Book 29 Ventilation

Question 1

Effective ventilation will accomplish four main objectives?

Answer 1

1. Save lives.
2. Assist in firefighter access.
3. Control the horizontal spread of fire.
4. Reduce the possibility of flashover and backdraft.

Question 2

With horizontal ventilation, there are two methods usually performed, which are?

Answer 2

natural and positive pressure ventilation.

Question 3

There are basically only TWO (2) types of ventilation holes?

Answer 3

Heat Hole (Offensive)

Strip Ventilation (Defensive).

Question 4

technique used when cutting plywood sheathing (4 cuts)?

Answer 4

Center rafter cut

Center rafter provides the largest hole possible with the minimum amount of cuts. Sheathing removal (louvering) requires a minimal effort.

Question 5

The material used to comprise the base and exterior covering for the roof. The base is the material attached to the roof rafters?

Answer 5

Decking

Question 6

A ____ cut is a single cut made through the roof decking, the same width as the chain saw blade. Although not as effective, the ___ cut can be used as an alternative to using the smoke indicator hole.

Answer 6

kerf

kerf

Question 7

Nailing blocks are usually made from a 2” x 4” laid flat between rafters to provide a nailing surface for the edge of the plywood sheathing. Since the plywood normally used is 4’ x 8’ in size, a nailing block will usually be found every ___ feet.

Answer 7

4

Question 8

A ____ cut is a small triangular piece of roof covering (composition), which is removed from the roof to expose the roof sheathing. A ____ cut is used to determine sheathing type and roof composition thickness.

Answer 8

plug

plug

Question 9

A ___ cut is a light cut of the roof covering, usually composition only. A ____ cut is used to facilitate the removal of multiple layers of roofing material (composition).

Answer 9

score

Question 10

A ___ cut is a light cut made with the chain saw, cutting through the roof covering and plywood sheathing. The saw is not inserted deep enough to cut through the rafters.

Answer 10

skim

Question 11

The skim cut is used on a panelized roof when you are performing the cutting technique known as?

Answer 11

“louver off a purlin.”

Question 12

A turbine-style ventilator is about ___% more effective when the turbine is spinning.

Answer 12

30

Question 13

45-degree inspection cut will tell you rafter type and rafter direction, the sheathing type, the thickness of roof composition and when complete, it can act as a smoke indicator hole.

A 45-degree inspection cut is accomplished by cutting through the roof decking at a 45-degree angle toward or away from any exterior wall. A 45-degree cut will ensure the saw will intersect a structural member. When the saw makes contact with a rafter, roll over the
rafter and continue the cut for approximately ___ to ___ inches. Complete the cut by removing a small triangle of decking directly over the structural member.

Answer 13

6 to 10

Question 14

The chain saw operator should cut a minimum of ___ dice cuts before the puller begins removing sheathing.

Answer 14

three

Question 15

The chain saw operator should cut a minimum of ___ dice cuts before the puller begins removing sheathing.

Always leave a minimum of one un-pulled section between the cutter and the puller.

Answer 15

three

Question 16

Center rafter louver

Move back to the first “outside” rafter and cut a parallel cut approximately ___ to ___ inches inside the rafter.

Answer 16

2 to 3

Question 17

Center rafter louver

Move back to the first “outside” rafter and cut a parallel cut approximately ___ to ___ inches inside the rafter.

Make parallel cut approximately ___ feet long.

Answer 17

2 to 3

3-1⁄2

Question 18

Cut ___ to ____ inches inside of the purlins to avoid hitting metal hangers.

Answer 18

4 to 6

Question 19

Louver off a lam-beam

While standing on a lam-beam, reach out approximately ___ feet, and make first cut parallel to rafters from purlin to purlin.

Answer 19

3-1⁄2

Question 20

louver off a purlin

While standing on a purlin, start “skim cut.” Reach out as far as you comfortably can, approximately ___ feet. Start at outside lam-beam.

Answer 20

3-1⁄2

Question 21

A strip ventilation hole should be placed well ahead of the fire, and the strip ventilation hole should extend the entire width of the building, creating a firebreak. Strip ventilation helps to stop the horizontal spread of fire. Strip ventilation must be done in conjunction with a heat hole. The heat hole must be accomplished first, which will slow down the horizontal spread of fire and allow the entire strip to be completed before the fire reaches the strip ventilation hole.

Answer 21

reference

Question 22

DIAPHRAGM NAILING

Plywood sheathing is installed so that the 8’ dimension of the plywood crosses the rafters or joists and the 4’ dimension parallels the rafters or joists. The sheets of plywood are then staggered much like a brick or block wall.

Answer 22

reference

Question 23

“H” CLIPS

“H” clips are metal clips used to hold the butted ends of plywood together. “H” clips are common on pitched roofs.

Answer 23

reference

Question 24

Smoke indicator holes should be placed along the path of access or egress every few yards.

Answer 24

reference

Question 25

45-DEGREE CUT

A 45-degree cut is a series of two cuts used to identify rafter direction “ONLY.” The first 45-degree angle cut is made toward or away from any exterior wall. A 45-degree cut will ensure the saw will intersect a structural member. When you hit a rafter, “STOP.” Make a second cut parallel
or perpendicular to the exterior wall.

Answer 25

reference

Question 26

Each year in the United States, there is an average of 100 deaths to firefighters in the fire service. On an average, 85 of those deaths are due to flashover, and the number is slowly rising each year.

Answer 26

reference