Stairs!

Ramp, Stair, & Roof Vignettes and Multiple Choice

Stairs!

Postby danieb1 » Tue Feb 06, 2018 8:39 pm

Got so many questions about this one...

1. does the handrail/guardrail between janitor landing and landing on floor 2 need to be drawn on both layers?
2. i came up with 9 risers between janitor and landing above -this yields treads of 16.5" (!) can this be right?
3. can/should the guardrails in the AOR be right up against the edge of the landing? is the 30"x48" AOR to the inside of this or can it include the handrails?
4. per program:"the least dimension [of the landing] in the direction of travel shall be 44"
- i'm showing 5' from wall to door based on the clearance diagrams. does the above direction change what that dimesnion should be somehow?

general questions:
a. per program:

"capacity of exit components shall be based on the individual floor with the largest occ load, provided that the exit capacity shall not decrease in the direction of egress travel."

ground floor: 360 occ load; 3 exits
second floor 180 occ load; 2 exits
janitor: 9 occ load; 1 exit

so assuming the stairs did NOT have to be 48" wide clear due to the AOC the exit capacity would be based on the ground floor? what if the second floor was greater? then the exit capacity WOULD decrease in the exit of travel, so it would still be base on the ground floor occupancy?

b. and finally, this instruction, which i don't get at all:

"when opening, doors shall not reduce the width of the landings to less than one-half of the width required"

is this an issue anywhere in this vignette? do they mean width or depth (in which case the dimesion in front of the door on the second floor might change?)
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Re: Stairs!

Postby Coach » Tue Feb 06, 2018 11:35 pm

danieb1 wrote:1. does the handrail/guardrail between janitor landing and landing on floor 2 need to be drawn on both layers?

Rails go with treads on cuts. Stop rails at cut line.

2. i came up with 9 risers between janitor and landing above -this yields treads of 16.5" (!) can this be right?

No. You set the thread size. No reason not to use 11" everywhere. Fill space with landing.

3. can/should the guardrails in the AOR be right up against the edge of the landing?

Draw all rail 2" off walls and edges.

is the 30"x48" AOR to the inside of this or can it include the handrails?

AOR must be clear.

4. per program:"the least dimension [of the landing] in the direction of travel shall be 44"
- i'm showing 5' from wall to door based on the clearance diagrams. does the above direction change what that dimesnion should be somehow?

Don't understand your question. Satisfy all code requirements.

general questions:
a. per program:

"capacity of exit components shall be based on the individual floor with the largest occ load, provided that the exit capacity shall not decrease in the direction of egress travel."

ground floor: 360 occ load; 3 exits
second floor 180 occ load; 2 exits
janitor: 9 occ load; 1 exit

so assuming the stairs did NOT have to be 48" wide clear due to the AOC the exit capacity would be based on the ground floor?

At the ground floor, yes, but not for the stair.

what if the second floor was greater? then the exit capacity WOULD decrease in the exit of travel, so it would still be base on the ground floor occupancy?

Huh? You're contradicting yourself.
Stair width is based on the larger of load or AOR requirement. Egress width must be maintained to exit and must increase if warranted by ground floor load.


b. and finally, this instruction, which i don't get at all:
"when opening, doors shall not reduce the width of the landings to less than one-half of the width required"
is this an issue anywhere in this vignette?

Anywhere there's a door, yes.

do they mean width or depth (in which case the dimesion in front of the door on the second floor might change?)

It says "width", which always refers to path of travel width.
Stair - Door & half width.jpg



Stair looks wider than required.
Elevation error.
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