Chapter 15 Wood-Framed Building Collapse

Question 1

What are the three ways a wood frame building can collapse during a fire

Answer 1

1. straight outward 90° angle
2. the entire building may lean over and collapse on its side
3. inward / outward collapse

Question 2

what is a warning signal of a 90° angle wall collapse

Answer 2

often signaled by the corners of the falling wall splitting apart from the remaining walls

Question 3

what are the warning signs on an inward outward collapse

Answer 3

may not exhibit any structural warning at all…. other than serious fire burning for a long time on the lower floor…hear sudden loud cracking noise

Question 4

one of the warning signs of a lean over collapse

Answer 4

often indicated by the building slowly starting to tilt or leaning to one side

Question 5

during a fire in a structure with masonry walls it is rare that more than one wall collapse, does that hold true of wood building collapse

Answer 5

no, braced frame wood buildings may have all four walls collapse

Question 6

which of the three major types of wood frame construction presents the greatest firefighter danger

Answer 6

braced frame wood construction

Question 7

why is it that braced frame wood construction with fire on the first floor of a three-story structure collapse more frequently than a two-story structure

Answer 7

fire destroys the bearing wall and the added weight causes collapse onto the unsupported side, the empty lot

Question 8

where the four most widely used methods of wood frame construction

Answer 8

braced frame
balloon frame
platform frame
lightweight wood frame

Question 9

brace frame construction is sometimes called

Answer 9

post and girt

Question 10

was a drawback of balloon frame construction

Answer 10

vertical bvoid between the wall studs that extends from the foundation still to the attic And allows hidden flames smoke to penetrate the walls and spread vertically for two or three floors

Question 11

what is the most widely used wood frame construction today

Answer 11

platform construction

Question 12

from a fire protection standpoint why as platform construction superior to balloon or brace frame construction

Answer 12

there are no concealed wall voids that extend more than one floor

Question 13

what is the danger of lightweight wood truss

Answer 13

his early floor and roof collapse, especially floors

Question 14

in 2008 the underwriters testing laboratory documented that lightweight wood truss and sheet metal fasteners failure in__

Answer 14

less than 10 minutes of fire exposure

Question 15

what are three factors that contribute to inward outward collapse of a brace frame wood building

Answer 15

1. fire destruction of bearing walls
2. failure at the mortise and tendon connection
3. exterior wall overload

Question 16

in older communities wood frame buildings were built closely together with the bearing walls usually being the ___, this practices change in suburban communities built from large plots of lands houses are designed to have bearing walls___

Answer 16

sidewalls

front and back walls

Question 17

when braced-frame wood timber collapses it fails at the weakest point which is

Answer 17

the mortise and tendon joint

Question 18

what effect does an exterior fire escape have on a wood frame building

Answer 18

the weight of his heavy metal structure attached to the outside wall can exert a slight pull on the starts causing axial loads to become eccentric loads

Question 19

two types of masonry surfaces apply to the outside of old wood buildings

Answer 19

brick-and-mortar veneer
stucco coating
increase the collapse danger by adding considerable weight to the structure, and hiding major structural defects

Question 20

are the three contributing causes of wood frame building collapse

Answer 20

fire destruction of bearing walls
mortise and tendon joint of brace frame wooden building
overload of exterior wooden wall