13 Stairway Collapse

Question 1

Three basic stair types:

Answer 1

A straight run stair
A U-return stair
L-shaped stair

Question 2

In multistory buildings, straight-run stairs are most often positioned directly over one another. These are called what?

Answer 2

Stacked straight-run stairs

Question 3

A continuous straight run stair does what?

Answer 3

Extends from the first floor to the top floor in one continuous flight of stairs.

Question 4

What support system does a straight-run stair have?

Answer 4

Floor beams extending up through openings in each floor. These stairs will collapse if the floor collapses.

Question 5

As a general rule, U-return stairs found in masonry enclosures are ___________________ of the floor structures and will not collapse during floor failure.

Answer 5

Independent

Question 6

Although the intermediate landing collapse is the most serious danger to a FF, the failure of a _____________________ is the most frequent cause of collapse of a U-return steel stair.

Answer 6

stone stair tread or step