2 story hoistway enclosure

[Sifu]

2018 IBC

3002.1 says a hoistway enclosure shall be a shaft enclosure complying with 712 AND 713. Following 712 you may have the out of 712.1.9, following 713 you have no way out. How do you comply with both sections without a rated enclosure?

So then, what is a “hoistway enclosure”? Is it enclosed if it is surrounded by walls, a roof, and a door, or only if those elements maintain a rating? Easy to answer if the elevator is open, like in an atrium, but what if it is enclosed by walls to the roof?

If using 712.1.9 a two-story opening is permitted if not concealed within the construction of a wall or floor ceiling assembly. This language has been revised from “concealed within building construction”. This seems deliberate, and maybe to answer this very question:

If you have a 2-story hoistway enclosure does it have to be a rated enclosure? Per 713? Per 712.1.9? But both?

 

[Sifu]

FYI, I read a lot of previous posts about this, with the same questions, but none really address the AND part of 3002.1.

 

[RLGA]

I do not like the way the code addresses this issue. At least it should use "or" instead of "and." Personally, Section 713 should not be referenced at all in Section 3002.1 and the title should be "Hoistways and Hoistway Enclosures." Here's why...

An elevator hoistway is not required to be enclosed. The IBC does not define a hoistway, so I defer to ASME/ANSI A17.1, which states it is "an opening through a building or structure for the travel of elevators, dumbwaiters, or material lifts, extending from the pit floor to the roof or floor above." Nowhere in that definition does it state that a hoistway is enclosed. ASME/ANSI A17.1 includes sections for each elevator type titled "Construction of Hoistways and Hoistway Enclosures"; thus, the elevator code distinguishes between a hoistway and a hoistway enclosure. If the hoistway is enclosed with wall construction, then it is a hoistway enclosure. If there are no walls enclosing the hoistway, then it is just a hoistway.

Prior to the 2018 IBC, all hoistway enclosures had to be shaft enclosures per the shaft enclosure section of Chapter 7 (wherever that was located at the time). Then, for the 2018 I-Codes development cycle, it was proposed and approved to include Section 712 to "permit the use of the exceptions contained in Section 712 for shaft construction," as stated in the Reason Statement for the change proposal. However, what they failed to realize is that by leaving in Section 713 and using the conjunction "and," they had essentially short-circuited Section 712 by allowing only the shaft enclosure option of Section 712.

Unfortunately, the 2021 IBC did not correct it, and the proposal submitted for the latest code development cycle for the 2024 IBC was approved but did not really resolve the conflict.

So, to answer your question more directly: if you enclose the hoistway, then it is a shaft and requires compliance with Section 713. If you do not enclose the hoistway, you can comply with Section 712, which has always been the case since Section 3002.1 only pertains to hoistway enclosures. Therefore, a two-story shaft that is enclosed must have a 1-hour shaft enclosure.

 

[Sifu]

OK, so I'm not crazy. I too looked at '21 to see if there was any clarification. The plan I have indicates an unrated CMU wall surrounding the hoistway. I assume that rating it is easy using the inherent properties of the cmu wall, but now we have a control room abutting the shaft. Which leads me to wonder about 3005.4 and "openings". "Openings" is another undefined term in the IBC. I am not sure if there will be "openings" or just penetrations, since it is a control room with only an IDU.

So here I have a two story opening with an open stair beside a rated elevator shaft enclosure that doesn't require the hoistway doors to be protected. It just doesn't make a ton of sense. I don't really support the main premise of requiring a rated shaft in this situation, but I think it will be easy to accomplish. Rating the control room may actually be a bigger PITA.

 

[RLGA]

OK, so I'm not crazy. I too looked at '21 to see if there was any clarification. The plan I have indicates an unrated CMU wall surrounding the hoistway. I assume that rating it is easy using the inherent properties of the cmu wall, but now we have a control room abutting the shaft. Which leads me to wonder about 3005.4 and "openings". "Openings" is another undefined term in the IBC. I am not sure if there will be "openings" or just penetrations, since it is a control room with only an IDU.

So here I have a two story opening with an open stair beside a rated elevator shaft enclosure that doesn't require the hoistway doors to be protected. It just doesn't make a ton of sense. I don't really support the main premise of requiring a rated shaft in this situation, but I think it will be easy to accomplish. Rating the control room may actually be a bigger PITA.

Elevator manufacturers have designed their elevator doors to have a 90-minute rating for fire only just for the very likely chance that the elevator is installed in a 2-hour hoistway enclosure. However, the doors do not comply with the requirements for smoke and draft control. Section 3006 addresses the additional protection required for smoke and draft control under certain circumstances.

If the control room is attached to the hoistway and there are through-penetrations between the two, then the control room will be required to have a rating equal to the hoistway enclosure per Section 3005.4. Are through-penetrations openings? It is a matter of opinion/interpretation since, as you pointed out, there is no IBC definition for an "opening." I would contend that a through-penetration is an opening since it is a weak point within an ASTM E119/UL 263 assembly. Even though the through-penetration may have a rating equal to the rated assembly it penetrates, if you have seen actual tests or videos of tests online, you will notice that there may still be some minor smoke leakage and heat transfer.

Section 3005.4, Exception 1, which applies to 2-hour hoistway enclosures, allows such rooms to have a 1-hour rating if they do not abut the hoistway enclosure and have no openings. This exception reinforces the intent that these rooms are required to be protected if the hoistway is protected. However, in my opinion, what makes a control room, machine room, etc. so important that it must be protected only if the hoistway is enclosed? For example, an unenclosed hoistway in an atrium does not require a rated control room at all--even if it abuts the hoistway. Yet, an enclosed hoistway with a control room located on a floor not served by the elevator and located on the other side of the building (if anyone would actually do that) would require at least a 1-hour rating. Go figure.

One of these days the elevator requirements in the IBC will catch up with current elevator technology--and logic.

 

[Sifu]

Elevator manufacturers have designed their elevator doors to have a 90-minute rating for fire only just for the very likely chance that the elevator is installed in a 2-hour hoistway enclosure. However, the doors do not comply with the requirements for smoke and draft control. Section 3006 addresses the additional protection required for smoke and draft control under certain circumstances.

If the control room is attached to the hoistway and there are through-penetrations between the two, then the control room will be required to have a rating equal to the hoistway enclosure per Section 3005.4. Are through-penetrations openings? It is a matter of opinion/interpretation since, as you pointed out, there is no IBC definition for an "opening." I would contend that a through-penetration is an opening since it is a weak point within an ASTM E119/UL 263 assembly. Even though the through-penetration may have a rating equal to the rated assembly it penetrates, if you have seen actual tests or videos of tests online, you will notice that there may still be some minor smoke leakage and heat transfer.

Section 3005.4, Exception 1, which applies to 2-hour hoistway enclosures, allows such rooms to have a 1-hour rating if they do not abut the hoistway enclosure and have no openings. This exception reinforces the intent that these rooms are required to be protected if the hoistway is protected. However, in my opinion, what makes a control room, machine room, etc. so important that it must be protected only if the hoistway is enclosed? For example, an unenclosed hoistway in an atrium does not require a rated control room at all--even if it abuts the hoistway. Yet, an enclosed hoistway with a control room located on a floor not served by the elevator and located on the other side of the building (if anyone would actually do that) would require at least a 1-hour rating. Go figure.

One of these days the elevator requirements in the IBC will catch up with current elevator technology--and logic.

Thank you for the detailed responses. FWIW, I did read your article on the matter, they are one of my first resources when I get lost.