13- Truck Company S&T- Vertical Ventilation

Question 1

Before stepping onto any roof, firefighters should ___(observe the condition of) and _____(test the condition of) the roof and they should continue to do so as long as they are on the roof.

Answer 1

Read (observe the condition of)
Sound (test the condition of)

Question 2

Whenever firefighters are on a roof, the building should be laddered on at least ___ sides.

(it should be laddered on all sides if resources permit)

Answer 2

Two

Question 3

If firefighters must walk the ridge of a peaked roof, they should walk:

Answer 3

With one foot on either side of the ridge

Question 4

In general, the strongest points of any roof are:

*3 answers

Answer 4

-Where the roof meets the outside walls
-Directly over roof supports
-At ridges or valleys

Question 5

In general, the weakest points of roofs are:

Answer 5

Between the supports

Question 6

Once firefighters are on the roof, they should:

Answer 6

Test the roof by gently bouncing on it while holding onto the ladder or parapet wall with one hand.

Question 7

A key factor in opening roofs safely and efficiently is knowing the location and extent of the ___ and the location and direction of the ____.

Answer 7

Fire ; Rafters

Question 8

If sounding does not reveal the location and direction of the rafters, a diagonal cut through the roof covering can be made with a chain saw or rotary saw at an angle of __ degrees to any exterior wall. The blade will usually encounter a rafter before the cut is __ feet long.

Answer 8

45 degrees

3 feet long

Question 9

A triangular hole, also know as a/an _____ ____, can be completed to determine spacing, roof thickness, and possible fire conditions in the attic.

Answer 9

Inspection Hole

Question 10

It is recommended that a clear space of at least __ feet be maintained in all directions from anyone using a cutting tool in vertical ventilation.

Answer 10

10

Question 11

The most common cutting tools used for vertical ventilations are:

*3 answers

Answer 11

Rotary Saw, Chain Saw, Pick Head Axe

Question 12

The most common pitch on residential roofs in areas with mild climates is:

Answer 12

5-in-12 roof (5 pitch)

Question 13

In gable roof assemblies, the rafters are commonly spaced at __ to __ inches on center.

Answer 13

16 to 24

Question 14

Pitched roofs should be vented at the ____ point, on the _____ side, directly over the fire or as close to it as safely possible.

Answer 14

Highest point ; Leeward side

Question 15

The ventilation open on pitched roofs should be cut ____ to the rafters and _____ to the ridge.

Answer 15

Parallel ; Perpendicular

Question 16

The ventilation exit opening should be AT LEAST __x__ feet, and in many cases may need to be larger.

Answer 16

4x4 feet

Question 17

____ Roofs are commonly supported by horizontal joists or rafters similar to the joists used in floor systems.

Answer 17

Flat

Question 18

Some types of fire-resistant plywood delaminate and weaken over time, resulting in a deck that may not support the weight of a firefighter even if it has not been damaged by a fire. Identifying these hazardous roofs during ____ ____ ____ is CRITICAL to firefighter safety.

Answer 18

Preincident Planning Surveys

Question 19

Unprotected metal deck roofs can be expected to fail within _______ minutes of flame impingement. Because the heat of a fire will soften metal and make it more pliable, metal decking around roof vents and other openings may not support the weight of a firefighter.

Answer 19

A few

Question 20

The single biggest hazard of arched roofs is:

Answer 20

The danger of sudden and total collapse (often without warning).

Question 21

The bridging effect of parallel chord trusses causes the top chord to always be in _____ and the bottom chord in ______.

Answer 21

Compression ; Tension

Question 22

Some wooden components can be held together by sheet metal gusset plates, aka gang nails. The gusset plates can vary in size, but ____ inch prongs are common.

Answer 22

3/8” prongs

Question 23

Common pitched roof truss configurations are the ____, ____, and ____ trusses.

Answer 23

Howe, Pratt, and Fink

Question 24

Wooden I-Beams consist of three main components: A top chord, a bottom chord, and a solid ___ inch plywood or OSB web.

Answer 24

3/8”

Question 25

The most common substrate is tar paper, also called _____ ____.

Answer 25

Roofing Felt

Question 26

There are two main differences between shakes and shingles.

The shape and thickness of _____ are not uniform.

_____ are somewhat less susceptible to ignition.

Answer 26

Shakes

Shakes

Question 27

Primarily a defensive maneuver, ____ ventilation (aka ____ ventilation) describes a ventilation opening that extends from one outside wall to the other, including the metal flashing at both ends.

Answer 27

Trench Ventilation or Strip Ventilation

(The terms are used interchangeably)

Question 28

Trench ventilation is accomplished by cutting an opening in the roof, at least __ feet wide, across the entire width of the building.

Answer 28

Four