Chapter 12-Ceiling Collapse

Question 1

Ceiling are NON LOAD BEARING structural elements that support ONLY their weight

Answer 1

Their collapse DOES NOT cause collapse of other structural parts
*ceilings can drop over FF’s and TRAP them inside burning buildings

Question 2

2 Types of Ceilings :

Answer 2

1. DIRECTLY AFFIXED to the floor or roof joist above

2. SUSPENDED several inches or feet below the joists by vertical strips of wood, steel hangers, or thin wires

Question 3

Older buildings–LATH/PLASTER ceilings :

Answer 3

• strips of wood or wire lath nailed to the underside of the lath
• several coats of wet gypsum plaster, applied to the underside of the lath

Question 4

New buildings use DRY GYPSUM BOARD:

Answer 4

-4’x8’ area, 1/4” to 3/8” thick, nailed directly to the underside of the joists

Less common: ornamental tin/wood paneling

Question 5

At fires – DIRECTLY AFFIXED CEILINGS, usually collapses in SMALL PIECES, rather than in one large section…

Answer 5

USUALLY does NOT cause serious injury

Question 6

Collapse of Ceilings is often cause by ?

Answer 6

WATER ABSORPTION from hose stream

Question 7

When plaster is only _____thick and the FF is equipped with a properly fitted helmet…there is usually no serious injury?

Answer 7

1-2 inches thick

Question 8

IN OLDER structures, where plaster ceilings are ______thick and _____height , the collapse of a large area of thick heavy plaster can knock a FF unconscious or cause serious head/neck injury?

Answer 8

3-4 inches

15-20 feet

Question 9

Degree of injury caused by collapsed plaster is based on:

Answer 9

• thickness of the falling plaster
• height of the ceiling from which it falls
• condition of the cushioning system inside the members helmet

Question 10

Most dangerous ceiling is ?

Answer 10

SUSPENDED CEILING

aka drop/hanging ceilings

Question 11

Suspended ceilings most often found in 3 types of occupancies?

Answer 11

• STORES
• RENOVATED BUILDINGS
• TOP FLOOR OF MD’S

Constructed several inches or feet below the supporting roof or floor joists above

ceiling hangs below the joists-connected by vertical hangers that may be STRIPS OF WOOD, OR THIN WIRE

STORES-covers old fashion ceilings
MD’s(top floor)-creates space to insulate a top floor from SUN RAYS
Renovated-every floor of every apartment and is used to reduce the floor height to conserve energy for HEATING/Cooling

Question 12

Suspended ceiling presents a serious hazard to FF’s ..

Answer 12

when if fails, at fires, the ENTIRE GRID FRAMEWORK , in addition to ceiling sheathing , collapses

Question 13

The ceiling grid system can weigh ______?

Answer 13

SEVERAL THOUSAND POUNDS

FF caught below could :

• become trapped in a void and crawl out
• trapped inside small sealed void space at rear or pinned beneath the heavy ceiling grid

also rapid fire increase after suspended ceiling collapse

Question 14

3 common Suspended ceilings ?

Answer 14

1. Wood grid system with permanently affixed ceiling
2. metal grid system with a permanently affixed ceiling
3. Lightweight metal grid system with removable panel ceiling

Question 15

Part of suspended ceiling which traps or pins FF is ?

Answer 15

GRID SYSTEM/FRAMEWORK behing ceilings sheathing

Question 16

What is the heaviest part of suspended ceiling ?

Answer 16

GRID SYSTEM

Question 17

Which suspended ceiling does NOT pin FF’s?

Answer 17

lightweight grid system with removable ceiling panels

Question 18

What determines seriousness of Entrapment hazard?

Answer 18

WEIGHT of suspended ceiling

Question 19

Average weight of lightweight metal ceiling is ?

Answer 19

1 pound per square foot

with permanently fixed wire lath -10 pounds per square foot

Question 20

Fire can enter suspended ceiling through:

Answer 20

• fire burns through ceiling directly above
• louvered openings used to transfer air to and from the plenum
• holes for recessed lighting fixtures that are NOT FIRE STOPPED
• fire burns through POKE THROUGH HOLE created by a light fixture or pipe recess
• removable panels that are removed and not in place or improperly replaced

Question 21

FF’s should open these ceilings with a ?

Answer 21

PIKE POLE

• may discover several layers of concealed space
• FF’s must check every layer

Question 22

Some old Commercial occupancies have 2 ceilings and 2 concealed spaces:

Answer 22

• there is a concealed space behind the original ceiling of tin or lath/plaster
• and a concealed space above an added suspended ceiling of a lightweight metal grid system with removable panels

When a 2nd suspended ceiling is constructed, NUMEROUS HOLSE are punched through the first –these create avenues for fire travel in all 3 ceilings

Question 23

When MULTIPLE suspended ceilings are discovered , Notify ?

Answer 23

INCIDENT COMMANDER

Question 24

Current NYC building code requires?

Answer 24

-BLACK IRON rod AND FRAME CEILING SUPPORT–redistributes loads during partial failure during fire

Question 25

The CEILING collapse killing FF's is ?

Answer 25

WOOD GRID SUSPENDED CEILING

Question 26

Immediately after a wood grip suspended ceiling collapses, there is sometimes a RAPID increase in fire in the space directly over fallen ceiling

Answer 26

When a fire is SMOLDERING in a space above a suspended ceiling , and the ceiling collapses, a large inrush of fresh air enters the space above the fallen ceiling, fill the vacuum and is mixed with SUPERHEATED GASES AND HEAT....an EXPLOSIVE FIRE MAY OCCUR - wood grid will FUEL the fire - very LITTLE TIME to rescue FF;s below

Question 27

FIRST STEP to rescue members under collapsed ceiling DURING A STORE FIRE is to?

Answer 27

SWEEP the collapse area ABOVE THE CEILING with a hose line and knock down the flames a LADDER should be ready at every fire to rescue trapped victims or firefighters suddenly trapped by ceiling and fire

Question 28

BEFORE committing members to a serious fire in a large area occupancy, an OFFICER should know ?

Answer 28

TYPE OF CEILING in structure - if suspended , NOTIFY IC - officers can order the ceiling opened up and examined asap

Question 29

When examining multiple ceilings?

Answer 29

FF should open up and SEE ROOF OR FLOOR JOISTS more than one ceiling--EACH CEILING MUST BE EXAMINED -spreading fire--consider defensive strategy

Question 30

Proper method of OPENING ceiling with a PIKE pole?

Answer 30

PULL DOWN SHEATHING , NOT GRID SYSTEM PULL DOWN WOOD LATH, NOT FURRING STRIPS

Question 31

AT SERIOUS fires where suspended ceiling collapse is POSSIBLE:

Answer 31

members should stay near large pieces of furniture or stock for SHELTER OPEN FLOOR AREA is dangerous

Question 32

Shoring:

Answer 32

PORTABLE LADDER CAN BE used TO SHORE UP CEILING

Question 33

Ceiling dismantling and rescue:

Answer 33

GRID SYSTEM must be cut apart with POWER SAW - then ceiling sheathing must be cut or pulled apart - FF's can then crawl beneath into shelters searching for victims

Question 34

Portable Ladder can be used for ?

Answer 34

TUNNELING-raising lever | -this may allow FF's to crawl beneath a fallen ceiling or break up a ceiling if the grid system is lightweight

Question 35

TOP FLOOR FIRES in MD'S and Renovated Dwellings:

Answer 35

A fF should remain at the TURNTABLE of a ladder to be ready to rescue FF trapped by a ceiling collapse who comes to a window to escape the ensuing Fire

Question 36

Rescue attempts from adjoining stores:

Answer 36

- a partition wall, separating stores in a large one story building , can be penetrated FASTER, then rear masonry wall - windows and stores at rear are usually bricked up or locked - hose lines should be positioned into adjoining stores to prevent fire spread

Question 37

Entry into store beneath a ceiling collapse can sometimes be achieved from below:

Answer 37

going down an outside cellar entrance may allow access to the store via an interior cellar entrance

Question 38

IC should:

Answer 38

- limit the number of members participating in the rescue attempt - WEIGHT of rescuers can be greater than weight of fallen ceiling and can crush members trapped below

Question 39

Stability of suspended ceiling in question:

Answer 39

- make an INSPECTION opening in the ceiling with a pike pole near the entrance - check for fire in the space above the suspended ceiling before you enter the room - if the ceiling suddenly collapses you have a better chance to escape