means of egress system
Building Design and Construction
FIRE 1102 – Principles of Fire Science Reference: Chapter 4 of Cote, Fundamentals of Fire Protection
UAE Tamweel Tower
Objectives of Fire-Safe Building Design
1. Life Safety
2. Property Protection
3. Continuity of Operations
4. Environmental Protection
5. Historical Preservation
Life Safety • Achieved by early warning of a fire, extinguishment
of a fire, proper egress for prompt escape
• Can the occupants get out before the room becomes untenable?
– We know that flashover is a time when the room is untenable,
– However there may be a time before flashover where a room is untenable where concentration of fire gases (CO) can create such a situation.
• We can do modeling of how long it takes for occupants to evacuate out of a building and predict when a room becomes untenable.
• Human Behavior Research
Fire Modeling of Station Night Club Fire
Human Behavior Research
Property Protection • Materials that can be replaced which have a dollar
value assigned to them.
• Billions of dollars are lost due to fires each year.
• Achieved by installing proper fire extinguishing systems, compartmentation features to limit spread and construction of building materials.
Heritage Preservation
• Irreplaceable items and artifacts.
• Accomplished using appropriate fire extinguishing systems.
Mona Lisa Original Copy of Declaration of Independence
Hand Written Quran National Museum of Saudi Arabia
Continuity of Operations
• Getting back to business
• Accomplished by installation of proper fire extinguishing systems
Environmental Preservation
• Protecting our environment from fire and/or fire extinguishing agent.
• Installation of fire extinguishing systems that limit fire size, minimize run-off from water, using agents that do not adversely affect the ozone layer.
Types of Building Construction
• NonCombustible Construction
– Type I
– Type II
• Combustible Construction
• Type III
• Type IV
• Type V
Type I Construction Non-combustible
• Fire Resistive • Constructed of concrete
and protected steel • Columns and beams are
covered with fire resistive spray on material.
• Primary hazard are the contents in the structure.
• High-rise office buildings, shopping centers
Type II Construction Non-combustible
• Non-Combustible • Lower degree of fire resistance than
Type I. • Fire resistant rating on all exterior
and interior load bearing walls. • May have combustible non-
loadbearing partition walls. • Columns and beams are not
protected and will be exposed during a fire.
• Office buildings, warehouses, automobile repair shops.
Type III Construction Combustible
• Ordinary Construction
• Office buildings, retail stores, mixed occupancies with store on first floor and dwelling on second floor.
• Exterior walls of the building have 2-hr fire resistance rating and non- combustible
• Interior members (walls, beams, floors, roof) are made of wood
• Hazards: smoke and fire spread through concealed spaces
Type IV Construction Combustible
• Heavy timber (mill construction)
• Exterior/interior walls noncombustible material
• Interior structural members (beams, columns, arches, floors) made of solid or laminated wood with no concealed spaces
• Found in old factories, warehouses, churches
Type V Construction Combustible
• Frame construction
• Exterior and interior structural members made of wood
• Fire Hazard: unlimited potential for fire extension, fire extension to nearby structures
• Typical residential home
Construction Materials
Wood
• Combustible • Char forms at surface (acts as insulator)
– Good for heavy timber
• Used as different building elements – structural material – Siding – Flooring – Roofing underlayment – Interior finish – Furniture
https://www.youtube.com/watch?v=a3Q3wwRAGiw Great Chicago Fire 1871
Steel • Used to form frame of building
– Beams, girders, columns, bar joists
• Noncombustible
• Expands when exposed to heat
• Conducts heat
• Loses 40 – 50% of its strength when exposed to temps of 900 – 1100 °F
• Most codes require steel to be protected with sprinklers
• May be protected by encasement, spray-on, gypsum
Concrete Masonry
• Mixture of cement, water, and aggregate (rocks/stones)
• Very fire resistive but can spall when water is forced out of the concrete.
Glass
• Not fire resistive, but resists passage of smoke.
• Improve resistivity by adding wire mesh into the glass.
• Fire-rated glass will have
Gypsum and Plaster
• Plaster made from gypsum rock, crushed and ground into powder – Water added to create paste-like
substance
• Gypsum board – Sheetrock, drywall
• Excellent fire resistive protection – Water is major component
• Must make certain that penetrations (holes) are filled in. – Fire and smoke can pass through
holes in the wall.
Fire Testing of Building Materials
• ASTM E119 – Standard Test Method for Fire Tests of Building Construction Materials
– https://www.youtube.com/watch?v=lW72-L0_n_M
– ASTM (American Society for Testing and Materials)
• Involves placing floor, wall, roof or door assembly into a furnace and subjecting it to the heat rates specified in the time temperature curve for the duration desired.
Time Temperature Curve
• Fire severity expressed in terms of temperature and duration.
• This curve represents a severe building fire.
• Required fire ratings are prescribed in codes that advise as to how long a door, wall floor, etc. can withstand a fire.
Flame Spread Ratings • The materials first involved in fire
ignition or spread are the contents, furnishings, and interior finishes.
• Materials that are used as interior finish on walls and ceilings must meet certain standards to resist fire spread.
• Materials are tested in a device called Steiner Tunnel
• Flame spread rating is a relative measure of how material will allow fire to spread across the surface. – Rating of 0 –25 Class A (Cement
asbestos has a rating of 0) – Rating of 26 – 75 Class B – Rating of 76-200 Class C (Road oak
has rating of 100)
Smoke Spread • Control of smoke is important from both life
safety and property protection standpoint. • Smoke management does following things:
– Maintain tenability in means of egress system – Confine smoke spread to area or compartment of
origin – Assist firefighting operations by maintaining
conditions outside fire area – Reduce property loss and minimize business
interruption.
• Accomplish smoke management via – Pressure differential across physical barrier – Remove smoke by large volume air flows – Dilute smoke with “fresh air”
Mechanical Smoke Control System , Santa Monica, California https://www.youtube.com/watch ?v=a3Rg4VJVVfI