Minimum Required Landing & Stairway width Requirement in California

[frankjr]

Hi everyone,

Long time lurker, first time post. Let me start by saying that everyone's knowledge on this site is impressive. "Merging" all the different codes to come up with your opinions & answers is a feat unto itself. The more I dig, the more I realize how little I understand, and how complicated a topic this is. Thank you in advance for any answers you all may offer.

I'm in the planning stages of doing a remodel on my existing commercial building. The upstairs portion is about 2200 square feet, and consists of 3 spaces. I don't know what the official "occupant load" of the upstairs is, but it is an "open" business office (6-10 people), a conference room (up to 12 people), and the owners office (4-5 with guests). The combined actual occupant load of the those three spaces at maximum will be no more than 30 souls if that matters. [I think in office space in California, the official occupant load is 1 for every 100 square feet? That would be 22! ]

Anyway, I'm trying to maximize the space in the warehouse that is adjacent to the second story. The warehouse has 22' foot ceilings. The actual upstairs is located South of the stairs that are pictured below. My questions are specific to this staircase (I have a 2nd staircase as well) .The wider this staircase has to be, the more it encroaches into my warehouse space.

So that brings me to my questions:
1. My interpretation of California code is that the staircase could be 36" wide based on my occupant load.
However, ADA requirements will force my staircase to be 44" wide minimum.
2. The landing at the bottom of the stairs on the PUSHSIDE of the door can be the same 44" wide, with 48" minimum depth of travel to the door. To stay at that 44" wide, I can't have a Closer AND a latch (Otherwise I need 12" more width on the strike side).

Are 1 & 2 correct? It has been suggested to me that I may need 60" width on the landing on the PUSHSIDE. My scanning of the code says the 60" clearances are only required on the PULLSIDE.

Once again, thank you for any insight you may provide in advance.

Here is the picture:

 

[mark handler]

2019 CBC 1009.3 Stairways
In order to be considered part of an accessible means of egress, a stairway shall meet 2019 CBC Chapter 11B, Sections 11B-210 and 11B-504, as applicable.

2019 CBC 1009.3.2 Means of egress, Stairway Width
Stairways shall have a clear width of 48 inches minimum between handrails.
Exceptions:
The clear width of 48 inches between handrails is not required in buildings equipped throughout with an automatic sprinkler system

 

[Mr. Inspector]

Doesn't CA code exempt accessible egress from existing buildings like the IEBC/IBC?
Doesn't CA code require an accessible route to the warehouse (over 1,000 sq ft. employee working space) like IEBC/IBC?

 

[BN4537]

You are correct about the ADA door clearance requirements, you only need a zone the width of the door and 48" back on the push side of a door that is front approach, no latch/closer.

However, if that door is supposed to be some type of fire door to protect the stairs, as is frequently necessary to meet code, you might need a closer and a latch for fire purposes, in which case you would need the 12" clearance on the latch side that you referred to, in addition to the 48" dimension.

The pull side of your door has plenty of clearance

 

[ADAguy]

You haven't mentioned if you are sprinklered?
22' ceiling on 2nd floor? ( Considered adding a mezzine?)
Restrooms on 2nd floor?

 

[frankjr]

Thank you everyone for your responses!

Sprinklers: Yes.

Mezzanine: Considered, Yes. I'm the second owner of this building. The original owner had an unpermitted metal mezzanine, but they went broke. The creditors came in and sold everything and anything they could to recover their debts before I got involved with the building. The mezzanine was cut from the floor and sold. My challenge is that the city obviously considers the mezzanine as square footage (and to their knowledge there was NO mezzanine), and the public works department is requiring a whole slew of concessions if I add 1,000 square feet or more, the worst of which is a large dedication of my street frontage and me redoing the signals, curbs. That is a NO go for me, so I have to stay under the 1000 square feet (i.e. no mezzanine add).

My compromise (probably more efficient for our operation as well, and on par with overall costs to add mezzanine [ I have to add more sprinklers, lights etc]) and avoiding adding extra square feet is a Vertical Parts Lift. It goes floor to ceiling. I've spoken with other dealers and this thing in a 130 sq. foot footprint replaces 1,500 to 2,000 square feet of traditional parts racking. It will utilize my warehouse height without adding square feet so public works can't impose their "major development" requirements. What is crazy is that they can make these lift units up to 50 meters tall for buildings that have that sort of design.
The way I will configure my machine is that it will be 30' long x 10'-6" deep and reach to the ceiling. That is why the staircase width is so important to me to maximize the size of the lift machine I can place in my warehouse.

Restrooms: Yes, there are two restrooms on the second floor.

So based on what you guys have said and what I've read, I believe this to be compliant, and the way I'm shooting for... This is layout is actually the 2nd story:

 

[frankjr]

I didn't show the external staircase in the lower left corner of the drawing by accident.
I think our biggest hurdle might be the distance rules between exits considering the furthest route from space 200.

 

[ADAguy]

Structural support for the unit? OK?

 

[frankjr]

Here is the math:

Works out to just under 55 lbs. per square inch on the slab.

 

[e hilton]

Reminds me of the old vertical filing systems from the 80’s.

 

[Yikes]

If I am reading your second floor plan correctly:
1. You have an elevator, and you intend that to be your accessible path of travel to the mezzanine.
2. CBC table 1004.5 for "business areas" says the occupant load factor is 150 SF per person. That's 15 occupants on a 2,200 SF mezzanine.
3. CBC Table 1006.2.1 - Maximum length of common path of egress travel in a non sprinklered building with an occupant load <30 = 100' for a B occupancy, or 75' for an M occupancy.
4. Per Mark's post #4, your stairway either needs to be 48" wide (so that emergency personnel can help carry out a person in a wheelchair) OR your elevator can serve as the accessible means of egress, if it is equipped with standby power per CBC 1009.4.1.
5. If your elevator serves as the accessible means of egress, and the stairs serves less than 50 people, then per CBC 1011.2 exception #1 the width of the stairs can be as small as 36".
6. At the exterior door, if that door has both a latch AND a closer, then the push side of that exit door needs an additional 12" clearance per CBC Figure 11B--404.2.4.1 (c).

See the following website for the code references:

https://up.codes/viewer/california/ibc-2018

 

[frankjr]

Thank you.

I apologize in advance if I'm just being ignorant... but...

I read CBC 1006 in the context of an occupant load of 15 and a B Occupancy, and my take away is that I can actually get away with only having
one (1) means of egress provided the path to that exit is 100 feet or less?

Can that really be? I have always been told by the professionals that any upstairs space that is a 1000sq feet or more had to have at least two exits/stairways ? Does a different code superseed like ADA or some other code in California?

 

[Yikes]

I don't know enough about your building to determine whether it qualifies as a "mezzanine portion of the "first story above grade plane", or whether is is the "second story above grade plane". See table 1006.3.3(2) below.

 

[frankjr]

Thank you Yikes!

In regards to Table 1006.3.3(2) wouldn't it be considered "First story" above grade plane? Either way "Second Story" or "First Story" I'm still under the Occupant load and distance (If I understand what I'm reading, I can have 100' travel distance because the entire building is sprinklered (Footnote b)

Here is kind of an overview of the entire building. Overall building is 22' tall. The finished floor is at 10'. Most of the entire building is a single level. The area in green is the second level.

 

[Yikes]

You need to decide whether you are going to call it a "second level" or a "mezzanine". Definition from CBC 202:

 

[ADAguy]

Doesn't the mezzanine have to be open to the floor it is above and part of?

 

[frankjr]

Thanks everyone.

I tried to educate myself to the term "Story above grade plane", and I think I get it now. In cases where the "grade plane" is perfectly flat (no slope), story's are exactly what a layperson thinks. Ground level story is the "First Story Above Grade Plane".

It seems to me that "Above or below" grade plane gets complicated when a building is on some sort of slope, and I would think the significance is important If you were trying to build something with more floors than local code allows. If your on a slope, you might be able to call the "first floor" a "below grade plane", and get away with having 3 floors where a local code only allows 2 Stories above grade.

So in my case with a perfectly flat site, the ground level is "First Story" above grade plane, and the upstairs is the "Second Story" above grade plane.
Did I get that right?

As to the Mezzanine vs. Second Level, could you please explain?
A little more information. The area of the building that is in the green area as well as the building area north of it has a roof at 22'. The building section that is to the east of the green area has a roof at approximately 17' None of the upper level is "open" to the floor it is above. The "first level" is at grade level.

In the context of the discussion we are having, I don't understand the ramifications of each, but here is my try:

Section 1006.3 specifically addresses exits from "Stories", not mezzanine.

If it is called a "story", then I would think as you pointed out, that 1006.3.3(2) would say Occupant load of < 29 and max travel distance of 75' and a single exit is permitted.

If it is called a "mezzanine", what governs the exists / staircases ?

As a layperson, it seems to me that it has to be called a story? What am I missing?