lecture 9

Question 1

tread

Answer 1

horizontal surface of a stair that we walk on

Question 2

riser

Answer 2

vertical component of a stair that separates one tread from another

Question 3

what is nosing

Answer 3

the front edge of a tread that overhands the riser

Question 4

whereare railings required?

Answer 4

required on both sides of the stairs

Question 5

when do you need a landing with stairs?

Answer 5

if our stairs change direction and every 12’

Question 6

what are the key elements of a stair

Answer 6

tread
riser
nosing
railings
landings

Question 7

what is the ratio of rise to run in a typical stair

Answer 7

(2) risers + (1) tread= 24” to 25”

6 1/2” -7” risers and 11” treads are very commonly used in REZ construction

Question 8

tread depth

Answer 8

10” min for rez
11” min for commercial

Question 9

riser height

Answer 9

between 4”-7 3/4” for rez
between 4-7” for commercial

Question 10

nosing overhang

Answer 10

is between 3/4- 1 1/4” for rez

Question 11

minimum stair width

Answer 11

36” in a single family rez
44” everywhere else

Question 12

what is the max rise of a stair before the landing is required?

Answer 12

12’

Question 13

what is the mim head clearance between a tread and the projection of a tread

Answer 13

80”
6’8”

Question 14

landing must be how wide

Answer 14

at least the width of the stairs

Question 15

striaght run stair

Answer 15

a stair that extends from one level to another without turns or winders

Question 16

how can a stair be turned?

Answer 16

quarter-turn stairs
half-turn stairs
winding stairs

Question 17

quarter-turn stairs

Answer 17

a stair that turns 90 degrees or that is L-shaped plan

Question 18

half-turn stairs

Answer 18

a stair that turns 180 degrees or that is U-shaped in plan

Question 19

winding stair

Answer 19

a stair that turns in some configuration using winders to create a circular stair @ the point of rotaion

Question 20

how can a stair sit in the round

Answer 20

circular stair
spiral stairs

Question 21

spiral stair

Answer 21

wedge-shaped treads that wind around a central post

Question 22

what is the difference between a handrail and a guardrail?

Answer 22

handrail= is present to assist a user in safely navigating the stairway- it is what IS HELD ON TO
guardrail= is present to keep a user from FALLING off the stairway- it is like a BARRICADE

Question 23

guardrail height

Answer 23

42” min off the treads

Question 24

handrail height

Answer 24

34 - 38” off the tread

Question 25

handrail diameter

Answer 25

1 1/4 - 2”

Question 26

handrail clearance

Answer 26

1 1/2” min to the wall

Question 27

what is the general construction of a stair

Answer 27

carniage
ledger
stringer

Question 28

cariage

Answer 28

inclined beams that act as a structual element of the stairs that span from floor to floor and support the treads
(also called rough stringers)

Question 29

ledger

Answer 29

a member that provides support for the carriages
(can be substituted with a joist hanger)

Question 30

stringer

Answer 30

sloped finish member running along the side of a staircase against which the risers and treads terminate

Question 31

open riser stair

Answer 31

a stair with voids at the riser condition so you can see through to below

Question 32

what is the max opening for a open riser stair

Answer 32

maximum of a 4” space between the treads

Question 33

what is the typical configuration of an accessible ramp

Answer 33

1:12= max slope
36”= min width of a ramp
30” the max rise of the ramp before you need a landing
60”= the min length of a landing

Question 34

what does 1:12 mean with ramps

Answer 34

a 1” rise for ever 12” of run

Question 35

what is the last ratio that is still considered to be a ramp rather than a sloped walk

Answer 35

1:20

Question 36

how large does the landing need to be? where does it go?

Answer 36

60” is the minimum length of a landing at each end of the ramp or when it changed direction

Question 37

hnadrail height for a ramp

Answer 37

4’ min height

Question 38

ANYTHING above _” rise requires a handrail for a ramp

Answer 38

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