Two Exits from a Catwalk?

[nealderidder]

I've got a two-story building with a very tall interstitial space between 1st and 2nd. Basically it's 20' 1st floor to 2nd floor and there is a catwalk hanging from the 2nd floor structure. The bottom of the catwalk is around 11' AFF and the 1st floor ceilings are at 10' (Suspend ACT). The building footprint is roughly 200' x 240'.

The catwalk is pretty extensive and has a trapeze on the side of it for conduit etc. I'm not sure how useful it is since you can only service the ceiling below within an arms reach of the catwalk. There are a couple of areas with bus bars that are accessed only from the catwalk.

We're adding some control areas on the first floor so we need fire barriers up to the 2nd floor deck. This will interrupt the catwalk in several areas. The catwalk is shown hatched on the attached and you'll see some "gaps" which is where the fire barriers will be. The places where the catwalk ends are at mechanical mezzanines.

So the question is... What are the requirements for egress from this catwalk? I remember there being a section in the IBC one time that dealt with catwalks but it seems to have disappeared and the only mention now pertains to theater catwalks and accessible means of egress. I believe two exits were not required in that old section.

When do I need two exits? Is there a max. exit access distance? I'm on 2016 CBC.


Any input would be appreciated!

 

[north star]

$ ~ $ ~ $ ~ $

From the 2003 IBC, Section 1014.6.1 - Gallery, Gridiron and Catwalk
Means of Egress: "The means of egress from lighting and access catwalks ,
galleries and gridirons shall meet the requirements for occupancies in Group
F - 2. Exceptions: 1. A minimum width of 22 inches ( 559 mm ) is permitted
for lighting and access catwalks. 2. Spiral stairs are permitted in the means of
egress. 3. Stairways required by this sub-section need not be enclosed.
4. Stairways with a minimum width of 22 inches ( 559 mm ), ladders or spiral
stairs are permitted in the means of egress. 5. A second means of egress is
not required from these areas where a means of escape to a floor or to a roof
is provided. Ladders, alternating tread devices or spiral stairs are permitted in
the means of escape. 6. Ladders are permitted in the means of egress".

This section is also listed in the 2006 IBC, at Section 1015.6.1.

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[nealderidder]

Exactly, but where is it in 2016?

 

[north star]

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O.K., ...I have looked & looked & looked in the `16 CBC
to no avail........In the `13 CBC, Catwalk MOE is addressed in
Section 1015.6.1.......In the `13 Edition, it mentions using
the Occ. Group of F-2.........Can you apply this Occ. Group in
the `16 Edition ?........The term "Catwalks" is still referenced
in Section 410.7 in the `16 CBC.

Also, maybe some of the folks from California on here
will chime in...

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[Builder Bob]

Unable to find in 2015 IBC as well

 

[north star]

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In the `15 IBC, refer to Section 410.6.3.4 & Section 410.7.

In the `16 CBC, ...1st refer to the definition of Technical Production Areas.
2nd, ...refer to Section 410.6.3.

Apparently the language referring to Catwalks is in the
Technical Production Areas.

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[nealderidder]

And there is a definition given for "Technical Production Area" which says ...for entertainment technicians...for servicing entertainment technology...

The building maintenance guy is pretty funny but I doubt anyone would call him an "entertainment technician" and 2x4 light fixtures are probably not "entertainment technology".

All of section 410 is about theaters and the like. The only other sections that mention catwalks refer to ladders (1011.16) and accessibility (11B-203.4) which isn't required thank goodness.

I've got a meeting with the B.O. next week, we'll see what his take is on it.

 

[ADAguy]

Nice catch, we await the B.O. response.
Sounds like a Building Standards Commission revision is necessary, wonder if this was caught for the 2019 CBC?
I'll check with DSA, we have lots of catwalks
Consider:
1. Number of occupants usually < 10.
2. Exit from catwalk is first to the ground or floor below.
3. Not an assembly area
4. Serves a maintenance area.
5. It is not a corridor
6. What does OSHA say?

 

[ADAguy]

Mystery solved! see CBC 505.3 Equipment Platforms. 9/1/17 Errata

 

[nealderidder]

Aha! Thank you ADAguy. I puzzled over the reason for the errata, it looks like they just changed "stairs" to "stairways".

This section does say that equipment platforms and the walkways providing access to them shall not serve as a part of the means of egress from the building. But is that the same as "no egress is required from these platforms" or are they just trying to prevent people from using a catwalk for egress from occupied spaces? I've got a meeting on Thursday with the B.O.

More to follow...

 

[ADAguy]

Use of Catwalks is for service personnel only; the general public typically does not have access to them.

 

[Sophilac]

Aha! Thank you ADAguy. I puzzled over the reason for the errata, it looks like they just changed "stairs" to "stairways".

This section does say that equipment platforms and the walkways providing access to them shall not serve as a part of the means of egress from the building. But is that the same as "no egress is required from these platforms" or are they just trying to prevent people from using a catwalk for egress from occupied spaces? I've got a meeting on Thursday with the B.O.

More to follow...

Hi Neal, I'm wondering if you had tha tmeeting with the B.O. and what came out of it regarding this issue?
Thank you.

 

[cda]

Hi Neal, I'm wondering if you had tha tmeeting with the B.O. and what came out of it regarding this issue?
Thank you.

Welcome to the humble forum

 

[alexga907]

If we install a catwalk that is 500 feet long from end to end, how many ladders do we need?

 

[north star]

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Welcome " alexga907 " to the Building Code Forum !

In the 2018 IBC, see Ch. 4, Section 410.5.3 for catwalks.

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[MADrkTEK]

We encounter many types of suspended or raised walkways in industrial uses, ones that do not fall under the scope of stags and platforms otherwise handled by chapter 4. Relative to your question, here are a few references that I rely upon to determine the intent of the Code:

IBC 2018 1006.2.1 Exception 3: Indicates unoccupied mechanical rooms an penthouses are not required to comply with the common path of egress travel distance limits.

2018 IBC 1017.3 Measurement (Egress Access Travel Distance) commentary elaborates that “The Travel Distance is measured from every occupiable point on a floor to the nearest Exit….”

Definition of Occupiable Space : A room or enclosed space designed for human occupancy in which individuals congregate for amusement, educational or similar purposes or in which occupants are engaged at labor, and which is equipped with means of egress and light and ventilation facilities meeting the requirements of this code.”

And the commentary Paragraph following that definition:
“…Additionally, some spaces are neither habitable nor occupiable. The code identifies crawl spaces, attics, penthouses and elevated platforms (mechanical or industrial equipment) as unoccupied spaces. Since the code generally sates how these spaces must be accessed but does not specifically require means of egress. Where access is limited to maintenance and service personnel, it is likely the space is not occupiable.”

With all of this, I interpret the code's intention(s), which I would apply to your question is/are:

• A means of egress is only required from all occupiable points in the building. not every possible space an occupant could gain access to with a little determination.
• Unoccupied spaces are not required to have a means of egress, unless the code specifies otherwise for specific conditions.
• Unoccupied spaces may be required to comply with code prescribed access requirements (roof access, ceiling access, etc.).
• Common Path of Egress Travel and Exit Access Travel Distances need only be measured from the unoccupied space's access point, unless the code states otherwise for specific conditions. One does not need to include the distances measure in and through an unoccupied space from its most remote point.
• Keep an eye on OSHA rules: you will find there are requirements therein which may apply and exceed the seemingly more-relaxed application of the building code when it comes to maintenance-only spaces.

 

[Paul Sweet]

It would be prudent to have one near each end, and possibly one near the middle if people need to use the catwalk often for equipment maintenance. If it's a catwalk for observation then it's a mezzanine and egress has to comply with chapter 10.

 

[DavidinStLouis]

We encounter many types of suspended or raised walkways in industrial uses, ones that do not fall under the scope of stags and platforms otherwise handled by chapter 4. Relative to your question, here are a few references that I rely upon to determine the intent of the Code:

IBC 2018 1006.2.1 Exception 3: Indicates unoccupied mechanical rooms an penthouses are not required to comply with the common path of egress travel distance limits.

2018 IBC 1017.3 Measurement (Egress Access Travel Distance) commentary elaborates that “The Travel Distance is measured from every occupiable point on a floor to the nearest Exit….”

Definition of Occupiable Space : A room or enclosed space designed for human occupancy in which individuals congregate for amusement, educational or similar purposes or in which occupants are engaged at labor, and which is equipped with means of egress and light and ventilation facilities meeting the requirements of this code.”

And the commentary Paragraph following that definition:
“…Additionally, some spaces are neither habitable nor occupiable. The code identifies crawl spaces, attics, penthouses and elevated platforms (mechanical or industrial equipment) as unoccupied spaces. Since the code generally sates how these spaces must be accessed but does not specifically require means of egress. Where access is limited to maintenance and service personnel, it is likely the space is not occupiable.”

With all of this, I interpret the code's intention(s), which I would apply to your question is/are:

• A means of egress is only required from all occupiable points in the building. not every possible space an occupant could gain access to with a little determination.
• Unoccupied spaces are not required to have a means of egress, unless the code specifies otherwise for specific conditions.
• Unoccupied spaces may be required to comply with code prescribed access requirements (roof access, ceiling access, etc.).
• Common Path of Egress Travel and Exit Access Travel Distances need only be measured from the unoccupied space's access point, unless the code states otherwise for specific conditions. One does not need to include the distances measure in and through an unoccupied space from its most remote point.
• Keep an eye on OSHA rules: you will find there are requirements therein which may apply and exceed the seemingly more-relaxed application of the building code when it comes to maintenance-only spaces.

Nice remarks! I'm wondering though - is there an accommodation in the codes (2015 IBC and/or NFPA) for these very sparsely occupied industrial processing buildings that are tall (because of the physical requirements of tanks and things needing to be elevated above grade or above other equipment)?

I'm looking at egress from a 3rd or 4th "floor" up platform where a worker or two would be stationed to monitor or control processes. There are only 2 workers; and they would be familiar with the surroundings and routes - so egress would be as easy as possible - e.g. low occupancy, knowledgeable workers, etc. But according to code "right out of the box" it appears that one might need two exits - and maybe even fire-rated "corridors".

Is there a code scenario that basically says, for this type of special use, if "you got in, you can get out" the same way?

Any input is appreciated!

 

[walker.t]

platform where a worker or two would be stationed to monitor or control processes.

Sounds to me like this “platform” is actually a mezzanine because workers are “stationed” on the “platform” which makes the area an occupied area, therefore it does not meet the definition of an equipment platform:

2018 IBC Definition of “Equipment Platform”
An unoccupied, elevated platform used exclusively for mechanical systems or industrial process equipment, including the associated elevated walkways, stairways, alternating tread devices and ladders needed to access the platform. [emphasis added]

Per IBC 505.2.2, means of egress from mezzanines has to meet the requirements of Chapter 10. You might be able to have a single means of egress if you meet the requirements of Table 1006.2.1 (Spaces With One Exit or Exit Access Doorway.)

Depending on the specific nature of the industrial process, I might consider using two means of egress even if only one was required.

Is there a code scenario that basically says, for this type of special use, if "you got in, you can get out" the same way?

Sorry, can’t help you with that, the only thing I’m familiar with in the code regarding a special exception for workers familiar with the environment would be the reference to “entertainment technicians” in technical production areas but that wouldn’t apply to what you’re doing.

 

[DavidinStLouis]

Sounds to me like this “platform” is actually a mezzanine because workers are “stationed” on the “platform” which makes the area an occupied area, therefore it does not meet the definition of an equipment platform:

Agreed.

Per IBC 505.2.2, means of egress from mezzanines has to meet the requirements of Chapter 10. You might be able to have a single means of egress if you meet the requirements of Table 1006.2.1 (Spaces With One Exit or Exit Access Doorway.)

Yes, that's one direction I'm looking into.

Depending on the specific nature of the industrial process, I might consider using two means of egress even if only one was required.

That's an understandable position. I believe it is typically best to have two exits from any space / room / building as a default position, when possible. Solves a lot of problems, when can be done.

Sorry, can’t help you with that, the only thing I’m familiar with in the code regarding a special exception for workers familiar with the environment would be the reference to “entertainment technicians” in technical production areas but that wouldn’t apply to what you’re doing.

You're referring to section 410 of the IBC, I gather?

 

[walker.t]

You're referring to section 410 of the IBC, I gather?

Yes, that’s correct. When making my post I pulled the term “entertainment technician” from the definition of “Technical Production Area” in Chapter 2.