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Fire rated floor between basement and ground floor requirements

Q

Question That

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I have a project that requires a 2 hour fire separation between 2 adjacent occupancies.
The fire separation wall is a simple design (one long wall) with one exception. Because we need a window in the fire wall I'm thinking jog the wall around the perimeter of the room containing the window so that the walls are 2 hour rated.
All of the building that the fire separation wall is adjacent to is slab on grade and wood stud walls. The window is in a stud wall as well. The main building foundation is CMU (for the slab on grade) and is common to a basement. The room in question that is the jog projects over the basement.

So, the questions are:
- Does the ceiling of the room with the jog need to be rated over to the fire rated walls and if so can it be rated from only one side if the gyp is attached to the bottom of roof trusses.
- Does the floor/ ceiling assembly of the room that jogs need to be rated as well at the floor trusses. Would like to keep the underside of the floor trusses open for inspection purposes for this area but if gyp is required I can work with that.
- Can I rate this floor ceiling assembly from only the interior side of the room?
- Is there a floor ceiling assembly that I can make work with providing rating components to only the floor side of the trusses (if that in fact is an option).

Thanks.
 
Do you need a fire wall, or do you need a fire barrier? You used both terms in your question, but they are not the same thing.

Are you trying to separate two occupancies within one building, or are you trying to create a fire separation between two buildings?

What is your role in the project?
 
Yankee Chronicler said:
Do you need a fire wall, or do you need a fire barrier? You used both terms in your question, but they are not the same thing.

Are you trying to separate two occupancies within one building, or are you trying to create a fire separation between two buildings?

What is your role in the project?
Click to expand...
Apologies for the confusion. Actually I'm not completely sure on the required Firewall type. Need to dig into this some more as I'm late to the game on the design of the building. Primarily to eliminate the need of a sprinkler system.

Responsible for design, code analysis & life safety (on a lot of levels) and detailing. These questions more related to detailing at this point but I need to get my head better wrapped around the purpose of the wall and I'm cold on the whole Fire Barrier/ Fire wall distinctions. Always have to rethink these things unfortunately.
 
Question That said:
Apologies for the confusion. Actually I'm not completely sure on the required Firewall type. Need to dig into this some more as I'm late to the game on the design of the building. Primarily to eliminate the need of a sprinkler system.

Responsible for design, code analysis & life safety (on a lot of levels) and detailing. These questions more related to detailing at this point but I need to get my head better wrapped around the purpose of the wall and I'm cold on the whole Fire Barrier/ Fire wall distinctions. Always have to rethink these things unfortunately.
Click to expand...

With all due respect, how are you responsible for code compliance if you don't even understand the difference between a fire wall and a fire barrier?
 
I was waiting on that response.
I do understand the difference once i get immersed in the code analysis/ compliance part of the project. I’m not there yet on this project. If i did this every day it would be different (maybe). I don’t have the code memorized and for this particular project there are some complicating factors. Think about it. If you had to ask me the question with the info i provided then that would mean the wall I’m discussing could be either. Right?
Not trying to be a smart a** but as i indicated im late to this particular project and the review of nomenclature currently being used on this project and ive got some catching up to do. But your point is well taken. Should have just waited to respond once i got my ducks in a row. But i thought i made it clear that thats where I’m heading. And again. Apologies for any confusion this end.
 
Question That said:
I was waiting on that response.
I do understand the difference once i get immersed in the code analysis/ compliance part of the project. I’m not there yet on this project. If i did this every day it would be different (maybe). I don’t have the code memorized and for this particular project there are some complicating factors. Think about it. If you had to ask me the question with the info i provided then that would mean the wall I’m discussing could be either. Right?
Not trying to be a smart a** but as i indicated im late to this particular project and the review of nomenclature currently being used on this project and ive got some catching up to do. But your point is well taken. Should have just waited to respond once i got my ducks in a row. But i thought i made it clear that thats where I’m heading. And again. Apologies for any confusion this end.
Click to expand...

I'm sorry, but concepts such as the difference between a fire wall and a fire barrier are not project specific. They have different definitions, different physical requirements, and are used for different purposes. You should not have to wait to "get immersed in the code" for this project to understand what you need a fire-resistance rated wall for, and what type of fire-resistance rated wall (fire wall, fire barrier, or fire partition) that should be. We are not dealing with "nomenclature currently being used on this project," we are dealing with nomenclature and definitions that have been in the code for decades.

Why do you need this wall to be a fire [something] to separate two occupancies? Are they the same occupancy/use group classification and you just want to reduce fire areas to avoid sprinklers, or are they different occupancies that require a separation because of Table 508.4? Or is the building too large to be constructed without sprinklers, so you need to reduce the area of the building (not just the fire area) to avoid sprinklers?

These are fundamental questions that should have been addressed by the design team at the outset, during schematic design or very early in design development. Unless and until these parameters have been clearly stated, nobody can begin to answer your questions.

  • How big is the building?
  • What type of construction is it?
  • What are the two occupancies involved?
 
I'll get back to you once I get a little more familiar with the requirements. Note that I mentioned in the first post that I'm 95% certain that the reason is to avoid needing to use a sprinkler system.
 
Question That said:
I'll get back to you once I get a little more familiar with the requirements. Note that I mentioned in the first post that I'm 95% certain that the reason is to avoid needing to use a sprinkler system.
Click to expand...
Jay Smith. I have an email with a response from you to this thread. For whatever reason it's not showing up here. Any idea why?
 
Question That said:
Jay Smith. I have an email with a response from you to this thread. For whatever reason it's not showing up here. Any idea why?
Click to expand...
Sorry about that. I deleted it. Just figured I’d wait and see what comes of the questions in the next reply after where mine was.
 
Question That said:
I'll get back to you once I get a little more familiar with the requirements. Note that I mentioned in the first post that I'm 95% certain that the reason is to avoid needing to use a sprinkler system.
Click to expand...

Yes, but there are different code paths to accomplish that -- one potentially involving a fire wall, the other involving a fire barrier.

Before you even investigate avoiding sprinklers, you have to define what criteria would require sprinklers. If you can't define that, you can't answer anything.
 
Question That said:
I have a project that requires a 2 hour fire separation between 2 adjacent occupancies.
The fire separation wall is a simple design (one long wall) with one exception. Because we need a window in the fire wall I'm thinking jog the wall around the perimeter of the room containing the window so that the walls are 2 hour rated.
All of the building that the fire separation wall is adjacent to is slab on grade and wood stud walls. The window is in a stud wall as well. The main building foundation is CMU (for the slab on grade) and is common to a basement. The room in question that is the jog projects over the basement.

So, the questions are:
- Does the ceiling of the room with the jog need to be rated over to the fire rated walls and if so can it be rated from only one side if the gyp is attached to the bottom of roof trusses.
- Does the floor/ ceiling assembly of the room that jogs need to be rated as well at the floor trusses. Would like to keep the underside of the floor trusses open for inspection purposes for this area but if gyp is required I can work with that.
- Can I rate this floor ceiling assembly from only the interior side of the room?
- Is there a floor ceiling assembly that I can make work with providing rating components to only the floor side of the trusses (if that in fact is an option).

Thanks.
Click to expand...
Sorry for being late to the discussion--I was at a conference for the past week.

For those of us who have difficulty visualizing what you are describing, can you provide a sketch of the situation?
 
Everyone-
Following reviewing this more the wall in question needs to be a fire BARRIER. The wall is designed to separate an assembly occupancy from a business occupancy into separate fire areas so that a sprinkler system is not required.

Since the wall in question is not required to be a fire WALL then I am going to argue that it doesn't make a whole lot of sense to jog the rated wall around this particular room when we can simply (relatively) use fire resistant rated glazing (as MTNArch pointed out).

So, at the moment not concerning myself with the floors etc. Will continue thinking that through when/ if it becomes necessary.

Stay tuned.
 
Question That said:
Since the wall in question is not required to be a fire WALL then I am going to argue that it doesn't make a whole lot of sense to jog the rated wall around this particular room when we can simply (relatively) use fire resistant rated glazing (as MTNArch pointed out).
Click to expand...

Simply does not equal inexpensively. Check the cost of fire-rated glazing for a window that large before you commit.

And which occupancy does the room you were going to jog around belong to? That's what determines where the fire barrier runs.

Got a plan?

Question That said:
So, at the moment not concerning myself with the floors etc. Will continue thinking that through when/ if it becomes necessary.
Click to expand...

The construction supporting a fire-resistance rated wall must be rated to the same or higher rating as the wall. If this wall isn't on the slab-on-grade portion, the supporting floor-ceiling assembly (and whatever supports that) must be 2-hour rated.
 
The room could be classified as a part of the business occupancy.
The Assembly area is slab on grade. The slab is on backfill retained by a cmu retaining wall that doubles as the basement wall. This cmu basement wall serves as the foundation wall for the fire barrier wall we are discussing. So, the 2 hour rating can continue from bottom of roof deck to top of wood stud plate continuing down to the slab then to the cmu foundation wall. Wood floor trusses at the basement side will be supported on a ledger attached to the cmu wall. Stud wall will not be connected to these floor trusses.

Anything I'm missing here?

Cost of window potentially that much money? Guess I need to look into that further. Thanks for the heads up.
 
Question That said:
Everyone-
Following reviewing this more the wall in question needs to be a fire BARRIER. The wall is designed to separate an assembly occupancy from a business occupancy into separate fire areas so that a sprinkler system is not required.
Click to expand...
Is this for a break room by chance or a theater or restaurant?
You don't always need to separate assembly from business with fire rated construction, but it is highly dependent upon the design considerations, programming and areas.
 
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