The fire wall is to create a separate building. The existing building is too large for an addition.
Just because a two hour wall is in place,,,,
Does not always mean it is a horizontal exit
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The fire wall is to create a separate building. The existing building is too large for an addition.
I would need to review the requirements for a horizontal exit and what is on the plans, but I do know that the wall is designed as a three hour rated fire wall, not a two hour fire wall, and that a certain floor area size is designated as a refuge area for those exiting INTO the proposed building.
Bringing this back up for some clarity and I didn't find another thread that addressed it.....CDA is adamant about the 2hr wall not necessarily being an HE....So, a firewall separating 2 buildings (with doors through) is only an HE if you need one?
Scenario: Single exit room egresses through the firewall into a different building...HE? Or no if they can still meet travel distance CPET from there?
Scenario: Single exit room egresses through the firewall into a different building...HE? Or no if they can still meet travel distance CPET from there?
This following does not address the question, but the scenario may not meet code.
2015 IBC
Section 1026 - " . . . A horizontal exit shall not serve as the only exit from a portion of the building . . ."
Ok my Mantra:::
A two hour wall does not make a horizontal exit.
Preface: I have zero formal training, the closest I get is reading this forum. I reserve the right to be wrong and change my opinion once it has been invalidated.
I will concur with cda in that a 2 hour fire wall does not necessarily make a horizontal exit.
The requirements for Horizontal Exits must also be met. If the refuge area is not large enough to accommodate all the people in the refuge area as well as the people coming through the door in the FW, then a horizontal exit does not exist. Opening Protectives (Table 716.5) only lists 3 hour and 4 hour rated Horizontal Exits in Fire Walls. The table does not list a two hour rated HE in FWs. Perhaps a 2 hour fire wall can never make a horizontal exit. Also, looking at the 3 and 4 hour rated fire walls vs 3 and 4 hour rated HE in FWs, the opening fire protection assembly requirements are not exactly the same. The door vision panel size and fire-rated glazing marking door vision panel are slightly different. I have not investigated the differences yet to see which is more stringent. A door vision panel is limited to 100 sq. in. in HEs in a FW while a vision panel in a FW is restricted to the maximum size tested to ASTM E119 in accordance with section 706.2. (Door vision panels in a FW could theoretically exceed the 100 sq.in. maximum allowed in HEs.)
IMO, if a design happens to create the correct Fire Wall conditions and meets all the Horizontal Exit requirements, an HE still does not exist without an Exit sign and proper Egress lighting.
Feel free to question or correct me.
steveray - Did I address the question or did miss it again?
Mech, thanks for the input and maybe you have found an un-addressed issue in the IBC...There are obviously 2hr FWs allowed....As also referenced in 1026.2...
2015 IBC Opening Protectives (Table 716.5) only lists 3 hour and 4 hour rated Horizontal Exits in Fire Walls. The table does not list a two hour rated HE in FWs.
Opening Protectives (Table 716.5) only lists 3 hour and 4 hour rated Horizontal Exits in Fire Walls. The table does not list a two hour rated HE in FWs. Perhaps a 2 hour fire wall can never make a horizontal exit. Also, looking at the 3 and 4 hour rated fire walls vs 3 and 4 hour rated HE in FWs, the opening fire protection assembly requirements are not exactly the same.