Building Construction Flashcards
NFPA # for Building Construction
NFPA Standard 220
Building Construction Types
Types 1-5
Type 1
Fire-resistive
Type 2
Noncombustible or limited combustible
Type 3
Ordinary construction
Type 4
Heavy timber
Type 5
Wood frame
Type 1 443 (numbers after #1 mean what?)
First number is hours resistant to fire (i.e. 4 hours) of EXTERIOR bearing walls
Second number is the fire resistance rating of STRUCTURAL frames/columns
Third number is the fire resistance rating for the FLOOR construction
Examples of Type 1 Construction
High-rises, jails/prisons, hospitals (protected steel infrastructure)
Type 1 Strengths
- Resists direct flame impingement
- Confines fire well
- Little collapse potential (from fire effect alone)
- Impervious to water damage
Type 1 Weaknesses
- Difficult to breach
- Difficult to ventilate
- Massive amounts of debris
- Floors, ceilings, walls retain heat
Type 2 make-up
Unprotected steel is most common characteristic
Materials with no fire-resistance ratings (i.e. untreated wood) may be used in small quantities
Open-web bar joist is very common w/ type 2
Examples of Type 2 Construction
Warehouses, restaurants, etc. (Walmart, malls, mechanic shop)
Type 2 Strengths
- Almost as fire resistive as Type 1
- Confines fire well
- Almost as structurally stable as Type 1
- Easier to vertically ventilate than Type 1
Type 2 Weaknesses
- Difficult to breach for access/escape
- Unprotected steel structure components can fail due to high heat
- Roof systems are less stable than Type 1
- Steel components may weaken by fire
- May weaken by rust or corrosion
- Massive debris following collapse
Type 3
Ordinary construction
May also be called brick and joist
Type 3 make-up
- Exterior walls and structural members made up of noncombustible or limited combustible material
- Interior walls, beams, floors, and roof are made completely or partially of small-dimension wood
Type 3 primary fire hazard
Smoke and fire spread through concealed spaces (i.e. cockloft or suspended ceiling) VOID SPACES
Type 4
Heavy timber
Rarely used today other than churches (used to be warehouses, mills, etc.)
Type 4 Primary Fire Hazards
- Massive amounts of combustible materials
- Heavy timbers remain stable for a long period under fire conditions
Type 5
Wood-frame construction aka residential (also lots of restaurants and convenient stores)
Type 5 makeup
Small-dimension wood and other materials (commonly used in single-family residence)
Balloon wood-frame vs. Platform wood-frame
Balloon is older victorian-style homes w/o firebreak (fire spreads very quickly) vs. Platform wood-frame is more modern construction, one floor built at a time with a firebreak in-between floors (slows down spread of fire)
Type 5 Primary Fire Hazards
- Almost unlimited potential for fire extension w/in a structure
- Fire extension to nearby structures
- Fire extension from doors and windows to exterior structure