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Good buildings make and are made by their settings, and they are appropriately different in different locations. Climate, culture, topography and materials have helped create regional architectural languages that seem curiously right for their locations and for all times.
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BUILDING CONSTRUCTION
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Types of Building Construction
• Most building codes have 5 types of building construction.
• Many buildings include several types of construction.
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Type I: Fire Resistive Construction
• Structural members made of noncombustible / limited combustible materials.
• Construction intended to confine fire and its byproducts to a given location.
• Primary fire hazard is contents of structure.
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Type II: Noncombustible Construction
• Lower degree of fire resistance than type I.
• Fire resistance rating on all exterior and interior load bearing walls.
• May have combustible features, as materials with no fire resistance rating may be used.
• Generally have flat roofs with combustible felt, insulation and roofing tar.
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Why is Size-up Important?
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Type III: Ordinary Construction• Exterior walls & structural
members of noncombustible / limited combustible materials.
• Interior members (walls, beams, floors, roof) are made of wood.
• Hazards: smoke and fire spread through concealed spaces.
• Fire stops to limit spread.
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Type IV: Heavy Timber• Exterior / interior walls
noncombustible material.• Interior structural members
(beams, columns, arches, floors etc.) made of solid or laminated wood with no concealed spaces.
• Found in old factories, warehouses, churches.
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Type V: Frame Construction
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Type V: Frame Construction
• Exterior and interior structural members made of wood.
• Fire Hazards: unlimited potential for fire extension, fire extension to nearby structures.
• Typical residential home
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Platform Frame
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“Silent Flooring”
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Poor Construction Methods
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Fire Effects on Common Construction Materials – Wood
• May be used in load bearing and non-load bearing walls.
• Reaction of wood to fire conditions is based on the size of the wood and its moisture content.
• Water does not have a negative effect on wood’s structural strength.
• Plywood, particle board, paneling may be highly combustible, produce toxic gases and rapidly deteriorate under fire conditions.
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Fire Effects on Common Construction Materials -
Masonry• Brick, concrete, and stonework.• Commonly used for firewalls to separate connected
structures and prevent fire spread.• May be used as load bearing or veneer.• Minimally affected by fire & high temperatures.• Mortar joints between bricks, blocks may
deteriorate. (mortar mix is weakest part of wall)• Rapid cooling of masonry by water may cause
cracking or spalling.
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Fire Effects on Common Construction Materials - Concrete• Concrete is a mixture of portland cement, sand,
gravel and water.• Often used as a fire resistive protection for
structural steel (reinforced concrete).• May crack or spall if heated, indication of damage
& reduced strength.• Heating may cause bond between steel and
concrete to fail.• Concrete tends to absorb and retain heat.
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Fire Effects on Common Construction Materials –
Reinforced Concrete
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Fire Effects on Common Construction Materials - Steel
• Primary use of steel is for structural members.
• Steel is an excellent conductor of heat.• Steel loses strength as temperature increases• Steel structural members will elongate
when heated.• Water can cool steel structural members
and reduce risk of failure or collapse.
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Fire Effects on Common Construction Materials - Steel
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Fire Effects on Common Construction Materials - Plastic
• Becoming integrated to replace/improve common building materials
• Plastics are oil-based (hydrocarbons)• Two general types
– Thermoplastics (melt, deform, vapourize = burns!)
– Thermosets (decomposes, only burns with extreme temps)
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Fire Effects on Common Construction Materials - Plastic
• General Rule of Thumb when fighting fires involving plastics…– Burn fast
– Very intense heat
– Dense black smoke
– Extremely toxic
• Can resemble a Class B Fire (flammable liquids)
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BREAK TIME
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Roof Types
Three Main Types:(a) Flat(b) Pitched(c) Arched
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Occupancy Versus Type of Construction
• Occupancy creates the fire load.• Building codes specify building type based
on occupancy classification.• Fire code determines fire protection based
on building and occupancy use.• Occupancies are residential, commercial,
business, industrial and educational.• Each type has a number of hazards.
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Occupancy Hazards
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Building Uses
• Ontario Fire Code and Ontario Building Code separate buildings in groups A-F, as related to their major use (or major occupancy)
• With each type of building comes various requirements/restrictions on building construction
• Private dwelling residences are exempt (with some exceptions)
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Building Uses
• A – Assembly– Theatres, libraries, schools, large bars, pubs and restaurants
• B – Institutional (compelled to sleep over)– Jails, hospitals, orphanages, nursing homes
• C – Residential– Apartment buildings (common area) , group homes, houses, motels
• D – Business and Personal Services– Banks, barber shops, offices (medico legal), laundromat
• E – Mercantile– Markets, stores, shops, supermarkets, restaurants, bars and pubs
• F – Industrial– Flammable liquid plant, television studio, freight depot
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Firefighter Hazards:Structure Fires
• Change in occupancy creating an unusually heavy fire load.
• Dangerous stockpiling and excessive stock creating access problems.
• Unknown design errors, renovations, contractor short cuts.
• Arsonists traps or tampering with fire protection systems.
• Occupancy may not be what it appears. (drug lab, boarding house, group home, etc.)
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Construction Features Assessed During Size Up
What constructions features are important during size-up?
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Construction Features Assessed During Size Up
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Firefighter Hazards:Structure Fires
• Combustible furnishings & finishes.• Wooden floors / ceilings.• Large open spaces.• Synthetic materials.
• Lightweight & truss construction.
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Lightweight Wood or Steel Truss Construction
=Very Dangerous Firefighting
Conditions
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Truss Roofs
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Bowstring Truss!
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Beware of the Truss!
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Structural Collapse
• Every structure fire has the potential for collapse.
• Firefighters must be aware and look for indicators to collapse.
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Signs of Potential Collapse
• Prolonged exposure.(time)
• Distorted structural members.
• Fire on floors below heavy machinery and heavy loads.
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Signs of Potential Collapse
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Building Collapse Zone
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Size Up – What do you see?
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The Back?
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The Side?