We have an elevator shaft consisting of 2HR rated shaft wall and metal studs. There is hung intermediate elevator rail support steel in the shaft. Does the hung steel need to be fireproofed or clad over with shaft board, or can the steel be exposed in the shaft? Where in the code would I go to find this?
Depends on a lot of factors. Construction type, building size, height, and use. Also how are you going to be paying for my consulting. ;)
Seriously though . . . .
Typically only the shaft walls and cap need to be rated. The elevator and it's supports within the shaft do not. Be sure to confirm that an elevator lobby isn't required.
This is not something you crowd source. What did the architect say when you called and asked?
Sep 12, 24 9:00 pm ·
·
Khafre
Response was that the elevator guide rail support steel needs to be attached to by the elevator contractor but that the shaft needs to maintain a 2 HR rating… so this is ambiguous in my opinion
Sep 12, 24 10:09 pm ·
·
Non Sequitur
What is your role in this?
Sep 13, 24 5:31 am ·
·
OddArchitect
Ask your architect for more clarification. There is a lot of unknowns in your post and there really isn't any way we can give you definitive advice of this without knowing more.
I have inspected this multiple times and you absolutely need to fireproof if the floor construction is required to be fireproofed. Look at Chapter 7 section on “continuity” (horizontal and vertical assemblies) as well as protection of secondary members (either chapter 6 or 7). But I would say this is not a secondary member. It is part of the floor construction, and if that needs to be fire rated, then the shaft wall needs to either extend to cover these members, or more easily, you can either spray or paint them to achieve the required continuity. Either way, you need to maintain the minimum clearances of the shaft when doing so.
Correct. You need to rate all the supporting construction of any rated fire partitions and fire barriers. There are exceptions to this however it wouldn't apply to a shaft.
Sounds like intumescent paint might be the best option to not encroach on the minimum dimensions. Thanks for your guidance here.
Sep 12, 24 10:16 pm ·
·
OddArchitect
You really need to research this for your situation. See section 713 of the IBC. The shaft needs to be a fire barrier. The supporting construction of the fire barriers s need to be rated the same as the fire barrier. Only in unique instances will the elevator support structure inside the shaft enclosure (the fire barriers) need to be rated. Of course this all depends on how the shaft has been constructed and how it interacts with the elevator support framing.
In addition; Depending on how the the elevator framing interacting with the shaft wall intumescent paint may not work. IP paint needs to cover the entire member or be sealed to another rated assembly. The IP need room to expand to provide the fire rating. You're going to need between 1/16" - 3/16" of IP to get a 2 hour fire rating. IP expands at about at 5:1 ratio. Do the math.
True, I'm just thinking they they still have one more layer to install. I just finished a project but the shaft wall was continuous to the top as required.
Sep 13, 24 11:28 am ·
·
OddArchitect
That's normally how I've designed shaft walls as well.
That's why we have the elevator support structure fully within the shaft wall. It the elevator structure penetrates the shaft wall assembly then the shaft wall fire rating needs to be continuous around said structure.
In it's current condition I'd agree. Still odd that that the shaft wall was built on the floor framing. Typically we frame the shaft wall behind the floor structure.
It is constructable for buildings up to 5 floors or so. Beyond that it is less costly to platform frame on each floor and rate the supporting construction.
The studs are supported on the first floor. Burn away clips are used to attach to structure where needed. . There won't be an issue with the elevator head if you use a secondary wall at the openings. I've done this on probably 60 low rise buildings.
sorry, can’t help myself: one more comment, by having the entire shaft wall assembly pass the steel, you are creating loading conditions on the shaft wall assembly that may exceed limiting heights for the depth and gauge of the CH stud. I would have just the shaft wall liner, not the ch stud and inner gypsum layers pass the steel to provide the vertical continuity or the fire rating for the edge of the floor assembly at the shaft, then rely on the floor finish and ceiling material below the steel to provide required the horizontal continuity for the floor construction.
For anything beyond five floors - yes. For anything five floors and under - not really. Use burn away clips to support the CH studs where needed.
As I said above - this isn't economical beyond five floors or so. Once you reach that point it's best to frame the wall congenitally using platformed framed metal studs and gwb.
On a related note - using CH studs on a platformed framed assembly is difficult to construct. You cannot install the slide in gwb panel unless you have 24 - 30" of space between the T.O. the CH stud and the B.O. the floor / roof assembly. In this situation you need to stop the CH studs 24-30" below the B.O. the floor / roof. Then you still have to infill the 24"-30" of space with traditional framing.
Sep 16, 24 10:23 am ·
·
OddArchitect
Forgot to add - when platform framing with the CH studs doing a side 'slide' assembly is the normal method. Alternatively you can push the gwb panels in from the bottom. Both of these assemblies require the use of j-channels and don't provide much lateral stability or resistance to deflection beyond 16'-0 in height. When you balloon frame the CH stud wall you get much better lateral stability and resistance to deflection.
Sep 16, 24 10:36 am ·
·
Block this user
Are you sure you want to block this user and hide all related comments throughout the site?
Archinect
This is your first comment on Archinect. Your comment will be visible once approved.
Exposed Steel In Elevator Shaft
We have an elevator shaft consisting of 2HR rated shaft wall and metal studs. There is hung intermediate elevator rail support steel in the shaft. Does the hung steel need to be fireproofed or clad over with shaft board, or can the steel be exposed in the shaft? Where in the code would I go to find this?
Depends on a lot of factors. Construction type, building size, height, and use. Also how are you going to be paying for my consulting. ;)
Seriously though . . . .
Typically only the shaft walls and cap need to be rated. The elevator and it's supports within the shaft do not. Be sure to confirm that an elevator lobby isn't required.
This is not something you crowd source. What did the architect say when you called and asked?
Response was that the elevator guide rail support steel needs to be attached to by the elevator contractor but that the shaft needs to maintain a 2 HR rating… so this is ambiguous in my opinion
What is your role in this?
Ask your architect for more clarification. There is a lot of unknowns in your post and there really isn't any way we can give you definitive advice of this without knowing more.
I have inspected this multiple times and you absolutely need to fireproof if the floor construction is required to be fireproofed. Look at Chapter 7 section on “continuity” (horizontal and vertical assemblies) as well as protection of secondary members (either chapter 6 or 7). But I would say this is not a secondary member. It is part of the floor construction, and if that needs to be fire rated, then the shaft wall needs to either extend to cover these members, or more easily, you can either spray or paint them to achieve the required continuity. Either way, you need to maintain the minimum clearances of the shaft when doing so.
And to clarify- I meant that I have inspected this type of condition in many many many BIG buildings.
Correct. You need to rate all the supporting construction of any rated fire partitions and fire barriers. There are exceptions to this however it wouldn't apply to a shaft.
Yeah, the way it is detailed in this photo - completely agree with BB
I could be incorrect however it dose look like the shaft wall was framed on the elevator support structure. If so . . . .
Sounds like intumescent paint might be the best option to not encroach on the minimum dimensions. Thanks for your guidance here.
You really need to research this for your situation. See section 713 of the IBC. The shaft needs to be a fire barrier. The supporting construction of the fire barriers s need to be rated the same as the fire barrier. Only in unique instances will the elevator support structure inside the shaft enclosure (the fire barriers) need to be rated. Of course this all depends on how the shaft has been constructed and how it interacts with the elevator support framing.
In addition; Depending on how the the elevator framing interacting with the shaft wall intumescent paint may not work. IP paint needs to cover the entire member or be sealed to another rated assembly. The IP need room to expand to provide the fire rating. You're going to need between 1/16" - 3/16" of IP to get a 2 hour fire rating. IP expands at about at 5:1 ratio. Do the math.
That is not a completed shaft wall as the gypsum board on the inside of the elevator shaft is not installed yet.
It look like it could be a CH or shaft wall. The gwb panel could already be installed on the 'inside'.
True, I'm just thinking they they still have one more layer to install. I just finished a project but the shaft wall was continuous to the top as required.
That's normally how I've designed shaft walls as well.
Interesting that I just saw this...
https://www.portlandoregon.gov...
That's why we have the elevator support structure fully within the shaft wall. It the elevator structure penetrates the shaft wall assembly then the shaft wall fire rating needs to be continuous around said structure.
this is what it needs to look like
In it's current condition I'd agree. Still odd that that the shaft wall was built on the floor framing. Typically we frame the shaft wall behind the floor structure.
Sorry, like this with CH studs and sealant to the inside of the steel floor framing.
How do you support the CH studs?
This is not constructible. I’ve worked on many highrise buildings, and you
You will have a problem at the elevator door head condition with the way you
It is constructable for buildings up to 5 floors or so. Beyond that it is less costly to platform frame on each floor and rate the supporting construction.
The studs are supported on the first floor. Burn away clips are used to attach to structure where needed. . There won't be an issue with the elevator head if you use a secondary wall at the openings. I've done this on probably 60 low rise buildings.
you also need an angle at the floor level to support the hoistway doors. Anyway- it’s complicated
sorry, can’t help myself: one more comment, by having the entire shaft wall assembly pass the steel, you are creating loading conditions on the shaft wall assembly that may exceed limiting heights for the depth and gauge of the CH stud. I would have just the shaft wall liner, not the ch stud and inner gypsum layers pass the steel to provide the vertical continuity or the fire rating for the edge of the floor assembly at the shaft, then rely on the floor finish and ceiling material below the steel to provide required the horizontal continuity for the floor construction.
For anything beyond five floors - yes. For anything five floors and under - not really. Use burn away clips to support the CH studs where needed.
As I said above - this isn't economical beyond five floors or so. Once you reach that point it's best to frame the wall congenitally using platformed framed metal studs and gwb.
On a related note - using CH studs on a platformed framed assembly is difficult to construct. You cannot install the slide in gwb panel unless you have 24 - 30" of space between the T.O. the CH stud and the B.O. the floor / roof assembly. In this situation you need to stop the CH studs 24-30" below the B.O. the floor / roof. Then you still have to infill the 24"-30" of space with traditional framing.
Forgot to add - when platform framing with the CH studs doing a side 'slide' assembly is the normal method. Alternatively you can push the gwb panels in from the bottom. Both of these assemblies require the use of j-channels and don't provide much lateral stability or resistance to deflection beyond 16'-0 in height. When you balloon frame the CH stud wall you get much better lateral stability and resistance to deflection.
Block this user
Are you sure you want to block this user and hide all related comments throughout the site?
Archinect
This is your first comment on Archinect. Your comment will be visible once approved.