Fire ratings for openings adjacent to and less than 180º from point of exit discharge

[George McGerd]

Per my interpretation of IBC 2012 - 1022.7 and with respect to protecting exterior walls OR stairway enclosure walls that form an angle less than 180º, my understanding of the requirement is that you must protect either the stair enclosure wall OR the building wall for a minimum distance of 10 feet with a rating of 1-hr to meet this requirement. I have a unique situation where there is exit door from the stairway AND a window in this corner of the building and BOTH are within 10 feet of the 90º angle (see attachment). I'd like to fire-rate the stair enclosure (and exit door) ONLY so that I don't have to rate the building exterior wall AND the window. However, the AHJ is saying I must also rate the window due to the fact that it is so close to the point of exit discharge. Is there anything in the code that requires openings near points of exit discharge to be rated or is my AHJ just exercising his due authority to require this window to be rated?Thanx.

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[cda]

Did Mr Ahj give you a code section??

 

[George McGerd]

No. That is why I am asking.

 

[cda]

I would nicely ask Mr. ahj what code section it came from so, I could research it.

 

[cda]

Looks like they may be correct, since you are less than

http://publicecodes.cyberregs.com/icod/ibc/2009f2cc/icod_ibc_2009f2cc_10_par228.htm?bu2=undefined

 

[mtlogcabin]

1022.7 is the correct code section and the AHJ is applying it correctly.

 

[mtlogcabin]

Looking at the commentary you could rate the exterior wall of the exit stairs and the doors in lieu of the window and the wall within 10 ft

Remember you are protecting the stairs from the 180 degree wall. 1022.7 only applies if the exterior wall of the stairs is non-rated

 

[George McGerd]

When I read the code I tend to agree w/ you (and the AHJ). But then when I read the commentary it implies that there are two paths of compliance: "Essentially, there are two alternatives where an exposure hazard exists: either (1) provide protection to the stairway by having a fire-resistance rating on its exterior wall or (2) provide a fire-resistance rating to the walls adjacent to the stairway." I'd like to follow path (1) by providing protection to the stairway's exterior wall ONLY and not the building's exterior walls that are adjacent to the stairway. I think my AHJ is saying that I have to protect the building's exterior walls and window regardless of if I protect the stairway's exterior wall or not.

 

[George McGerd]

Thanks. I will show him the commentary and see if he agrees. If not, I will do what he says since he is the AHJ and after all…I am not.

 

[steveray]

Agree with MT....You are protecting the stair (exit), not necessarily the discharge...

 

[cda]

Agree with MT....You are protecting the stair (exit), not necessarily the discharge...

I think you are protecting the exit discharge, like in an exterior stair you want the people to go down the stairs, without the flame and smoke getting to them.