Ch 12 Operations In Lightweight Buildings

Question 1

What is a truss? Pg 335

Answer 1

Allows large areas to be spanned with pieces of material that are much smaller than, and may be spaced father apart than, a standard beam.

Question 2

What are lightweight steel trusses know as? Pg 335

Answer 2

Bar Joist

Question 3

What is considered the deadliest style or roof construction per incident? Pg 337

Answer 3

Bowstring Trusses

Question 4

What is the usual spacing between trusses, how many feet? Pg 337

Answer 4

20 feet

Question 5

What is the collapse zone for a bowstring truss roof? Pg 338

Answer 5

2 1/2 times the height of the wall

Question 6

What makes the flat timber truss different from the bowstring truss roof? p. 339

Answer 6

Exterior appearance

Question 7

What size hole would open up with the failure of one truss in a bowstring truss building? p. 337

Answer 7

40-foot

Question 8

Where does the problem lie with a metal deck roof? p. 343

Answer 8

Steel’s behavior

Question 9

What will be a warning sign to roof firefighters if the metal deck roof is going to collapse? p. 344

Answer 9

The roof will sag/drop

Question 10

Under which conditions do the dangers of trusses exist? p. 335

Answer 10

Fire

Question 11

Approximately what is the maximum length that can be spanned using a standard wood beam? p. 335

Answer 11

25 feet

Question 12

What part of the wall is pushed out when the hip rafters
fail? p. 338

Answer 12

Top

Question 13

What is an indicator that a bowstring truss roof is present on a building?
p. 337

Answer 13

Hump shaped roof

Question 14

What is the tool of choice when opening a building’s sidewalls to direct a stream into the truss loft?
p. 347-348

Answer 14

Elevating platform

Question 15

Which is a primary difference between standard and lightweight construction? p. 335

Answer 15

Member mass

Question 16

In what arrangement are the elements of the truss constructed?
p. 336

Answer 16

Triangles

Question 17

What type of hose stream should interior crews working under the metal deck roof use to cool the steel?
p. 344

Answer 17

Straight

Question 18

What should be the minimum collapse zone be at the end walls that have rafters resting on a truss and bearing on a wall? p. 338

Answer 18

2 1/2-times the height of the wall

Question 19

What shape is the steel bar bent into to form a steel bar joist? p. 343

Answer 19

Z

Question 20

What is the biggest drawback of lightweight truss designs? p. 340

Answer 20

Lack of mass

Question 21

What is the primary hazard to the roof firefighters when operating on a metal deck roof? p. 343

Answer 21

Falling into the ventilation hole

Question 22

Which dangerous member is marketed as a non-squeaking
floor board? p. 342

Answer 22

Plywood I-beam

Question 23

What should be the next step taken after the fire is knocked down in a building with lightweight roof and
floors? p. 348

Answer 23

Assess the structure

Question 24

What can be used as a guide to determine if the risk to
firefighters outweighs possibly saving the lives of occupants? p. 347

Answer 24

Has fire entered the voids?

Question 25

Until which time was the most common construction Class 3
or Class 5? p. 335

Answer 25

1960’s

Question 26

How far into the wood does the gusset plate penetrate into
the wood members of a truss?
p. 340

Answer 26

1/4 inch

Question 27

What type of load does the top chord in a truss bear? p. 336

Answer 27

Compressive