Collapse Of Burning Building

Question 1

What is the leading cause of fire fighter death

Answer 1

Floor failure is the leading cause of fire Fighter death by collapse

Question 2

Types of floor collapse

Answer 2

The floor deck may collapse were only the wood deck may burn through in collapse leaving this supporting joist intact
Floor beam collapse were several floor Joyce fail causing a localized failure of a section of floor within Room is more deadly collapse
A multi level floor collapse describes a progressive floor failure here a floor collapse triggers the sub suit quint collapse of floors below in of one or more inclosing walls

Question 3

Multi level floor

Answer 3

Collapse most often happens in burning buildings that have columns in girders supporting floors a building with the frontage of 25’ or more usually has columns and girders a build and 25’ or less can have floor beams supported by bearing walls on each side

Question 4

What is the most dangerous time for floor collapse

Answer 4

The most dangerous time for floor collapse is during the end of the fire in the decay stage after it has been extinguished

Question 5

Purlin

Answer 5

A purlin is a timber laid horizontally and perpendicular to support the common rafters of a roof

Question 6

Sloping roof construction

Answer 6

3 types the trussed roof has the largest area of unsupported roof deck the plank and beam roof as the next largest area in the roof rafter roof as the least amount making it the safest to walk on

Question 7

Danger of slate and tile roofs

Answer 7

Slate and tile are considered fire retarded roof coverings they protect a wooden deck from sparks or air borne burning embers which land on a roof this fire retarding effect however also slows any fire and he in an attic from traveling upward

Question 8

Truss construction

Answer 8

Most dangerous roof system for firefighters collapses during the early stages of fire it will cause subsequent collapse of the front or rear masonary enclosure wall of the structure

Question 9

What is a purlin

Answer 9

A perlin is it timber lead horizontally and perpendicular to support the common roof rafters of a roof

Question 10

Sloping roof construction

Answer 10

The trussed roof has the largest area of unsupported roof deck thou plank and beam roof has the next largest area in the rafter roof the least amount making it the safest roof to walk on

Question 11

What are the types of timber truss roofs

Answer 11

Inclined plane truss Gable shaped roof number 2 parallel chord truss flat roof number 3A bowstring truss arch shaped roof

Question 12

Roof venting for a bowstring truss roof

Answer 12

Is too dangerous to perform by firefighters to quickly determine if fire has spread and the roof space of a bowstring truss a triangular cut may be made in front or rear from the safety of a aerial platform

Question 13

What are the sloping roof pitches

Answer 13

2/12 is a low pitch skip

15 and 12 is a stremely high pitched
5 or 6 in 12 is a medium pitch

Question 14

Evacuating a trussed roof

Answer 14

A building 100’ with trust sections 20’ on center will collapse a 4000 ft² section of roof
A fire fighter should proceed perpendicular to the failing trust to reach the adjoining truss for temporary safety

Question 15

Place of worship

Answer 15

Large open space in a place of worship usually means timber trussed roof
Chiefs should recommend a defensive attack outside with emphasis on protecting nearby exposures and preparing for collapse

Question 16

What is the most unstable place in the community

Answer 16

It is found to be places of worship and the part of the place of worship that is most unstable is the tower and steeple

Question 17

Aggressive interior attack on a place of worship

Answer 17

Upon arrival scene size a if the fire is too big in exterior defense of attach should be initiated if the fire is extinguishable 1st line taken to the seat of the fire a second large diameter hose line should immediately backup the 1st line.
If 2 lines do not extinguish fire firefighters should withdraw

Question 18

Dangers of wall collapse in a place of worship

Answer 18

If the roof starts to collapse it could push out the side walls In bearing walls

The exposure A-B-D side of a burning place of worship is the most dangerous areas during a fire
The c side rear is the safest

Question 19

Most common Collapse type of masonary wall failure

Answer 19

90ﾟ angle collapse

Question 20

Tunnel And trenching operation

Answer 20

Pass along method used to clear debris firefighters in a single line passing material

Question 21

Flat roofs

Answer 21

Light weight construction liked unprotected steel bar gioras construction can fail in 5 or 10 minutes of fire exposure must be documented in program into fire dispatch systems

Question 22

Roof support systems

Answer 22

when a fire building has steel bar joist systems horizontal ventilation of windows and doors in advance of hose lines is preferred.

Question 23

Wood joist

Answer 23

Solid wooden Joist most common flat roof supporting member
Provides more stability then it’s a light weight counterpart wood joist arb speeds close enough together so that if one becomes weakened by fire the adjoining Joyce assumes the roof load

Question 24

Brick cavity

Answer 24

A beam can support more weight near its encased end and will not support is much weight at it’s unsupported center

Question 25

Corbel shelf

Answer 25

A beam and that is simply resting on a corbel shelf Functions as a fire cut beam this is a self releasing or unrestrained beam

Question 26

Steel bar Joist &c beam roof construction

Answer 26

Steel starts to do store in lose strength when fire reaches 1000-1100ﾟ It takes 2400ﾟ to melt steel which is rarely reached at a structure fire

Question 27

Fire protection methods

Answer 27

The best method to protects deal from my firefighters point of view is to in case it in concrete

Question 28

Mem brane ceilings | To protest steel beams

Answer 28

Suspended ceiling system of steel frame in rods holding one hour fire retarding ceiling panels The metal frame holding the panels and the hangar rods are the collapse hazard to fire fighters

Question 29

Hazards of light weight steel bar Joist

Answer 29

In a unprotected type to steal building fire ground commanders should consider a strategy of horizontal ventilation in defensive exterior attack

Question 30

Spacing of light weight steel bar joists

Answer 30

Open Web steel bar Joist can be space up to 8' apart When cutting the roof if it is not directly over a bar Joist The cut roof deck may suddenly bend or hinge downward into the fire Solid wood Joist typically are spaced 16" on center

Question 31

Causes of failure of unprotected steel | 4 factors

Answer 31

Temperature of the fire the load stress the steel thickness and the fire size

Question 32

2 important facts of the time temperature curve

Answer 32

Within the 1st 5 minutes the temperature of the fire will rise to 1000ﾟF That 10 minutes the temperature reaches over 1/2 the total temperature rise 1300ﾟF attain after 8 hours

Question 33

Type 2 noncombustible unprotected steel buildings are designed for low hazard occupancy hes like schools offices in retail shops

Answer 33

Should not house high hazard occupancies like wood work in shops furniture storage flammable liquids and furniture refinishing plants unless Deluge type sprinklers and smoke detectors are installed

Question 34

Dangers of plaster ceilings

Answer 34

Plaster ceilings can be 3 or 4" thick and 15 to 20' in height collapse of a large area of thick plaster can knock a fire fighter unconscious or cause serious head or neck injury

Question 35

Suspended ceilings

Answer 35

The most dangerous ceiling is a suspended ceiling Suspended ceilings are most often found in 3 types of occupancy in stores top floors of multiple dwellings and renovated buildings

Question 36

Rescue a fire fighters trapped below ceiling collapse most important step

Answer 36

Sweet the collapse area above the ceiling with a hose line and knock down the flames

Question 37

3 types Of stair construction Straight run You return stairs L shaped stairs

Answer 37

You turn stairs found in masonary enclosures are independent of the floor structure and will not collapse during floor failure

Question 38

Danger of steel you return stairs

Answer 38

When the intermediate landing collapses

Question 39

Steel u return stairs dangers

Answer 39

The steel you return stairs that sustain most intermediate landing collapses are those which have treads in landings constructed of stone unsupported by a steel Pan

Question 40

The safest fire escape

Answer 40

Exterior screen stairway used as an exit from schools and theaters are enclosed by a high metal screen or rillons and extends from the top floor of the building to the street