Deck 35: Stairs

Question 1

Given a multistory building with a floor- to- floor height of 10 ft and an optimal riser height of 7 in., how many treads would you use for a U- shaped stair with a midlanding between floors? (The landing is not counted as a tread.)

A)15
B)16
C)17
D)18
E)None of the above

Answer 1

A

Question 2

In a typical prefabricated steel stair, the stringers are cut to accommodate treads and risers.

Answer 2

False

Question 3

A stair with treads cantilevered from a central column is a(n)

A)helical stair.
B)circular stair.
C)spiral stair.
D)U- shaped stair.
E)L- shaped stair.

Answer 3

C

Question 4

An approximate formula generally used in determining the tread dimension (T)and riser dimension (R)in a stair is

A)2T + R = 24 in. to 25 in.
B)2T + 2R = 24 in. to 25 in.
C)R + T = 24 in. to 25 in.
D)2R + T = 24 in. to 25 in.
E)none of the above.

Question 5

In a typical prefabricated steel stair, the number of stringers required is determined by the

A)floor- to- floor height.
B)spanning capacity of the tread- riser units.
C)width of the stair.
D)spanning capacity of the stringers.
E)all of the above.

Question 6

The rise of one flight of stair is generally limited by building codes to

A)12 ft.
B)7 ft.
C)8 ft.
D)10 ft.

Question 7

A riser must be vertical. It cannot be inclined.

Question 8

The minimum riser height required by building codes for a nonresidential stair is

A)5)5 in.
B)4)5 in.
C)6)0 in.
D)5)0 in.
E)4)0 in.

Question 9

The stringers in a typical prefabricated steel stair are generally made of

A)wide- flange sections.
B)channel sections.
C)plates.
D)A and B.
E)B and C.

Question 10

A U- shaped stair has been provided between the first floor and the second floor of a building with a midlanding. This stair has

A)one flight.
B)two flights.
C)three flights.
D)four flights.

Question 11

The maximum nosing projection allowed for a stair is

A)1- 1/2 in.
B)3)0 in.
C)2- 1/2 in.
D)1- 1/4 in.
E)2 in.

Question 12

The landing frame in a typical prefabricated steel stair is generally hung from the building's structural frame.

Question 13

In a typical wood stair, the number of stringers required is determined by the

A)width of the stair.
B)floor- to- floor height.
C)thickness of the treads.
D)spanning capacity of the carriage material.
E)all of the above.

Question 14

The minimum tread width required by building codes for a nonresidential stair is

A)11.5 in.
B)12.5 in.
C)13.0 in.
D)12.0 in.
E)11.0 in.

Question 15

The minimum width of a stair in a dwelling unit is

A)3 ft 6 in.
B)2 ft 6 in.
C)4 ft.
D)3 ft.
E)none of the above.

Question 16

A stair constructed without risers is generally called a(n)

A)closed- riser stair.
B)open- riser stair.
C)hollow stair.
D)no- riser stair.

Question 17

In a typical wood stair, inclined beams that are cut to allow for the support of treads are called

A)finish stringers.
B)rough stringers.
C)balusters.
D)all of the above.
E)none of the above.

Question 18

In a prefabricated steel stair, treads and risers are generally two separate components.

Question 19

The minimum height of a guardrail in a stair is

A)34 in.
B)36 in.
C)38 in.
D)40 in.
E)none of the above.

Question 20

A handrail and a guardrail in a stair are synonymous.

Question 21

What are the requirements of the International Residential Code for minimum tread width (T)and riser height
(R)for a single family home?

Question 22

Fire- escape stairs in contemporary buildings are generally constructed of prefabricated, U- shaped stairs with an intermediate landing between adjacent floors. How are they supported?

Question 23

Explain why a prefabricated steel stair is most commonly used even in buildings that are built with a reinforced- concrete frame structure.

Question 24

Is a means of egress stair required in a single- family home?

Question 25

List the factors that determine the width of a stair.

Question 26

A rule- of- thumb formula is used in proportioning the tread width (T)and riser height (R)of a stair. Write the formula and the rationale behind it.

Question 27

Provide the approximate expression used in proportioning the dimensions of the treads and risers of a stair. What is the basis for this expression? List building codes' restrictions on the dimensions of treads and risers.

Question 28

Using a sketch, explain the difference between a handrail and guardrail of a stair, and give their code- mandated heights.

Question 29

Using a sketch, describe a cantilevered freestanding stair.

Question 30

What are the requirements of the International Building Code for minimum tread width (T)and riser height (R)of a stair?

Question 31

A self- supporting cantilevered stair can be made only of reinforced concrete.

Question 32

Stairs are essential in any building with two or more stories. They serve two important functions: (i)transport people between stories and (ii)serve as fire escape stairs. However, because of a stair's rhythmic form, the stairs were historically designed as an aesthetic element in entrance foyers of many buildings. The entrance foyers of contemporary buildings do not include any stairs. What is the reason for this change?

Question 33

What is a stringer in a stair?

Question 34

A self- supporting cantilevered stair is supported on intermediate landings only.

Question 35

What is a stringer in a steel stair made of?

Question 36

What is the minimum fire resistance rating of the shaft enclosure for a fire- escape (means- of- egress)stair?

Question 37

What are the requirements for minimum width of a fire- escape (means- of- egress)stair?

Question 38

Using sketches, explain how a steel stair's landing frame can be supported. Which one of these support methods is most commonly used?

Question 39

With the help of at least two sketches, explain what a flight of stairs implies. What is the code- mandated maximum height of a flight of stairs?

Question 40

What is the difference between a guardrail and handrail in a stair?