-step process:
- Pre-incident study
- Pre-fire familiarization of actual buildings
- On-scene pre-and post incident experience
Type ____ through ____ can normally be easily identified from the street whereas type ___ and ____ can only be identified from the interior building, if at all.
3 through 5
1 and 2
Wood platform buildings can be subdivided into three styles
- Conventional (contents & geometry)
- Legacy (trusses nails/staples) (difference between conv’l-geometry & size, soffits)
- Engineered lightweight (glues, gusset plates)
Of the 3 types of exterior walls in Type II, this is the most susceptible to collapse from expanding and failing steel structural members and can easily collapse outwards this distance
-Unreinforced Masonry
(URM)
- Twice its height
The primary hazard to the UNPROTECTED STEEL in Type II buildings is ____
The contents within the building and their proximity to the steel structural members
The name on the exterior of a commercial building is a ____ indicator of the contents
Great
This should be a primary consideration in Type II multistory buildings, particularly residential and commercial residential buildings
Extension of fire and its by-products
In Type III Construction, this is primary problem in mulitstory buildings, especially Type III commercial residential buildings
Vertical extension and it’s by-products (major contributor to loss of life)
Dimensions for load-carrying wood Type IV
- Floors columns- 8 in
- Roofs/ceilings columns -
6in wide
8 in deep - Floors beams - 6 in wide
10 in deep - Floors - 3 in thick
- Roof deck - 2 in
With Stacked Log construction, what is the weak link in the building?
Roof Decking
NFPA uses a combination of numerals to define five types of building construction and the fire resistance of their primary structural components. The first designation is a ____ numeral that refers to the type of construction.
Roman
The principal hazards within a Type II building are:
- Combustible materials that compromise the roof, in combination with…
- Contents
These two items affect fire spread the most in Legacy platform buildings:
- Interior contents
- Geometry
This type of platform construction relies on members of less than 2 x 4“ elements made from glued wood pieces, glue use for connection points, geometry in place of mass for structural members, and the concept of assembly building techniques to achieve strength.
Engineered wood platform
The primary hazards for this type of platform construction are:
- small-dimension lumber
- metal hangers
- plywood/OSB sheathing
Legacy
The primary hazards for this type of platform construction are:
- rapid fire spread due to milled and glued lumber
- open web lightweight trusses
- use of OSB
Engineered platform
What is the primary fire spread and collapse concern for Stacked Log?
Incorporation of lightweight construction in the roof
What is the primary PROBLEM in multistory buildings, especially Type III commercial residential buildings?
Vertical extension of fire in its byproducts
