NFPA 13, 8.15.4 - Vertical Openings

[Haldorson]

Hello,

Consider vertical openings between two levels that are not used for stairways or staircases and are not large openings (i.e. greater than 20' dimensions and area greater than 1000 square feet). NFPA 13 seems unclear whether closely spaced sprinklers and draft curtains are required in these cases.

In the NFPA 13 (2010) Handbook it states "closely spaced sprinklers are required around a vertical opening only when it would otherwise be required to be protected by a barrier by the building code or NFPA 101...Smaller vertical openings may be referred to in the local building code or NFPA 101 as communicating spaces or convenience openings. These spaces are not required to have a barrier around the opening perimeter (See Section 8.6, Vertical Openings, in NFPA 101 for more details)". It goes on to say "Escalator openings in department stores are examples of vertical openings that would not be considered a convenience opening or convenience space, and as a result they would be required by NFPA 101 to be enclosed to protect against vertical fire spread."

In cases where a portion of a floor area is "Open to Above" to an adjacent floor but the opening is not used for a moving stairway or staircase and is not a "Large Opening", are closely spaced sprinklers and draft curtains required?

 

[cdafd]

If it does not strictly meet nfpa 13 requirements for opening protection

No

Not sure what 101 says but not aware of anything in ibc that would require it

 

[Haldorson]

cdafd:

In my opinion NFPA 13 is not clear on the requirements for opening protection as it pertains to my example where the opening is not used for a moving stairway or staircase and is not a large opening (> 1000 sq.ft.).

 

[cdafd]

Ok if you look at A.8.15.4.1 appears if the building code requires enclosure protection, and not there then 8.15.4.1

from 101:: I am not sure if there is similar language in the IBC



8.6.6 Communicating Space. Unless prohibited by Chapters 11 through 43, unenclosed floor openings forming a communicating space between floor levels shall be permitted, provided that the following conditions are met:


(1)
The communicating space does not connect more than three contiguous stories.


(2)
The lowest or next-to-lowest story within the communicating space is a street floor.


(3)
The entire floor area of the communicating space is open and unobstructed, such that a fire in any part of the space will be readily obvious to the occupants of the space prior to the time it becomes an occupant hazard.


(4)
The communicating space is separated from the remainder of the building by fire barriers with not less than a 1-hour fire resistance rating, unless one of the following is met:


(a)
In buildings protected throughout by an approved automatic sprinkler system in accordance with Section 9.7, a smoke barrier in accordance with Section 8.5 shall be permitted to serve as the separation required by 8.6.6(4).


(b)
The requirement of 8.6.6(4) shall not apply to fully sprinklered residential housing units of detention and correctional occupancies in accordance with 22.3.1(2) and 23.3.1.1(2).




(5)
The communicating space has ordinary hazard contents protected throughout by an approved automatic sprinkler system in accordance with Section 9.7 or has only low hazard contents. (See 6.2.2.)


(6)
Egress capacity is sufficient to allow all the occupants of all levels within the communicating space to simultaneously egress the communicating space by considering it as a single floor area in determining the required egress capacity.


(7)*
Each occupant within the communicating space has access to not less than one exit without having to traverse another story within the communicating space.


(8)
Each occupant not in the communicating space has access to not less than one exit without having to enter the communicating space.

 

[Haldorson]

Thanks for your response. Very helpful.

 

[SprinklerDesigner2]

About the escalator openings and closely spaced sprinklers.

I think this was four, or maybe it was six I honestly don't remember, years ago I spent one week at a series of continuing education classes put on by the NFSA where the discussion came up.

It was in the context of "why was OH2 .19 gpm and OH3 .21...." and where exactly did these numbers come from?

What was told at this meeting was these numbers were simply taken from thin air or just made up because they sounded good.

What the speaker, who is an FPE but it wasn't Stookey, told to the assembled group was the escalator drawing would not be leaving the standard any time soon because the drawing of the escalator was done by the daughter of someone very influential on the 13 committee. We all have art work our children created still on the refrigerator door sort of thing.

Kind of like having a standard sidewall sprinkler between 4" and 6" below the ceiling... is that really the best place to put it? Or ceiling pockets... we were drilled always to place sprinklers up in the pockets because hot air rises and they would go off first except it appears upon testing maybe it is better to place the heads down on the beam forming the pocket.

 

[stookeyfpe]

A very good analysis by Garner Palenske, P.E., who I hold in high respect, was presented last year in the SFPE Magazine. You may find this helpful in understanding the basis of how the NFPA 13 technical committee derived the values for control mode sprinklers designed based on a minimum dischrage density over the most hydraulically-demanding design area.

http://magazine.sfpe.org/sprinklers...tem-design-density-curves-where-did-they-come