# Stairwell Pressurization - Exit  door to self close against 50Pa pressure differential across door?



## ncmiata (Sep 24, 2020)

Hi,
I would like clarification regarding whether if it is required by NFPA or IBC for the exit door to self close after it has been opened? The staircase pressurization fan would be running to maintain a pressure differential of 50Pa across the all the staircase door when they are all kept closed. 

Please note that the exit door in question opens towards the exit direction.


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## Paul Sweet (Sep 24, 2020)

IBC 716.5.9 requires fire doors to be latching and self-closing.  NFPA 80 has a similar requirement in Chapter 5 and more specifically in par. 6.1.3.2.1.

50 Pa is about 1 PSF, or 20 lb. on a 3'-0" x 6'-8" (roughly 900 x 2000 mm) door.  This is within the opening force allowed by IBC 1010.1.3.


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## RLGA (Sep 24, 2020)

Do you mean exit door (door from building into the stairway) or exit discharge door (exterior door at bottom of the stairway to the outside)?


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## ncmiata (Sep 26, 2020)

@RLGA 
I mean the exit discharge door. In this case the door opens to a lobby that leads to outside.  See below depiction of the layout. Circled in red is the door I am asking about. Does the door need to self close completely in the following situation ?:

Staircase pressurization system running and maintaining a pressure differential of 50Pa across the doors when all doors are closed.
The door circled in red is opened for a person to exit the staircase (all other doors within the stair case are still closed).


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## cda (Sep 26, 2020)

ncmiata said:


> @RLGA
> I mean the exit discharge door. In this case the door opens to a lobby that leads to outside.  See below depiction of the layout. Circled in red is the door I am asking about. Does the door need to self close completely in the following situation ?:
> 
> Staircase pressurization system running and maintaining a pressure differential of 50Pa across the doors when all doors are closed.
> The door circled in red is opened for a person to exit the staircase (all other doors within the stair case are still closed).




if that is a rated enclosure

Than the door should and normally is required to be rated,

If required to be rated,,,,    It shall close,,,

No matter if every other door in the building is shut.


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## RLGA (Sep 27, 2020)

ncmiata said:


> @RLGA
> I mean the exit discharge door. In this case the door opens to a lobby that leads to outside.  See below depiction of the layout. Circled in red is the door I am asking about. Does the door need to self close completely in the following situation ?:
> 
> Staircase pressurization system running and maintaining a pressure differential of 50Pa across the doors when all doors are closed.
> The door circled in red is opened for a person to exit the staircase (all other doors within the stair case are still closed).


Yes, the walls surrounding the stairway are required to be fire barrier assemblies. All openings in a fire barrier assembly are required to comply with Section 716, which states in Section 716.2.6 (2018 IBC) "Fire doors shall be *latching and* *self- or automatic closing* in accordance with this section." If it was an exterior door opening to the outside, then the door would likely not be required to comply with Section 716 unless Section 705.8 required it.


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## ncmiata (Oct 1, 2020)

RLGA said:


> Yes, the walls surrounding the stairway are required to be fire barrier assemblies. All openings in a fire barrier assembly are required to comply with Section 716, which states in Section 716.2.6 (2018 IBC) "Fire doors shall be *latching and* *self- or automatic closing* in accordance with this section." If it was an exterior door opening to the outside, then the door would likely not be required to comply with Section 716 unless Section 705.8 required it.



Thank you for your help. That makes sense.


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