3 Story R2 NFPA 13 or 13R?

[Francis Vineyard]

Previewing a set of apartments under 2012 IBC; 3 story, four R2 dwelling units per floor served by a single open access stairway. Travel distance under 125 ft. per Table 1021.2(1) The configeration are 4 sets of towers or buildings under one roof with open breezeways in-between.

The stairway is surrounded with exterior walls on 3 sides and access from outside the dwelling units through an open breezeway between buildings.

Is NFPA 13 required throughout the buildings and exterior stairway with draft curtains even though it's outside?

1009.3 Exit access stairways.

Floor openings between stories created by exit access stairways shall be enclosed.

Exceptions:

1. In other than Group I-2 and I-3 occupancies, exit access stairways that serve, or atmospherically communicate between, only two stories are not required to be enclosed.

2. Exit access stairways serving and contained within a single residential dwelling unit or sleeping unit in Group R-1, R-2 or R-3 occupancies are not required to be enclosed.

3. In buildings with only Group B or M occupancies, exit access stairway openings are not required to be enclosed provided that the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, the area of the floor opening between stories does not exceed twice the horizontal projected area of the exit access stairway, and the opening is protected by a draft curtain and closely spaced sprinklers in accordance with NFPA 13.

4. In other than Group B and M occupancies, exit access stairway openings are not required to be enclosed provided that the building is equipped throughout with an automatic sprinkler system in accordance with :Next('./icod_ibc_2012_9_par054.htm')'>Section 903.3.1.1, the floor opening does not connect more than four stories, the area of the floor opening between stories does not exceed twice the horizontal projected area of the exit access stairway, and the opening is protected by a draft curtain and closely spaced sprinklers in accordance with NFPA 13.



Francis

 

[RJMCGUIRE]

i think it really depends on your travel distance. from your 3 floor down and out. if you can do that within the allowed distance than you don't have to enclose the exit stair. if you can not then you need to enclose your stair.

i've done NFPA 13r on a 4 story multifamily project; corridors and units were sprinkled. and the stairs where enclosed as fire barriers. our jurisdiction allows us not have to sprinkle the roof truss if it is filled with insulation; minus the 1" air gap between insulation and the underside of the roof deck.

 

[cda]

Not required enclosure or 13

 

[Lynn]

Francis

There might be another issue.

Take a look at Table 1019.2 which alows buildings with a single exit.

You can only have the one stair if the travel distance from the most remote point of the apt is no more than 50' to the building exit.

Footnote c lets you have the three stories, but if the travel across the unit and down the stair to the exterior of the building exceeds 50' you will have to have two stairs, or the stair breezeway will have to be satisfy the code as an exterior exit stair (1 hour rated fire barrier walls with 60 minute doors with closers)

 

[Francis Vineyard]

Thanks RJMCGUIRE and cda.

To clarify if these same open stairs were to be inside the exterior walls then this 3 story R2 building would require the 13 system?

Seems the open stairs are under the fire area whether inside or outside the building’s exterior walls.

Lynn, T1019.2 is '06, I'm working out of 2012.

Francis

 

[cda]

Should be able to do 13r no matter where the stairs are located

 

[mtlogcabin]

This is a new term in the 2012

EXIT ACCESS STAIRWAY. An interior stairway that is not a required interior exit stairway.

INTERIOR EXIT STAIRWAY. An exit component that serves to meet one or more means of egress design requirements, such as required number of exits or exit access travel distance, and provides for a protected path of egress travel to the exit discharge or public way

It is a required stair so I do not believe it meets the definition of an "exit access stairway"

 

[AegisFPE]

Ditto MLC. I think you may have Exterior Stairways per 1026.

 

[Francis Vineyard]

Ditto MLC. I think you may have Exterior Stairways per 1026.

Imagine if you will one of the buildings is in the shape of the letter "C" and adjacent to a building in the shape of the letter "I". The breezeway or more appropriately the corridor runs along the "I" in-between buildings and is opened to atmosphere at both ends. The open stair is situated inside the "C"; unfortunately this design does not meet a requirement for an exterior exit stairway.

CI

1026.4 Side yards.

The open areas adjoining exterior exit stairways or ramps shall be either yards, courts or public ways; the remaining sides are permitted to be enclosed by the exterior walls of the building.

Table 1021.2(1) permits a second option that allows for a single means of egress when it reaches the level of exit discharge is less than the maximum travel distance.

I'm still confuse about when 1009.3 exception 4 applies? When they are floor openings that are not to be used as a means of egress.

Francis

 

[Oldfieldguy]

Still 13R unless the building is a podium under 2009 IBC Section 509