Ch 16 - Building Materials & Structural Collapse

Question 1

Steel compromising temperature

Answer 1

570°F
May only support 40% of intended load after flashover temps

Question 2

Plaster and lath instead of drywall

Answer 2

Pre-1950 buildings

Question 3

Type I collapse

Answer 3

Unlikely to collapse. Contents burn, not the structure. Small localized collapses possible

Question 4

Type II collapse

Answer 4

Unprotected steel structural members will expand when heated and contract when cooled, causing floors and walls to collapse

Question 5

Type III collapse

Answer 5

Exterior masonry walls may collapse in one piece or crumble

Question 6

Type IV collapse

Answer 6

Least likely to collapse. Heavy Timbers resistant to heat failure. Exterior masonry walls may collapse

Question 7

Type V collapse

Answer 7

Interior collapses, not usually outward exterior collapses. Lightweight trusses and engineered floor systems

Question 8

Factors contributing to collapse

Answer 8

-construction type
-building condition
-length of fire exposure
-stage of fire
-building contents/fire load

Question 9

Collapse zone distance

Answer 9

1.5 times building height

Question 10

Indicators of structural collapse

Answer 10

-roof sagging/spongy
-Fire involvement of trusses or engineered structural members
-floors sagging
-noises from structural movement
-falling ceiling tiles
-little water runoff from building (holding water weight)
-cracks in exterior walls
-deteriorated mortar
-excessive weight of building contents