Building Construction

• A - assembly
• B - institutional
• C - residential
• D - business & personal service
• E - mercantile/commercial
• F - industrial

Dead and live

Wind, static, impact, repeated, and concentrated

Forces applied to a building or structural member by the wind

Loads that are applied slowly and remain nearly constant (filling of a water tank)

Loads delivered in a short time with a striking/collision effect

Loads applied intermittently (rolling bridge crane)

Loads applied over a small contact area

Axial, eccentric, and torsional

Applied to the centre of the cross section of a structural member and perpendicular to that cross section.

Applied perpendicular to the cross section of the structural member but is offset from centre, tends to bend the member

Offset from the centre of the cross section and at an angle to or in the same plane as the section, tends to twist the member

Compression, tension, and shearing.

Force that is crushing or pushing the mass of the material together

Force that tends to pull the material apart

Force that tends to cause adjacent planes in a structural member to slide past one another.

The maximum heat that can be produced if all the combustible materials in a given area burn

The ability of a structural assembly to maintain its load-bearing ability under fire conditions.  For walls, partitions, ceilings, etc. it also means the ability of the assembly to act as a fire barrier

• Combustibility
• Thermal conductivity
• Decrease of strength at elevated temperatures
• Thermal expansion when heated

• Type I: fire-resistive
• Type II: noncombustible
• Type III: ordinary
• Type IV: heavy timber
• Type V: wood frame

• Studs are continuous from foundation to roof
• Floor joists are nailed into the studs without a header
• Creates the potential for collapse
• Basement fires can spread up walls into the attic

• Each floor is built as a separate section
• The studs are only as high as the ceiling on each floor
• Header creates a fire stop

Flat, pitched, and curved

• Sagging
• Cracking noises
• Extensive fire involvement
• Fire that has burned for a prolonged period

9"

1000 degrees Fahrenheit/538 degrees Celsius

• Have no fat
• Failure of any element of the truss can cause the entire truss to fail
• Tying of adjacent trusses together to resist wind load may cause successive truss failure
• Carbon monoxide may accumulate in the voids and could cause a backdraft

After 5 to 10 minutes of fire exposure

Walls which carry a load or some part of the structure in addition to the weight of the wall itself

Walls which support only their own weight

1.5 times the building's height

• Cracks/separations in walls, floors, ceiling, or roof structures
• Evidence of existing structural instability (presence of tie rods and stars that hold the wall together)
• Loose bricks, blocks or stones falling from the building
• Deteriorated mortar between masonry
• Leaning walls
• Distorted structural members
• Fires beneath floors that support heavy machinery or other extreme weight loads
• Prolonged fire exposure to structural members
• Unusual cracks/creaking noises
• Structural members pulling away from the wall
• Excessive building contents weight

V-type, lean-to, pancake, and cantilever

Centre core or pigeon hole

• Floors are constructed around central core which contains stairwells, elevators, utilities, etc.
• Floors may be laid out completely different on one floor to the next depending on occupancy
• Generally constructed of metal

• Constructed in a uniform fashion
• Each floor is identical to the floor above/below
• Generally constructed of concrete and generally house apartments

• Beyond the reach of fire department aerial equipment
• Fires on upper floors must be fought from inside the building
• Poses the potential for significant "stack effect"
• Requires unreasonable evacuation time

Scissors and return

• Open stair shafts, elevator shafts, AC systems are the main channels that carry smoke
• Voids created by poke-through construction are often not sealed which can allow for smoke spread

Hallways, ducts, concealed spaces, and AC systems

• HVAC systems can suck smoke in and push it through to different areas of a building
• In the summer, AC can cool smoke which prevents it from rising as it normally would

• The condition where heated gases expand and rise, reaching the top of a building and banking down to fill floor after floor with smoke and hot gases
• If the fire is not vented the heat will continue to build up until combustibles remote from the fire can ignite

The creation of layers of smoke and fire gases on floors below the top floors of unvented multi-storey buildings.